Conformable Preconditioned Adhesive Sealing Tape

An improved pressure sensitive flashing tape that is conformable over uneven or irregular surfaces for use in the construction industry, where a moisture and air seal having full adhesive contact to the adherend is required. The subject tape includes a topsheet layer and an adhesive underlayer. The topsheet is stabilized dimensionally as to tape length and width for ease in application, but is preconditioned with a plurality of diaphragm elements embossed into the topsheet and compacted under pressure so as to enable the tape to conform to raised and indented features, including lap joints, protruding screw heads, dents, holes, cracks and the like, in surfaces associated with flashing and associated building surfaces; thus improving weathertight sealing. The topsheet may also have fold lines disposed relative to the diaphragm elements so as to be complementary in function, the fold lines serving to further enhance conformability and adaptability during and after application.

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Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to and claims priority to U.S. Provisional Patent No. 61/796,873 entitled “Tape backing of pressure sensitive tape with embossed collapsed diaphragms that enhance adhesive conformance to rough surfaces and lap joints”, filed 23 Nov. 2012, which is herein incorporated in full by reference for all purposes.

GOVERNMENT SUPPORT

Not Applicable.

FIELD OF THE INVENTION

The invention is directed to a flashing tape for weatherproofing, the tape having a topsheet layer and a pressure-sensitive adhesive underlayer. The topsheet is preconditioned with embossed, collapsed diaphragms that are surprisingly effective in conforming the tape to raised and indented features of surfaces, the preconditioned tape having a residual memory tension after installation that is less than the release tension of the adhesive.

BACKGROUND

Pressure sensitive adhesive tapes are utilized when applying flashing to create either an air or water seal. Performance is commonly inhibited by the phenomena referred to in the trade as “adhesive bridging” (or “tenting”). This phenomenon is easily demonstrated for example by placing a short piece of transparent general office tape (often referred to as “scotch tape”) on a flat surface of an adherend. Another piece of that same tape is then crossed at a 90 degree angle over the first piece of tape to double the thickness and forming a lap joint on either side edge. At the point where the second tape bridges up from the undersurface to cross over the first tape, a lap joint void will occur where the adhesive separates from the adherend. In practice, the initial application contact may be fully sealed by pressing the tape into the gap, but over time the tape retracts to its starting dimensions and the void regrows. The elastic memory “tension” or “elastic rebound” inherent in the stretched tape is greater than and defeats the adhesive bond strength. Vents and cavities grow where the adhesive separates, resulting in loss of weather seal. The separation is often accelerated at higher temperatures. Because of this, when a flashing tape is stretched during application, as over a lap joint, the tape progressively recovers to its unstretched form and, disadvantageously, forms unsealed gaps. Moisture or cold air can penetrate through the gaps. Adhesive bridging also occurs where tapes are applied with stretching over any rough or uneven surface.

Most pressure sensitive tapes are subject to adhesive bridging. However, the problem often is not easily evaluated because the tape overlayer(s) and the adhesive are not transparent, so that gaps in adhesion continuity are difficult to observe. Preferably, flashing tapes for the building construction industries should perform for years without weatherproofing seal failure, and thus slow creep elastic rebound and tension memory can lead to significant construction problems.

In general, flashing tapes are made by a roll-to-roll process. Properties of the film may differ in the machine direction (MD) corresponding to the process feed direction, and the cross direction (CD) across the roll. Tapes known in the art are preferred to be dimensionally stable for ease of installation, i.e., some dimensional stiffness is needed for handling. Many tapes utilize multilayer, pre-stretched film such as by Valeron or Hutamaki. The process re-orients polymer molecules in the film and limits later stretching in use. This type of high strength film is desirable in that it provides dimensional stability to the tape, minimizes adhesive bleed through, and is durable to abrasions.

Alternatively high density polyolefin, polypropylene and polyethylene films are used as barrier films. Typically these films range in thickness from 30.0 to 60.0 mils (0.00762-0.01524 cm). This type of pressure sensitive tape is referred to in the industry as a self-adhered flashing tape. Numerous well known brands of self-adhered flashing tape are made, and include Fortifiber, Protecto Wrap, and others. One such tape is described in US Pat. Publ. No. 2010/0285259, which is incorporated by reference by way of background on weatherproofing in construction.

In evaluating flashing tapes, it has been found that there are a few tapes that do not demonstrate significant adhesive bridging in the MD direction. There are several tapes that are creped by various methods so that the tape may be stretched in length during application without creating memory tension. These tapes are significantly more expensive than non-creped products. Since the material is creased across the full CD width of the tape, the tape is by design condensed together by as much as 60-70 percent in MD length. This allows the tape to be purposely stretched back toward its original length in a nonlinear fashion, and allows the tape to be fanned out around corners or arches. However, the lack of dimensional stability in MD length makes creped tapes unsuitable for many applications. Moreover, the volume of adhesive required to fill the pleated voids of the creases is substantial. For example, to achieve a final 20 mil (0.0508 cm) adhesive thickness, a 30-40 mil (0.0762-0.1016 cm) adhesive thickness may be required because the adhesive thins as the tape is stretched in length. Also, the manufacturing speed with creped tapes is significantly reduced, both in steps for pleating the overlayer and for applying the adhesive. An example of this type of product is described under EI Du Pont De Memours and Company's US Patent Publ. No. 2006/0083898, which discloses a self-adhering flashing system having high extensibility and low retraction.

U.S. Pat. No. 8,490,338, titled, “Self-Adhering Window Flashing Tape with Multi-Directional Drainage Plane” to Longo and Patent Application Publication US 2008/0307715 to Pufahl, provide for an exterior surface that is patterned to promote gravity drainage of water. This approach necessarily must form rigid dimples to facilitate water drainage from the tapes exterior exposed surface, and would not suggest a flaccid diaphragm construction. A construction that would allow the surfaces to deform or collapse would defeat the teachings because placing building siding and trim over the tape would flatten the drainage channels. Rigidly dimpled tapes will not reliably stretch or conform to seal over a rough or uneven surface.

It is desired to have a flashing tape that minimizes adhesive bridging while being both economical and suitable for weatherproofing applications with a wide variety of adhesives. It is desirable for such a tape to be dimensionally stable in length and width during installation, yet have minimal elastic rebound when applied over irregular and uneven surfaces. None of the flashing tapes known in the art directly address issues related to adhesive bridging, dimensional stability, and control of adhesive thickness in an economical manner. Thus, there is a need in the art for a flashing tape that overcomes the above disadvantages and limitations.

SUMMARY

The invention is directed to improved flashing tapes for construction weatherproofing, the tapes having a weather-resistant layer or film, termed here a “topsheet”, and a smooth adhesive underlayer composed of pressure sensitive adhesive. The tapes are generally made by a roll-to-roll process. To improve the resistance of the tape to seal failures resulting from adhesive bridging, the topsheet is “preconditioned” during the manufacturing process by embossment with diaphragm elements at densities of 10 to 400 diaphragm elements per square inch, more preferably 25 to 200 diaphragm elements per square inch, each diaphragm having a collapsible wall. Stretching that occurs during manufacture as the film is rolled on embossment teeth or pits results in embossed diaphragm elements with thin, collapsible walls, the stretching process having exceeded the yield point of the film (without rupture).

Subsequent compression of the diaphragm elements improves the flexibility of the film. In a process termed “conditioning,” the diaphragms are compressed or collapsed in height. The result is a tape or sheet having an essentially uniform thickness and relatively smooth adhesive undersurface. Typically the diaphragm structures are compressed 20% to 70% but retain a capacity to expand or extend to their pre-conditioned dimensions without memory tension.

This preconditioning is surprisingly effective in enabling flashing tapes of the invention conform and adhere to raised and indented features of surfaces without tenting or adhesion bridging, features that include seams, nail or screw heads, holes, cracks, and surface irregularities commonly encountered in building construction. This benefit has been shown to be long-lasting, and is believed to be a permanent change in the structure of the tape:adherend combination. The improved performance results from the novel tape structure, the features of which include limited memory tension of an weather resistant topsheet having collapsed diaphragm elements, increased adhesion surface area of the topsheet, and localized stretchability for conforming to irregularities in the adherend surface, while retaining generally stable tape dimensions of length and width for ease of application.

Embossments that exceed the yield point of the film sheet material result in irreversible localized stretching and thinning of the film wall thickness around the diaphragm elements, and result in a tape having a residual memory tension that is less than the release tension of the adhesive bond. By providing an adhesive bond over a greater surface area that is greater than any memory tension storage capability of the tape, adhesive bridging is reduced or prevented. Advantageously, preventing or reducing elastic rebound and adhesive bridging results in inventive flashing tapes having better sealing over the building lifetime, as realized in tests reported here.

The embossed diaphragm elements have been stretched into the plastic region of a stress/strain plot for the topsheet film, and are thinner than the interconnecting strands at the junctions between the diaphragms. The interconnecting strands form a net that provides stability to the MD and CD dimension of the tape and limit its overall elasticity to a useable range. However, individual strands have a narrow individual structure and limited strength, and can be locally stretched (irreversibly) during installation. This allows the interconnecting strands to conform to undersurface features with minimal elastic rebound.

In alternate embodiments, diaphragm elements may be embossed in regular patterns of alternating concave and convex diaphragm elements. The adjacent concave and convex areas deform to a greater degree than each individual diaphragm alone, and have limited elastic rebound. By way of illustration, during installation of a tape of the invention over a screwhead, concave diaphragms are inverted and fuse with adjoining convex diaphragms so as to form a larger convexity conforming to the raised surface. The opposite is true for depressed areas of the adherend such as lap joints. Because the material is pre-yielded, little or no elastic memory results.

Variations in design of the ECD elements, including variations in size, pattern, separation, and depth, serve to optimize conformance and adhesion when applied to rough or uneven surfaces. The patterned embossed conditioned diaphragm (ECD) elements of the invention enhance the ability of the topsheet and adhesive to conform over rough surfaces and adhere, while maintaining reasonably consistent tape thickness. A preferred embodiment is a topsheet web having an embossed diaphragm pattern made of adjoining alternating convex and concave tetrahedron frustum diaphragm elements at a density of 25 to 200 diaphragm elements per square inch, where each diaphragm element has been irreversibly stretched beyond the yield point of the material by 5% or more and is readily collapsible.

Alternatively, the diaphragm elements are formed to be uniformly either concave or convex. A release liner may also be provided and optionally is used to receive the adhesive layer such that the topsheet is rolled against the adhesive with a release liner backing already in place.

In another embodiment, the performance of the flashing tape may be further enhanced due to a plurality of “fold lines” or “creases” created by the embossed pattern. The fold lines break the tendency of the topsheet to resist folding in multiple simultaneous dimensions. Synergically, by forming adjoining diaphragm elements in regular patterns or arrays, fold lines and creases may be formed in the cross direction (CD), in the machine direction (MD) or at one or more angles that are not perpendicular or parallel to the feed direction so as to better conform to surface features. The patterns are optionally arrayed to form a plurality of linear or curvilinear fold lines in crossed and intersecting directions such as triangular, diamond, or hexagonal patterns.

In a preferred embodiment, an arrayed pattern of alternating convex and concave tetrahedron frustum diaphragm elements provides un-compacted or flat fold lines across the tape width in the CD direction. In effect, the fold lines provide pre-creasing of the topsheet but no compaction. This pre-creasing allows the topsheet to be compacted in the MD direction in an accordion configuration with minimal residual elastic force. An important application of this structure is found in overcoming “fish mouth”, a communicating void that forms at the edge of a flashing tape when applied over a protrusion such as a screwhead.

Methods are also provided. In a first aspect, the invention is a roll-to-roll process for manufacturing a flashing tape, which includes steps for (a) embossing a precursor web of a polymeric material on a roller surface of an embossing roller, the precursor web having a first face, a second face, a thickness, a mid-thickness reference point centered therein, a width, and a linear dimension in the machine direction, the polymeric material having a yield point, the embossing roller surface having a regular pattern of adjoining three-dimensional pyramidal polyhedrons having a density of 20 to 400 polyhedra per square inch, more preferably 25 to 200 polyhedra per square inch, the polyhedra each having at least one positive or negative radial dimension greater than the thickness of the precursor web, at least one radial dimension having a radius relative to a rotational center of the embossing roller such that the yield point of the material is exceeded when pressingly contacted with the roller surface, thereby forming a topsheet web having a first side, a second side, and an array of adjoining diaphragm elements thereon, the array of diaphragm elements having an uncompacted height measured peak-to-peak thereof that is greater than the thickness of the precursor web and the diaphragm elements having an irreversibly stretched film wall thereof having a thickness that is less than the thickness of the precursor web; (b) extruding an uninterruptedly coating layer of a pressure-sensitive glue onto a release liner layer; (c) using a pinch roller having a pinch roller pressure adjusted so as to enable simultaneously:

    • i) contacting the second side of the topsheet web with the continuous layer of the pressure-sensitive glue on the release liner;
    • ii) compacting each the diaphragm element and film wall thereof to a compacted fractional height that is less than the uncompacted height;
      and thereby form a conditioned flashing tape rollstock having a topsheet layer, a glue layer, and a release liner layer, the glue layer having a generally smooth external surface when the release liner is removed, the topsheet layer having diaphragm elements characterized by irreversibly stretched and compacted film walls that are generally flattened, crinkled, pliant and irresilient; and, (d) optionally forming smaller rolls from the rollstock by division thereof. In this instance the process of applying the glue layer and compacting the diaphragm cells may be performed in a single step. In selected aspects, the process may also include compacting the topsheet so that the compacted fractional height measured peak-to-peak is 20 to 70% of the uncompacted height. In another aspect, the pattern of adjoined three-dimensional pyramidal polyhedrons on the roller surface defines a pattern of fold lines there between. The fold lines further contribute to the pliancy of the product as will be described in more detail below. Other method variants are also described.

In another aspect, the invention is a flashing tape product by process, such that the product is produced by a method including: (a) irreversibly yielding a precursor web to form an array of unit diaphragm cells at a density of 10 to 400 diaphragm cells per square inch of web, more preferably 25 to 200 diaphragm cells per square inch of web, the array having a peak-to-peak height that is a multiple of the thickness of the precursor web and the diaphragm cells of the array having a film wall thickness that is a fraction of the thickness of the precursor web; thereby defining a topsheet intermediate; (b) compacting the diaphragm cells of the topsheet intermediate, thereby forming a conditioned topsheet intermediate having a peak-to-peak height that is 20 to 70% of the peak-to-peak height of the topsheet intermediate of step (a); (c) coating a bottom side of the conditioned topsheet intermediate with an uninterrupted glue layer; and thereby forming a flashing tape having a topsheet embossed with conditioned diaphragms and a glue layer coated thereunder. The product may be further characterized by evidence of a manufacturing step for sandwiching the glue layer between the conditioned topsheet intermediate and a release liner. Alternatively, self-wound rolls may be manufactured by applying a release formula so that the glue layer will not bond to a top side of the conditioned topsheet intermediate when the tape is rolled up, thereby eliminating the need for a release liner. Generally, products formed by these processes may include fold lines disposed between the unit diaphragm cells.

More broadly, or in other terms, the invention is a flashing tape for weatherproofing, the flashing tape including a weather-resistant topsheet overlayer and a weather-resistant adhesive underlayer, the topsheet overlayer having a regular array of embossed and compacted unit diaphragm cells formed from a feedstock film, the compacted unit diaphragm cells having pliant, crinkled, flattened, and irresilient walls such that the release tension of the adhesive is greater than the elastic memory tension of the unit diaphragm cells or clusters thereof. Clusters may behave cooperatively in sealing over fasteners and other defects. Cluster size is dependent on the construction features to be sealed and may be optimized by engineering diaphragm size, amplitude, wall thickness, shape, and other characteristics as described here.

In a currently preferred embodiment, the flashing tape comprises unit diaphragm cells that are engineered with dimensions selected for pliantly sealing over construction fasteners, lap joints and defects of commonly encountered sizes, the unit diaphragm cells having a size ranging from 5 diaphragm cells per linear inch to 20 diaphragm cells per linear inch, and more preferably about 25 to 200 diaphragm cells per square inch. Also currently preferred is a flashing tape having unit diaphragm cells characterized by a stretched embossment dimension of height that is a multiple of the original thickness of the feedstock web and a compacted “conditioned” dimension of height that is fractionally 20 to 70% of the peak-to-peak height of the embossments prior to conditioning.

The flashing tapes of the invention may be a component of a building sealing system or a fenestration unit. The flashing tapes may be installed on site at a building project, or may be pre-installed on modular units transported to the building site for final assembly.

The elements, features, steps, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which presently preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustration and description only and are not intended to define limits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The teachings of the present invention are more readily understood by considering the drawings, in which:

FIGS. 1A and 1B render an isometric view and a cross sectional view of a K-Lath screwhead as mounted in a solid substrate.

FIG. 2 is a prior art view of a cross-sectional through a pressure sensitive tape applied over the screwhead of FIG. 1, and is presented for comparison with FIG. 3.

FIG. 3 is a cross section view of a pressure sensitive tape of the invention applied over the screwhead of FIG. 1.

FIG. 4 is an isometric view of a pressure sensitive tape of the prior art applied over the screwhead of FIG. 1. The view illustrates adhesive bridging and “fish mouth” phenomena associated with conventional tapes, and is presented for comparison with FIG. 5.

FIG. 5 depicts an isometric view of a pressure sensitive tape of the invention applied over the screwhead of FIG. 1.

FIG. 6 is a cross-section view of a pressure sensitive tape of the prior art illustrating a lap joint formed by crosslapping the tape at 90 degrees across a similar tape applied to the same adherend. The prior art view is presented for comparison with FIG. 7.

FIG. 7 depicts a cross section view a pressure sensitive tape of the invention crosslapped at 90 degrees across a similar tape applied to the same adherend.

FIG. 8 illustrates a plan or top view of a flashing tape of the invention, the tape exhibiting a regular embossed pattern of adjacent tetrahedron frustum diaphragm elements. MD indicates “machine direction”; CD indicates “cross direction” relative to the machine feed of the feedstock material.

FIG. 9 is a dimensional view from above a tape of the invention, showing a pattern of tetrahedron frustum diaphragm elements having a triangular base.

FIG. 10 is an isometric view of the tape of FIG. 9 showing a regular pattern of rows of alternating concave and convex tetrahedron frustum diaphragm elements.

FIG. 11 is a cross-sectional section view of a precursor feedstock film (or “web”) prior to being embossed.

FIG. 12 is a cross-sectional view of an embossed topsheet showing the structure of two diaphragm embossments before a conditioning process step.

FIG. 13 depicts a cross section view of two diaphragm cells after embossing and subsequent conditioning (termed here “embossed conditioned diaphragms” or “ECDs”).

FIG. 14 illustrates cooperatively distended ECDs in cross-section.

FIG. 15A is a dimensional plan view (as in FIG. 9), but showing the location of cross-sectional slices taken for FIGS. 15B, 15C, 15D and 15E.

FIGS. 16A and 16B are two perspective views of individual three-dimensional pyramidal polyhedra, each here a pyramidal frustum with triangular base, also termed a tetrahedron frustum. FIG. 16A is a view of a convex pyramidal polyhedron; FIG. 16B is a concave pyramidal polyhedron.

FIG. 16C is a representation showing a repeating pattern of rows of tetrahedron frustum elements of FIGS. 16A and 16B, the rows having alternating convex and concave tetrahedral polyhedra separated by crease lines. A cylindrical tessellation of the pattern of FIG. 16C also defines at least a part of the surface of an embossing roller such as is used in making an intermediate during manufacture of the tape of the invention, which is then conditioned to form the finished ECD elements.

FIGS. 17A and 17B are two perspective views of individual three-dimensional pyramidal polyhedra, each here a pyramidal frustum with rectangular base, also termed a rectangular pyramidal frustum. FIG. 17A is a view of a convex pyramidal polyhedron; FIG. 17B is a concave pyramidal polyhedron.

FIG. 17C is an isometric view showing a repeating pattern of rows of tetrahedron frustums of FIGS. 17A and 17B, the rows having alternating convex and concave rectangular pyramidal polyhedra separated by fold lines. A cylindrical tessellation of the pattern of FIG. 17C defines at least a part of the surface of an embossing roller as is used in making an intermediate during manufacture of the tape of the invention, which is then conditioned to form the finished ECD elements.

FIG. 18 is a view of diaphragm elements showing positively distended, negatively distended, and compressed spherical sections.

FIG. 19 is a plan view of a topsheet embossed with ECDs in a repeating four-sided diamond pattern or array. Precursor web material not forming the embossed diamonds (i.e., reticulum) is treated to form fold lines across the MD direction, and imparts dimensional strength and elasticity to the topsheet web.

FIG. 20 is a plan view of a topsheet embossed with ECDs in a pattern of adjoining square pyramidal frustums.

FIG. 21 is a plan view of a topsheet embossed with a curvilinear pattern of four sided rectangular ECDs.

FIG. 22 is a plan view of a topsheet embossed with a patterned array of ECD elements shaped on a hexagon pyramidal frustum-covered surface of an embossing roller. Only part of the array is shown.

FIG. 23 is a plan view of a topsheet embossed with a patterned array of ECD elements shaped on a hexagon pyramidal frustum-covered surface of an embossing roller. The frustum of each of the polygonal teeth or depressions on the roller is modified with a pit or dimple so as to further yield the web during processing, increasing the distended ECD surface area.

FIGS. 24A-C illustrate perspective views a plurality of tape materials of the invention as strips. Patterns are shown schematically. Each strip of material may be formed into a roll and may include a release liner. FIG. 24A shows a hexagonal ECD pattern; FIG. 24B shows a diagonal ECD pattern with crisscross fold lines; FIG. 24C a tape product having a center strip of ECD elements bordered on both outside edges by flat tape.

FIG. 25 is a representation of an air pressurized, water spray test apparatus for detecting sealing integrity in test panels.

FIGS. 26A and 26B are views of clear plastic test slides and applied flashing tape. Drawn for comparison is an adhesive side view of a prior art tape (FIG. 26A) and a tape of the invention (FIG. 26B) approximating a vinyl window frame with integral window flange in the test panel.

FIG. 27 tabulates experimental results for comparative flashing tapes of the art versus two flashing tapes having arrays of ECDs made by the teachings of the invention as disclosed here. Shown are test pressures in pounds per square foot (PSF).

FIGS. 28A and 28B are drawings of ductwork having a seal wrapped around a pipe joint, the seal formed by a tape of the prior art (FIG. 28A) versus a tape of the invention (FIG. 28B).

FIG. 29 is a representative stress strain curve for a topsheet web material or feedstock having utility in flashing tapes of the invention.

The drawing figures are not necessarily to scale. Certain features or components herein may be shown in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity, explanation, and conciseness. The drawing figures are hereby made part of the specification, written description and teachings disclosed herein.

NOTATION AND NOMENCLATURE

Certain terms are used throughout the following description to refer to particular features, steps or components, and are used as terms of description and not of limitation. As one skilled in the art will appreciate, different persons may refer to the same feature, step or component by different names. Components, steps or features that differ in name but not in function or action are considered equivalent and not distinguishable, and may be substituted herein without departure from the invention. Certain meanings are defined here as intended by the inventors, i,e., they are intrinsic meanings Other words and phrases used herein take their meaning as consistent with usage as would be apparent to one skilled in the relevant arts. The following definitions supplement those set forth elsewhere in this specification.

Adherend—The surface to which an adhesive adheres; also: one of the bodies held to another by an adhesive; an undersurface or substrate to which a flashing tape is applied.

Adhesive bridging (or tenting)—An area under a tape where the adhesive releases from the adherend, creating a void or break in the seal. Adhesive bridging is found due to movement of the adherend or more commonly due to the effect of elastic memory tension in areas where the tape has been stretched and the memory tension defeats the adhesive bond over time. Stretched tape will tend to return to a relaxed position in which the glue separates from the adherend and the memory tension is relieved. This tension may come from stretching the tape over a raised surface feature such as a screwhead, bending the tape over a lap joint and pressing the tape down into the junction, thermal expansion of the adherend (or the tape or the adhesive), or inadequate bond strength of the adhesive. While an initial seal may be formed, adhesive bridging manifests itself in open voids under the tape and resulting weatherseal failures over weeks, months or years.

Adjoining—in contact or located adjacently at a boundary or baseline, as of a pair of diaphragm elements having an adjoining or contiguous boundary. With reference to a pair of adjoining pyramidal polyhedrons of the embossments of the invention, indicates a base of a first polyhedron sharing an adjacent or contiguous edge with a base of a second polyhedron.

CD—The width of an adhesive tape or “Cross Direction” of the tape on the machine which it was made; the direction generally crosswise to the “machine direction” of the tape feed.

Diaphragm—A diaphragm is an area of the topsheet that is semi-flexible, having been stretched either positively or negatively out of the native plane of the precursor film by locally deforming the film beyond its yield point. References providing general background on embossment processes include U.S. Pat. No. 7,655,104 to McKenna and US Pat. Publ. No. 2010/0230857 to Muhs, and are incorporated herein in full by reference. Stretch deformation may be concentrated circumferentially around a tooth or depression of an embossment tool, or may be concentrated at the apex of the tool. Irreversible deformation results when the film thickness begins to yield and is thinned or “necks” as seen in the area of a stress-strain curve to the right of the elastic deformation region (FIG. 29). By releasing the stretching force before the point of rupture, a permanently stretched diaphragm results and is localized in the area of the embossment. In the flashing tapes of the invention, closely spaced arrays of diaphragms serve as flexible and expanded areas of the topsheet layer having limited memory tension. The increased surface area is pliant and irresilient, allowing the adhesive to flow as needed to minimize interfacial tension and maximize the adhesive bond. Diaphragm elements may be considered individually as “unit cells” or may be considered cooperatively as arrays of unit cells, each unit cell corresponding to an individual diaphragm or a cluster of adjacent diaphragms. Cooperative effects are not necessarily merely additive and synergies result from the combined effects of embossing, conditioning (see below, ECD), and folding.

In a preferred embodiment, the “diaphragms” defined here are advantageously formed by embossing the precursor film with closely spaced regular arrays of teeth or depressions having the shape of a three-dimensional (concave or convex) pyramidal polyhedron, where at least one radius (“radius” being defined relative to a center of rotation of an embossment roller) of each polyhedral tooth or depression is greater than the thickness of the precursor film, and generally is a multiple thereof. One skilled in the art will recognize that the polyhedral features of a roller are not Platonic geometric forms, but are formed with a taper and shoulder radii so as to avoid rupture of the film during the embossment process. Pyramidal frustum shapes are contemplated, in particular tetrahedron frustum, hexagon frustum, square pyramid frustum, and diamond frustum shapes, without limitation thereto.

Embossed Conditioned Diaphragm (ECD)—Refers to a diaphragm that has been formed by an embossing process and also has been “conditioned” by a compression step that fractionally “compacts” or “collapses” the height of the embossed diaphragms. The product tape is formed by a method of embossing diaphragms using an embossing roller having convex teeth and/or concave depressions disposed on the roller surface. The peripheral wall of the diaphragm may be un-stretched while the center area of the diaphragm is stretched and thinned, or in other embodiments, the diaphragm's center is stretched and thinned while the peripheral wall retains more thickness. The plurality of ECD's in the topsheet may be in a pattern that is random or geometrically designed but is preferentially designed so as to include a regular pattern and fold lines.

The film forming the diaphragm element may be displaced either positively or negatively from the “relaxed” or “original” plane of the precursor topsheet. Conditioned diaphragms can be flexed or folded. The design force to move a conditioned diaphragm film will be less than the pressure required to move the original un-stretched material of the topsheet. The conditioning reduces the film's elastic memory tension to move in the third dimension back toward the original plane of the topsheet or extended beyond in the reverse original position of a diaphragm. Diaphragms can be distended or collapsed when conformed to an adherend. Conditioning by compression thins the embossed film back toward the original unconditioned plane of the precursor topsheet. The embossing process may result in an increase in film rigidity as compared to the same film in its precursor state, but subsequent compression results in making the embossed areas more flaccid and irresilient. The amplitude of ECD elements after tape fabrication, as controlled in the process, provides a balance between thickness of adhesive required for reliable seal, conformability for adhesion, handling characteristics, appearance and other design criteria. An ECD pattern allows multiple adjoined diaphragms to be moved cooperatively either positively or negatively so as to minimize the topsheet elastic memory tension on the corresponding adhesive—and thereby increase its ability to form and to maintain a seal. ECD patterns also provide fold lines where the topsheet memory is further reduced along adjoining perimeters of the ECD, allowing the film to contract in an accordion style with minimized elastic memory tension when flattened against the adherend. Advantageously the individual embossed area may be about 0.005 to 0.050 inches (0.0127-0.127 cm) in amplitude prior to conditioning and about 0.070 to 0.200 inches (0.1778-0.5080 cm) across. Variations from these parameters may be advantageous depending on the texture of the adherend. Advantageously, diaphragms minimize added adhesive cost while providing a significant increase in conformable surface.

Lap Joint—Where a tape crosses a first layer of similar tape applied to the same adherend. Lap joints are subject to seal loss where the second tape bridges the top surface of the first tape and the exterior surface of the underlying adherend.

MD—The linear dimension of an adhesive roll of tape or “Machine Direction” corresponding to the feed direction of the tape on the machine which it was made.

Pressure Sensitive Adhesive (PSA)—An adhesive that forms a bond with an adherend when pressure is applied to the outside surface of a tape. No solvent, water, or heat is needed to activate the adhesive. Some suitable adhesives include acrylic adhesives; butyl rubber or hybrid-butyl based adhesives, polymeric and rubberized asphalt adhesives. Other useful adhesives may include vinyl ether, styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-ethylene-butylene-styrene (SEBS), ethylene propylene-diene monomer, and combinations thereof, while not limited thereto. Advantageously hybrid acrylic, hybrid butyl rubber, butyl rubber, polymeric or rubberized asphalt based PSA adhesives are used. These adhesives are known to flow and may seal around penetrating fasteners when applied in layers thicker than 4 or 5 mils.

Topsheet—The top film layer of an adhesive tape. Generally this is a weather resistant exterior layer and is preferable an impervious material made of a nonwoven sheet such as a plastic film. Metal films and papers may also be used alone or in combination with a plastic layer. Exemplary materials include a polymer film, metal film, nonwoven fibrous polymer sheet or a combination operative to maintain an embossed pattern when exposed to temperatures as high as or about 200° F. (93.3° C.). Topsheets are generally substantially impermeable to water. Other materials useful in selected topsheet applications may include aluminum or other metal film; a non-woven sheet comprised of substantially continuous fibers, such as polyethylene, polypropylene, polyester, nylon and combinations thereof; a non-fibrous polymeric film, for example polyethylene, polypropylene, ethylene vinyl acetate, rubber, nylon, polyester, polyvinyl chloride or a combination thereof. In the case of a multilayer combination, the combined materials should have high resistance to delamination during installation and use. The topsheet may be impregnated or coated to lessen permeability and may be selected to be permeable to gases and water vapor. In manufacture, an adhesive is bonded to a topsheet so that the topsheet can be glued to a chosen adherend. In some tapes the topsheet is treated on one face so that an adhesive on another face will not stick to the treated surface, eliminating the need for a separate release liner during handling and installation.

Tetrahedron Frustum Diaphragms—As defined here, a tetrahedron frustum is a member of the set of geometric shapes termed “pyramidal polyhedrons”. A “tetrahedron” (plural: tetrahedra or tetrahedrons) is a polyhedron composed of four triangular faces, three of which meet at each corner or vertex. It has six edges and four vertices. A “diaphragm” is a thin film that is embossed to acquire the shape of the embossing tool, so that a diaphragm formed over a tetrahedron frustum-shaped tool has a generally tetrahedron frustum shape, but is hollow and merely the skin of the geometric solid on which it was formed. A diaphragm also lacks an enclosing surface corresponding to the base of a polyhedron, but otherwise the shape of an embossing tool, tooth or depression and the shape of the resulting diaphragm are referred to here, according to the context, by naming of the geometric shape they derive from. Analogously, the diaphragms of the invention include four sided pyramidal frustums, tapered blunt hexagons, conical frustums, and so forth, but a preferred form is that of a tetrahedron frustum. Arrays of polyhedrons may be formed in straight, curvilinear patterns, or waveforms, but in a yet more preferred an array of tetrahedron frustums is arranged in rows corresponding to alternatingly concave and convex polyhedral shapes sculpted into the embossing roll used to form them. While it is possible to mold or cast arrays and sheets of diaphragms, the most economical method of manufacture is by a roll-to-roll embossing process. Advantageously, by this method, fold lines between the rows may be formed in a single process step.

In general, unless otherwise explicitly stated the disclosed materials and processes may be alternately formulated to comprise, consist of, or consist essentially of, any appropriate components, moieties or steps herein disclosed. The disclosed materials and processes may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants, moieties, species and steps used in the prior art compositions or that are otherwise not necessary to the achievement of the function and/or objective of the present disclosure.

When the word “about” is used herein it is meant that the amount or condition it modifies can vary some beyond the stated amount so long as the function and/or objective of the disclosure are realized. The skilled artisan understands that there is seldom time to fully explore the extent of any area and expects that the disclosed result might extend, at least somewhat, beyond one or more of the disclosed limits. Later, having the benefit of this disclosure and understanding the concept and embodiments disclosed herein, a person of ordinary skill can, without inventive effort, explore beyond the disclosed limits and, when embodiments are found to be without any unexpected characteristics, those embodiments are within the meaning of the term about as used herein.

General connection terms including, but not limited to “connected,” “attached,” and “affixed” are not meant to be limiting and structures so “associated” may have other ways of being associated.

Relative terms should be construed as such. For example, the term “front” is meant to be relative to the term “back,” the term “upper” is meant to be relative to the term “lower,” the term “vertical” is meant to be relative to the term “horizontal,” the term “top” is meant to be relative to the term “bottom,” and the term “inside” is meant to be relative to the term “outside,” and so forth. Unless specifically stated otherwise, the terms “first,” “second,” “third,” and “fourth” are meant solely for purposes of designation and not for order or for limitation. Reference to “one embodiment,” “an embodiment,” or an “aspect,” means that a particular feature, structure, step, combination or characteristic described in connection with the embodiment or aspect is included in at least one realization of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment and may apply to multiple embodiments. Furthermore, particular features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments.

It should be noted that the terms “may”, “can” and “might” are used to indicate alternatives and optional features and only should be construed as a limitation if specifically included in the claims. It should be noted that the various components, features, steps, or embodiments thereof are all “preferred” whether or not it is specifically indicated. Claims not including a specific limitation should not be construed to include that limitation. The term “a” or “an” as used in the claims does not exclude a plurality.

“Conventional” refers to a term or method designating that which is known and commonly understood in the technology to which this invention relates.

Unless the context requires otherwise, throughout the specification and claims that follow, the term “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense that is as “including, but not limited to.”

The appended claims are not to be interpreted as including means-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase “means for.” Markush claims, if present, are recognized by a series of alternative selections joined by the “or” conjunction.

A “method” as disclosed herein refers to one or more steps or actions for achieving the described end. Unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the present invention.

DETAILED DESCRIPTION

The invention is directed to a flashing or sealing tape for construction weatherproofing, the flashing tape having a topsheet overlayer and an adhesive underlayer, wherein the topsheet is embossed with a regular pattern of diaphragm elements that are then compressed such that the memory tension of the topsheet layer is engineered to be less than the adhesive tension of the adhesive: adherend bond. Advantageously, by embossing the topsheet with closely spaced “embossed collapsed diaphragm” (ECD) members at a density of about 25 to 200 diaphragms per square inch, a measureable improvement in sealing performance is demonstrated. Diaphragm members are found to operate cooperatively in a relaxed state and seal over protrusions, chips, lap joints and other irregularities commonly encountered in building construction without significant adhesion bridging over time. Fold lines in the designs and the crinkling that occurs during compression of the diaphragms also contributes to this effect, as will be described in more detail below.

The topsheet of the invention is comprised of a plurality of ECDs in an engineered pattern. Each ECD element formed in situ by an embossment and compression process. Each diaphragm is irreversibly stretched either positively or negatively out of the native plane of the precursor film by locally deforming the film beyond its yield point, thus thinning the enclosing film forming the diaphragm and rendering it pliant and irresilient. The pattern, size, amplitude and direction of the ECD's are designed to meet the level of conformity required to avoid adhesive bridging of the tape as installed. The diaphragms may be conjoined or spaced by reticula or web members which are not stretched or embossed; the interrelationship, size and orientation of the unstretched members are engineered to meet a desired level of dimensional stability suitable for processing and handling during installation.

By way of introductory illustration, when windows are installed in a structure, the window mounting flange is used as the interface with the building's weather resistive barrier to keep moisture out of the structure. The mounting flange is also used to secure the window to the structure, typically the mounting flange is screwed or nailed in place, such as with flat headed K-Lath screws or galvanized roofing nails. The head of the fastener forms a protrusion above the flat plane of the flange. Using conventional products, adhesive bridging, voids and fish mouth channels are formed around the fasteners. Because the window flange is typically about 1 inch (2.54 cm) in width, the edge of the fastener is about 0.5 inches (0.127 cm) or less from the edge of the flashing tape used to seal out water and air a good adhesive seal is essential. Adhesive bridging occurs at this location with almost all precursor tapes.

FIGS. 1A and 1B are renderings of an isometric and a cross section of view of a K-Lath screwhead 1 mounted in a solid substrate. The common K-Lath screwhead used for window installation is approximately 0.5 inches (1.27 cm) in diameter. The opportune contact point of a tape applied over the screwhead 1 on the adherend 2 is approximately 0.58 inches (1.473 cm) in width as measured flat on the adherend. The arched distance over the screwhead is approximately 0.60 inches (1.524 cm) or an increase of 0.02 inches (0.051 cm). The difference is the root cause of adhesive bridging.

FIG. 2 shows a prior art view of a cross-section of a pressure sensitive flashing tape 3 of the prior art as applied over a screwhead of FIG. 1. Even after vigorous effort to fully contact the tape around the base of the screwhead, adhesive bridging around the screwhead 1 has opened significant voids 4 on either side of the protrusion and the tape has become tented. While the topsheet may be worked during installation to conform to the screwhead 1, elastic memory tension in the topsheet layer 5 to return to a shorter length defeats the bond strength of the pressure sensitive adhesive layer 6.

FIG. 3 is a cross section view of a pressure sensitive flashing tape 10 of the invention applied over a screwhead 1 of FIG. 1. The ECD conditioning allows the topsheet layer 11 and adhesive layer 12 to maintain contact with the adherend 2 and seal around the screwhead with minimal voids. Compressed diaphragm elements contribute to the apparent roughness of the tape; features which are exaggerated for clarity. For a screwhead of this size, five to ten diaphragm elements may operate cooperatively to ensheath the defect. Little or no void volume is evident around the screwhead as compared to obvious voids 4 apparent in FIG. 2 of the prior art.

FIG. 4 is a prior art view of a conventional pressure sensitive flashing tape applied over a screwhead 1 of FIG. 1. This view illustrates adhesive bridging and “fish mouth” phenomena associated with conventional tapes. The tape 3 exhibits prominent adhesive bridging in a broad area 7 around the screwhead 1. The adhesive bridging extends away from the screwhead toward the edge of the flashing tape, forming what is referred to in the trade as “fish mouth” (8). This communicating void frequently results in loss of weatherseal.

For comparison, FIG. 5 demonstrates a patterned ECD tape 30 of the invention applied over a screwhead 1 where the topsheet shows limited adhesive bridging in a narrowed area 31 around the raised screwhead. Due to the pliancy of the ECD and the capacity of fold lines in the tape to reduce the fish mouth effect, adhesive bridging does not extend away from the screwhead and the weatherseal is intact. Fold lines allow diaphragm elements in the topsheet to be pressed down like a closing accordion such that the dimensions of the tape are reduced to accommodate the extended topsheet length.

A similar problem occurs where conventional tapes are lapped at the corners of a window or door, and adhesive bridging again leads to communicating voids that break the weatherproof seal. This occurs immediately during installation, weeks, or months later as the elastic energy contracts the topsheet so as to separate the adhesive from the adherend.

In FIG. 6 and FIG. 7, two lap joints (40, 50) are compared. In FIG. 6, a first strip of a conventional flashing tape 41 is laid down on an adherend surface 2 and a second piece 42 is laid over it crosswise. The adhesive layer 43 of the second tape must step up over the edge of the first tape. The topsheet 44 of the second tape must bridge to the higher plane or shoulder of the first topsheet 45. Without ECD conditioning a significant void 46 is left at the lap joint that may leak air and moisture. This condition occurs regardless of how well the tape has been stretched to comply and compressed onto the adherend. The stretching of the topsheet needed to achieve adhesive contact at the lap joint results in a memory force that returns the topsheet to its native dimension. That memory force is opposed by the adhesive bond force, but over time the memory force exceeds most adhesives capacity to maintain a seal.

In contrast, as shown in FIG. 7, lap joint 50 is made by lapping a first tape strip 51 with a second tape piece, where the second piece 52 is an ECD processed flashing tape of the invention. The adhesive layer is marked 53. The topsheet 54 of the second tape must bridge to the higher plane or shoulder of the first topsheet 55. The resulting seal around lap joint 50 admits a minimal or no void space and is generally filled by adhesive 56. This substantial improvement in the lap joint minimizes the potential of air and water leaks at this critical and frequent occurrence of tapes.

Conformance is improved by the capacity of the closely spaced diaphragms to fold against each other (compress) where needed inside a corner and to expand around a corner. This folding capacity is a characteristic of the patterned diaphragm members and can be enhanced with fold lines formed in the topsheet during embossment. Smaller diaphragm members may also improve this performance. In general, for both protrusion-type defects and lap joint defects, the diaphragm pattern, size, spacing, and amplitude can be engineered to optimize sealing according to the expected size of the defects. A size of 20 to 400 ECD elements per square inch, more preferably 25 to 200 ECD elements per square inch, is useful for most standard construction applications in need of flashing or sealing tape.

FIG. 8 demonstrates an array pattern 60 formed from adjoining tetrahedron frustum diaphragms 61 having triangle base edges 62 which is longer in the CD direction of the film, i.e., an Isosceles triangle. The tetrahedron is pyramidal in shape in the height dimension relative to the base plane of the film and tapers to a frustum 63. In general, the frustum is parallel to the base plane of the film. The pyramidal polyhedrons may be convex, concave, or alternatingly convex and concave. The triangular bases adjoin nearest neighbours, and alternate head-to-tail so as to continuously fill a row 64. Each row is separated from the next by a fold line 65 in the CD direction. The size and shape of the frustum top plane 63 relative to its bottom plane and the amplitude of the frustum are design elements which will enhance the tapes performance relative to the intended surface conformity of the tape.

As will be described in more detail, this view is of an intermediate in manufacture of the finished tape. Following formation of the embossments in the precursor film, compression rollers are used to reduce the height on the polyhedrons, resulting in a uniformly flatter and crinkled appearance. The fractional compression in the vertical dimension may be 20-70% of the original pyramidal height and is an independent engineering parameter of the ECD film.

The plan view of FIG. 9 and isometric view of FIG. 10 show a tape having a tetrahedron frustum pattern or array 70 of the invention. As shown in FIG. 10, the tape consists of a topsheet overlayer 71, an adhesive underlayer 72, and an optional release liner layer 73. As illustrated, the topsheet 71 is about 0.004 inches (0.0102 cm) in thickness, and may for example be a high density polypropylene film. In these views, the topsheet precursor film has been embossed across the full length and width of the tape with tetrahedron frustum diaphragms (74, 75, 76) of about 0.100 inches (0.254 cm) in width. The diaphragms are tightly spaced with little or no un-stretched film between the edges of the triangular bases. Diaphragm unit cells are alternatingly concave 75 and convex 76 and are fitted head-to-tail to fill each row 77 (FIG. 9). Also shown is a fold line 78 extending edgewise along the row 77. The peak-to-peak amplitude of the embossment (at frustums 75a, 76a), relative to the initial plane of the precursor film (prior to compression) is about 0.023 inches (0.05842 cm), or about five times the initial film thickness.

For assembly of the topsheet to the completed tape, by way of example, a hybrid butyl blend adhesive layer 72 is first applied to a polyolefin release liner 73 in a continuous layer of about 0.015 inches (0.0381 cm) in generally uniform thickness. This ensures that when the release liner 73 is peeled away during installation, the adhesive 72 is exposed and has a smooth bottom surface. In other instances the topsheet may be coated first with adhesive and then the release liner nipped in to the adhesive. The topsheet 71 is then applied to the adhesive and compressed by a nip roller to a fractional height. The completed tape combination is then slit in widths from 2 inches (50.08 cm) to 36 inches (91.44 cm) in width, or as desired, and rolled on 3 or 5 inch (7.6 cm or 12.7 cm) cores in lengths of about 75 to 100 feet (22.86 m to 30.48 m). While not limiting thereto, the peak-to-peak amplitude of the compressed diaphragms after conditioning will be in the range of about 0.005-0.015 inches (0.0127-0.0381 cm), or about 20 to 70% of the stretched topsheet thickness prior to “conditioning”, as per the engineering needs of the application. Thus in some instances the topsheet layer is embossed with diaphragm features having vertical dimensions that are a multiple of its original thickness, and then compacted to be almost or essentially flat again. In this process the surface area of the topsheet is significantly expanded and the film walls are irreversibly stretched, thinned and crinkled. Rows may be separated by fold lines 78 for added compliancy during installation.

The topsheet precursor film may be a high density polypropylene and the adhesive an acrylic, asphalt, butyl, hybrid hotmelt or other polymer-based adhesives. Adhesives may include thermoplastic rubber resin adhesives, solvent-based rubber adhesives, and acrylic polymer based adhesives. Generally extrusion is a preferred method for applying an adhesive layer or film of a suitable thickness. In another embodiment the release liner may be perforated or split (e.g., kiss cut) to allow only portions of the adhesive to be exposed at one time so as to aid in installation.

FIGS. 11 through 14 demonstrate a stepwise process of forming a conditioned topsheet. The diaphragm elements are shown in relative scale for comparison of wall thicknesses and stretched dimensions. FIG. 11 shows a CD cross-section of precursor film 79. The film is 0.0040 inch (0.01016 cm) in thickness and 0.2000 inches (0.5080 cm) in width L. FIG. 12 shows the topsheet after embossment with a regular pattern of repeating diaphragm unit cells 81. The diaphragm walls 82 have been stretched irreversibly and are thinned relative to the starting film and the remaining frustum members 83. Wall thickness where stretched at the pyramidal wall 82a is compared to its frustum portion 83a. The peak-to-peak frustum elevation is referenced by the dashed line at 84. The overall top surface width or linear dimension LD of the film (including ups and downs) was stretched to 0.221 inches (0.56134 cm) in width, an expansion of 0.021 inches (0.05334 cm). FIG. 13 demonstrates the effect of a compression step (termed here, “conditioning”) in formation of a conditioned topsheet 80. The reduction in peak-to-peak height at the frustum is shown at 84a. The structure of the pyramid has been crinkled from its prior form. This crinkling increases compliance during subsequent installation. FIG. 14 demonstrates the capacity of the ECD topsheet 80 to expand to a convex dome shape, such as to cover a screwhead as described in FIG. 3. As many as five diaphragm elements (if configured at about ten diaphragms per linear inch) may be confluently expanded as a dome 85 to cover a half inch (1.27 cm) screwhead, for example. The surface width of the film is generally smooth, taking advantage of the stretching that occurred during embossment (FIG. 12). The ECD's elevation 86 is now significantly above reference line 84 in FIG. 12, and demonstrates the cumulative effect of small increments in surface distance. FIG. 1 demonstrated that the surface differential of the typical K-Lath screw is 0.02 inches (0.051 cm). In this example five ECD elements provide ample expanded film surface to conform to the screwhead without the defects described in FIG. 2 and FIG. 4. In other words, the periodicity of the unit diaphragm cells of an ECD array in the inventive tapes can be engineered to match common construction sealing challenges. Periodicities as currently preferred are in the range of five to twenty diaphragm unit cells per linear inch.

As seen in FIGS. 11 through 13, in another embodiment, the invention is a process for treatment of topsheet films during manufacture of flashing tapes. Typically an ECD pattern will be impressed into a precursor film, termed here a ‘topsheet’, by an embossing roller as described in FIG. 12. Embossing rollers may employ rigid teeth impressed into an opposing roller having a designed soft durometer cover or interdigitated rigid teeth of an opposing roller. In some instances the film web may be heated to enhance the embossing process and then cooled following treatment by the embossing roller. The embossed topsheet is an intermediate in the process.

The embossed process intermediate is then forwarded to an adhesive extrusion line to combine the topsheet overlayer, adhesive underlayer, and an optional release liner layer into flashing tape rollstock. Depending in part on the heat levels required for adequate adhesive flow rates during extrusion, the release liner may be coated with adhesive (if the ECD film will not deform during the adhesive extrusion process, the topsheet may be coated with adhesive). After adhesive coating, the topsheet, adhesive and release liner are joined together in a sandwich, typically using a pinch roller operation. The pressure of the pinch rollers is needed to fully contact and bond the layers, but for manufacture of an ECD product, advantageously, a higher level of compression is applied by opposing pinch rollers so as to also compress and compact the diaphragm elements in one step. Thus the pinch rollers may have a dual roll in the ECD process, and pinch roller pressure level is adjusted to compact the diaphragms, increasing their pliancy and irresilience. In some instances, the pressure applied is sufficient to return the topsheet to a vertical profile approaching its original un-embossed thickness. Typically the pressure between the rollers will be adjusted to compress the embossments by a factor of 20 to 70% of their vertical dimension, while maintaining the desired adhesive thickness.

Variants on the process are possible. In-line cooling of the extruded adhesive may be needed before subsequent processing steps. A roller coated adhesive may be used instead of an extruded adhesive. In another variant of the process, if the tape is to be a self-wound product without a release liner, a release coating typically will be applied to the surface of the topsheet limiting adhesion of overlapping layers of tape in the roll. In self-wound products, the embossed film typically will be conditioned by compression through pinch rollers to form the ECD diaphragms either inline but subsequent to the embossing process or separately prior to the final tape fabrication steps. For product distribution, flashing tape rollstock may be trimmed and cut or slit into smaller individual rolls by methods known in the art.

FIG. 15A is a plan view of a row of tetrahedron frustum diaphragm unit cells as in FIG. 9, but showing the position of cross-sectional slices taken for FIGS. 15B, 15C, 15D and 15E. Convex diaphragm elements 74 alternate with concave diaphragm elements 75. Also shown is a frustrum member 76.

For comparison, FIG. 15E shows a tape section along a fold line, the section having a topsheet overlayer 91 and an adhesive underlayer 92 where the topsheet is relatively flat and hinge-like. Topsheet 91 includes locally thicker material present as a reticulum. Reference line 90 in the cross-sectional views indicates the expected mid-plane of the precursor topsheet 91 without embossment and is taken as a zero plane corresponding to fold line 78 between rows of diaphragms 77 as shown in FIG. 9 and FIG. 10 at 78.

In each of the cross-sectional views FIGS. 15B through 15D, the adhesive base layer 92 is approximately 0.016 inches (0.0406 cm) on average, but varies with the embossment pattern. The adhesive thickness is sufficient to fully fill and cover the embossments and provide a smooth bottom surface 93 for adhering the tape. A release liner is not shown.

FIG. 15B is a cross-section through the apices 74a of the frustum members of convex diaphragm elements 74. Embossment deformation extends the topsheet 91 above and below reference level 90. In the wall areas, the topsheet thickness has been stretched past its yield point in the embossment step, and is thinned to improve compliance and to reduce memory tension. The crinkled pattern is characteristic of an embossed conditioned diaphragm layer (ECD).

FIG. 15C is a cross-section through apices 75a of the frustum members of concave diaphragm elements 75.

FIG. 15D shows a cross-sectional slice through the bases of raised frustum members 76 of diaphragms 74. It can be seen that alternating islands of thicker topsheet are connected by loosely crinkled valleys and hills of thinner wall material, surprisingly providing the structure with the capacity to expand or contract in any direction according to the underlying shape of the adherend. Thicker material provides strength and elasticity; thinner crinkled material provides laterally expansible or laterally compressible surface area. By adjusting the amplitude, density and size of the diaphragm elements, the fineness and capacity of the film to comply according to defect size is readily adjusted. Thus a flashing tape may be designed and manufactured using ECD principles to accommodate most commonly encountered defects in the building trade. The outside dimensions of the tape as supplied are not affected by these treatments.

FIG. 16A demonstrates an isometric view of a convex tetrahedron frustum element 100, that is the frustum face 101 is represented to be elevated with respect to the page and the base of the polyhedron is a triangle 102. FIG. 16B is a concave tetrahedral frustum 103, that is the frustum face 104 is represented to sunken with respect to the page and the base is a triangle base edge 105. Both are members of a set of polyhedrons termed “pyramidal frustums”, i.e. having a) tapered sidewalls, b) a truncated pyramidal frustum cut, and c) a polygonal base, where the frustum and the base form parallel planes. These figures may be taken to represent the ideal shapes of a film formed in the embossing process, but more conveniently can be understood to represent the definite shapes of the “teeth” and “depressions” or “concavities” used as embossment tools to form the stretched diaphragms in the flashing tapes of the invention. While the teeth and concavities are rigid shapes, the thin film diaphragms of a topsheet are by definition almost flaccidly collapsible, so the corresponding geometric shapes formed in the film are transitory in the manufacturing process and not readily identified in the finished product.

FIG. 16C is an isometric view of adjacent tetrahedral frustums mounted on an embossing roller 110 outside surface (indicated here by a dashed line along an imaginary roller edge). The height and depth of the polyhedral teeth and depressions may be conveniently expressed as a radius from the center of rotation of the roller and the design may be executed in polar coordinates for computer aided manufacture. The exemplary roller depicted here is covered with a tessellation of tetrahedral frustums that are laid out in rows, alternating convex teeth 111 and concave depressions 112 head-to-tail. Baseline edges 113 defining the triangular bases of the individual teeth and concavities are generally contiguous in this embodiment, but steps may optionally be inserted between the adjacent polyhedrons so as to modify the toughness of the film by creating a reticulum of thicker material extending along the baselines of the tetrahedrons. Fold lines 114 separate the rows. Using embossing rollers of this kind, a flat precursor film run across the roller surface acquires a significant increase in conformable surface with each diaphragm element that is formed. Embossing rollers are generally used in pairs; both may be hard surfaces patterned to mate to each other, or one may have a durometer suitable for impressing the film against a hard roller carrying the pattern. Typical patterns may include 20 to 400 pyramidal polyhedral per square inch, more preferably 25 to 200 pyramidal polyhedra per square inch. The polyhedra may be convex or concave and may be oriented, spaced and otherwise dimensioned to meet performance specifications. In general a soft radius is formed on the shoulders and edges of the polyhedra so as to avoid tears or punctures in the film during processing.

FIG. 17A demonstrates an isometric view of a convex rectangular pyramidal frustum element 120, that is the frustum face 121 is represented to be elevated with respect to the page and the base of the polyhedron is a rectangle 122. FIG. 17B is a concave rectangular pyramidal frustum 123, that is the frustum face 124 is represented to sunken with respect to the page and the base is a rectangle base edge 125. These are also members of the set of polyhedrons termed “pyramidal frustums”, i.e. having a) tapered sidewalls, b) a truncated pyramidal frustum cut, and c) a polygonal base, where the frustum and the base form parallel planes. The set includes square pyramidal frustums, hexagonal pyramidal frustums, and so forth, without limitation, and the pyramids may be concave or convex.

FIG. 17C is an isometric view of adjacent rectangular pyramidal frustums mounted on an embossing roller 130 outside surface (indicated here by a dashed line along an imaginary roller edge). The height and depth of the polyhedral teeth 131 and depressions 132 may be conveniently expressed as a radius from the center of rotation of the roller and the design may be executed in polar coordinates for computer aided manufacture, for example. The exemplary roller 130 depicted here is covered with a tessellation of tetrahedral frustums that are laid out in rows, alternating convex teeth 131 and concave depressions 132 head-to-tail. Fold lines 133 define the rows in the CD direction; fold lines 134 also define the array in the MD direction.

A variety of patterns may be used in the design of ECD tapes of the invention. Patterns having triangular or hexagonal base geometry may be advantageous because of the added dimensionality of folding that is realized. While square and rectangular patterns will preferentially bend along a straight line, triangular and hexagonal patterns may bend (with expansion of unit diaphragm cells) along bent lines or circular outlines because the individual bending angle between the cells is not a right angle and because combinations of two or more cells can result in a variety of intermediate angles with a combined bending radius of the fold matching the required outline or bend of the underlying substrate. While regular patterns are generally preferred, fields of irregularly patterned elements may also find applications. The selection of pattern and pattern parameters relate to differing adherend rough surfaces. The film may be embossed in only a positive or negative direction from the original plane of the film, or in an alternating array of convex and concave elements as in the examples above, and arrayed patterns or random patterns depend on the tape's design criteria.

FIG. 18 demonstrates an alternative embodiment of a flashing or sealing tape 140 having circular embossed areas in a concave 141, a convex 142 and a compressed 143 state. While not polygonal, the spherical sections demonstrate common properties of ECD elements, which are characterized by thinner collapsible walls engineered to improve compliance and relieve localized memory tension around surface defects over which the tape is installed. Also shown here are areas 144 of unstretched material that interconnect in a lacelike network or reticulum between the diaphragm elements. These contribute to dimensional stability of the tape and can be adjusted to obtain the required length, MD stability and toughness for handling.

FIG. 19 is a plan view of a topsheet 150 embossed with an array of ECDs in a repeating four-sided diamond 151 pattern. Precursor web material 152 is treated to form fold lines 153 across the MD direction. The reticulum of the web imparts dimensional strength but also some elasticity to the topsheet web, and is used conservatively depending on the polymer material chosen. The diamond pattern may be alternately concave and convex in the MD or in the CD direction. The distances between the design elements, their amplitude and relative scale will control the ECD's degree of conformance and rigidity.

FIG. 20 is a plan view of a topsheet formed on an embossing roller having a array pattern 160 of adjacent square pyramidal frustums for forming individual ECD diaphragm unit cell elements 161. Individual pyramidal frustum faces 162 may be convex or concave. The diaphragms are separated into rows and columns by fold lines 163 and 164. While the diaphragm elements are engineered to render the tape laterally expansible and laterally compressible, fold lines contribute synergy in cooperation with the diaphragms to the pliancy of the material and are useful when excess material needs to be laterally pleated (in the manner of a compression accordion fold) so as to avoid the fish mouth problem of the prior art. The geometric regularity of the pattern is characteristic of the topsheet at an intermediate manufacturing step and the diaphragm elements may be amorphously collapsed in the manufacture of finished product.

FIG. 21 is a plan view of a topsheet embossed with an embossing roller having a pattern 170 of four sided rectangular pyramidal frustum diaphragms for forming ECD elements 171 in a curvilinear array. Individual pyramidal frustum faces 172 may be convex or concave. The diaphragm unit cells are separated into rows and columns by fold lines 173 and 174, which may be curved or sinusoidally traced to provide additional folding flexibility. Any geometric regularity of the pattern is characteristic of the topsheet at an intermediate manufacturing step and the diaphragm elements may be amorphously collapsed or compacted in the manufacture of finished product as described with reference to FIGS. 11 through 15 and in installation.

FIG. 22 is a schematic plan view of a topsheet embossed with a array pattern 180 of pyramidal frustum ECD elements 181 shaped on an embossing roller having a hexagon pyramidal frustum-covered surface. Individual frustum faces 182 may be convex or concave. The diaphragms are separated into rows and columns by stepped fold lines 183. The fold lines may define thicker material between the hexagons, as in a reticular network for reinforcing the width 185 and length 186 dimensions of the flashing tape, generally indicated here with dashed lines as cut by a nip roller, so as to improve handling during processing and installation.

FIG. 23 is modified from the pattern shown in FIG. 22 to form a new array pattern 190 having central dimples 191 or pits in each polyhedral diaphragm unit cell 192. This has the effect of about doubling the actual surface area per diaphragm element available for expansion. By modifying the frustum face 193 of each of the polygonal teeth or depressions on the roller, the frustum face of a concave hexagonal frustum surrounds a raised dimple and the frustum face of a convex hexagonal frustum surrounds a pit. These features are then collapsed to form a complex ECD element. When stretched over a protruding surface, the excess surface area expands confluently to cover the defect without an increase in memory tension. Stepped fold lines 194 may also be incorporated for added capacity to compactingly pleat the material where the surface area of the tape is greater than the corresponding area of the adherend. Tape width 185 and length 186 are represented schematically.

Alternatively, instead of central dimples and pits, smaller nested or compound polyhedral features may be embossed within diaphragm unit cell polyhedra. The net effect is to produce ECD elements having compound concavoconvex geometries and substantially increased surface area.

FIGS. 24A-C show examples of tape strips made with the ECD process of the invention. Patterns are shown schematically. Each strip of material may be formed into a roll and may include a release liner. FIG. 24A is substantially smooth with a hexagonal ECD pattern. About 1-1.5 inches (2.54-3.81 cm) along one edge of the topsheet will be conditioned with ECD's. FIG. 24B a diamond pattern with crisscross fold lines. FIG. 24C shows a patterned ECD surface in a midline strip 211 bounded on both sides by smooth tape (210, 212) borders.

Test Methods

Samples of numerous flashing tapes available commercially were tested utilizing a test apparatus of FIG. 25 with conditions similar to those defined by ASTM E 331 in an air pressurized test chamber 300 having a spray nozzle assembly 301 for delivering a uniform colored water spray 302 (indicated by arrows and droplets to be generally fanned shaped) into the test assembly through hose 303. The chamber is pressurized by a vacuum/blower unit with pressure control 304 hose while colored water was delivered by a recirculating pump assembly. The tests were structured in a manner to evaluate the ability of the tapes (when applied over a window assembly with integral flange secured in place with K-Lath screws) to seal against water leakage in an air-pressurized environment. The tapes 310a, 310b, 310c and 310d were lapped over the edges of a rectangular vinyl window assembly 305 with 1 inch (2.54 cm) window flange mounted in a wall 306 of the test chamber. Screw fasteners, window welds, elevation drop transitions from the flange and cross laps (as present in FIGS. 26A and 26B) were included to evaluate the ability of the tapes to create a seal. The testing did not evaluate the various tapes as described by their manufactures as part of a full window installation system but rather was a test to determine if the tapes sealed water as a discrete element. Prior to testing the test panels were equally sealed with J-roller and hand compression to close all voids which might later allow water to leak. The test panel was then left for at least 12 hours prior to testing allowing a short interval for adhesive bridging to occur. The table shown in FIG. 27 lists the tapes tested and the results obtained. All prior art tapes leaked water through unsealed voids at 3.2 psf (15.6 ksm) or less within a single 5 minute period. This is typically the low acceptable test pressure for window's and flashing assemblies as tested on residential, multifamily and light commercial building structures. Advantageously, ECD flashing tapes of the invention (manufactured by Sure Flash LLC, Seattle Wash.) did not leak water at pressures up to or higher than 6.0 psf (29.3 ksm) during the test period, indicating a satisfactory seal. This would be considered a high test pressure for those same building structures.

A second method was developed to demonstrate various pressure sensitive tapes performance related to adhesive bridging. Since the adhesive layer and the topsheet are not transparent it is difficult to evaluate the performance of the tape and in particular the areas of adhesive bridging. However, as shown in FIGS. 26A and 26B (viewed from adhesive side), by adhering tapes to clear plastic sheets (test slides) about 0.0625 inches (0.15875 cm) in thickness, the adhesive side of the tape can be visually evaluated for the presence of voids. The configuration of the test slides and the placement of the pressure sensitive tape on the panels approximate the construction of a window flange placed on a wall substrate. The tape edges approximate conventional distances from screwheads to potential entry points for water or air to leak through in an actual window flashing assembly.

A wide variety of flashing tapes having differing adhesive and topsheet compositions, including many tapes conventionally used in the construction industry for window and door installation, were tested to determine the degree to which adhesive bridging occurred. In addition, a wide variety of other topsheet materials were evaluated including mesh, fabric, film, aluminum, woven and non-woven materials and composites.

The test slides 400 of FIGS. 26A and 500 of 26B are built up from a plastic sheet (401, 501) about 8 inches (20.3 cm) by 7 inches (17.8 cm). Another plastic sheet (402, 502) about 6 inches (15.2 cm) by 5 inches (12.7 cm) is overlaid on the first plastic sheet. A perimeter of 1 inch (2.54 cm) is maintained around the edge of the second sheet. Small screw holes are drilled through both sheets at intervals about 0.25 inches (6.35 mm) from the outer edge of the smaller plastic sheet (402, 502). Screwheads, noted at (403, 503) but present at 6 locations, one each at the top and bottom and two on either side in a similar position relative to the edge of the tapes, are placed in the holes, providing a protruding surface for the tape to bond over. The test slides were subjected to temperatures as high as 180° F. (82.2° C.) for several hours, radiant heat from sunlight and evaluated again several weeks after initial testing.

In FIG. 26A, a representative PSA tape 407 of the prior art is placed horizontally across the bottom lapping onto the upper plastic sheet 402 and onto the lower plastic sheet 401 and across screw head 408. Then tape 404 of the prior art is applied vertically along both sides over the upper plastic sheet 402 and onto the lower plastic sheet 401 crossing over the prior tape 407 and screw heads 408 creating lap joints 406. A prior art PSA tape 405 is placed horizontally across the top of both prior tapes 404, across screw head 408 creating lap joints 409. With the exceptions previously noted the tapes demonstrated adhesive bridging at lap joints 406, 409 and over protruding screwhead surfaces 408. The areas of release are represented by the areas denoted by “+” and “\/”. It was found that some adhesive tapes developed adhesive bridging after several weeks while most failed in minutes or hours. In FIG. 26B, PSA tape 508 of the invention is placed horizontally across the bottom lapping onto the upper plastic sheet 502 and onto the lower plastic sheet 501 and across a screwhead 503. Then tape 504 of the invention is applied vertically along both sides over the upper plastic sheet 502 and onto the lower plastic sheet 501 and across screwheads 503 crossing over the prior art tape 508 creating lap joints 507. A PSA tape of the invention 505 is placed horizontally at the top across the top of both prior tapes 504 and across screwhead 503 creating lap joints 509. Several adhesives were tested including acrylic, synthetic rubber, rubberized asphalt and a hybrid butyl with similar results, indicating that the benefit rests principally with the ECD treatment, not the nature of the adhesive. The significantly reduced areas of adhesive bridging at 507 and 509 (comparing 406 and 409 of FIG. 26A). Adhesive bridging at screwheads 503 (comparing 408 of FIG. 26A) similarly was reduced as previously illustrated in FIG. 4 and FIG. 5. These improvements make a significant improvement in weatherseal barrier preventing both air or water leakage and are representative of a flashing or sealing tape with an ECD topsheet.

A prior art pressure sensitive tape 603 is shown in FIG. 28A applied to wrap around an HVAC pipe 601 with raised joints 602. It is common in the installation of aluminum piping for raised joints 602 to be used in connection of two pipes or to facilitate pipe bends. Smooth surfaced tapes 603 with aluminum foil topsheet are often used to seal the joints against moisture and air leakage. These tapes leave a wrinkled surface 604 having fluidly connected channels that can leak air or moisture. FIG. 28B shows an ECD tape 703 applied in the same manner around a duct pipe 601 and over raised joints 602 leaving no wrinkles or voids in the tapes adhesive.

FIG. 29 is a representative stress-strain plot for topsheet precursor materials useful in the invention. As known to those skilled in the art, material characteristics define an elastic region bounded by a yield point defining a stress at inelastic yield and a plastic region at higher stresses where the polymer material stretches irreversibly. Too much stress and the material ruptures, but within the plastic region, materials can be significantly stretched with thinning, a phenomenon also termed “necking”. Preferred materials yield with thinning. When stress is released, an irreversibly stretched specimen retains little or no elastic memory, as indicated by the dashed line 900, where stress drops essentially to zero with little dimensional recovery on the strain axis. It is this characteristic that permits the ECD process to realize extended lateral coverage over protruding defects and lateral compression or pleating in tight corners such as lap joints. Candidate films also include polyethylenes, polyesters, polyvinylidene chlorides, polyvinyl chlorides, ethylene vinyl acetate copolymers, polyolefins, or a laminated or co-extruded combination thereof, optionally comprising a metallized film layer. The yield point may be temperature dependent, allowing a variety of materials to be used in temperature controlled processes.

The above disclosure is sufficient to enable one of ordinary skill in the art to practice the invention, and provides the best mode of practicing the invention presently contemplated by the inventor. While above is a complete description of the preferred embodiments of the present invention, various alternatives, modifications and equivalents are possible. These embodiments, alternatives, modifications and equivalents may be combined to provide further embodiments of the present invention. Further, all foreign and/or domestic publications, patents, and patent applications cited herein, whether supra or infra, are hereby incorporated by reference in their entirety for all they teach. The inventions, examples, and embodiments described herein are not limited to particularly exemplified materials, methods, and/or structures. Various modifications, alternative constructions, changes and equivalents will readily occur to those skilled in the art and may be employed, as suitable, without departing from the true spirit and scope of the invention. Therefore, the above description and illustrations should not be construed as limiting the scope of the invention, which is defined by the appended claims.

INCORPORATION BY REFERENCE

All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and related filings are incorporated herein by reference in their entirety.

SCOPE OF CLAIMS

While the above is a complete description of selected embodiments of the present invention, it is possible to practice the invention use various alternatives, modifications, combinations and equivalents. In general, in the following claims, the terms used in the written description should not be construed to limit the claims to specific embodiments described herein for illustration, but should be construed to include all possible embodiments, both specific and generic, along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.

Claims

1. A flashing tape for weatherproofing, said flashing tape comprising a topsheet overlayer and an adhesive underlayer, the topsheet overlayer having a regular array of embossed and compacted unit diaphragm cells formed from a feedstock film, said compacted unit diaphragm cells having pliant and irresilient walls such that the release tension of the adhesive is greater than the elastic memory tension of the unit diaphragm cells or clusters thereof.

2. The flashing tape of claim 1, wherein said unit diaphragm cells are dimensioned for pliantly sealing over construction fasteners, lap joints and defects, said unit diaphragm cells having a size ranging from 5 diaphragm cells per linear inch to 20 diaphragm cells per linear inch, and more preferably about 25 to 200 diaphragm cells per square inch.

3. The flashing tape of claim 16, wherein said unit diaphragm cells are embossments of said topsheet and are characterized by a stretched dimension that is a multiple of the original thickness of said feedstock web and a compacted dimension that is fractionally 20 to 70% of the peak-to-peak height of the embossments of said array.

4. The flashing tape of claim 3, wherein said unit diaphragm cells are embossments having a triangular base or a hexagonal base.

5. The flashing tape of claim 1, wherein said flashing tape is a component of a building sealing system or fenestration unit.

6. A roll-to-roll process for manufacturing a flashing tape, which comprises

(a) embossing a precursor web of a polymeric material on a roller surface of an embossing roller, said precursor web having a first face, a second face, a thickness, a mid-thickness reference point centered therein, a width, and a linear dimension in the machine direction, said polymeric material having a yield point, said embossing roller surface having a regular pattern of adjoining three-dimensional pyramidal polyhedrons having a density of 25 to 200 polyhedra per square inch, said polyhedra each having at least one positive or negative radial dimension greater than said thickness of said precursor web, said at least one radial dimension having a radius relative to a rotational center of said embossing roller such that said yield point of said material is exceeded when pressingly contacted with said roller surface, thereby forming a topsheet web having a first side, a second side, and an array of adjoining diaphragm elements thereon, said array of diaphragm elements having an uncompacted height measured peak-to-peak thereof that is greater than said thickness of said precursor web and said diaphragm elements having an irreversibly stretched film wall thereof having a thickness that is less than said thickness of said precursor web;
(b) extruding an uninterruptedly coating layer of a pressure-sensitive glue onto a release liner layer;
(c) using a pinch roller having a pinch roller pressure adjusted so as to enable simultaneously: i) contacting said second side of said topsheet web with said continuous layer of said pressure-sensitive glue on said release liner; ii) compacting each said diaphragm element and film wall thereof to a compacted fractional height that is less than said uncompacted height;
thereby forming a conditioned flashing tape rollstock having a topsheet layer, a glue layer, and a release liner layer, said glue layer having a generally smooth external surface when said release liner is removed, said topsheet layer having diaphragm elements characterized by irreversibly stretched and compacted film walls that are generally flattened, crinkled, pliant and irresilient; and,
(d) forming smaller rolls from said rollstock by division thereof.

7. The process of claim 6, wherein said compacted fractional height measured peak-to-peak is 20 to 70% of said uncompacted height.

8. The process of claim 6, further wherein said regular pattern of adjoining three-dimensional pyramidal polyhedrons on said roller surface defines a pattern of fold lines therebetween.

9. The process of claim 8, further comprising configuring said embossing roller to align said fold lines in the machine direction, the cross direction, or to intersect at an angle intermediate to the machine direction and the cross direction.

10. The process of claim 9, further comprising aligning said fold lines at intersecting angles defining the base of a triangle or a hexagon.

11. The process of claim 6, wherein said pyramidal polyhedrons are selected from concave pyramidal polyhedron, convex pyramidal polyhedron, or concavoconvex pyramidal polyhedron.

12. The process of claim 11, wherein said regular pattern comprises an array of alternatingly concave and convex pyramidal polyhedrons.

13. The process of claim 6, wherein said pyramidal polyhedrons are selected from:

i) a concave or convex pyramidal frustum defining an isosceles triangular base;
ii) a concave or convex pyramidal frustum defining an equilateral triangular base;
iii) a concave or convex pyramidal frustum defining a right angle triangular base;
iv) a concave or convex pyramidal frustum defining a diamond-shaped base;
v) a concave or convex pyramidal frustum defining a square-shaped base;
iv) a concave or convex pyramidal frustum defining a rectangle-shaped base;
or,
v) a concave or convex pyramidal frustum defining a hexagonal base.

14. A flashing tape product by process, produced by a method comprising:

(a) irreversibly yielding a precursor web to form an array of unit diaphragm cells at a density of 10 to 400 diaphragm cells per square inch of web, more preferably 25 to 200 diaphragm cells per square inch of web, said array having a peak-to-peak height that is a multiple of the thickness of the precursor web and said diaphragm cells of said array having a film wall thickness that is a fraction of the thickness of the precursor web; thereby defining a topsheet intermediate;
(b) compacting said diaphragm cells of said topsheet intermediate, thereby forming a conditioned topsheet intermediate having a peak-to-peak height that is 20 to 70% of the peak-to-peak height of the topsheet intermediate of step (a);
(c) coating a bottom side of said conditioned topsheet intermediate with an uninterrupted glue layer; and,
thereby forming a flashing tape having a topsheet embossed with conditioned diaphragms and a glue layer coated thereunder.

15. The product by process of claim 14, further comprising sandwiching said glue layer between said conditioned topsheet intermediate and a release liner.

16. The product by process of claim 14, further comprising applying a release formula so that said glue layer will not bond to a top side of said conditioned topsheet intermediate when said tape is rolled up, thereby eliminating the need for a release liner.

17. The product by process of claim 14, wherein said array comprises fold lines disposed between said unit diaphragm cells.

18. The product by process of claim 17, wherein said fold lines are disposed in a machine direction, a cross direction, or a crisscross direction.

19. The product by process of claim 17, wherein said fold lines are disposed to intersect at angles defining a triangular, hexagonal, square, rectangular, diamond, or circular unit cell.

20. The product by process of claim 17, wherein said fold lines define a reticulum of unyielded precursor web between said unit diaphragm cells.

Patent History

Publication number: 20140147611
Type: Application
Filed: Nov 22, 2013
Publication Date: May 29, 2014
Applicant: SURE FLASH LLC (Seattle, WA)
Inventor: Dale Stanley Ackerman, JR. (Seattle, WA)
Application Number: 14/087,566

Classifications

Current U.S. Class: Release Layer (428/41.8); Forming, Or Cooperating To Form Cells (428/178); Surface Deformation Only Of Sandwich Or Lamina (e.g., Embossed Panels) (156/219)
International Classification: E04D 13/15 (20060101); E04F 19/02 (20060101);