US 3913510 A
A tufted carpet with an elastomeric net backing is disclosed. The tufts of the carpet are inserted through the net while the net is under tension whereafter the tension on the net is released thereby holding the tufts in place without the need for conventional adhesive materials such as latexes.
Description (OCR text may contain errors)
United States Patent UNITED STATES PATENTS Miller 112/410 x 'Larsen Oct. 21, 1975  TUFTED CARPETS WITH ELASTOMERIC 2,725,835 12/1955 Mather 112/266 X NET BACKING 3,110,905 11/1963 Rhodes 112/410 3,240,176 3/1966 Morrison 112 266  Inventor: Ronald Leslie Larsen, Mmneapolis, 77,973 4 9 3 whitesel et al 112 410 x Minn. 3,694,873 10/1972 Crowley 112/410 X  Assignee: Conwed Corporation, St. Paul,
Minn. Primary Examiner-H. Hampton Hunter Filed: Jan. 1974 Attorney, Agent, or FzrmEyre, Mann & Lucas 21 A 1. No.: 436 214 1 pp [57 ABSTRACT  us. 61 112/410; 112/266 A tufted Carpet with an elastemerie net backing is [511 Int. Cl. D05C 17/02 elesed- The tufts 0f the Carpet are inserted through the  Field of Search 112/266, 410, 411; net While the net is under tension whereafter the 264/1 7 209; 425/375 381 3 2 sion on the net is released thereby holding the tufts in 4 place without the need for conventional adhesive ma- 5 Referenes Cited terials such as latexes.
7 Claims, 2 Drawing Figures US. Patent Oct. 21, 1975 TUFTED CARPETS WITH ELASTOMERIC NET BACKING The present invention relates to a new and useful carpet which has an elastomeric net backing.
Tufted carpets are well known in the art and have been produced for quite a number of years. The carpets are usually produced from continuous strands of nylon, polyester, acrylic or similar materials. The continuous strands are poked through a fabric mesh-type backing material so that loops are formed, which loops are positioned adjacent each other. The material is then held in place in the backing material by a suitable adhesive such as a latex which is applied to the underside of the carpet. The backing materials commonly employed are woven fabrics and perhaps the most common fabric in use today is one formed from polypropylene wherein the polypropylene is first made as a film, slit into strips, and then woven to form the fabric. While these prior art carpets have proven quite satisfactory, they have a number of process disadvantages. For example, the additional step of applying the backing adhesive such as the latex is costly and expensive since additional application apparatus is required. Environmental problems have also been encountered of late with respect to disposal of the excess adhesive material and the cleaning up of equipment used in the application of the material.
In accordance with the present invention these disadvantages of prior art carpets are overcome by using as a backing material an elastomeric net. The elastomeric net is placed under tension, preferably in both longitudinal and transverse direction, whereafter the carpet material is poked through the holes of the net. The tension of the net is then released whereby the net holds the loops of pile in position without the need for adhesive.
While one of the primary advantages of the present invention is the elimination of the need for the adhesive backing material, it will be understood that adhesive material can be used with carpets made according to the present invention where it is desired to have additional strength, or where the adhesive material also serves as the underlaying pad. It will therefore be understood that the present invention is not limited to the exclusion of adhesive materials.
It will also be understood that it is not necessary to stretch the elastomeric net when tufting the carpet. It is only necessary that the net be held under tension. The carpet material can then be poked through the holes in the net and the net will expand due to its elasticity when the tufts are poked through and then when the poking tool is removed, the net material will relax and hold the tufted carpet material.
One of the principal advantages of the present invention is that the carpet can be made with great speed as compared to the speed of existing processes. Furthermore, the relative accuracy of location of the tufts is enhanced because of the uniformity of the elastomeric net.
The material from which the carpet backing of the present invention is formed is an elastomeric material. The elastomeric material must have an elongation of at least 50 percent with a tensile set under 50 percent of that elongation. Preferred compounds for use in the present invention are the polyurethanes, either the polyester or the polyether prepolymer being suitable.
The formation of nets with strands which are integrally extruded at the joints is well known in the art.
Processessuitable for making these nets are taught for example in US. Pat. Nos. 3,384,692, 3,252,181, 3,112,526, 3,089,804, 3,178,328, 3,019,147, 3,118,180, 2,919,467 and 3,700,521. The preferred carpet backing materials made in accordance with the present invention are formed according to US. Pat. Nos. 3,252,181 and 3,384,692 wherein a plurality of parallel longitudinal strands are extruded and a plurality of parallel transverse strands are extruded integrally therewith at spaced intervals.
In the preferred form of the present invention, there are two sets of parallel strands which are extruded integrally to each other. However, it will be appreciated that the carpet backing material according to the present invention could comprise more than two sets of strands. Furthermore in accordance with the present invention, it is preferred that all of the sets of strands be of the elastomeric material. However, there are applications where only one set of the strands need to be made of the elastomeric material, e.g., where not much strength is required to hold the loop piles. Elastomeric carpet backing materials in which only one of the sets of strands are elastomeric can suitably be prepared according to U.S. Pat. No. 3,700,521. Where only one set of strands is elastomeric, the other sets of strands can suitably be polyethylene, polypropylene or the like.
These and other features of the present invention may be better understood with reference to the FIGS. which are a schematic representation of a process suitable for tufting carpet in accordance with the present invention. It will be understood that the Applicants invention is the elastomeric net backing material and is not apparatus for the tufting of carpets. In the FIGS.,
FIG. 1 shows the carpet material before it has been poked through the net; and
FIG. 2 shows the finished product.
Referring now to FIG. 1 there is shown a net 10 with longitudinal strands 12, transverse strands 14 and integral joints 16 bonding the longitudinal and transverse strands to each other. The net is being held under tension in both the longitudinal and transverse directions by suitable means (not shown). A strand of carpet 18 is positioned below the net 10 with a poking apparatus 20 positioned therebeneath. The poking apparatus has spindles 22 thereon corresponding to each of the open areas 24 of the elastomeric net. In operation the poking apparatus is oscillated in the up and down manner of arrow 26 whereby the strands of carpet 18 is inserted through the net at each of the perforations 24 of the net. This process is repeated for each row of perforations in the net. After the strand of carpet has been tufted through the perforations of the net, the tension of the net is relaxed whereby the tufts are held in place. It will be understood that two or three or as many as desired strands of material can be poked through the rows of net perforations at the same time. Multiple strands can be poked through the row of perforations of the net or a plurality of strands can be poked through a plurality of rows of perforations simultaneously, the latter being accomplished by using a plurality of rows of poking apparatuses 20.
In FIG. 2 there is shown a cut-away view of a carpet made in accordance with the present invention, as for example by the apparatus shown in FIG. 1. The strands of carpet material 18 with loops 28 is being held in position by net 10 comprising longitudinal strands 12 and transverse strands 14. It will be understood that loops 28 could be sheared at the top to .form a sheared pile rather than the loop pile shown. This shearing process is well known in the art.
In one specific example, an elastomeric carpet backing material was made according to the apparatus of U8. Pat. No. 3,252,181. The backing material was extruded with integral joints and had 15 strands per inch in the direction of extrusion (machine direction) and 1 5 stands per inch in the transverse direction. The resin used was a polyester polyurethane resin known as Texin 591A available from Mobay Chemical Company. The extruded carpet backing material was cut to suitable shape and was found to have elongation in excess of 50 percent and a tensile set of under 50 percent at that elongation. More specifically, the net had a percent tensile set at 100% elongation and a 32 percent tensile set at 200 percent elongation. The elastomeric net was found to be suitable as a carpet backing material in accordance with the present invention and was found to have the desired properties of holding tufted carpet material in position without the need for adhesive.
it will be understood that the claims are intended to cover all changes and modifications of the preferred embodiments of the invention, herein chosen for the purpose of illustration, which do not constitute departures from the spirit and scope of the invention.
What is claimed is:
l. A tufted carpet consisting essentially of a carpet material and an elastomeric net backing material, said elastomeric net comprising a plurality of spaced sets of strands crossing each other at an angle whereby there are perforations in the elastomeric net, crossings formed by the strands of one set crossing the strands of another set forming integral joints at the crossings, wherein at least one of the sets of strands is composed of an elastomeric material having an elongation of at least 50 percent and a tensile set of less than 50 percent at that elongation, said carpet material passing through the perforations in the net and said elastomeric net helping to hold the carpet material in position.
2. The carpet of claim 1 wherein all of the sets of strands of the elastomeric net are composed of elastomeric material having an elongation of at least about 50 percent and a tensile set of less than 50 percent at that elongation.
3. The carpet of claim 1 wherein there are only two sets of strands in the elastomeric net.
4. The carpet of claim 3 wherein the two sets of strands are normal to each other.
5. The carpet of claim 4 wherein both of the sets of strands are composed of elastomeric material having an elongation of at least about 50 percent and a tensile set of less than 50 percent at that elongation.
6. The carpet of claim 1 wherein the elastomeric material in the net is polyurethane.
7. A process for making a tufted carpet the steps of:
a. tensioning at least one set of elastomeric strands of an elastomeric net comprising a plurality of spaced sets of strands crossing each other at an angle whereby there are perforations in the elastomeric net, crossings formed by the strands of one set corssing the strands of another set forming integral joints at the crossings, at least one of the sets of strands being composed of an elastomeric material having an elongation of at least about 50 percent and a tensile set of less than 50 percent at that elongation.
b. positioning at least one continuous strand of carpet material immediately adjacent said net;
c. poking said carpet material through a plurality of the perforations in said net; and
d. relaxing the tension on said elastomeric net.