The key to PVC roofing tile production lies in formulation design and extrusion molding. The formulation must be precisely controlled; the addition of calcium-zinc stabilizers should range from 3% to 5%. Insufficient amounts can cause yellowing, leading to customer complaints; excessive fillers reduce toughness and cause cracking, a problem commonly seen in factories with poor cost control. Extrusion temperatures must be strictly controlled: 140–170°C in the three sections of the barrel and around 120°C at the die. If temperatures are too high, decomposition and smoke emission may occur, ...
