Carpet waste composite
11773592 · 2023-10-03
Assignee
Inventors
- David E. Murdock (Dublin, OH)
- Douglas Mancosh (Palm Beach Gardens, FL, US)
- James P. Przybylinski (St. Helena, CA)
Cpc classification
Y10T428/24802
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y10T428/31971
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y02W30/62
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B29K2711/14
PERFORMING OPERATIONS; TRANSPORTING
Y10T428/31554
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B32B2272/00
PERFORMING OPERATIONS; TRANSPORTING
Y10T428/31551
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y10T428/24612
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y10T428/31935
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
C08L97/02
CHEMISTRY; METALLURGY
Y10T428/24438
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B29B17/0042
PERFORMING OPERATIONS; TRANSPORTING
B02C19/186
PERFORMING OPERATIONS; TRANSPORTING
E04C2/246
FIXED CONSTRUCTIONS
Y10T428/31942
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y02P20/143
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
C08J5/04
CHEMISTRY; METALLURGY
Y10T428/24479
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y10T428/31946
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y10T428/31594
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
E04C2/24
FIXED CONSTRUCTIONS
B02C19/18
PERFORMING OPERATIONS; TRANSPORTING
B29B17/00
PERFORMING OPERATIONS; TRANSPORTING
C08J5/04
CHEMISTRY; METALLURGY
C08L97/02
CHEMISTRY; METALLURGY
Abstract
A composite material is produced from carpet waste and a binding agent, in intimate association, and may also include wood fiber or chips and/or other additives. A method of manufacturing a composite material includes shredding carpet waste, coating the carpet waste with a binding agent, and subjecting the shredded, coated carpet waste to elevated heat and pressure. As an additional step, the composite material may be actively cooled to prevent deformation of the material.
Claims
1. A composite building material, comprising: a first layer comprising: a processed carpet waste comprising a reduced amount of inorganic filler relative to an amount present within an unprocessed carpet waste; and a first binding agent in intimate association with the processed carpet waste; and a second layer disposed on the first layer and comprising natural fibers and a second binding agent.
2. The composite building material of claim 1, wherein the first binding agent comprises at least one of methylenediphenyldiisocyanate (MDI) or a product of a reaction involving methylenediphenyldiisocyanate (MDI).
3. The composite building material of claim 1, wherein the second binding agent comprises at least one of phenol formaldehyde (PF) or a product of a reaction involving phenol formaldehyde (PF).
4. The composite building material of claim 1, wherein the carpet waste comprises carpet fibers having a length from about 0.25 inches to about 1.0 inch.
5. The composite building material of claim 1, wherein the carpet waste comprises carpet fibers having a length of about 1.0 inch.
6. The composite building material of claim 1, further comprising at least one of a patterned surface, a cover layer, or a sanded surface.
7. The composite building material of claim 6, wherein the patterned surface comprises at least one of a molded surface, an embossed surface, a colored surface, or a wood grain pattern.
8. The composite building material of claim 6, wherein the cover layer comprises a coating selected from the group consisting of primers, paints, stains, polyurethane, and acrylic.
9. The composite building material of claim 1, further comprising at least one of a molded patterned surface, an embossed patterned surface, or a hot-stamped layer.
10. The composite building material of claim 1, further comprising additional inorganic filler relative to an amount present in the processed carpet waste.
11. The composite building material of claim 1, further comprising fiberglass.
12. The composite building material of claim 1, wherein the composite building material comprises polypropylene.
13. The composite building material of claim 1, further comprising a third layer disposed on an opposite side of the first layer and comprising natural fibers and the second binding agent.
14. A method of manufacturing a composite building material, the method comprising the steps of: forming a first layer comprising: a processed carpet waste comprising a reduced amount of inorganic filler relative to an amount present within an unprocessed carpet waste; and a first binding agent in intimate association with the processed carpet waste; applying a second layer to the first layer, the second layer comprising natural fibers and a second binding agent; and heating and pressing the first layer and the second layer together to form the composite building material.
15. The method of claim 14, wherein the first binding agent comprises at least one of methylenediphenyldiisocyanate (MDI) or a product of a reaction involving methylenediphenyldiisocyanate (MDI).
16. The method of claim 14, wherein the second binding agent comprises at least one of phenol formaldehyde (PF) or a product of a reaction involving phenol formaldehyde (PF).
17. The method of claim 14, wherein the carpet waste comprises carpet fibers having a length of about 1.0 inch.
18. The method of claim 14, further comprising adding at least one of a patterned surface, a cover layer, or a sanded surface to the composite building material.
19. The method of claim 18, wherein the method comprises adding the patterned surface, and wherein the patterned surface comprises at least one of a molded surface, an embossed surface, a colored surface, or a wood grain pattern.
20. The method of claim 18, wherein the method comprises adding the cover layer, and wherein the cover layer comprises a coating selected from the group consisting of primers, paints, stains, polyurethane, and acrylic.
21. The method of claim 14, further comprising adding at least one of a molded patterned surface, an embossed patterned surface, or a hot-stamped layer to the composite building material.
22. The method of claim 14, wherein forming the first layer comprises adding inorganic filler relative to an amount present in the processed carpet waste.
23. The method of claim 14, wherein forming the first layer comprises adding fiberglass.
24. The method of claim 14, further comprising applying a third layer to an opposite side of the first layer, the third layer comprising natural fibers and the second binding agent.
Description
DESCRIPTION OF DRAWINGS
(1) Other features and advantages of the present invention, as well as the invention itself, will be more fully understood from the following description of the various embodiments, when read together with the accompanying drawings, in which:
(2)
(3)
(4)
(5)
DETAILED DESCRIPTION
(6) The new systems and methods can be used to process and combine recycled carpet waste with a binding agent to form a PC with equivalent properties to those PCs made with virgin plastics at reduced cost.
(7)
(8) In addition to the binding agent, the composite 10 may incorporate natural fibers to help provide the composite with the appearance and feel of a natural wood product. Types of natural fibers, such as wood fillers or the like, include wood chips, wood flour, wood flakes, wood shavings, sawdust, flax, jute, abaca, hemp, kenaf, rice hulls, like materials, and combinations thereof. The sizes of the various natural fibers is not critical and may range from that of sawdust and wood flour, up to and exceeding 1″ long wood chips, though fibers and chips less than about 0.5″ may be preferred. The composite may include additives such as colorants, lubricants, flame retardants, compatiblizers, coupling agents, other materials, and combinations thereof. The relative amounts of components (i.e., recycled carpet waste, filler, additives, etc.) may be modified as desired for a particular application. The various component amounts, ratios of components, and finished composite properties in certain embodiments, are described in more detail below.
(9) Unless otherwise noted, the use of one material when describing a particular application, process, or embodiment does not limit the described application, process, or embodiment to the specific material identified. The materials may be used interchangeably, in accordance with the described teachings herein. Moreover, the terms “PCs,” “composite sheets,” and the like, are used interchangeably herein to describe plastic composite boards or sheets made from recycled carpet waste which may include additional additives. In addition to PCs, other composite products may be manufactured utilizing, in whole or in part, recycled carpet waste. A non-limiting list of such composite products include plastic piping, molded articles such as flower pots or seeding trays, building siding or roofing, fencing, furniture, or other types of extruded, injection molded, and/or compression molded products.
(10)
(11) The carpet waste is made up of selvedge, post-industrial carpet waste, post-consumer carpet waste, or waste carpet reclaimed from landfills. Post-industrial carpet waste refers generally to waste material produced as a byproduct to the manufacturing process, such as trimmed carpet segments, as well as to carpet that fails to pass quality or other inspections, thus rendering it unsuitable for consumer use. Post-consumer carpet waste refers generally to carpet waste that is generated during installation at a consumer site or that is removed from a consumer site during demolition and/or replacement. Regardless, the terms selvedge, carpet waste, waste carpet, reclaimed waste, recycled waste, and similar terms are used herein interchangeably and may be used in the processes described herein interchangeably. These materials generally will be in baled form to begin the size reduction phase of the pre-processing. The bales vary in size but usually are about 1000 lb. to about 2000 lb. All of the equipment described in the carpet reduction processes below may be supplied by Pallmann Maschinenfabrik GMBH, of other manufacturers that produce similar equipment. Alternative manufacturers of specific equipment are identified below.
(12) The first step in the size reduction phase includes reducing the waste to a manageable size for the remainder of the process. As depicted in
(13) The waste optionally can be run through a separator which acts as a hammer mill/cyclone to remove the dirt from the carpet waste. In this step, some of the carpet backing containing inorganic fillers may also be removed. Generally, however, it is unnecessary to deliberately separate the various carpet components prior to incorporating the recycled carpet waste into PCs. All of the components of carpet may be used, not only one component, such as the carpet fibers, as certain known methods disclose. Thus, manufacturing time is decreased, since the step of component separation is not utilized. The slightly-size reduced material, due to the hammer mill effect, is ready for the next step, the agglomeration process, while the dirt and carpet backing materials that may have been removed from the small chunks are disposed. Carpet backing that is not removed, however, does not have any adverse effect when incorporated into a PC using recycled carpet waste. The fiber fluff, regardless of the use of the separator or not, also may be blended with other materials such as wood or natural fibers, synthetic fibers (i.e., fiberglass), inorganic fillers, or other reinforcing fillers. The fiber fluff material or the blended material is then conveyed to the agglomeration step.
(14) The agglomeration of the above materials occurs inside the agglomerator. The materials enter a horizontal drum containing a revolving rotor that is shaped so as to force the fiber fluff or blends against the drum wall. The drum wall is perforated so that, as the rotor forces the contained materials against the perforated wall, the material is forced through the perforations, thereby forming strands of a fixed diameter. On the outside of the drum are stationary knives which cut the strands into a fixed length. During this process, the material is heated by friction to a temperature that remains below the melting point of the highest melting point material in the blend. The temperature is controlled by the speed of the rotor, the diameter of the perforations, and the thickness of the drum wall. As each component of the carpet waste, i.e., backing and carpet fibers, is pressed against the wall of the drum, that material heats up due to friction, until the material sufficiently softens, such that it is then pressed through the perforated drum by the rotor. The agglomerating machinery could be replaced by a pellet mill manufactured by Bliss Industries or California Pellet Mill Co.
(15) The granules that are formed in the agglomeration step are generally cylindrical in shape and approximately 0.125″ in diameter and about 0.125″ to about 0.25″ long. The diameter and length of the granules can be modified by changing the diameter of the holes in the drum wall and/or changing the speed of the rotation against the knives. Because the granules are hot when they are formed and cut to length, some of the granules may be stuck to one another. Therefore, for better size consistency, the granules next pass through a grinder which separates any stuck granules. This grinder step may also be used to reduce the size of the granules, and/or the granules may be further reduced in size by a pulverizer. For example, if the final desired dimension is less than 0.125″, the pulverizer may be used to reduce the particle size to 8-16 mesh. This is the equivalent of about 0.04″ to about 0.10″.
(16) As an optional step, the granules or pulverized particles may be fiberized. The fiberizing process includes a mechanical roughing of the surface so that the surface takes on a fuzz-like characteristic that may be desirable for the composite product process described below. After processing to the desired condition, the material is then sent to the composite production process.
(17) As an alternative to the above process, Process Option B may be used to reduce carpet waste to a fiberized mass. First, a major capacity grinder reduces the carpet waste to fibers about 0.25″ to about 1.0″ in length and about 1/32″ to about 0.125″ in diameter may be utilized. These random-sized fibers are ready for the agglomeration process or for alternative processes not requiring agglomeration. Next, the material optionally may be passed through a separator, as described above. The fibers may then be passed through the agglomeration process as described above, or the fibers may pass directly to the fiberizer equipment. Again, the fiberizer changes the surface characteristics of the fibers, giving them a fuzz-like surface with greater surface area and a different bulk density. The fiberizing step is again optional, and may not be required for all end uses of the composite products. Next, the fibers pass through a blender where wood or natural fibers, synthetic fibers (i.e., fiberglass), inorganic fillers, or mineral fillers (if any) may be added. Once the blending of the fibers and added materials is complete, the blend is ready for the composite production process.
(18) Significantly, it has been determined that it is not necessary to separate or classify the various materials contained in selvedge or carpet waste, even though most carpet surface materials are nylons, polyester, polypropylene, or wool and the backing material is usually polypropylene and/or highly filled synthetic latex. These materials exhibit considerably different physical properties and processing properties, but the entire waste product may be used in the composite sheet material, regardless of the differences in the components that comprise the carpet waste. The waste carpet, having been made into an agglomerate, a fiberized agglomerate, a pulverized agglomerate, a fiberized, pulverized agglomerate, a fiberized fluff, etc., becomes the base material for the composite product. Additionally, other waste fiber or fiberized waste fiber may also be used to manufacture a composite product. The whole range of materials in carpet waste may be part of the composition.
(19) After the size reduction process(es), the carpet waste is ready to be formed into composite sheets, a process for which is depicted in
(20) The MDI-coated carpet waste and other additives (if applicable) are conveyed to a mat forming station that includes conveyors, metering scales, spreader heads and a control management system. The spreading equipment distributes the material onto a forming belt such that the spread material becomes a mat which has a generally uniform thickness, width and initial density. Board properties may be determined by the shape of the carpet waste composite particles/fibers and by their position in the formed mat. Additionally, the forming station can distribute more than one type of material for a multi-layered board. For example, the spreader head in the forming station could spread a mat of fibers on the forming belt, then a second spreader head could spread a mat of pellets on top of the fibers, then a third spread head could spread a top layer of fibers onto the pellets. Many different combinations of materials can be spread onto the forming belt to make various types of boards. The number of layers per board also can be varied. For example, a board could be manufactured to have an outer layer of carpet waste with a fiberglass core, or an outer layer comprising carpet waste pellets, and carpet waste fiber underlayers with a carpet waste pellet core.
(21) After the mat is spread formed, the forming belt then transports the mat into a pre-heater, a pre-press, or directly to a press machine. The pre-heater and pre-press may be utilized to reduce total processing time of the composite sheet. Due to the thermal inertia and thickness of the material, heat from the press platens or rolls may take longer to penetrate the total thickness of the mat, thereby extending process time and costs. Preheating brings the temperature of the entire mat up to a higher starting temperature. The pre-press compresses the starting materials to a thickness that is more appropriate for introduction into the final presses and, additionally, the pre-heater and pre-press may be a single unit or separate units. In certain embodiments, the temperature of the mat can be elevated from about 65° F. to about 200° F. before entering the board forming process. This rapid heat transfer to the carpet waste may be accomplished by microwaves or by the injection of a steam/air mix (moist air) alternately from either surface into the mat. The steam condenses during this process, transferring the heat into the mat. The pre-heater may also pre-press or compress the material before it enters the board forming process. The heated mat is then transferred by an intermediate belt conveyor to the compression section of the infeed end of a continuous roll press or into a cycle press which is the beginning of the board-forming process.
(22) In one embodiment, composite sheets are manufactured using a cycle press, which may have single or multi-daylight openings. Ranges of various process parameters for manufacturing various embodiments of PCs utilizing recycled carpet waste in a cycle press are presented in Table A-1, below. The composite material is transferred into the cycle press where it is subjected to temperature and pressure from a top and bottom platen that compresses the mat to a predetermined thickness or height. The elevated temperature and pressure activates the binding agent and, depending on the temperature, melts certain of the carpet components while leaving others unmelted, to produce in a finished board or sheet. During the cycle press process, steam may be injected into the mat to ensure thorough heating of the binding agent and bonding of the composite material. The cycle press may also use an active cooling cycle to reduce the temperature of the board before it exits the press. The platens may be engraved with a pattern to give the board outer surface a structured pattern.
(23) TABLE-US-00001 TABLE A-1 Composite Sheet Processing Parameters (Cycle Press) Range High Low Total Time for heating material, during 360 60 press-cycle [sec] Temperature of Heating Plates 600 100 [° F.] Pressure of Heating Press [psi] 6000 150 Internal Temperature of Board [ ° F. ] 500 340 Cure Time [sec] 30 5 Transition Time from Heating 600 0 to Cooling Press [sec] Total Time for cooling material, 360 60 during press-cycle [sec] Temperature of Cooling Plates 300 32 [° F.] Pressure of Cooling Press [psi] 6000 150 Internal Temperature of Board [ ° F. ] 300 70
(24) Heat is generally delivered to the platens in the form of hot water, steam, electric coils, or circulating heated chemicals. In certain embodiments of the process, the platens may be heated from about 100° F. to about 600° F. Temperature ranges from about 200° F. to about 550° F., and about 340° F. to about 420° F. also may be desirable. Additionally, temperature ranges from about 420° F. to about 550° F. may be utilized. Final internal temperatures of the composite being compressed within the cycle press will be dependent at least in part on the temperature of the platens and compression time. If left in the cycle press for a sufficient period of time, the internal temperatures of the composite material will generally equal those of the platens, the ranges of which are given above. Final internal temperatures up to about 250° F., about 300° F., about 340° F., about 350° F., about 400° F., about 420° F., and about 480° F. have produced composite sheets displaying acceptable performance. Unlike known recycled carpet waste composite sheet material manufacturing processes, which heat the composite sheets to a temperature below the melting points of the carpet fibers and other carpet components, it has been discovered that heating the carpet waste to higher temperatures may be desirable. For example, temperatures of approximately 340° F. will melt polypropylene, a component in many modern carpet constructions, without melting any nylon fibers (that melt at about 420° F.). The melted polypropylene, combined with binding agent resins of the types disclosed herein, form a sheet material having very desirable properties. The unmelted nylon provides additional structural strength to the finished composite and may increase flexural strength, though completely melting the carpet fibers can also produce a PC displaying acceptable performance properties. Pressures applied by the platens in the heating press may range from about 150 psi to about 6000 psi or greater, to obtain a the desired thickness and density.
(25) The cycle press may include channels within the platens that thereafter circulate water or chemical coolant(s) to reduce the temperature of the board. The water or coolants may be chilled and volumetric flow rates controlled to reduce the total cooling time for the board to achieve acceptable manufacturing cycle time. This cooling step may take place in the heating press or the board may be transferred from the heating press to a cooling press. If the board is transferred from the heating press to the cooling press, the transfer time should be minimized to avoid warping of the PC. It has been determined that transfer time of less than about 600 seconds are acceptable. The cooling platens may have a temperature range of about 300° F. to about 32° F. Cooling temperature ranges from about 390° F. to about 65° F. may also be desirable. Ranges from about 250° F. to about 180° F. may also be utilized. If left in the cycle press for a sufficient period of time, the internal temperatures of the composite material will generally equal those of the platens, the ranges of which are given above. Final internal temperature of as high as 300° F., however, may be desirable to minimize warping of the composite sheet. Additionally, final internal temperatures of about 100° F., about 80° F., and about 70° F. have produced composite sheets displaying acceptable performance. The board is rapidly cooled under pressure to maintain its flatness. Due to its high polymer content, the board will usually warp if allowed to cool unrestrained using ambient air. Pressures applied by the platens in the heating press may range from about 150 psi to about 6000 psi or greater.
(26) Table B presents the ranges of various components that may be utilized in composite formulations to produce acceptable PCs. Specifically, materials utilized may include colorants, wood filler, fire retardants, fiberglass, mold inhibitors, binders, and recycled carpet waste. The recycled carpet waste can be about 20% to about 98% of the total formula weight and still retain acceptable physical properties in the composite sheet. Certain embodiments may include carpet wastes in the amount of about 90% to about 98% total weight. Still other embodiments may include carpet wastes in the amount of about 94% to about 95% total weight. It has been found that composites that utilize approximately 95% carpet waste and about 5% binding agent produce a composite that exhibits satisfactory performance while being economically advantageous, due to the low cost associated with using recycled carpet waste versus virgin materials. In other embodiments, a 9:1 ratio of carpet waste to MDI, up to a 49:1 ratio of carpet waste to MDI may be utilized. Table B also presents percentages of additives, such as wood filler, color, fire retardant, fiberglass, and mold inhibitor that may be added to the binder/carpet waste mixture. The percentages of these additives may be up to those identified in Table B, relative to the carpet waste/MDI content. Additionally, there is no discernible difference in the performance of the composite when using recycled carpet waste obtained from post-industrial carpet waste or post-consumer carpet waste, as compared with using virgin materials.
(27) TABLE-US-00002 TABLE B Formulation Ranges for Composite Sheets Range Low High Material % % Carpet Waste 80 98 Moisture Content 0 10 Additives: Binders: MDI 2 20 UF 2 20 MF 2 20 PF 2 20 Wood filler 0 65 Color 0 25 Fire Retardant 0 25 Fiberglass 0 50 Mold Inhibitor 0 25
(28) Tables C-1 to C-4 present formulations and performance parameters for PCs made in accordance with the cycle press process described above. Tables C-1, C-2, and C-3 present this information for PCs made with different types of binding agents, but having the same total percentage of binding agents. The water absorption, thickness swell and moisture content testing was performed in accordance with the ASTM D1037-96A testing standard. The PC described in Table C-1 is made with MDI and has higher modulus of rupture (MOR) and modulus of elasticity (MOE) values, with lower moisture absorption properties.
(29) TABLE-US-00003 TABLE C-1 Example 1 Formulations and Performance Properties Material % Carpet Waste 90.2% Moisture Content 4.8% Additives: Binders: MDI 5.0% UF 0.0% MF 0.0% PF 0.0% Wood filler 0.0% Color 0.0% Fire Retardant 0.0% Fiberglass 0.0% Mold Inhibitor 0.0% total 100% Thickness (inch) 0.250 Density (pcf) 53.3 MOR (psi) 1,866 MOE (psi) 80,331 Tensile - Perpendicular [IB] 728 (psi) Tensile - Parallel (psi) 14 Linear Expansion 0.10% Thickness Swell (inch) 0.002 Thickness Swell (%) 0.00% Moisture Content (%) 0.27%
(30) Table C-2 presents information for a PC utilizing PF as the binding agent, that results in significantly lower, though still acceptable, MOR and MOE values.
(31) TABLE-US-00004 TABLE C-2 Example 2 Formulations and Performance Properties Material % Carpet Waste 90.2% Moisture Content 4.8% Additives: Binders: MDI 0.0% UF 0.0% MF 0.0% PF 5.0% Wood filler 0.0% Color 0.0% Fire Retardant 0.0% Fiberglass 0.0% Mold Inhibitor 0.0% total 100% Thickness (inch) 0.250 Density (pcf) 48.0 MOR (psi) 971 MOE (psi) 49,600 Tensile - Perpendicular [IB] 716 (psi) Tensile - Parallel (psi) 58 Linear Expansion 0.54% Thickness Swell (inch) 0.007 Thickness Swell (%) 2.97% Moisture Content (%) 4.12%
(32) Table C-3 presents information for a PC manufactured with a mixture of MDI and UF as binding agents. While this formulation displays performance characteristics higher than those listed for the Table C-2 sample, the performance values are not as high as the sample using MDI as the binding agent, presented in Table C-1.
(33) TABLE-US-00005 TABLE C-3 Example 3 Formulations and Performance Properties Material % Carpet Waste 90.2% Moisture Content 4.8% Additives: Binders: MDI 1.25% UF 3.75% MF 0.0% PF 0.0% Wood filler 0.0% Color 0.0% Fire Retardant 0.0% Fiberglass 0.0% Mold Inhibitor 0.0% total 100% Thickness (inch) 0.250 Density (pcf) 45.4 MOR (psi) 1,359 MOE (psi) 66,716 Tensile - Perpendicular [IB] 1002 (psi) Tensile - Parallel (psi) 44 Linear Expansion 0.31% Thickness Swell (inch) 0.007 Thickness Swell (%) 2.78% Moisture Content (%) 3.02%
(34) Table C-4 presents a composite sheet utilizing 25% wood filler, with double the amount of binding agent utilized in the Table C-1 through Table C-3 samples. Estimates of the performance properties of this sample utilizing wood filler are identified with an asterisk.
(35) TABLE-US-00006 TABLE C-4 Example 4 Formulations and Performance Properties Material % Carpet Waste 60.0% Moisture Content 5.0% Additives: Binders: MDI 10.00% UF 0.00% MF 0.0% PF 0.0% Wood filler 25.0% Color 0.0% Fire Retardant 0.0% Fiberglass 0.0% Mold Inhibitor 0.0% total 100% Thickness (inch) 1.000 Density (pcf) 66.7 MOR (psi) 2,815 MOE (psi) 236,000 *Tensile - Perpendicular [IB] (psi) 1500 *Tensile - Parallel (psi) 100 *Linear Expansion 0.40% *Thickness Swell (inch) 0.010 *Thickness Swell (%) 3.00% *Moisture Content (%) 3.00%
(36) The differences in the performance properties of the above-identified examples indicate that the types and amounts of binders may be varied as desired to achieve acceptable results. Binder type and amount may be varied to effect cost or other properties. Although particular embodiments have not yet been tested, additives such as fire retardants may be added to produce a composite sheet having a Class A fire rating.
(37) According to an alternative embodiment, the PC may be manufactured using a continuous roll process. The continuous roll press is a double belted press capable of maintaining a range of temperatures and pressures on the mat to allow the binding agent reaction and melting of select components to take place. The continuous roll press belts may be steel or other material. Process parameters for a continuous roll press are depicted in Table A-2. Temperatures utilized are generally similar to those utilized in the cycle press process.
(38) TABLE-US-00007 TABLE A-2 Composite Sheet Processing Parameters (Continuous Roll Press) Range High Low Temperature of 600 100 Heating Rolls [ ° F. ] Pressure of Heating Rolls [psi] 6000 150 Internal Temperature of Board 500 340 [ ° F. ] Temperature of Cooling Plates 300 32 [° F.] Pressure of Cooling Rolls [psi] 6000 150 Internal Temperature of Board 300 70 [ ° F. ]
(39) For example, pressures from about 150 psi to about 6000 psi are used to squeeze the fiber mat to the desired thickness and density of the final product. The continuous roll press consists of a press structure that tensions the belts. In general, the press includes a number of frame units, depending on the length of the press and pressure that is required for a particular application. Cylinders arranged at the frame units in various combinations exert the desired pressure. The press includes top and bottom heated platens which roller rods and the belts travel over. The press has an infeed head to guide the roller rods, belts and mat to be pressed. The roller rods are located between the heated platens and the belts and support the mat as it is moved from one cylinder to the next. The belts are driven by two or more drums at generally opposite ends of the roll press. Drum scrapers may be used to keep the board from sticking to the belts. A release agent also may be sprayed onto the belts to keep the mat from sticking to the belts, allowing the composite to exit easily the press at the completion of forming. A control system regulates the operation of the press, such as the speed of the belts, temperature, pressure, thickness of the mat, etc.
(40) The continuous roll press transfers heat to the binding agent-coated composite material. As the heat activates the coating, the cylinders press the mat together to achieve the desired thickness. Thus, while the mat material moves from the infeed section of the press, the mat's thickness is reduced while being heated to a temperature that ensures activation of the binding agent and melting of certain fibers. As the mat moves through the continuous roll press, the platens gradually reduce the thickness of the mat to a predetermined thickness. Depending on the amount of material introduced to the infeed section of the press, the density of the finished board is directly related to its final thickness.
(41) After the binding of the material and desired height dimension of the mat has been reached in a continuous roll press, a board is formed which is in the shape of a continuous ribbon. When the ribbon exits the press, it undergoes a continuous edge trimming operation to reach the desired width and then it is cross-cut to a pre-selected length. The ribbon is transported through the trimming and cross-cutting operations by a roller conveyor and pinch rollers. The cut boards are then transported to a cooling station. The cooling station can employ a variety of different machines such as a star cooler, with subsequent stacking, or a stacking roller conveyor. The star cooler is a large diameter wheel with multiple rows of spoked arms extending from the wheel. The arms lift each board from the conveyor and allow the boards to rotate with the wheel and be air cooled. If needed, the continuous roll press can have a cooling section with chilled rollers near the press outlet. This will cool the board (as described above) eliminating the need for further cooling. The board is then conveyed to a stacking operation and stored for future use. Alternatively the boards may be conveyed to a separate cooling press as described above. The boards are now ready to be shipped or they can go through a variety of decorating alternatives.
(42)
(43) The profile may also be changed using thermoforming methods. In this case, the composite product is placed in a mold of the desired profile and with heat and pressure the product takes on the shape of the mold. This profile change offers an additional decorating capability in that the desired color and/or pattern may be on a transfer foil placed in the mold. With the application of the heat and pressure during the process, the color and/or pattern are transferred from the carrier foil to the composite product. Thus, at the end of the thermoforming process, the composite product has the desired profile and also the desired decoration.
(44) The composite product may be embossed after manufacturing. The embossing is accomplished with an embossing plate or roll. The plate or roll has the pattern to be transferred to the product on the surface of the plate or roll. This surface is heated to a temperature that will soften the surface of the composite product. Then the plate or roll is pressed onto the surface of the product to give the desired pattern transfer. As the surface of the composite product cools, the embossed pattern becomes fixed on the surface of the composite product. The embossed composite product is now ready to be coated, or if no coating is required for the end-use product, it is ready for packaging.
(45) Composite products that will be decorated first pass through a sander. This smoothing of the surface prepares the product for coating, transfers, and laminating. The sanded or embossed composite product may be coated with primers, finish paints, or stains. The coating application employs various conventional spray techniques using exhaust systems to remove the excess spray and solvents. Either penetrating or film-forming coatings may also be applied, and the choice is dependent on the desired finished product appearance and application. The sanded composite product can also act as a core to which decorative and protective layer(s) may be hot stamped from a foil or film or laminated to achieve improved physical and visual enhancement. In this regard, U.S. patent application Ser. No. 11/054,258, filed Feb. 9, 2005, and published as U.S. Patent Application Publication No. 2006/0147693, and U.S. Provisional Patent Application Ser. No. 60/641,308, filed Jan. 4, 2005, describe exemplary processes and are incorporated by reference herein in their entireties.
(46) The composite product also may be decorated using transfer foils. Once again the product is first sanded to smooth the surface, then an adhesive layer is applied to the profile using a conventional application technique. The transfer foil has the desired color and/or pattern on a polymeric substrate, and is brought into contact with the surface of the product using stamping equipment designed for the specific application. Using heat and pressure, the color and/or pattern is transferred from the foil to the product. The heat required for the transfer activates an adhesive layer on the surface of the profile ensuring bonding of the decoration to the profile. With the color and/or pattern now on the composite product, the spent foil is then collected for disposal, and the finished product has the desired decorated effect.
(47) Another decorating method that may be employed is lamination. Several materials may be used as the laminate surface, such as wood veneers, synthetic veneers, foils, films, and polymeric sheets. The application of rigid laminates like wood veneers is done using conventional laminating equipment. Generally, an adhesive system (either a wet adhesive system or a hot-melt adhesive system) employing a primer and an adhesive is applied to the PC substrate. The rigid surface laminate is then applied to the substrate and temperature and pressure are applied. After the temperature-pressure step, the laminated product is then set for a fixed period of time to allow the adhesive system to cure. In the case of the composite product, the composite product is the substrate. The adhesive system, usually a hot-melt adhesive, is applied to the composite product. The rigid veneer is then placed on the adhesive layer forming a sandwich of composite product, adhesive, and rigid laminate. The sandwich is then pressed to secure the bond of the laminate to the composite product. After curing the laminated product with the desired decorative appearance is ready for packaging.
(48) Another laminating technique used with the composite product is foil laminating. This technique can be referred to as wrapping; wherein, the composite product profile is wrapped in the decorative foil. After the composite product profile has been sanded, the profile passes through a wrapping device that takes the foil wrap from a coil then applies the adhesive (and primer, if required) to the foil. In a continuous process, the foil wrap is then passed over the composite product profile. Using a series of rollers, the foil wrap is shaped to the composite product profile. The foil wrap may incorporate an integral topcoat material, such as polyurethane, acrylic, or other protective materials, for physical property enhancement. If, however, the foil wrap integrates only the decorative elements, then the wrapped composite product will require a separate topcoat for certain applications.
(49) If the end-use product application requires significant surface property enhancements, such as abrasion resistance, a topcoat may be added to the decorating process. The topcoat can be polyurethane, acrylic, or other protective material that will impart better physical properties to the surface of the wrapped finished product. The topcoat may be spray applied or hot melt applied. If spray applied, the wrapped composite product will pass through a spray applicator and then may or may not pass through a curing device, such as an ultra-violet radiation station. If the topcoat is hot melt applied, then a layer of polyurethane is applied to flat surfaces of the decorated composite product. The cure process for this type of material is time dependent and could take several days depending on the hot melt topcoat chosen for a specific end-use application for the completed finished product.
(50) A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.