CONCRETE FORM PANELS AND PROCESSES FOR MAKING THE SAME

Concrete forms and manufacturing methods thereof are disclosed herein. In one aspect, a concrete form panel includes: a wood-based composite structural panel having a first side and a second side. The concrete form panel includes a urethane layer coupled to the first side of the panel. In another aspect, a method for manufacturing a concrete form panel includes sanding a first side of a wood-based composite structural panel; loading the panel into a manufacturing line; conveying the wood-based composite structural panel to a spray booth; spraying a urethane layer onto the first side of the panel; conveying the panel out of the spray booth and into a curing station; curing the urethane layer onto the first side of the panel; and sanding the urethane layer. In another aspect, a concrete form includes a plurality of concrete form panels having a urethane layer coupled to a first side of the panel.

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Description
CONCRETE FORM PANELS AND PROCESSES FOR MAKING THE SAME

The present application claims priority to U.S. Provisional Application Ser. No. 63/753,702 entitled “Concrete Form Panels and Processes For Making The Same,” filed on Feb. 4, 2025, the entirety of which is hereby incorporated by reference.

TECHNICAL FIELD

This application is directed, in general, to concrete forms and in particular to concrete form panels and processes for making the same.

BACKGROUND

The following discussion of the background is intended to facilitate an understanding of the present disclosure only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge at the priority date of the application.

Concrete form panels are used to form concrete forms for use in forming concrete blocks, components, or structures. Form panels are assembled to form a barrier wall or retainer for containing wet concrete. The form panels may be manufactured from materials such as wood composites. The concrete forms are filled with wet concrete, which adopts the configuration of the concrete form. Once the concrete cures and is hardened, the form panels are removed. In some applications, concrete form panels are utilized to form concrete structures and objects, such as floors, walls, columns, and other structural components of a building or structure. While concrete form panels and formworks using concrete form panels are known in the art, improvements are desired. In some instances, the formation of concrete structures may be inefficient due to the time required to create the concrete forms, the time needed for the concrete to cure, and the time needed to take down the form. In other instances, formation of the concrete structures and objects may be inefficient due to the need to replace concrete form panels, which may delay construction time and increase material and labor costs.

It would be highly desirable to have a concrete form suitable for use during such procedures to improve efficiency and reduce costs.

SUMMARY OF THE INVENTION

In one aspect, a concrete form panel is provided comprising: a wood-based composite structural panel having a first side and a second side. The concrete form panel includes a urethane layer coupled to the first side of the panel. The urethane layer comprises a resin component. The resin component includes a polyol mixture having at least one natural oil; a micronized wax; a catalyst; and at least one additive. The urethane layer also comprises an isocyanate component. In some embodiments, the wood-based composite structural panel is plywood or oriented strand board (OSB). In alternative embodiments, the urethane layer has a thickness in the range of 5-100 mils. In some embodiments, the polyol mixture includes polyethylene ether diols and triols; polypropylene ether diols and triols, saturated polyester diols and triols, unsaturated polyester diols and triols, polycaprolactone diols and triols, polytetrahydrofuran diols, diamine initiated quadrols, or mixtures thereof. In additional embodiments, the at least one natural oil of the polyol mixture comprises hydroxyfunctionalized plant-based oils, animal-based oils, or castor oils. The resin component may include between 40 wt. % to 90 wt. % of the polyol mixture. The resin component may include between 1 wt. % to 10 wt. % of the micronized wax.

In another aspect, a method for manufacturing a concrete form panel comprising the steps of: sanding a first side of a wood-based structural panel to a desired thickness, smoothness, or texture; loading the wood-based composite structural panel into a manufacturing line; conveying the wood-based composite structural panel to a spray booth; spraying a urethane layer onto the first side of the wood-based composite structural panel; conveying the wood-based composite structural panel out of the spray booth and into a curing station; curing the urethane layer onto the first side of the wood-based composite structural panel; and sanding the urethane layer to a desired thickness, smoothness, or texture. In some embodiments, the wood-based composite structural panel is plywood or oriented strand board (OSB). The urethane layer comprises a resin component. The resin component includes a polyol mixture having at least one natural oil; a micronized wax; a catalyst; and least one additive. The urethane layer also comprises an isocyanate component. In some embodiments, the method further includes mixing the resin component and the isocyanate component prior to the spraying step. In additional embodiments, a ratio by volume applied of the resin component and the isocyanate component ranges from 1:2 to 6:1. The curing step may be for a period of time ranging from 2 minutes to 6 minutes.

In yet another aspect, a concrete form includes a plurality of concrete form panels. The plurality of concrete panels are coupled to each other to form a retainer or reservoir for retaining uncured concrete. At least one of the plurality of concrete panels comprises a urethane layer coupled to the first side of the panel. The urethane layer includes a resin component. The resin component comprises a polyol mixture having at least one natural oil; a micronized wax; a catalyst; and at least one additive. The urethane layer further includes an isocyanate component.

DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present disclosure are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein and wherein:

FIG. 1 is a schematic, perspective view of an illustrative embodiment of a concrete form utilizing concrete form panels;

FIG. 2. is a schematic perspective view of an illustrative embodiment of a concrete form panel;

FIG. 3 is a schematic, elevation view of a portion of an illustrative embodiment of a concrete form panel;

FIG. 4 is a schematic diagram of an illustrative embodiment of a process for manufacturing a concrete form panel;

FIG. 5 is a schematic, elevation view of an illustrative embodiment of a manufacturing line for manufacturing a concrete form panel; and

FIG. 6 is a schematic, plan view of the manufacturing line of FIG. 5.

FIG. 7 is a graphical representation of the performance of an embodiment of a form panel having a urethane layer in the Experimental Example.

FIGS. 8A and 8B are graphical representations of performance of an embodiment of a form panel having a urethane layer compared to a conventional form panel.

 DETAILED DESCRIPTION OF THE DRAWINGS

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is understood that other embodiments may be utilized, and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the disclosure. To avoid detail not necessary to enable those skilled in the art to practice the disclosure, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present disclosure is defined only by the claims. Unless otherwise indicated, as used throughout this document, “or” does not require mutual exclusivity.

As used in the specification, the term “diol” should be understood to mean a chemical compound containing two hydroxyl groups, such as a di-functional alcohol.

The term “triol” should be understood to mean a chemical compound containing three hydroxyl groups, such as a tri-functional alcohol.

The term “quadrol” should be understood to mean a chemical compound containing four hydroxyl groups, such as a tetra-functional alcohol.

The term “wood” should be understood to refer to pieces of timber, lumber, logs, flitches, cants, beams, posts, studs, boards, veneers, strands, and/or any other pieces of wood smaller than the whole tree and larger than sawdust.

The term “wood-based composite” should be understood to cover engineered wood products made from pieces of wood that are secured together using adhesives and/or binders to produce a composite wood product. Different types of engineered wood products can be manufactured from different wood-based feedstocks, such as strands, fibers, chips or thin layers (plies). Common engineered wood products include particle board, fiberboard particles, oriented strand board (OSB), and plywood, e.g., medium-density fiberboard (MDF). Engineered wood products can vary in their structural and/or non-structural properties and find a variety of uses such as in furniture and construction.

The term “urethane” should be understood to cover a reaction product of a first functional group with a second functional group that forms a polymeric material, where that polymeric material may be a polyurethane, a polyurea, or a polyurethane/polyurea hybrid formulation (i.e., a polymer comprising both urethane and urea functional groups).

Referring now to FIG. 1, a concrete form 100 will be discussed. The concrete form 100 includes a plurality of form panels 104. Each form panel 104 has a first side 108 and a second side 112. The form panels 104 are coupled to each other so that the concrete form 100 has a retainer or reservoir portion 116. The form panels 104 are coupled together so that the first side 108 of the form panels 104 is on the inside of the concrete form 100, and the second side 112 of the form panels 104 is on the outside of the concrete form 100. As discussed in more detail below in relation to FIGS. 2 and 3, the first side 108 of the form panels 104 includes a urethane layer 120 that acts as a durable release coating for the concrete form 100.

The concrete form 100 is used to form concrete structures having a desired size or configuration. The form panels 104 are coupled to each other so that the reservoir portion 116 has the same size or configuration that it is desired for the concrete block or structure to have. Wet concrete is poured into the reservoir portion 116 of the concrete form 100 to the desired level. The concrete is allowed to cure, at which point the concrete hardens to form a block or structure. Once the concrete is sufficiently hardened, the form panels 104 are uncoupled from each other to expose the finished concrete block or structure having the size or configuration defined by the size and configuration of the reservoir portion 116.

Since the first side 108 of each form panels 104 is on the inside of the concrete form 100, the first sides 108 are the side of the form panels 104 that are exposed to the wet concrete during use of the concrete form 100. As mentioned above and discussed further below, the first side 108 of the form panels 104 includes the urethane layer 120.

The urethane layer 120 provides a hard and durable surface to increase the performance and longevity of the concrete form 100 and the form panels 104. The urethane layer 120 provides both a mechanical and chemical barrier from the concrete. The urethane layer 120 provides a mechanical barrier that may prevent or reduce damage to the form panels 104 that may occur during the process of use of the concrete form 100. For example, the urethane layer 120 may reduce physical abrasion caused by the concrete, mixing of the concrete, or shaking of the concrete that occurs during the process of forming a block or structure while using the concrete form 100. The urethane layer 120 also may reduce chemical damage to the concrete form 100 and form panels 104 that may occur when the concrete form 100 is exposed to wet concrete. For example, many wet concrete mixtures are strongly alkaline in nature, and the urethane layer 120 may be impervious to or resistant to basic solutions, at least for the time period that the concrete form 100 and form panels 104 are exposed to such conditions.

The urethane layer 120 may comprise one or more components. In some embodiments, the urethane layer 120 may comprise two components. The urethane layer 120 may comprise a resin component and an isocyanate component. The resin component may comprise a single polyol or it may comprise a mixture of polyols. For example, the resin component may contain one polyol, two polyols, three polyols, or four or more polyols. In some embodiments, the resin component may comprise a polyol mixture, which may include a blend of one or more oils, a micronized wax component, and at least one of fillers, catalysts, or other additive materials.

As provided in the present application, oils used in the polyol mixture may include chemical compounds including diols, triols, quadrols, and mixtures thereof. Examples of suitable diols, triols, and quadrols for the polyol mixture include, but are not limited to, polyethylene ether diols and triols; polypropylene ether diols and triols, saturated polyester diols and triols, unsaturated polyester diols and triols, polycaprolactone diols and triols, polytetrahydrofuran diols, diamine initiated quadrols, and mixtures thereof. Other suitable oils for the polyol mixture include natural oils including, but not limited to, hydroxyfunctionalized plant-based oils, animal-based oils, and castor oils. Examples of hydroxyfunctionalized plant based oils for the polyol mixture include, but are not limited to, olive oil, sunflower oil, linseed oil, tall oil, soybean oil, colza oil, fish oil, cottonseed oil, palm oil, palm kernel oil, coconut oil, canola oil, flaxseed oil, high oleic canola oil, safflower oil, other saturated and unsaturated vegetable oils, and mixtures thereof. In some embodiments, the resin component comprises a polyol mixture having at least one natural oil, such as a hydroxyfunctionalized plant-based oil.

The micronized wax component of the resin component may comprise a broad range of petroleum-based wax, bio-based wax, synthetic wax, paraffin wax, and additional waxes known to the relevant art or mixtures thereof. For example, the micronized wax component may comprise a blend of two or more petroleum-based waxes, a blend of petroleum-based wax and bio-based wax, or a blend of petroleum-based wax and synthetic wax. One of ordinary skill in the art would be able to identify and produce blends of waxes having the desired physical properties using any of petroleum-based waxes, bio-based waxes, synthetic waxes, other suitable waxes or mixtures thereof.

The term “petroleum-based wax” refers to any wax derived from oil refining. Petroleum-based waxes can be defined by the amount of oil, microcrystalline wax and paraffinic wax that they contain. In an embodiment, the petroleum wax may be a petroleum slack wax. Slack wax is the crude wax produced by chilling and solvent filter-pressing wax distillate. Blends of different slack waxes, along with oil, petrolatum, pure paraffinic, and scale waxes can be emulsified for use as sizing agents.

The term “biowax” refers to a broad category of animal- or plant-derived waxes made of unhydrogenated, partially hydrogenated and fully hydrogenated fats and oils. Examples include partially or fully saturated beef tallow, vegetable fats and oils, or oils derived from a variety of other plant-based sources (for example, nuts, soy, sunflower, palm, corn, seeds, castor oil, or palm oil).

A filler may also be included as a component in the resin component. Examples of fillers include glass, sand, rock, rubber crumb, architectural stone, low density fillers such as polystyrene beads (expanded or unexpanded) or expanded glass beads, natural bio-based fillers including, but not limited to, cellulosic fillers such as wood flour, wood chips, wood flakes, sawdust, pulp, wheat and rice straw, rice husk, ash, starches, lignin, plant-derived fibers (i.e., cotton, linen, flax, jute, sisal, and hemp), filler particles derived from animals, biological products outside of the plant kingdom (i.e., fungi or sea sponges), and combinations thereof. In some embodiments, the suitable fillers may include ground or milled recycled glass, ground or milled calcium carbonate, ground or milled silicate, ground or milled mica, ground or milled diatomaceous earth, engineered hollow glass spheres, hollow synthetic plastic spheres, and reclaimed ceramic particles. The filler materials may be at least 1 micron. In other embodiments, the filler materials may be at most 200 microns. In additional embodiments, the filler materials may range from 1 microns to 200 microns. The glass may be of any type and may be clear, tinted, and/or colored.

Other additive materials that may be included in the resin component include air release additives, filler wetting aides, catalysts, color pigments, and rheology modifiers. Exemplary materials that may be included in the resin component include, but not limited to, fumed silica, thixotropes, controlled flocculation additives, air release additives (e.g., silicone and solvents), defoaming additives, non-tin organometallic catalysts, non-mercury organometallic catalysts, mineral wetting/dispersing agents, inorganic pigments, and moisture scavenging additives.

In some embodiments, the resin component may comprise 40 wt. % to 90 wt. % of the polyol mixture relative to the total weight of the resin component. Thus, the resin component may comprise 40 wt. %-85 wt. %, 42 wt. %-83 wt. %, 44 wt. %-81 wt. %, 45 wt. %-80 wt. %, and 46 wt. %-79 wt. % of the polyol mixture relative to the total weight of the resin component. For example, the resin component may comprise 40 wt. %, 41 wt. %, 42 wt. %, 43 wt. %, 44 wt. %, 45 wt. %, 46 wt. %, 47 wt. %, 48 wt. %, 49 wt. % 50 wt. %, 51 wt. %, 52 wt. %, 53 wt. %, 54 wt. %, 55 wt. %, 56 wt. %, 57 wt. %, 58 wt. %, 59 wt. %, 60 wt. %, 61 wt. %, 62 wt. %, 63 wt. %, 64 wt. %, 65 wt. %, 66 wt. %, 67 wt. %, 68 wt. %, 69 wt. %, 70 wt. %, 71 wt. %, 72 wt. %, 73 wt. %, 74 wt. %, 75 wt. %, 76 wt. %, 77 wt. %, 78 wt. %, 79 wt. %, 80 wt. %, 81 wt. %, 82 wt. %, 83 wt. %, 84 wt. %, 85 wt. %, 86 wt. %, 87 wt. %, or 88 wt. %, or a range formed from any two of the foregoing weight percentages, including any sub-ranges therebetween, of the polyol mixture relative to the total weight of the resin component.

In embodiments where the polyol mixture comprises at least one natural oil, the polyol mixture may comprise a single polyol (or a blend of polyols) ranging from 10 wt. % to 50 wt. % relative to the total weight of the resin component and at least one natural oil ranging from 30 wt. % to 70 wt. % relative to the total weight of the resin component. For example, the polyol mixture may comprise 12 wt. %, 14 wt. %, 16 wt. %, 18 wt. %, 20 wt. %, 22 wt. %, 24 wt. %, 26 wt. %, 28 wt. %, 30 wt. %, 32 wt. %, 34 wt. %, 36 wt. %, 38 wt. %, 40 wt. %, 42 wt. %, 44 wt. %, 46, wt. %, 48 wt. %, or a range formed from any two of the foregoing weight percentages, including any sub-ranges therebetween, of a single polyol (or a blend of polyols) relative to the total weight of the resin component; and 32 wt. %, 34 wt. %, 36 wt. %, 38 wt. %, 40 wt. %, 42 wt. %, 44 wt. %, 46 wt. %, 48 wt. %, 50 wt. %, 52 wt. %, 54 wt. %, 56 wt. %, 58 wt. %, 60 wt. %, 62 wt. %, 64 wt. %, 66 wt. %, 68 wt. %, or a range formed from any two of the foregoing weight percentages, including any sub-ranges therebetween, of at least one natural oil relative to the total weight of the resin component.

In some embodiments, the resin component may comprise 1 wt. % to 10 wt. % of micronized wax relative to the total weight of the resin component. For example, the resin component may comprise 2 wt. %, 2.2 wt. %, 2.4 wt. %, 2.6 wt. %, 2.8 wt. %, 3 wt. %, 3.2 wt. %, 3.4 wt. %, 3.6 wt. %, 3.8 wt. %, 4 wt. %, 4.2 wt. %, 4.4 wt. %, 4.6 wt. %, 4.8 wt. %, 5 wt. %, 5.2 wt. % 5.4 wt. %, 5.6 wt. %, 5.8 wt. %, 6 wt. %, 6.2 wt. %, 6.4 wt. %, 6.6 wt. %, 6.8 wt. %, or 7 wt. %, or a range formed from any two of the foregoing weight percentages, including any sub-ranges therebetween, of micronized wax relative to the total weight of the resin component.

In some embodiments, the resin component may comprise 0.1 wt. % to 3 wt. % of a catalyst relative to the total weight of the resin component. For example, the resin component may comprise 0.3 wt. %, 0.4 wt. %, 0.5 wt. %, 0.6 wt. %, or 0.7 wt. %, 0.8 wt. %, 0.9 wt. %, 1.0 wt. %, 1.1 wt. %, 1.2 wt. %, 1.3 wt. %, 1.4 wt. %, 1.5 wt. %, 1.6 wt. %, or 1.7 wt. %, 1.8 wt. %, 1.9 wt. %, 2 wt. %, 2.1 wt. %, 2.2 wt. %, 2.3 wt. %, 2.4 wt. % 2.5 wt. %, 2.6 wt. %, or 2.7 wt. %, or a range formed from any two of the foregoing weight percentages, including any sub-ranges therebetween, of a catalyst relative to the total weight of the resin component.

In some embodiments, the resin component may comprise 7 wt. % to 18 wt. % of other additive materials relative to the total weight of the resin component. For example, the resin component may comprise 8 wt. %, 8.5 wt. %, 9 wt. %, 9.5 wt. %, 10 wt. %, 10.5 wt. %, 11 wt. %, 11.5 wt. %, 12 wt. %, 12.5 wt. %, 13 wt. %, 13.5 wt. %, 14 wt. %, 14.5 wt. %, 15 wt. %, 15.5 wt. %, or 16 wt. %, 16.5 wt. %, 17 wt. %, or a range formed from any two of the foregoing weight percentages, including any sub-ranges therebetween of other additive materials relative to the total weight of the resin component.

An example embodiment of the resin component may be as follows: 10 wt. % to 50 wt. % polyol, 30 wt. % to 70 wt. % natural oil, 0.1 wt. % to 3 wt. % catalyst, and 7 wt. % to 18 wt. % other additives.

The resin component is reacted with the isocyanate component to form the urethane layer. The isocyanate component should have at least one isocyanate functional group. The functional group may be an aliphatic isocyanate, a cycloaliphatic isocyanate, an aryl isocyanate, an aromatic cyanate, or a combination thereof. The functional group may be 1,6-hexamethylene diisocyanate, 1,4-butylene diisocyanate, furfurylidene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,4′-diphenylethane diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 4,4′-diphenylpropane diisocyanate, 4,4′-diphenyl-3,3′-dimethyl methane diisocyanate, 1,5-naphthalene diisocyanate, 1-methyl-2,4-diisocyanate-5-chlorobenze, 2,4-diisocyanate-s-triazine, 1-methyl-2,4-diisocyanato cyclohexane, p-phenylene diisocyanate, dianisidine diisocyanate, bitolylene diisocyanate, 1,4-xylylene diisocyanate, 1,3-xylylene diisocyanate, bis-(4-isocyanatophenyl)methane, bis-(3-methyl-4-isocyanatophenyl)methane, polymethylene polyphenyl polyisocyanates or a combination thereof. In a particular embodiment, the isocyanate component may be a polymeric methyl diphenyl diisocyanate. The aforementioned list of isocyanate functional groups is representative of the isocyanate functional groups that may be used. However, the isocyanate functional groups suitable for use are not particularly restricted. U.S. Pat. No. 5,422,385, hereby incorporated by reference in its entirety, provides additional isocyanates that may be used.

The urethane layer 120 is configured to remain on the front side 108 of the form panels 104 for the lifetime of the concrete form 100. Optionally, in some embodiments, a secondary release agent may be applied to the front side 108 of the form panels 104 of the concrete form 100 following application and curing of the urethane layer 120. In addition, the first side 108 of the form panels 104 may be sanded or textured in a desired manner, which may assist in release of the concrete block or structure from the concrete form 100 and form panels 104 and produce a desired finish on the concrete block or structure.

As discussed above, the urethane layer 120 acts as a durable release coating for the concrete form 100 and form panels 104. As a durable release coating, the urethane layer 120 assists in removal of the concrete form 100 and form panels 104 from the hardened concrete block or structure. Once sprayed and polymerized on the form panels 104 of the concrete form 100, the urethane layer 120 yields a low surface energy. This low surface energy imparts the urethane layer 120 with properties to allow the urethane layer 120 to function as a release coating for the concrete form 100. The low energy surface of the urethane layer 120 is a result of the components of the urethane and the application temperature. In particular, the one or more oils of the polyol mixture and the micronized wax component of the resin component function as lubricants. Once the resin component and the isocyanate component polymerizes into the urethane layer 120, the one or more oils of the polyol mixture and the micronized wax components of the resin component retain their properties as a lubricant, and thus, provide the urethane layer 120 with releasing properties.

It will be appreciated by those skilled in the art that the concrete form 100 depicted in FIG. 1 is illustrative in nature and that in other embodiments other sizes, shapes, and configurations may be used to produce the desired hardened concrete block or structure. In addition, it will be appreciated by those skilled in the art, that the concrete form 100 need not be formed exclusively with form panels 104, depending on the particular application of the concrete form 100 and the form panels 104.

In some applications, the concrete form 100 or the form panels 104 may be used for building high rise buildings or other buildings from concrete. Many types of forms are used during the construction of concrete buildings and structures, and the form panel 104 may be incorporated and utilized within this process. Typically, forms are used for making columns, walls, floors and other structural components of concrete buildings, for example, tables may be used to form floors and ceilings. While the size and design of the forms 100 vary depending on the particular application, the forms typically are made from supporting materials such as supporting scaffolding made from steel or other metals. Form panels 104 are coupled to the supporting scaffolding to form barriers or reservoirs for containing wet concrete to be poured into. The wet concrete is allowed to cure and the formworks, including the form panels 104, are removed. For example, one type of form used in such construction techniques is referred to as a “table.”

The table is used to form floors within the concrete structure. The table is assembled in the place within the partially built concrete structure at the location that a floor is desired. The supporting scaffolding of the table extends upward towards the location of the floor to be poured. Form panels 104 are coupled to the structural scaffolding so as to form a flat planar barrier to contain the wet concrete that will become the floor. The form panels 104 are abutted edge to edge to form the barrier structure. The first side 108 of the form panels 104 faces upward and delineate what will become the bottom surface of the floor to be poured. Wet concrete is poured onto the top surface of the formworks (i.e., the first side 108 of the form panels 104) and allowed to cure to hardness. The formworks, including the form panels 104, are removed and relocated to the next desired location for a floor.

Referring now primarily to FIGS. 2 and 3, an illustrative embodiment of the form panel 104 will be discussed. The form panel 104 includes a structural panel 124 and a urethane layer 120. The structural panel 124, formed from a wood-based composite, provides the rigidity and support needed to support the urethane layer 120 and to provide the necessary structural rigidity of the form panel 104 for a particular concrete form application. In some embodiments, the wood-based composite is a plywood or oriented strand board (OSB) panel.

The structural panel 124 has a first side 136 and a second side 140 or opposing side. The urethane layer 120 is coupled to the first side 136 of the structural panel 124, so that the urethane layer 120 is the outermost layer on the first side 108 of the form panel 104.

The form panel 104 has a length 144 and a width 148. In some embodiments, the length 144 and the width 148 are each in the range of 1-12 feet. In some embodiments, the length is in the range of 4-12 feet. In some embodiments, the width is in the range of 3-5 feet. In some embodiments, the length is approximately 8 feet, and the width is approximately 4 feet. Those skilled in the art will appreciate that other dimensions may be used.

The structural panel 124 has a thickness 152. In some embodiments, the thickness 152 is in the range of 0.25-1.00 inches. In some embodiments, the thickness 152 is in the range of 0.35 to 0.725 inches. In some embodiments, the thickness 152 is approximately ⅜. ½, ⅝ or ¾ of an inch. Those skilled in the art will appreciate that other dimensions may be used.

The urethane layer 120 has a thickness 156. In some embodiments, the thickness 156 is in the range of 5-100 mils. In some embodiments, the thickness 156 is in the range of 20-40 mils. In some embodiments, the thickness 156 is approximately 30 mils. Those skilled in the art will appreciate that other dimensions may be used.

Referring primarily to FIGS. 4, 5, and 6, an illustrative method 160 for manufacturing form panels 104 will be described. The method 160 starts by loading a stack of structural panels 124 onto a loader 166. Each of the structural panels 124 are separated into individual panels, which are then transported to a spray booth 168. At the spray booth 168, the first side 136 of the structural panels 124 are sprayed with a two-part reactant mixture (as described more fully below), which, once cured, forms the urethane layer 120 (FIGS. 2 and 3). Each structural panel 124, after spraying, is transported to a curing station 172, at which point the structural panels 124 are held for sufficient time to allow for curing of the urethane layer 120. Once the urethane layer 120 is sufficiently cured, the completed form panels 104 are transported to a stacking unit 174 where the form panels 104 are stacked and, optionally, strapped in bundles. It should be noted that a secondary release agent may be applied a separate step following curing of the urethane layer 120. In some embodiments, the release agent is part of the chemical makeup of the urethane layer 120.

Referring primarily to FIGS. 5 and 6, an illustrative manufacturing line 164 and method for manufacturing form panels 104 will be described. FIG. 5 depicts the manufacturing line 164 in elevation view. FIG. 6 depicts the manufacturing line 164 in plan view. The manufacturing line 164 is a two-level manufacturing line, with an upper portion 180 (FIG. 5) and a lower portion 184, to conserve space. However, those skilled in the art will appreciate that a single level manufacturing line 164 may be used to manufacture form panels 104.

The manufacturing process begins at the loader 166, which is located on both the upper and lower portions of the manufacturing line 164. A stack or bundle of structural panels 124 is loaded into the lower-level portion of the loader 166. The loader 166 then, sequentially and individually, lifts each structural panel 124 from the stack of structural panels 124 to the upper-level portion of the loader 166. At which point, each structural panel 124 is, individually and sequentially, placed onto a conveyor 188.

The conveyor 188 conveys each structural panel 124 to the spray booth 168. While within the spray booth 168, at least the first side 136 of each structural panel 124 is coated with a two-part reactant mixture, which when cured will form the urethane layer 120. In some embodiments, the two-component reaction mixture is sprayed using at least one sprayer head. Example sprayer heads that may be used with these embodiments include, but are not limited to, equipment such as a Graco® PROMIX 2KE or 2KS. In some embodiments, the first side 136 of the structural panel 124 is sprayed using 3-6 spray heads. Those skilled in the art will appreciate that other sprays and spray heads may be used. The process of spraying will involve arranging the sprayer heads into a configuration to ensure that the spray patterns do not collide and degrade in flight from the emitting tip of the sprayer to the panel. In some embodiments, the sprayer heads may be arranged in an echelon configuration. In alternative embodiments, the sprayer heads may be arranged in a staggered configuration.

The mixing of the resin component and the isocyanate component takes place in a mixing apparatus. The resin component and the reactive component may be present in amounts that allow a complete reaction therebetween. Prior to mixing, the resin component and the isocyanate component are heated to a temperature ranging from 120 °F to 170 °F. The mixing apparatus may be a static mixing apparatus or a dynamic mixing apparatus. In embodiments comprising a static mixing apparatus, the resin component and the isocyanate component of the urethane layer 120 are blended using a flow current. The resin component and the isocyanate component of the urethane layer 120, at the desired ratios, may be placed into a tube, or mixer channel, with flow control elements, such as static mixer elements, or a mixer bore, mounted end-to-end on the inside. In embodiments comprising a dynamic mixing apparatus, the resin component and the isocyanate of the urethane layer 120 may be fed into a mixing chamber of the sprayer head. The spray tip of the sprayer head may be pressurized in the range of 2,000 psi to 3,600 psi. At this pressure, the resin component and the isocyanate component are mixed and atomized. The ratio of the resin component to the reactive component may be determined based on a number of considerations, including, but not limited to, the components being mixed to form to the polymeric composition, and environmental conditions such as ambient temperature, humidity, etc. For some embodiments, the ratio by volume applied of the resin component and the isocyanate component may range from 1:2 to 6:1. In some embodiments, the resin component and the isocyanate may be applied in a 1:1 ratio by volume. The resin viscosity of the resin component may range from 500 cP to 2000 cP.

After spraying occurs, the conveyor 188 conveys the sprayed structural panels 124 to the curing station 172. The purpose of the curing station 172 is to provide sufficient delay between spraying each structural panel 124 and stacking each resulting form panel 104 to allow the urethane layer 120 to sufficiently cure (i.e. polymerize) so that the form panels 104 may be stacked without the second side 112 of a particular form panel 104 damaging or sticking to the first side 108 (having the urethane layer 120) of the form panel 104 below it in the stack of form panels 104. The urethane layer 120 should be undisturbed during this step in order to allow the material to completely adhere to the wood or wood product.

The form panels 104 may be cooled by a fluid, such as air or by other cooling measures during the time it takes for the urethane layer 120 to cure or harden. Or the form panels 104 may simply be held at room or ambient temperature while within the curing unit 172.

The curing unit 172 also serves the purpose of lowering each form panel 104 from the upper portion 180 of the manufacturing line 164 to the lower portion 184 of the manufacturing line. In the illustrative embodiment of FIGS. 5 and 6, each sprayed structural panel 124 is separated from vertically adjacent sprayed structural panels 124 by fingers within the curing unit 172 that slowly lower each sprayed structural panel 124 from the upper portion 180 to the lower portion 184. Upon curing of the urethane layer 120, a bond is formed between the first side 136 of the structural panel 124 and the second side 132 of the urethane layer 120, and the form panel 104 is thus formed.

Upon exiting the curing station 172, each form panel 104 is loaded onto a conveyer 192, which transport each form panel 104 to the stacker 176. The stacker 176 receives each completed form panel 104 and stacks the completed form panels 104 into bundles for transporting.

In this process, the rate of polymerization rate is a function of a number of factors including, but not limited to, the amount of catalyst, panel temperature, the panel moisture content, and ambient temperature. The rate of polymerization should be chosen such that the urethane layer 120 is tack-free and solidly attached to the wood or wood product once polymerization is complete. Since the urethane layer 120 is a release coating, it does not adhere to itself, and it cannot be recoated upon the panel 124. Thus, the urethane layer 120 should be applied to the panel 124 in a single pass. In addition, once mixed and sprayed on the panel 124, the components of the urethane layer 120 interact such that the time between “gelation” (i.e., an early stage in the polymerization process where the mixture is no longer a free-flowing liquid) and time the panel is ready for stacking is longer than a traditional spraying process. Thus, the process variables must be controlled in order to allow for proper curing of the panel 124.

In some embodiments, the rate of polymerization from spraying the first side 136 of the structural panel 124 until the time that the urethane layer 120 is cured is in the range of 1-15 minutes. In some embodiments, the time from spraying the first side 136 of the structural panel 124 until the time that the urethane layer 120 is cured (i.e., the rate of polymerization) is in the range of 2 minutes to 6 minutes. In one embodiment, the rate of polymerization may be 6 minutes. In another embodiment, the rate of polymerization may be 5.5 minutes. In still another embodiment, the rate of polymerization may be 5 minutes or less. In yet another embodiment, the rate of polymerization may be 4.5 minutes.

In some embodiments, the method includes the step of sanding or performing other surface preparations on each structural panel 124 prior to spaying the first side 136 of the structural panels 124. In some embodiments, the first side 136 of the structural panel 124 is sanded to 120-220 grit. Sanding prior to spraying may reduce surface imperfections in the first side 136 of the structural panel 124 that could telegraph through to the first side 128 of the urethane layer 120 after spraying the first side 136 of the structural panel 124.

In some embodiments, the method includes the step of sanding or texturing the first side 128 of the urethane layer 120 after spraying the first side 126 of the structural panel 124. In some embodiments, the first side 128 of the urethane layer 120 is sanded or textured after the urethane layer 120 has fully cured. For example, the first side 128 of the urethane layer 120 may be sanded to 60-150 grit to remove surface imperfections, to flatten any ridges or valleys on the first side 128 of the urethane layer 120, or to bring the first side 108 of the form panel 104 into accordance with construction or architectural standards or desires.

Likewise, the first side 128 of the urethane layer 120 may be textured after spraying the first side 136 of the structural panel 124. For example, designs, images, or patterns may be formed into the first side 128 of the urethane layer 120 once the urethane layer 120 is fully cured, or designs, images, or patterns may be imprinted or embossed into the urethane layer 120, while the urethane layer 120 is partially cured.

EXAMPLES

The invention can be further understood by reference to the following example:

Experimental Example—Concrete Form Performance

This example demonstrates the performance of an embodiment of a form panel of a concrete form when subjected to concrete pouring, where the form panel includes a urethane layer. The form panels are formed from plywood and include a first side and a second side. The form panels include a urethane layer. To form the urethane layer, a liquid, two-component urethane was sprayed onto a surface of the first side of the form panel using an air-assisted spray system to ensure uniform coverage and to form a coating. The two-component urethane was formed by combining a resin component and an isocyanate component. The coating on the form panel was allowed to cure for a period of three minutes. The urethane had a resin viscosity ranging from 500 cP to 2,000 cP. The resulting product exhibits strong inherent release properties when in contact with curing concrete.

The resin component includes the following ingredients:

Ingredient Weight % (Range) Polyol 28% (10-50%) Plant based oil 60% (30-70%) Micronized Wax 4% (1-10%) Catalyst 0.4% (0.1-3%)  Inorganics + 8% (7-18%) Plasticizer

The isocyanate component comprises a blend of oligomeric and polymeric MDI.

In the study, the form panels having the coated urethane layer were subjected to 60 cycles of pouring the concrete, curing the concrete, and releasing the concrete release. Residual concrete buildup on the panel surface was quantified using an optical contrast/color change technique. Color variation was expressed as a percentage relative to the original panel color. After each cycle, the surface color was recorded and compared to the baseline (the original color of the coated surface). A variance of approximately 20% is considered the self-releasing threshold. Below the self-releasing threshold, the form panel having the coated urethane layer is considered to be free of any significant concrete buildup.

FIG. 7 depicts the performance of the form panel having a urethane layer when subjected to the 60 cycles of concrete pouring, curing, and release. FIG. 7 shows the average color variation (n=5) with standard deviation as a function of the number of pours. The dashed line represents the self-release threshold (~20%). As shown in the figure, initial cycles of concrete pours demonstrated transient increases in color variation, which is an indication of the formation of temporary residue formation upon the panels. However, throughout subsequent cycles of concrete pours, the percentage of color variation would decrease and either return to or below the self-releasing threshold. Thus, the form panels having the urethane coating demonstrated resistance to cumulative buildup though the testing cycle. In addition, the data indicates that over time, the form panel coated with the urethane layer demonstrates repeated self-release of any concrete buildup throughout the pouring cycles. This trend demonstrates the coating's permanent non-adhesive behavior under extended cyclic exposure. Furthermore, the data shows that the form panels having the urethane layer coating may be repeatedly used for numerous concrete pours before a need for replacement. Thus, throughout these cycles, the form panel having a urethane layer according to the present application consistently delivered exceptional performance, releasing concrete without the need for additional release agents or panel replacement.

FIGS. 8A and 8B depict percentage of color change (ΔE) versus number of pours for an embodiment of a form panel for a concrete form having a urethane layer and a conventional form panel for a concrete form not having a urethane layer, respectively. The percentage of color change is an indication of surface degradation and concrete buildup. A percentage of color change greater than 10% indicates that there is significant surface degradation and concrete buildup to the form panel. As shown in FIG. 8A, the percentage of color change (ΔE) the form panel for a concrete form having a urethane layer remains between 0% and 5% up to 75 pours, illustrating the self-release of any residual concrete buildup from the form panel having a urethane layer, which allows for the repeated use of the form panel without a need for replacement. After 75 pours, the percentage of color change for the form panel having a urethane layer begins to increase above 5%, reaching a percentage greater than 10% after about 88 pours. In contrast, FIG. 8B shows the percentage of color change of the conventional form panel for a concrete form begins at about 10% and after a slight decline, the percentage continues to increase with each use. After about 12 pours, the conventional panel demonstrates a percentage of color change (ΔE) greater than 10%, indicating the conventional panel has significant surface degradation and concrete buildup. In addition, after about 12 pours, the conventional form panel could not receive any additional concrete pours and no further data could be measured.

Accordingly, FIGS. 8A and 8B show that the form panel having a urethane layer according to the present application was able to receive about 7 times the number of pours as a conventional form panel without a urethane layer. These findings indicate that the form panel of having a urethane layer can significantly reduce maintenance costs and downtime in industrial concrete forming operations by eliminating the need for external release agents and minimizing panel replacement.

Additional Examples

There are many examples of the various embodiments described herein. A number of examples also follow:

Example 1. A concrete form panel comprising:

    • a wood-based composite structural panel having a first side and a second side;
    • a urethane layer coupled to the first side of the panel;
    • wherein the urethane layer comprises
      • a resin component comprising
        • at least one natural oil;
        • a micronized wax;
        • a catalyst; and,
        • at least one additive; and
      • an isocyanate component.

Example 2. The concrete form panel of example 1, wherein the wood-based composite structural panel is plywood or OSB.

Example 3. The concrete form panel of example 1-2, wherein the urethane layer has a thickness in the range of 5-100 mils.

Example 4. The concrete form panel of example 1-3, wherein the thickness of the urethane layer is about 30 mils.

Example 5. The concrete form panel of example 1-4, wherein the first side of the concrete form further comprises a secondary release agent.

Example 6. A method for manufacturing a concrete form panel comprising the steps of:

    • sanding a first side of a wood-based structural panel to a desired thickness, smoothness, or texture;
    • loading the wood-based composite structural panel into a manufacturing line;
    • conveying the wood-based composite structural panel to a spray booth;
    • spraying a urethane layer onto the first side of the wood-based composite structural panel;
    • conveying the wood-based composite structural panel out of the spray booth and into a curing station;
    • curing the urethane layer onto the first side of the wood-based composite structural panel; and
    • sanding the urethane layer to a desired thickness, smoothness, or texture.

Example 7. The method of example 6, wherein the wood-based composite structural panel is plywood or OSB.

Example 8. The method of example 7, wherein the urethane layer has a thickness in the range of 5-100 mils.

Example 9. The method of example 7, wherein the urethane layer comprises

    • a resin component comprising,
      • at least one natural oil;
      • a micronized wax;
      • a catalyst; and,
      • at least one additive; and
    • an isocyanate component.

Example 10. The method of example 8, further comprising applying a secondary release agent to the first side of the wood-based composite panel following to the curing step.

Example 11. A concrete form comprising:

    • a plurality of concrete form panels, wherein the plurality of concrete form panels are
    • coupled to each other to form a retainer or reservoir for retaining uncured concrete;
    • wherein at least one of the plurality of concrete form panels comprises:
      • a wood-based composite structural panel having a first side and a second side;
      • a urethane layer coupled to the first side of the panel;
      • wherein the urethane layer comprises,
      • a resin component comprising,
        • at least one natural oil;
        • a micronized wax;
        • a catalyst; and,
        • at least one additive; and
      • an isocyanate component.

Example 12. The concrete form panel of example 11, wherein the wood-based composite structural panel is plywood or OSB.

Example 13. The concrete form panel of example 11, wherein the urethane layer has a thickness in the range of 5-100 mils.

Example 14. The concrete form panel of example 13, wherein the thickness of the urethane layer is about 30 mils.

Example 15. The concrete form panel of example 1, wherein the first side of the concrete form further comprises a secondary release agent.

Although the present invention and its advantages have been disclosed in the context of certain illustrative, non-limiting embodiments, it should be understood that various changes, substitutions, permutations, and alterations can be made without departing from the scope of the invention as defined by the claims. It will be appreciated that any feature that is described in a connection to any one embodiment may also be applicable to any other embodiment.

In the detailed description above, numerous specific details are set forth to provide a thorough understanding of claimed subject matter. However, it will be understood by those skilled in the art that claimed subject matter can be practiced without these specific details. In other instances, methods, devices, or systems that would be known by one of ordinary skill have not been described in detail so as not to obscure claimed subject matter.

Reference throughout this specification to “one embodiment” or “an embodiment” can mean that a particular feature, structure, or characteristic described in connection with a particular embodiment can be included in at least one embodiment of claimed subject matter. Thus, appearances of the phrase “in one embodiment” or “an embodiment” in various places throughout this specification are not intended to refer to the same embodiment or to any one particular embodiment described. Furthermore, it is to be understood that particular features, structures, or characteristics described can be combined in various ways in one or more embodiments. In general, of course, these and other issues can vary with the particular context of usage. Therefore, the particular context of the description or the usage of these terms can provide helpful guidance regarding inferences to be drawn for that context.

Claims

1. A concrete form panel comprising:

a wood-based composite structural panel having a first side and a second side; and,
a urethane layer coupled to the first side of the panel,
wherein the urethane layer comprises; a resin component, comprising: a polyol mixture comprising at least one natural oil; a micronized wax; a catalyst; and, at least one additive; and an isocyanate component.

2. The concrete form panel of claim 1, wherein the wood-based composite structural panel is plywood or oriented strand board (OSB).

3. The concrete form panel of claim 1, wherein the urethane layer has a thickness in the range of 5-100 mils.

4. The concrete form panel of claim 1, wherein the thickness of the urethane layer is about 30 mils.

5. The concrete form panel of claim 1, wherein the polyol mixture comprises polyethylene ether diols and triols; polypropylene ether diols and triols, saturated polyester diols and triols, unsaturated polyester diols and triols, polycaprolactone diols and triols, polytetrahydrofuran diols, diamine initiated quadrols, or mixtures thereof.

6. The concrete form panel of claim 1, wherein the at least one natural oil of the polyol mixture comprises hydroxyfunctionalized plant-based oils, animal-based oils, or castor oils.

7. The concrete form panel of claim 6, wherein the hydroxyfunctionalized plant-based oils comprise a saturated or an unsaturated vegetable oil.

8. The concrete form panel of claim 7, wherein the hydroxyfunctionalized plant-based oils comprise olive oil, sunflower oil, linseed oil, tall oil, soybean oil, colza oil, fish oil, cottonseed oil, palm oil, palm kernel oil, coconut oil, canola oil, flaxseed oil, high oleic canola oil, safflower oil, or mixtures thereof.

9. The concrete form panel of claim 1, wherein the resin component comprises between 40 wt. % to 90 wt. % of the polyol mixture.

10. The concrete form panel of claim 1, wherein the micronized wax comprises petroleum-based wax, bio-based wax, synthetic wax, paraffin wax, or mixtures thereof.

11. The concrete form panel of claim 1, wherein the resin component comprises between 1 wt. % and 10 wt. % micronized wax.

12. The concrete form panel of claim 1, wherein the isocyanate component comprises at least one isocyanate functional group selected from the group consisting of an aliphatic isocyanate, a cycloaliphatic isocyanate, an aryl isocyanate, an aromatic cyanate, and combinations thereof.

13. A method for manufacturing a concrete form panel comprising the steps of:

sanding a first side of a wood-based structural panel to a desired thickness, smoothness, or texture;
loading the wood-based composite structural panel into a manufacturing line;
conveying the wood-based composite structural panel to a spray booth;
spraying a urethane layer onto the first side of the wood-based composite structural panel;
conveying the wood-based composite structural panel out of the spray booth and into a curing station;
curing the urethane layer onto the first side of the wood-based composite structural panel; and
sanding the urethane layer to a desired thickness, smoothness, or texture.

14. The method of claim 13, wherein the wood-based composite structural panel is plywood or oriented strand board (OSB).

15. The method of claim 13, wherein the urethane layer has a thickness in the range of 5-100 mils.

16. The method of claim 13, wherein the urethane layer comprises

a resin component comprising: a polyol mixture comprising at least one natural oil; a micronized wax; a catalyst; and, at least one additive; and
an isocyanate component.

17. The method of claim 13, further comprising, mixing the resin component and the isocyanate component prior to the spraying step.

18. The method of claim 17, wherein a ratio by volume applied of the resin component and the isocyanate component ranges from 1:2 to 6:1.

19. The method of claim 13, wherein the curing step is for a period of time ranging from 2-6 minutes.

20. A concrete form comprising:

a plurality of concrete form panels, wherein the plurality of concrete form panels are coupled to each other to form a retainer or reservoir for retaining uncured concrete;
wherein at least one of the plurality of concrete form panels comprises: a wood-based composite structural panel having a first side and a second side; a urethane layer coupled to the first side of the panel,
wherein the urethane layer comprises, a resin component comprising, a polyol mixture comprising at least one natural oil; a micronized wax; a catalyst; and, at least one additive; and an isocyanate component.
Patent History
Publication number: 20260348175
Type: Application
Filed: Feb 3, 2026
Publication Date: Nov 5, 2026
Applicants: Martco L.L.C. (Alexandria, LA), The Willamette Valley Company, LLC (Eugene, OR)
Inventors: Bobby J. Byrd (Alexandria, LA), J. Evan Davis (Denver, CO), Sudip Chowdhury (Eugene, OR), Ryan Joel Breker (Eugene, OR), Michael Ryn Wetherell (Eugene, OR), Michael DeSimone (Eugene, OR)
Application Number: 19/468,484
Classifications
International Classification: E04G 9/04 (20060101);