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  Building materials from needle-punched fiber mats with granular heat-activated adhesivesUSPTO Application #: 20070066174Title: Building materials from needle-punched fiber mats with granular heat-activated adhesives Abstract: Dry adhesives are embedded within needle-punched fiber mats used for manufacturing wood-like building materials. During a cross-lapping operation that lays large ribbons of combed fibers (such as nylon fibers from shredded carpets) on top of a large moving conveyor, one or more layers of granular, pellet, fibrous, film, or other dry adhesive are embedded within the loose mass of fibers. For example, dimpled rollers, shaker trays, or similar devices loaded with granular or pelleted adhesives can be positioned above the conveyor, between cross-lapper machines. The fiber mass with embedded adhesive is then needle-punched into a stable, compact, flexible form that can be stored and shipped. When desired, the mats are run through a heated press that melts the adhesive, converting it into a binder that turns the mats into stiff sheets of material comparable to plywood. (end of abstract) Agent: Patrick D. Kelly - St. Louis, MO, US Inventor: Forrest C. Bacon USPTO Applicaton #: 20070066174 - Class: 442408000 (USPTO) Related Patent Categories: Fabric (woven, Knitted, Or Nonwoven Textile Or Cloth, Etc.), Nonwoven Fabric (i.e., Nonwoven Strand Or Fiber Material), Hydroentangled Nonwoven Fabric The Patent Description & Claims data below is from USPTO Patent Application 20070066174. Brief Patent Description - Full Patent Description - Patent Application Claims
PRIORITY CLAIM [0001] This application claims priority under 35 USC 120(e) based on U.S. provisional application 60/408,946, filed on Sep. 7, 2002. BACKGROUND OF THE INVENTION [0002] This invention relates to solid materials handling and to chemical adhesives, and discloses methods for converting needle-punched fiber mats (from sources such as shredded recycled carpets) into waterproof building materials, such as substitutes for plywood, roofing shingles, etc. [0003] A method for creating sheets of wood-like materials, comparable to plywood but essentially waterproof and bug-proof, using nylon fibers obtained from shredded discarded carpet segments, is described in published PCT application WO 01/76869 (arising from PCT/US01/11895), by Forrest Bacon et al, the same Applicants herein. The contents of that published application are hereby incorporated by reference, as though set forth fully herein. [0004] The above-cited PCT application describes a new use for needle-punched fiber mats. Those types of needle-punched mats, which have been made for years, are manufactured by a series of steps that include the following: [0005] a. segments of discarded carpet are shredded, using a rotating claw cylinder, to create a mass of rough yarn material; [0006] b. the rough yarn material is then combed and pulled apart, to create a relatively light and fluffy mass of nylon fibers; [0007] c. the fiber mass is combed into large continuous ribbons roughly two feet wide and an inch or more thick; [0008] d. machines called "cross-lappers" are used to deposit these ribbons transversely, across a slow-moving conveyor system (which typically is 13 feet wide, in order to make fiber mats that can be side-trimmed to exactly 12 feet wide); after the ribbons from several cross-lapper machines (typically, four machines are used in series) have been deposited onto the conveyor system, the resulting mass of fibers that rests on top of the travelling conveyor is more than a foot thick, with low density, and with essentially all fibers laying in roughly horizontal directions; [0009] e. the thick mass is compressed to roughly 1/2 inch thickness, by compression rollers, to form a fibrous mat; [0010] f. the fibrous mat passes through a needle-punch machine, which contains a wide steel "platen" with thousands of long needles having small nicks or barbs on the surfaces of their shafts; [0011] g. the platen and the barbed needles are hammered against the mat, about 5 times per second, as the mat passes slowly through the needle-punching zone; [0012] h. the barbs on the shafts of the needles grab individual fibers in the mat, and yank those fibers both upward and downward. [0013] When the mat emerges from the needle-punch machine, it is strong and cohesive, and cannot be pulled apart by hand without great effort, because of the dense intertwining of the fibers. If the needle-punching operation is carried out properly, with a combination of plate width and conveyor speed that establish a sustained "dwell time" in the needle-punching zone, multiple thousands of fibers per square yard will be yanked into a "vertical" (transverse) position. As a result, a needle-punched mat made from recycled carpets has the general shape, feel, and flexibility of an extra-thick woolen blanket, and it is held together entirely by the fibers within the mat, with no need for expensive chemical adhesives. [0014] In the past, these types of mats have been used mainly for two purposes: (i) as underlayments (also called pads, cushions, etc.) for carpets installed in high-traffic areas, such as in stores, office buildings, theaters, etc; and, (ii) as padding and sound insulation in vehicles, such as in automobile trunks. However, there is a not a high level of demand for these mats, since those uses are limited, and people generally prefer to have rubbery foam underlayers, which provide a spring-like bouncy feel, installed beneath carpets in homes and apartments. [0015] PCT application WO 01/76869 describes an entirely new and different use for these types of needle-punched mats. In this new use, a liquid adhesive is spread between two or more mats, and the mats are then compressed against each other, using high pressures to drive the adhesive throughout the entire thickness of both (or all) mats. This process can be aided by using a two-component adhesive mixture that undergoes a chemical reaction that releases millions of tiny gas bubbles, soon after the two components are mixed together; the formation and release of the gas helps drive the liquid adhesive throughout the entire thickness of both of the dense fibrous mats that are being compressed against each other. One such subclass of adhesives includes specialized types of poly-alcohol resins that can be mixed with cyanate catalysts, to form polyurethane adhesives. In one example of a manufacturing operation, the two liquids can be mixed together, using a mixing nozzle, immediately before the resulting liquid mixture is spread across the juncture where two needle-punched mats will be compressed against each other, by rollers. The mats will then be held against each other, under pressure until the adhesive sets and hardens; this can be done by using a "moving belt press", of the type that is commonly used to manufacture plywood, oriented strand board, particle board, and similar types of materials, generally referred to herein as "sheetwood" materials to distinguish them from planks and other forms of sawed lumber. [0016] The resulting material, which contains needle-punched mat(s) that have been thoroughly impregnated with hardened adhesive, has a stiffness, hardness, and "workability" (i.e., it can be sawed, drilled, etc.) that are comparable to plywood, oriented-strand board, etc. However, the stiffened fiber-and-adhesive materials can be substantially stronger and more resilient than wood, and are also essentially waterproof and bugproof. [0017] The main drawback and limitation of this manufacturing process is that two-component adhesives which will release gas bubbles, after being mixed together, tend to be expensive, and make up the large majority of the total cost of manufacturing these types of boards. Even when the total costs of collecting, shredding, combing, cross-lapping, and needle-punching discarded carpet segments are factored in, the purchase price of the adhesive is likely to be roughly 70 to 80 percent of the total cost of the final material. However, in the tests that were carried out prior to this invention, less expensive types of adhesives were not able to provide the consistency and uniformity that will be required to achieve widespread acceptance and commercialization of these types of wood-substitute materials. [0018] The primary obstacle that prevented the successful use of inexpensive adhesives, prior to this invention, was the difficulty that was encountered in getting candidate adhesives to somehow permeate, diffuse, or otherwise be distributed in an even, consistent, uniform, and reliable manner, throughout the entire thickness of a needle-punched fiber mat. As anyone who has personally inspected a needle-punched mat made from shredded carpets can attest, the thickness and density of the mat, combined with the dense and complex intertwining of the fibrous matrix in the mat, poses a formidable and daunting challenge to any attempt to successfully drive any form of liquid, granular, or powdered material through the mat, in an even, consistent, and uniform manner. [0019] This poses a major challenge, since evenness, consistency, and uniformity are essential to sheetwood materials that must compete against plywood or OSB. If even a single small seam fibrous mat material, which did not receive enough adhesive to harden properly, is present in a sheet of a plywood substitute, then that entire sheet will be unreliable and even dangerous to use in a building; it will be effectively worthless, since its sale might subject the seller to large legal liabilities if it is incorporated into a building and then subsequently fails, due to the one small seam. [0020] Nevertheless, the Applicant herein has developed a new method of creating sheetwood substitutes and other building materials, from needle-punched fiber mats, using granular adhesives. The crucial step in this invention centered on creating and developing a method for distributing a granular adhesive throughout the thickness of the fiber mat while it is being formed by the cross-lapper machines and the conveyor system, before the mat reaches the needle-punch machine. [0021] Therefore, this new method of manufacture enables the selection and use of lower-cost granular adhesives, which fall within a class that is referred to within the industry as "hot melt" adhesives. [0022] Accordingly, one object of this invention is to disclose a method of distributing and embedding heat-activated adhesives, in granular, powdered, or similar form, throughout the thickness of a needle-punched fiber mat, to render the mat useful for manufacturing a plywood substitute or other building material. Continue reading... Full patent description for Building materials from needle-punched fiber mats with granular heat-activated adhesives Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Building materials from needle-punched fiber mats with granular heat-activated adhesives patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. 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