The present invention relates to fabrics having a textured, multicolor, appearance, woven from expansible threads having at least two coatings, or layers, of different colors, wherein each coating is eccentric with the prior coating or coatings. During heat activated foaming of the woven fabric, the first and second coatings expand at different rates depending upon their relative melt viscosities and blowing agent percentages, to produce a textured multicolor fabric.
Fabrics woven from vinyl coated yarns are well known in the art. Such fabrics have the attributes of open mesh construction allowing breathability and drainage, protection of yarn filaments from fiber/fiber abrasion at weave crossover points, and multicolor random, plaid or tweed effects achieved without subsequent overprinting operations. In general, vinyl coated yarns can be manufactured either by extrusion coating, or by plastisol dip coating, also referred to as a dip/die coating.
The extrusion coating process is discussed in great detail in U.S. Pat. No. 3,100,926 (Method of Producing Expanded Fabric-Like Material--E. B. Richmond). As discussed in that patent, the extrusion coating operation utilizes a crosshead extruder, much like wire coating, wherein a multifilament strand, such as polyester, nylon, rayon or glass is encapsulated with melted vinyl in the crosshead using a pressure or tubing die and then cooled in a water bath. There is virtually no penetration of vinyl among the yarn filaments due to the relatively high viscosity of the liquid vinyl.
In the plastisol dip coating process, as disclosed in copending U.S. Patent Application Ser. No. 744,018, filed on Nov. 22, 1976, now U.S. Pat. No. 4,144,371 (Flattened and Bonded Fabric of Foamed Vinyl Plastisol on a Filament Core and Method of Preparing Same--Okie et al), hereafter referred to as the Okie et al application, incorporated by reference herein, a multifilament strand, such as polyester, nylon, rayon or glass, is immersed in a liquid vinyl plastisol, and the excess coating is wiped off by passing through a suitable orifice, such as a wire drawing, or sizing, die, to properly size the yarn. The strand is then passed through a heated oven to at least partially cure, or solidify, the coating. In this case, there will be a considerable amount of impregnation or penetration of the filament bundle by the vinyl, depending on the yarn twist and the viscosity temperature relationship of the plastisol. The impregnation or penetration is referred to as "wet-out".
A further modification can be made to yarns produced by extrusion coating and plastisol dip coating by incorporating a thermally activated chemical blowing agent in the vinyl formulation which remains latent during coating and curing, but which, after the coated yarns are woven into fabric and heat-finished, decomposes at fabric finishing temperatures to yield an expanded cellular structure in the vinyl. One such blowing agent is azodicarbonamide, which decomposes between 302.degree. and 392.degree. F. The technology of yarns with latent foaming characteristics is described in the aforementioned U.S. Pat. No. 3,100,926 for extruded yarns, and in the aforementioned Okie et al application for plastisol dip yarns. As pointed out in the Okie et al application, the latent foam feature allows the yarn produced by the plastisol dip process to undergo significant flattening during finishing due to the expanding vinyl being present among the filaments as previously described. In contrast, a yarn produced by the plastisol dip process, which does not contain a latent chemical blowing agent, has a finished width in a typical fabric of about half that containing a blowing agent.
In fabrics woven from these types of yarns, it is further known to improve styling by utilizing a number of colors or patterns including solid colored stripes as described in copending U.S. Patent Application Ser. No. 939,705, filed on Sept. 5, 1978 (Fabric Having Multiple Solid Colored Stripes--Worrall), hereafter, the Worrall application, incorporated herein by reference. A stripe effect can be introduced into the fabric by alternating groups of warp or filling yarns. By using a clear vinyl coated yarn without a foam structure as a filling yarn, the solid stripe effect is closely approximated, especially if the filling yarn utilizes a polyester core fiber.