... we use webbed Polyamid(PA), for strength and durability and to make sowing possible.As a middle layer ,we use black Polyethylene ... called VC-disease.Furthermore,additives are not bound to the plastic and leach out .To make PVC soft, a lot of softeners have ... :Polyamids can occur both naturally,examples being proteins, such as wool and silk, and can be made aritificially, one example is ...