PP-R 90-Degree Elbow Injection Mold: Design and Manufacturing Overview The PP-R (polypropylene random copolymer) 90-degree elbow injection mold is a precision tool designed for producing high-quality pipe fittings used in plumbing and HVAC systems. This mold is engineered to create durable, leak-proof elbows that ensure smooth fluid flow in pressurized piping networks. Below is a detailed breakdown of its key aspects: 1. Material and Application PP-R is chosen for its excellent thermal resistance, chemical stability, and long service life, making it ideal for hot/cold water systems. The 90-degree elbow is a critical component for directional changes in pipelines, requiring precise dimensions and consistent wall thickness to meet industry standards (e.g., ISO 15874, DIN 8077). 2. Mold Design Features - Cavity and Core System: The mold typically features multi-cavity designs (e.g., 1+1 or 2+2) to optimize production efficiency. The cavity shapes the elbow’s outer surface, while the core forms the inner diameter. - Cooling Channels: Strategically placed cooling channels ensure uniform heat dissipation, reducing cycle times and preventing warpage. - Ejection Mechanism: Automatic ejector pins or plates release the molded part smoothly without damage. - Venting System: Micro-vents eliminate trapped air to avoid defects like burns or incomplete filling. 3. Manufacturing Process - Material Preparation: PP-R pellets are dried and fed into the injection molding machine. - Injection Phase: Molten PP-R is injected into the mold under high pressure (typically 600–1,200 bar) to fill the cavity completely. - Cooling and Solidification: The mold cools the material rapidly to maintain dimensional accuracy. - Ejection and Finishing: The elbow is ejected, and excess material (flash) is trimmed. Some molds include in-mold labeling for branding. 4. Quality Control - Dimensional Checks: Critical parameters (e.g., inner/outer diameter, curvature radius) are verified using CMM or laser scanners. - Pressure Testing: Samples undergo hydrostatic pressure tests to ensure leak-proof performance. - Surface Inspection: Smooth inner walls and absence of sink marks or bubbles are confirmed visually and via microscopy. 5. Advantages of the Mold - High Precision: CNC-machined mold components guarantee tight tolerances (±0.02 mm). - Durability: Hardened steel (e.g., H13 or P20) extends mold life beyond 500,000 cycles. - Energy Efficiency: Optimized cooling reduces energy consumption. Conclusion The PP-R 90-degree elbow injection mold combines advanced engineering with robust manufacturing techniques to produce reliable fittings. Its design prioritizes precision, efficiency, and longevity, meeting the demands of modern plumbing systems while adhering to international quality standards.