1. Corrosion Properties of Raw Materials: PVC raw materials (especially rigid PVC) decompose at excessively high processing temperatures, releasing hydrogen chloride (HCl) gas. This gas causes severe corrosion on metal components of pipe-making machines, such as feed tubes and screws. This is the fundamental cause affecting the equipment's corrosion resistance.
2. Material Selection and Design: To withstand HCl corrosion, the pipe-making machine requires specialized "corrosion-resistant" design. For instance, dedicated machinery and feed tubes should be employed, with screw compression ratios kept moderate to prevent excessive shear-induced heating and accelerated decomposition of raw materials. The corrosion resistance of the equipment's materials directly determines its service life.
3. Production Process Control: Maintaining barrel temperature is of paramount importance. Excessive temperatures directly cause PVC decomposition, producing HCl. Therefore, an accurate temperature control system is essential to prevent raw material overheating and decomposition, thereby protecting equipment from corrosion.
4. Operating and Maintenance Practices: Daily operating and maintenance methods directly impact the equipment's corrosion resistance. For instance, before shutdown, reduce the barrel temperature and thoroughly clean residual PVC using standard plastic. Otherwise, residual PVC will continue decomposing inside the barrel, severely corroding the screw and barrel. Additionally, installing auxiliary cooling equipment such as fans on the feed pipe helps prevent overheating.