Stress Relaxation of Tufted Carpets and Carpet Components: Analysis of the Tufted Carpet Structure

Dimensional stability of tufted carpets has been a continuing problem in the carpet industry for years. When a tufted carpet is installed by the stretch-in method, it experiences stress relaxation over time which can cause the carpet to buckle, wrinkle and become loose with the only option being a costly re-stretching of the carpet. Analysis of the various components of the tufted carpet composite structure was performed to identify the role each component plays in the phenomenon of stress relaxation. A biaxial loading system was used to test various samples of the primary backing alone, primary backing after tufting (with tufts), secondary backing alone, and the finished carpet after attaching the backings with various binder weights per area. The four variables under consideration included primary and secondary backing constructions, tufting density, and latex weight. A rheological model that includes representations of each component in the carpet structure was developed and will be presented in a following paper.