US Patent 9644314 Primary carpet backing

A primary carpet backing including at least a first and a second layer of fibers, characterized in that both the first and the second layer of fibers is a nonwoven layer of randomly laid fibers, that both the first layer of fibers and the second layer of fibers has a uniform composition throughout the layer, wherein the linear density of the fibers is in the range of 1 to 25 dtex, wherein both the first layer of fibers and second layer includes at least two different polymers and wherein at least one polymer included in the first layer is different from the polymers included in the second layer.