Notes: Extrusion coating is the same process as melt casting a film but the film is cast onto a fabric substrate (or other substrate like paper, nonwovens, etc.).
Adhesion of the PAL Compound when extrusion coated onto the fabric or substrate is a critical issue. For your general information, almost all of the mechanical properties of extrusion coated fabrics come from the fabric mechanical properties being coated and obtaining acceptable adhesion to the substrate. Polyolefins like PAL will adhere very well to other polyolefins (PP or PE). The best way to obtain acceptable adhesion to a non-polyolefin fabric or substrate with PAL Compounds (especially polyester (PET)) is for the woven fabric to have a more open weave so that the PVC/PAL can drink into the fabric from one side or both sides of the fabric and form as much of a mechanical adhesion as a chemical adhesion between the molten (PVC/PAL) and the often times fibrous substrate fabric or non-woven. A hairier fabric substrate (like you get from textured yarns or natural fibers like cotton/wool/other) is much easier to form a mechanical bond with the PAL compound.
PAL will not chemically adhere that well to PET (polyester) but if the polyester fabric is made from textured yarns then there is more surface area for the PAL to mechanically entrain itself and an acceptable adhesion can occur. This is why it is important that the fabric weave be open enough for the PAL to drink into the fabric and mechanically entrain the PET yarns. The more texture and/or hairier the yarns are, the easier it is to get an acceptable mechanical adhesion between the PAL extrusion coating and the substrate made from such yarns/fibers.