Carpets are backed with flexible plastics for various reasons. In the Automotive sector the layer of LDPE makes the carpet thermoformed able. This means that the carpet can be hot pressed into the shape desired and it has enough rigidity to stay in that shape in service and processing. For both domestic and automotive carpet, the powder layer provides another function that of an adhesive-locking the carpet fibres down so that during service the fibres cannot be pulled out of the carpet. Some manufacturers use the powder adhesive to glue other non woven fabrics onto the carpet as a non slip or finishing under layer.
CARPET BACKING PROCESS
Coarse powders of typically Polyethylene (LDPE) are scatter coated onto the reverse of a carpet that then moves slowly through a series of infra-red heating ovens. The powder layer, which is a thermoplastic, melts onto the back of the carpet and works like a glue to laminate other backing fabric/roll materials. The whole laminate is then cooled and solidified and the carpet is then rolled up and made ready for shipping.