首页>
外国专利>
Reduced-knitline thermoplastic injection molding using multi-gated non-sequential-fill method and apparatus, with a heating phase and a cooling phase in each molding cycle
Reduced-knitline thermoplastic injection molding using multi-gated non-sequential-fill method and apparatus, with a heating phase and a cooling phase in each molding cycle
展开▼
机译:使用多浇口非连续填充方法和设备的缩结线热塑性注塑成型,在每个成型循环中都有加热阶段和冷却阶段
展开▼
页面导航
摘要
著录项
相似文献
摘要
Hard to fill large-surface-area parts and/or thinwalled configurations of optical lenses and reflective optical elements are among the difficult-to-mold thermoplastic products which require precision replication of the molding surfaces, in micro detail. We combine multiple opposing gates (to reduce the meltflow pathlength) with non-isothermal steps of firstly, heating these mold surfaces (with circulating heat transfer fluids supplied by a hot side supply system, to a temperature setpoint sufficiently high to retard solidification), then secondly, injecting the melt through these opposing gates, then thirdly, rapidly cooling to solidification (by circulating heat transfer fluids of much lower temperature, supplied from a cold side supply system). To run fastest injection molding cycle time, the fast heating phase comes from combining high-thermal-conductivity copper alloy mold cavity materials with very large thermal driving force (high delta T) from high-heat-transfer-rate fluids (preferably, steam). Fluid control units and electronic process sequence control units are interconnected to govern the flow of these fluids into and out of the injection mold and the supply systems in accordance with the predetermined logic of the process flowsheet. To reduce geometric constrictiveness during filling of the mold cavity, an injection compression process sequence with pre-enlarged variable-volume mold cavity can be created before injection starts, then compressed toward original dimensions during injection.
展开▼