Shanghai Daoqin Plastics Co., Ltd.

injection molding parts molding is engineering technology, it and inner is will plastics is has use can maintain has property can products. injection molding important process conditions is effect/influence flow and cooling temperature degree, pressure and versus 应 各 function time. 一, temperature degree control 1, material temperature degree: injection process need control temperature degree has material temperature degree, nozzle temperature degree and mold temperature degree and other. front temperature degree main/primary effect/influence plastics and flow, rear types temperature degree main/primary is effect/influence plastics flow and cooling. types plastics tool has different flow temperature degree, types plastics, due to or grade different, its flow temperature degree and separation understanding temperature degree is has 差别, this is due to molecular weight and molecular weight distribution different 致, plastics in different type type injection machine inner process is different, selection material temperature degree same. 2, nozzle temperature degree: nozzle temperature degree usually is low material most high temperature degree, this is is anti material in 直通式 nozzle can can 发生 流涎 phenomenon. nozzle temperature degree can low, will formed material 早凝而 will nozzle 堵死, or due to material mold cavity effect/influence products property can 3, mold temperature degree: mold temperature degree for products inner in property can and table/sheet quality effect/influence very large. mold temperature degree high low 决定于 plastics crystallization property has 无, products dimensions and structure, property can requirements, and its it process conditions （熔 material temperature degree, injection speed degree and injection pressure, cycle and other ）. 二, pressure control: injection molding parts process in pressure 包括塑化 pressure and injection pressure types, 并直接 effect/influence plastics and products quality. 1, pressure: （ back pressure ） using/adopting screw injection machine 时, screw 顶部熔 material in screw rear 退时 受 to pressure is pressure, back pressure. this type of pressure large small is can through liquid pressure system in 溢流阀 adjustment. in injection in, pressure large small is screw speed 都不变, increase pressure 时即会 improve/increase melt temperature degree, decrease small speed degree. in addition, increase pressure can make melt temperature degree uniform, color material mixed combined uniform and melt in gas 体. generally as in, pressure 决定应 in ensure products quality excellent front lower low good, its specific value is use plastics product types 而异, usually very less ultra- 20公斤/ cm 2, injection pressure: in currently production in, has injection machine injection pressure is 以柱塞 or screw for plastics pressure （由油路 pressure 换算 ） is 准. injection pressure in injection molding parts molding in function is, plastics from material toward type flow retardant force, to material speed rate and for material pressure 实. 三, molding cycle formed one-time injection process time molding cycle, 也称模塑 cycle. it 实际包括 below/following separation: molding cycle: molding cycle effect/influence 劳动生间 rate and equipment utilizing rate, therefore in production process in,应 in ensure quality front lower,尽 amount shrink short molding cycle in has time. in molding cycle in,以 injection time and cooling time most important, it for products quality has property effect/influence. injection time in time 直接反 ratio 于充模 speed rate, production in time generally is 3-5秒. injection time in holding pressure time is for type inner plastics pressure time, in injection time inner ratio/proportion relatively large, generally is,20-120秒(特 thick made parts can high 达5~10 separation 钟). in gate material 封冻之 front, holding pressure time how much, for products dimensions property has effect/influence,若 in rear,则无 effect/influence. holding pressure time has most value, already it 依赖于 material temperature, mold temperature and runner and gate large small. if runner and gate dimensions and process conditions is positive 常, usually 即以 出 products shrinkage rate scope/range most small pressure value is 准. cooling time main/primary 决定于 products thick degree, plastics hot 泪盈眶 property can and crystallization property can,以 and mold temperature and other. cold hot time 终点,应以 ensure products demolding 时不引起变动 is 原则, cooling time property generally in 30~120秒钟 between, cooling time long has necessary, not only reduce production efficiency, for complex made parts also will formed demolding difficult, strong/high demolding 时甚至会 generate demolding force. molding cycle in its it time and production process is 否连续化 and 自动化以 and 两化 程 degree and other has 关.