I. Product Overview The 72-cavity pin-valve hot runner system is a high-end full-hot-runner solution developed for multi-cavity, high-precision, and high-volume injection molding scenarios. It adopts a pneumatic pin-valve timing control structure, with a compact and reasonable cavity arrangement, and a balanced and stable runner distribution. It is suitable for various plastic raw materials such as PP, PE, PC, PBT, ABS, and fiber-reinforced modified plastics. It is widely used in high-speed mass production in industries such as packaging bottle caps, medical consumables, precision electronic accessories, and small daily-use plastic parts. It has the advantages of stable molding, no stringing, no drooling, and no post-processing required, and is suitable for automated assembly-line production. ### II. Core Structural Design - **72-cavity balanced runner layout** The manifold is made of high-quality hot-working die steel, which undergoes overall quenching and tempering and nitriding treatment. The inner part of the runner is mirror-polished, with no dead corners, no material accumulation, and easy color change. Through professional mold-flow analysis to optimize the distribution path, the feeding pressure, flow rate, and temperature of the 72 cavities are highly balanced. The weight and size consistency of a single product are good, effectively avoiding defects such as short shots, shrinkage, deformation, and color differences. - **Precise pin-valve glue-sealing structure** High-hardness alloy valve pins and special valve sleeves are used, featuring strong sealing, wear resistance, and high-temperature resistance. Relying on pneumatic timing control, the valve precisely opens for feeding during injection, and immediately seals and cuts off the material when the pressure-holding ends. The gate is flat without marks, no stringing, and no cold-material drooling. After the product is molded, there is no need for manual gate trimming, directly meeting the appearance and assembly requirements. - **Independent-zone precise temperature control system** The system uses multiple independent temperature-control zones, equipped with high-quality heating coils and high-precision thermocouples. The temperature-control error is small, the heating is uniform, and the heat loss is low. A molding temperature curve can be customized according to the characteristics of different plastic raw materials to prevent material carbonization, yellowing, and the generation of black spots, and is suitable for long-term continuous and stable 24-hour production. - **High-strength wear-resistant material configuration** Core components such as hot nozzles, valve pins, manifolds, and glue-sealing inserts are all made of special high-temperature-resistant, corrosion-resistant, and wear-resistant steel. After hardening and nitriding treatment, they can resist the scouring of plastic materials and the wear of fiber-reinforcement, have a long service life, and greatly reduce the later maintenance and replacement costs.