US 20050042413 A1
The amount of waste carpeting that is landfilled or otherwise disposed of is significantly reduced, as is the need for the mining mineral fillers, by utilizing specially processed waste carpeting as a filler in the production of new hot melt carpet backcoating, roofing materials, or other similar products. Waste carpeting (post consumer and/or waste from new carpet manufacture) is collected and size reduced, typically in a first coarse size reduction, and then after densification to a finer size reduction. The size reduced waste carpeting is added as filler to at least one other material, such as polymers in standard latex, EVA, or PVC carpet backcoatings, to provide a hot melt composite used in the manufacture of a useful product (like carpet backcoating), and then the composite material is used to make the useful product (such as carpet backcoating, which is used as a primary or secondary backcoating in the manufacture of new carpeting). The waste carpeting may provide between about 40 100% of the filler of carpet backcoating, with any remainder made up by conventional fillers, such as calcium carbonate.
18. Carpeting having a face, primary backing, primary backcoating, and at least one secondary backcoating; and wherein at least one of said primary and secondary backcoatings comprises a polymer and filler, and wherein at least about 40% of said filler is size-reduced waste carpeting, at least one of said primary backcoating or secondary backcoating including a hot melt compound applied as a molten mixture of polymers and fillers and cooled to form said one backcoating.
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In the conventional manufacture of floor coverings, e.g., carpeting and carpet tiles, hereafter sometimes collectively called carpeting, tufted pile yarns or like facings are held in place by a primary backing, and typically a secondary backing, as well as possibly other layers. At least some of the carpet backings (particularly latex, EVA, PVC, or other polymer-based backings) use filler as an important component thereof. The standard filler that is used is a mineral filler, typically calcium carbonate, alone, or in combination with some other common metal salts.
During the carpet manufacturing process there is waste carpeting produced, which is typically landfilled or burned. When new carpets are installed in place of old carpeting, the used, waste, carpeting (which is post-consumer waste at that point) is ripped up and also typically landfilled or burned. The calcium carbonate, or like mineral fillers, that are used in carpet backings are mined, and therefore have associated therewith the conventional problems associated with the mining of materials.
According to the present invention methods of recycling waste carpeting and producing carpeting utilizing recycled materials, are provided which substantially eliminate or significantly reduce the problems discussed above. According to the present invention instead of using calcium carbonate, which is mined, as the filler for a carpet backing, recycled waste carpet (from new carpet production and/or from post-consumer waste) is used as the filler material in a hot melt application process in which the molten material including these waste products are applied to the carpet backing to deliver the desired physical properties such as strength and dimensional stability. This substantially eliminates, or at least significantly reduces, the amount of landfilling or other waste disposal that is necessary for waste carpeting while enabling the manufacture of fresh floor coverings using the waste materials.
The invention is also applicable to the production of other materials containing fillers, including various extruded thermoplastic and thermoset materials that typically use calcium carbonate filler, including, but not limited to, roofing materials, road paving materials, awnings, and tarps.
In a preferred embodiment according to the present invention, there is provided a method of manufacturing floor coverings using waste carpeting as at least part of backing material for the covering, comprising substantially sequentially the steps of (a) collecting waste carpeting, (b) effecting size reduction of the waste carpeting, (c) adding the size-reduced waste carpeting as a filler to at least one other material to form a molten mixture for backcoating a primary backing of the floor covering, (d) applying the molten mixture and a fabric material to a primary backing to form a laminate on the floor side of the primary backing and (e) cooling the laminate on the primary backing to form a floor covering having the backcoating containing the waste carpeting on a floor side of the primary backing.
In the method step a) may be practiced to collect substantially only post-consumer waste carpeting, substantially only waste carpeting from new carpeting manufacture, or a blend of both. Post-consumer waste carpeting can be cleaned by any conventional cleaning technique before use, if desired or necessary. While the method is typically practiced utilizing all of the face yarn and primary backing, and backcoatings, under some circumstances the method may further comprise, between a) and b), separating the face yarn and primary backing from waste carpeting backcoating to produce a substantially face yarn and primary backing-free waste carpeting backcoating, and using substantially only the waste carpeting backcoating in step b). Also, various carpet backcoatings may be separated from each other so as to use only one particular carpet backcoating, such as the primary or secondary backcoating.
The invention may also further comprise, between steps b) and c), step f) densifying the size reduced carpeting, and effecting a further size-reducing thereof. Also step c) may be practiced so as to provide between approximately 40-100% of the filler of the carpet backcoating as size-reduced waste carpeting. For example in one embodiment of the invention, steps c) and d) are practiced to produce a carpet backcoating with about 5-18% EVA copolymer, about 32-45% resin, about 20-50% size-reduced waste carpeting filler, and about 0-30% calcium carbonate filler. Also in the practice of the method, steps b) and f) may be practiced to produce waste carpet coating have a particle size and range substantially the same as calcium carbonate filler.
The method includes latex carpet backcoatings and is not restricted to thermoplastic resin such as PVC carpet backcoatings, EVA, or other polymer-based backcoatings.
The invention also further typically comprises making new carpeting with the carpet backcoating.
Alternatively according to the present invention, steps c) and d) may be practiced to produce extruded thermoplastic or thermoset products and/or to produce awnings, roofing materials, road paving materials, or tarps, with a particle size of the waste carpeting filling between about 20-100 mesh.
According to another aspect of the present invention there is provided carpeting having a face and primary backing, primary backcoating, and at least one secondary backcoating; and at least one of the primary and secondary backcoatings comprising a polymer and filler, and wherein at least about 40% of the filler is size-reduced waste carpeting, at least one of the primary backcoating or secondary backcoating including a hot melt compound applied as a molten mixture of polymers and fillers. At least one of the backcoatings may comprise about 5-18% EVA copolymer, about 32-45% resin, about 20-50% size-reduced waste carpeting filler, and about 0-30% calcium carbonate filler. The size-reduced waste carpeting may comprise size-reduced post consumer waste carpeting, and the filler may have a particle size and range substantially the same as calcium carbonate filler.
It is the primary object of the present invention to produce new materials including floor coverings utilizing recycle waste carpeting to eliminate disposal problems, while at the same time reducing the mining or other production of filler materials typically used in carpet backing, or other products. These and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.
A standard construction of carpeting is illustrated schematically by reference numeral 10 in
The carpeting 10 may also have any number of other layers, depending upon use. For example the carpeting 10 may have a conventional secondary backing (typically a woven or needle-punched fabric adapted to contact the floor or padding). Thus, the primary backcoating 12 may include a filler of size-reduced waste carpeting with one or more secondary backcoating 13 layers including or not filler of size-reduced waste carpeting. Preferably, however, the secondary backcoating 13 includes the filler of size-reduced waste carpeting in conjunction with a fabric material laminated to the primary backcoating 12.
It is contemplated that according to the present invention the waste carpeting that is subsequently employed in the manufacture of new carpeting utilizes substantially all components of waste carpeting, including the face yarns, primary backing, and primary and secondary backcoatings, and perhaps other components. However under some circumstances for either part or all of the waste carpeting it may be desirable to separate the face and primary backing and backcoatings from each other before further procedures. The optional separation of the carpet components is illustrated schematically at 21 in
Whether or not procedure 21 is utilized, the waste carpeting is subjected to size-reduction. As illustrated at 22 in
While under some circumstances only the size-reduction 22 may be utilized, oftentimes it is necessary or desirable to effect densification and further size-reduction of the waste carpeting. Densification, as illustrated at 23 in
Preferably after densification at 23, there is a second, finer, size-reduction of the waste carpeting, as indicated at 24 in
In the preferred procedure according to the present invention, the size-reduced waste carpeting from 20 through 24 is used as a filler with other standard carpet backcoating components, either for primary backcoating, or a secondary backcoating, or other backing elements of carpeting (typically collectively referred to as main coats). For example latex, EVA, or PVC backcoatings of conventional construction are particularly suitable for utilization of the waste carpeting filler from 20 through 24 in
While a wide variety of polymers or other materials may be used to produce the carpet backcoatings according to the present invention, one exemplary carpet backcoating will be described below. A standard hot melt backcoating such as the Lees Unibond™ backcoating system may contain, for example [all percentages given herein are by weight unless other indicated]:
According to the invention, instead of using all calcium carbonate as the filler, a significant amount of the calcium carbonate usually added to the molten resin and copolymer can be replaced by the size-reduced waste carpeting according to procedures 20 through 24 of
The waste carpeting filler according to the present invention is mixed with the other component(s) using standard hot melt mixing equipment and techniques as indicated at 25. In a preferred embodiment as indicated in
While the preferred embodiment of the invention is the utilization of waste carpeting in new carpet manufacture, other uses are also possible. For example as illustrated schematically at 30 in
During any of the procedures described above various conventional refinements may be employed. For example screening or other contaminant removal may be practiced where desired, as can be testing, sampling, or any other suitable techniques that are necessary or desirable in order to produce a product with desired properties.
It will thus be seen that by practicing the present invention it is possible to substantially eliminate or significantly reduce landfilling or other disposal of waste carpeting, and at the same time to reduce the mining of mineral fillers, without sacrificing new product quality, by using processed waste carpeting as a filler for new carpet backcoatings, roofing materials, or in other situations.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.