. . . . "HDPE and PVC provide a desirable combination of rigidity and low weight, but other materials, including steel, polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyvinylidene fluoride (PVDF), high density polyethylene (LDPE), polycarbonate (PC), polymethylmethacrylate (PMMA), polyphenylene sulfide (PPS), and fluoroethylene-propylene (FEP) can be used as well." . .