PVC Collapsible Pipe Injection Mould: Design and Functionality A PVC collapsible pipe injection mould is a specialized tool used in the manufacturing of flexible, collapsible PVC pipes through the injection moulding process. These pipes are widely used in applications requiring easy storage, transport, and deployment, such as in irrigation, drainage, and portable water systems. The mould must be precisely engineered to produce pipes with consistent wall thickness, durability, and collapsibility while maintaining high production efficiency. Key Design Features 1. Material Selection The mould is typically made from high-grade steel (e.g., P20, H13, or stainless steel) to withstand high injection pressures (typically 500–1500 bar) and repeated thermal cycling. Hardened steel is often used for critical components like the core and cavity to resist wear and prolong mould life. 2. Collapsible Core Mechanism Unlike rigid pipe moulds, a collapsible pipe mould incorporates a collapsible core or segmented design that allows the pipe to be easily ejected without deformation. The core retracts or folds inward after cooling, enabling the pipe to maintain its flexible, collapsible structure. 3. Cooling System Efficient cooling channels are integrated into the mould to ensure uniform cooling of the PVC melt, preventing warping or uneven shrinkage. Proper cooling is critical for maintaining dimensional accuracy and reducing cycle times. 4. Venting and Ejection Venting slots are strategically placed to release trapped air and gases during injection, preventing defects like burns or voids. Ejection pins or sleeves are designed to smoothly remove the finished pipe without damaging its thin walls. 5. Multi-Cavity Design High-production moulds often feature multiple cavities to increase output. Each cavity must be balanced to ensure consistent filling and uniform pipe quality. Injection Moulding Process 1. Material Preparation PVC resin, along with plasticizers, stabilizers, and lubricants, is fed into the injection moulding machine’s hopper. The material is heated to a molten state (160–210°C) before injection. 2. Injection and Packing The molten PVC is injected into the mould under high pressure, filling the cavity completely. A packing phase ensures material density and minimizes sink marks. 3. Cooling and Ejection The mould is cooled (often with water channels) until the PVC solidifies. The collapsible core then retracts, and ejector pins release the pipe. Quality Considerations - Wall Thickness Consistency: Critical for flexibility and durability. - Surface Finish: Smooth interiors reduce friction in fluid transport. - Dimensional Accuracy: Ensures compatibility with fittings and connectors. Applications PVC collapsible pipes are used in agriculture, construction, and emergency water transfer due to their lightweight, space-saving design. The injection mould must balance precision, durability, and cost-effectiveness to meet industry demands. In summary, a well-designed PVC collapsible pipe injection mould ensures high productivity, consistent quality, and long service life, making it essential for modern flexible piping solutions.