Abstract: A multiple cell window covering having a fold and a tab is constructed using a strip of fabric as the input, which is then folded, welded, prepared with adhesive, stacked, and cured in an oven. The apparatus used to construct double, triple, and multi-cell honeycomb products includes a folder, ultrasonic welder, adhesive applicator and drier, a fabric accumulator, a cutter, a stacker, and an oven.

Abstract: A composite bubble-pack assembly comprising (i) a first bubble-pack having a first thermoplastic film having a plurality of portions wherein each of the portions defines a cavity and a second thermoplastic film in sealed engagement with the first film to provide a plurality of closed cavities; (ii) a second bubble-pack having a third thermoplastic film having a plurality of portions wherein each of the portions defines a cavity, and a fourth thermoplastic film in sealed engagement with the third film to provide a plurality of closed cavities; (iii) and a film selected from the group consisting of a thin foil of metal or a metallized thermoplastic film interposed between and bonded to the first bubble-pack and the second bubble-pack.

Abstract: A multilayer insulation having a plurality of layers laminated together, and a plurality of depressions positioned proximate to edges of the multilayer insulation, the plurality of depressions forming insulated tabs on the multilayer insulation. An adhesive layer may be provided on one or more insulated tabs. In one embodiment, the depressions are positioned and sized to allow folding of the insulated tabs to form an integrated spacer. In another embodiment, the depressions are positioned and sized to allow receiving of an insulated tab of an adjacent insulation. In this regard, the depressions and the insulated tabs are preferably sized the same width to allow interlocking of the multilayer insulation to an adjacent multilayer insulation. A method of installing insulation is also described for providing an integrated spacer or interlocking adjacent insulation pieces. A method of manufacturing insulation with a depression that defines an insulated tab is also described.

Abstract: Structurally strong composite sandwich panels are made using phenolic resin adhesives to bond the face sheets to the honeycomb. Certain configurations and combinations of phenolic resins and fire protection agents were found to provide low flame, smoke and toxicity (FST) panels which have high structural strength.

Abstract: A composite bubble-pack assembly comprising (i) a first bubble-pack having a first thermoplastic film having a plurality of portions wherein each of the portions defines a cavity and a second thermoplastic film in sealed engagement with the first film to provide a plurality of closed cavities; (ii) a second bubble-pack having a third thermoplastic film having a plurality of portions wherein each of the portions defines a cavity, and a fourth thermoplastic film in sealed engagement with the third film to provide a plurality of closed cavities; (iii) and a film selected from the group consisting of a thin foil of metal or a metallized thermoplastic film interposed between and bonded to the first bubble-pack and the second bubble-pack.

Abstract: A method for making a flexible film having pressure sensitive adhesive protected from inadvertent adherence. The method coats a forming screen with an interconnected layer of pressure sensitive adhesive and places a piece of flexible film in contact with the layer of adhesive. The layer of adhesive preferentially adheres to the piece of flexible film. The forming screen has a plurality of recesses therein. The coating step applies the layer of adhesive without bridging the recesses. Another step forms the piece of flexible film to create a plurality of protrusions extending into the recesses. The plurality of protrusions are registered with the interconnected layer of pressure sensitive adhesive by virtue of using the same screen to transfer adhesive and to form protrusions. The forming screen may be wrapped around a rotating drum and the piece of flexible film may be a portion of a continuous web of flexible film. Preferably, the plurality of protrusions are conical, with a base diameter of 0.

Abstract: A plate-shaped safety-component made of a composite material is equipped with support elements in opposite end regions of said component for anchoring to a supporting structure. To achieve an anchoring which allows for deformation of extension under an applied force, said support elements have bearing members made of honeycomb material disposed in at least one end region, are pressure loaded as a result of said anchoring forces (K), and in which the axial direction (T) of the honeycomb is aligned to the respective direction (R) of the anchoring force.

Abstract: An inflatable web, and method and apparatus for inflating the web, which generally includes two sheets having inner surfaces sealed to each other in a pattern defining a series of inflatable chambers of predetermined length, each of the chambers having at least one change in width over their length; an inflation port located at a proximal end of each chamber, the inflation ports being formed by intermittent seals between the sheets; and longitudinal flanges formed by a portion of each of the sheets that extend beyond the inflation ports and intermittent seals.

Abstract: A rocket motor assembly is insulated or thermally protected with a rocket motor ablative material formed from a prepreg. The prepreg contains at least an impregnating resin matrix and, as a precursor prior to carbonization, either carded and yarn-spun solvent-spun staple cellulosic fibers, solvent-spun cellulosic filaments, or a combination thereof. When patterned and carbonized, the rocket motor ablative material can be lined or otherwise placed into a rocket motor assembly, such as between the solid propellant and case, in the bulk area of the exit nozzle liner, or at susceptible portions of a re-entry vehicle, such as the nose cone.

Abstract: An inflatable, conformable, cushioning, packaging product comprises a plurality of individual inflatable strips of multiple bubble cushioning structures. Each individual inflatable strip has a plurality of bubble chambers with each bubble chamber interconnected to an adjacent bubble chamber by an interconnecting passageway which is smaller in size and internal volume than the bubble chambers, but which is sufficiently large to enable air volume and pressure in one inflated bubble chamber to be transmitted to adjacent bubble chambers for distributing a shock load on one bubble chamber along the entire length of the individual inflatable strip of interconnected bubble chambers. Each individual inflatable strip is defined between two laterally extending spaced apart peripheral seal lines which have an undulating configuration free of corner shapes which could concentrate stresses.

Abstract: Air cell dunnage is disclosed which collapses for shipment and is constructed to be subsequently inflated for use. The air cell dunnage is a bubble sheet containing a multiplicity of gas cells and a base layer fused to the bubble layer. The bubble layer further includes conduits interconnecting selected groups of the selected cells and a common channel extending longitudinally on the sheet in fluid communication with each of the selected groups. The conduits provide access to selected groups of gas cells for collapsing and inflating the cells for shipment and use, respectively.

Abstract: A modular fiber reinforced polymer (FRP) composite deck module having one or more hexagonal components and one or more double trapezoidal components. A hexagonal component is a hexagonal cell with all sides being of equal length and forming a hexagonal space. A double trapezoidal component has a top side, a bottom side, a first trapezoid having a first top and a first bottom, and a second trapezoid having a second top and a second bottom. The first and second trapezoidal components are of equal dimensions and configured such that the first trapezoid is inverted resulting in the first top of the first trapezoid is adjacent to the second top of the second trapezoid, thereby creating a center seam and an extensive bonding surface. The double trapezoidal and hexagonal components are made of multiple layers of multi-axial fiber reinforcement and a resin matrix, the layers being continuous throughout the entire shape of the components.

Abstract: A method of preparing a cellulosic article includes a step of combining cellulosic material and binder resin to form treated cellulosic material. A mat is formed of a plurality of layers of the treated cellulosic material. The method also includes the steps of interfering with bonding of resin between two adjacent layers of the mat, and applying heat and pressure to the mat to form a cellulosic composite article having an internal blistered pattern. A consolidated cellulosic article includes a consolidated cellulosic mat and a layer of blisters disposed in the consolidated cellulosic mat.

Abstract: A flexible shock absorbing component providing cushioning for surfaces, especially wall and floor surfaces, is described. The shock absorbing component includes two sheets of thermoplastic, each sheet with inwardly facing, opposing, resiliently compressible indentations extending into a cavity between the two sheets. The shock absorbing component also includes a layer of particulate matter applied to and adhered to the outer surface of one of the sheets, to provide wear and weather resistance. A moderator may also be attached to the outer surface of the sheet.

Abstract: The invention relates to a relatively soft, largely planar, though three-dimensional product, obtainable by means of an embossing tool for converting a relatively soft, planar starting product as a result of embossing to the extent that an embossing pattern exists which comprises a plurality of “hinged parallelograms” that are limited by lines of compressed material such that when tractive forces are applied, this hinged parallelogram structure behaves like a pantograph and a secondary bulk is superimposed as a result of a stretching process on the primary bulk produced by the embossing.

Abstract: A protector pad (10) for a sportsman includes and outer protector (11) adapted to at least partially assume the shape of the area to be protected and an inner shock absorbing pad (12) in the form of an air cushioned pad. The outer protector (11) is formed from moulded plastics material and has longitudinal ribs (13) which permit the protector to achieve a curvature fit around the area to be protected.

Abstract: A multilayer foil insulation, and related method of manufacturing the insulation, that is used for dissipating heat and attenuating sound. Layers of foil are stacked in a spaced apart relationship, and include perforated layers and an imperforate layer adjacent to or sandwiched between the perforated layers. Each of the perforated layers includes a pattern of perforations that define a plurality of standoffs that extend from the perforated layers and that contact an adjacent layer, thereby defining insulating spaces therebetween and maintaining the spaced apart relationship. The perforations permit sound to enter the multilayer foil insulation, wherein sound is acoustically scattered as it passes into the multilayer foil insulation through the perforations and the imperforate layer acoustically absorbs the sound within the multilayer foil insulation.

Abstract: A method of manufacturing a resin bag whereby the peripheral edge of the bag such as a resin air baa is not bulky, the bonding strength is still sufficient, and the productivity is increased, is provided. A first resin sheet 1 and a heat-resisting sheet 3 are overlaid on each other and are disposed in a cavity 13 of a mold 7. The diameter of the heat-resisting sheet 3 is smaller than that of the first resin sheet 1 so that a portion of the sheet 1 is exposed outside the heat-resisting sheet 3. After injecting resin 2′ into the cavity 13 through a sprue bush end 12, the resin 2′is pressed and expanded to mold a second resin sheet 2 and bond the sheet 2 to the sheet 1 at the peripheries thereof.

Abstract: An inflatable, conformable, cushioning, packaging product comprises a plurality of individual inflatable strips of multiple bubble cushioning structures. Each individual inflatable strip has a plurality of bubble chambers with each bubble chamber interconnected to an adjacent bubble chamber by an interconnecting passageway which is smaller in size and internal volume than the bubble chambers, but which is sufficiently large to enable air volume and pressure in one inflated bubble chamber to be transmitted to adjacent bubble chambers for distributing a shock load on one bubble chamber along the entire length of the individual inflatable strip of interconnected bubble chambers. Each individual inflatable strip is defined between two laterally extending spaced apart peripheral seal line which have an undulating configuration free of corner shapes which could concentration stresses.

Abstract: A comfort liner including a sealing layer of material, a plurality of bubble members formed on the sealing layer of material, and a thermal material formed within each of the plurality of bubble members. The thermal material is a heat absorbing material whose absorption of heat will provide cooling within a range of at least 70 degrees F. to 85 degrees F.

Abstract: The present invention is a thermoformer which produces zero scrap during the heating, forming and cutting of a blister package. In one embodiment, the thermoformer comprises a precut roll having a series of adjacent webs connected by a cut area. Each of the webs are defined by an overall length L, a width W, and a radius R. Each of the cut areas are defined by a cut depth D1, said cut depth D1 being in the range of about 25% to 90% of the width W of the webs. The thermoformer further comprises a heating station adapted to heat each of the webs. The thermoformer further comprises a forming station adapted to form each of the webs. The thermoformer further comprises a cutting station adapted to separate the webs from each other, by making a cut along each of the cut areas connecting the webs.

Abstract: A sheet-form structure of expandable thermoplastic resin is provided which is capable of undergoing a pseudo-one-dimensional expansion in its thickness direction and which enables manufacture of thermoplastic resin foams having reduced variations in thickness and weight precisions, increased compressive strength, and excellent properties such as surface smoothness. A method of manufacturing the sheet-form structure, as well as such thermoplastic resin foams, are also provided. A sheet-form structure 1 of expandable thermoplastic resin including granules 2 of expandable thermoplastic resin arranged generally uniformly for integral connection thereof through a thin film 3 of expandable thermoplastic resin.

Abstract: A sheet-form structure of expandable thermoplastic resin is provided which is capable of undergoing a pseudo-one-dimensional expansion in its thickness direction and which enables manufacture of thermoplastic resin foams having reduced variations in thickness and weight precisions, increased compressive strength, and excellent properties such as surface smoothness. A method of manufacturing the sheet-form structure, as well as such thermoplastic resin foams, are also provided.

Abstract: A platform is provided for the manufacture of microwave, multilayer integrated circuits and microwave, multifunction modules. The manufacturing process involves bonding fluoropolymer composite substrates into a multilayer structure using fusion bonding. The bonded multilayers, with embedded semiconductor devices, etched resistors and circuit patterns, and plated via holes form a self-contained surface mount module. Film bonding, or fusion bonding if possible, may be used to cover embedded semiconductor devices, including embedded active semiconductor devices, with one or more layers.

Abstract: A webstock device for providing a signaling function while being relatively camouflaged includes sheet-like webstock material, a cavity in the webstock material, a signaling device at least partly contained in the cavity, and means for retaining the signaling device at least partly in the cavity. The cavity in the webstock material is closed by respective layers of material and a cover layer can be printed with desired information, instructions, etc. The signaling device may be an accousto-magnetic signaling device, an RF device or other signaling device. The invention also includes methods and apparatus for making the webstock device and methods for using the device.

Abstract: An absorbent article comprising a polysaccharide-based highly absorbent material, which is produced by desiccating a cross-linked hydrogel using a polar solvent.

Abstract: A cleaning article comprising a detergent-retaining layer containing a hydrophobic material and detergent gradual-releasing layers having a higher density than the detergent-retaining layer, and the detergent-retaining layer is sandwiched between the detergent gradual-releasing layers.

Abstract: A heat dissipation arrangement for chip modules on multilayer ceramic substrates, in particular multichip modules, in which passages for a heat-conducting medium are provided in the ceramic substrate. The multilayer ceramic substrate is mounted on a metal heat sink. Thermal passages, in particular in the form of a hole pattern or array, are provided in the top layer of the multilayer ceramic substrate, in the region of the chip to be mounted. A cavity functioning as an evaporation chamber is provided in the layer of the multilayer ceramic substrate directly beneath the top layer, in the region of the chip to be mounted, and a trough-shaped recess functioning as a condenser is provided in the metal heat sink, in the region of the chip to be mounted.

Abstract: A dynamic structural panel having one or more compliant dimple layers connected together by one or more reinforcing layers engaging ends of dimples on the dimple layer to create a cavity between the layers. The dimples are spaced apart from one another to form a dimple layer region. The dimple layer region may be either curved relative to the dimples or corrugated, thereby providing compliancy for the dynamic structural panel. The connection of the dimple layer and reinforcing layers creates an integral structural panel that can be planar by having identical heights of the dimples on the dimple layer to create a planar panel (flat) or nonplanar (curved) by varying the heights of the dimples on the dimple layer or through planar spacing adjustment. The panel can be modified in various ways such as by choice of materials and/or geometries of the various layers and/or incorporation of additional structural features.

Abstract: A party favor is disclosed that integrates a noise-making article with removable graphics for the purpose of proving amusement. This party favor is a lamination of several layers generally including but not limited to a noise making cellular sheet material layer, an adhesive layer and a graphic layer. The cells of the noise making cellular sheet material layer may be popped to produce a multitude of popping noises for the entertainment of the user. The graphics layer decorated the party favor and may include removable graphics including but not limited to stickers, posters, place mats, tattoos, banners, signs, game boards, cut-outs, or cling images.

Abstract: A thermally insulating bubble pack for use in framed structures, walls, crawl spaces and the like; or wrapping for cold water heaters, pipes and the like wherein the bubbles contain a fire retardant material. The improved bubble pack comprises a first film having a plurality of portions wherein each of the portions defines a cavity; a second film in sealed engagement with the first film to provide a plurality of closed cavities; the improvement comprising wherein the cavities contain a fluid or solid material. The flame retardant-containing bubble pack provides improved fire ratings, flame spread indices and smoke development numbers.

Abstract: A modular fiber reinforced polymer (FRP) composite structural panel component for structural support systems having a plurality of cells adjacently connected forming a top side, a bottom side, a first edge side and a second edge side. Each cell is defined by at least four sides, wherein at least two adjacent sides intersect at an obtuse angle resulting in the first edge side and the second edge side providing a means for joining two panel components and having an extensive bonding surface. A structural panel component is comprised of a plurality of layers of multi-axial fiber reinforcement, e.g., multi-axial fabrics, mats, woven cloth and unidirectional rovings, and a resin matrix, and the layers are continuous throughout the shape of the cells and a structural panel component. The structural panel component is manufactured using the Vacuum Assisted Resin Transfer Molding or pultrusion process.

Abstract: A three-dimensionally shaped fiber network structure having both resiliency and improved softness and aesthetic properties is composed of a deformed textile fabric formed from at least one monofilament and at least one multifilament yarn and having a plurality of deformations formed as a two-dimensional array in a base region of the deformed textile fabric. The deformed textile fabric is preferably a knitted or a woven fabric. The network structure is made by forming a deformable fabric from the monofilament and the multifilament yarn and then subjecting the deformable fabric to an area-enlarging deformation process, e.g., a thermomechanical process, to produce the deformed textile fabric having the deformations formed in a base region thereof. The three-dimensional network structures may be used in a variety of articles, including cushioning materials, impact-absorbing materials, and load-bearing materials.

Abstract: A cargo liner and cargo holder system includes a mat having a plurality of protrusions extending from a base. Locking members include a plurality of engagement members extending from a body and are adapted to engage with the protrusions of the mat. The mat includes a plurality of geometrically-shaped protrusions which can be octagonally shaped or cylindrically shaped. The locking members can be secured to boxes or other objects for securement to the mat. Engagement members engaged to the mat are able to move to a limited extent; this motion allows each engagement member to be captured by mat protrusions with the same degree of capture force. The mat also includes a lip extending around the perimeter of the mat for containment of any liquids therein. The mat also includes two layers, a polyethylene first layer and an olefin-friendly rubber layer. The locking members can be modified and secured to a bag-hanging device.

Abstract: An improved closed-cell foam sheet stock and method for producing constant force characteristics in elastomer cushions. A closed cell foam is formed as a corrugated cardboard with regular cavities and support elements between two surface sheets. The resulting stock material possesses similar flexibility to foam stock but with an elongated force curve. A method for modifying this or other corrugated elastomers for efficient constant force curves is further provided where alternating support members are conjoined or buttressed to fold in controlled sigmoid shape under load. The resulting collapsible truss or space frame structure produces a cushion with improved cushioning, load distribution, shock absorption and resistance from lateral collapse while folding uniformly and efficiently to a smooth, compact and comfortable support under full compression.

Abstract: An expandable and contractible cellular panel 10 comprises a plurality of parallel, aligned, elongated tubular sections 12 secured together at the median region of their adjacent longitudinal margins to form the panel 10. The adjacent tubular sections 12 of the panel 10 are made of a pair of substantially identical separate strips of sheet material from those forming the other adjacent tubular sections 12. The various adjacent pairs of strips are laminated together along their confronting longitudinal margins. Each strip is made of at least two separate flexible substrate sheets 18,20 having completely different appearances, and are secured together by welding together their longitudinal margins.

Abstract: An embossed multiple ply paper product having a nested latticework embossment pattern providing a cloth-like, quilted appearance and a process for embossing and bonding such multiple ply paper product. The multiple ply paper product comprises a latticework of cells composed of n rows of embossment elements nested within an interfacing latticework of cells composed of n+1 rows of embossment elements.

Abstract: The present invention relates to a method for making a shielded automobile component and the shielded automobile component itself. The component includes a composite formed of a metal sheet which includes protrusions which extend from a surface of the metal sheet and a blow-molded thermoplastic layer formed around the protrusions which fixes the blow-molded layer to the metal sheet during the molding process. The protrusions on the metal sheet define plain polygonal areas which are free of protrusions.

Abstract: A bladder usable in the sole of a shoe for supporting the plantar area includes a plurality of chambers designed to provide a resilient resistance force. In the fabrication of the bladder, each of the chambers is formed in fluid communication with each other, and fluid is supplied into the chambers at a selected location. After the chambers have been pressurized to the desired internal pressure, the fluid communication port(s) is sealed. Although certain of the chambers are pressurized to the same internal pressure, different resistance forces are provided by forming the chambers with different volumes.

Abstract: A multilayer ceramic device has top and bottom green ceramic layers machined and fired. Intermediate green ceramic layers are machined, have conductors laid down in the machined areas, are laminated, and are fired to form an enclosure layer. The areas of the layers which will be in contact with each other are coated with a bonding agent. The layers are aligned and bonded to form a structure having arbitrarily shaped, interior channels adjacent to the top and bottom layers which are not subject to detrimental nonplanarities.

Abstract: A machine and method for the manufacture of a continuous production of pneumatically filled packaging pillows for use as void fill packaging for the safe shipping of articles. A strip of flattened preformed film material with a repeated sealing pattern is advanced along a path through the machine and include a common inflation channel that is guided onto a longitudinally extending inflation tube at a first station. The inflation tube has an orifice through which pressurized air is expressed in controlled fashion to inflate pillow chambers that emanate off the common inflation channel of the film material. The film material is advanced to a second station where continuous longitudinally extending heat seals are formed in the film material in a manner to trap and confine a quantity of air inside the inflated pillow chambers. The film material is then advance to a third station where the common inflation channel is slit open in order to release the film material from the inflation tube of the machine.

Abstract: Structural element characterized by its rigidity and very light weight per unit but simpler and readily formed at every scale, which is constructed using a first piece or preform which comprises a plurality of projections and a second piece which can be a second preform, a sheet or a mesh, wherein both pieces are fixed by means of the plurality of tips of the plurality of projections fixing them by any fixing means appropriate to the materials used and to the application of the structural element.

Abstract: A space truss composite panel is excellent in structural mechanics and capable of being efficiently and economically produced. The space truss composite panel has a construction in which a sheet 1 provided with a series of slits 2 is formed into a space framework 3 through a press working. The space framework 3 is provided with a series of polygonal unit lattices in one of its opposite sides and a series of polygonal pyramids in the other of the opposite sides, wherein each of the polygonal unit lattices has an intersection of its adjacent sides 3a, 3a connected with a ridgeline portion 3b of each of the polygonal pyramids, and the space framework 3 has at least one of its opposite sides connected with a board-like member 4.

Abstract: A barrier for containing an explosion in a room or the like. The barrier is a structural panel comprising a base sheet, a plurality of truncated polyhedral elements secured to and projecting from the base sheet, and a face sheet covering and secured to the truncated apexes of the polyhedral elements. The face sheet is constructed to separate from the polyhedral elements to expose them in the event of an explosion. Each polyhedral element is constructed to collapse in the event of an explosion, is filled with a liquid, and has an opening therein that is closed by a closure device that is openable or removable in response to the collapse of the polyhedral element caused by an explosion. The openings in the polyhedral elements are of a size to effect a misting action of the liquid therein when it is ejected from the openings by the collapse of the polyhedral elements caused by the explosion. The liquid mist serves to absorb and dissipate the heat and energy of the explosion.

Abstract: A support device for a computer mouse (mouse pad) comprises, extending over the lower foil made of foam material, at least one thin, colored liquid layer which is enclosed between two foils welded together along the edge in a liquid-tight manner and is visible through the transparent foil or foils. The liquid occupies the available cavity only incompletely and it spreads out in puddle-like patterns to define void spaces which change continuously due to the actuation of the mouse, thereby providing the mouse pad with an optically interesting appearance.

Abstract: A composite material and method of forming such composite material is provided in which first and second layers of plastic film are laminated together and define a multiplicity of spaced apart, gas filled cavities therebetween, and a third layer of a fibrous or other suitable material is mechanically bonded to one of the first and second layers of plastic film.

Abstract: A shock attenuation barrier including a plurality of layers successively arranged including a first layer, a second layer having a plurality of molded geometric shapes, a third layer including foam, a fourth layer having a plurality of molded geometric shapes and a fifth layer. Cavities defined by inside surfaces of the geometric shapes and a surface of the foam layer preferably are filled with a shock absorbing filler material.

Abstract: A sound-absorbing cellular component is produced in multiple-chamber array, using a grid of spaced elongate rods, and by engaging to the rods of said grid a foil of deformable sheet material which is then drawn by deformation through spaces between rods, to thereby define adjacent partition walls of adjacent chambers. Various embodiments are described, involving retention and/or removal of the rods, and/or involving application of one or more insulating or finishing materials continuously over outwardly facing bottoms of the chambers of the array.

Abstract: A device outer wall structure includes a rubber covering covered on a device for example a bicycle hand grip or saddle, the rubber covering having a plurality of hollow convex portions filled with air and a plurality of air passages in communication between the convex portions for guiding air from one convex portion to another when the convex portions bear an external pressure.

Abstract: A method of making an monolithic metallic sandwich structure includes selecting at least two chemically clean metal core sheets having superplastic characteristics and placing them face-to-face. The core sheets are welded together into a core pack along intersecting lines that will form junction lines of webs defining cells between the core sheets when the core pack is expanded superplastically. Gaps are left adjacent to the intersections of the weld lines to produce openings through which gas can pass to pressurize each cell. The position of the gaps adjacent the weld line intersections minimizes strain on the marginal regions around the openings as the core pack is inflated, to reduce the tendency of the sheets to tear or rupture around the openings. A gas pressure line fitting is inserted between one edge and the core pack is welded around its periphery with the gas fitting protruding from the edge for connection to a gas source that will purge and pressurize the core pack with gas.