... extrusion line1. Free style expansion boards and co-extruding expansion boards produced by PVC expansion boards production line have top-grade quality, one ... with high security. 4. PVC expansion boards can resist damp, mildew and water, as well as quakeproof. 5. PVC expansion boards are made ... at break, % 15-20, Shore Hardness, D type, 45-50 water absorption, % ≥1.5, Vicat softening point, °C 73-76 fire ...