Shanghai Daoqin Plastics Co., Ltd.

due to plastics in separation amount light, tough property good, molding easy, low and other benefits, is in 古代财产 and day use material in, 愈 愈 more use plastics 庖代玻璃, 出格操 as optical device and packaging 财产方面, formed long especially active 络. can is due to its transparent property need good, wear resistance need high, impact resistant tough parts need good, is for plastics formed separation, injection molding full process process, equipment, mold and other, need large as, 以保障 this used for 庖代玻璃 plastics （ below/following 简称 transparent plastics ）, quality 精采, from to as 请求.
　　今朝 market upper as transparent plastics has polymethyl methacrylate (PMMA) （PMMA, 即俗称 pressure force or has machine 玻璃, ）, polycarbonate (PC) （PC）, terephthalic acid ethylene glycol 脂（PET）, transparent nylon, propylene styrene copolymer （AS）, polysulfone (PSU) （PSF） and other, its in 我们接触 most more is PMMA, PC and PET三 types plastics, lower 面就以 this types plastics is 例, and transparent plastics features and injection molding process.
　　1, transparent plastics property can
　　 transparent plastics 首先必 must has high transparency degree, its need has strong/high degree and wear resistance, can impact resistant, heat resistant property need good, chemical resistance need excellent, water absorption need small, has this dry in as in, can meet/satisfy transparent degree 请求而悠久不变, lower 面列出 table/sheet l, 斗劲一 lower PMMA, PC and PET property can.
　　2, transparent plastics injection molding process in positive 视 配 combined issues issues
　　 transparent plastics due to light transmittance need high, 必定请求 plastics products quality 请求残酷, can has 任何花纹, gas 孔, 泛白, 雾晕, 斑点, color, gloss and other 毛病舛误, is in full injection molding process for raw materials, equipment, mold, 甚至产 material design, need non positive and 提出残酷甚至不凡 请求. its due to transparent plastics more is melting point high, property 差, is 感触保障产 material quality, need in relatively low temperature degree, injection pressure, injection speed degree and other process parameters as fine micro agent, make plastics can 布满 模, also generate internal stress 而激发产 material deformation and cracking.
　　 lower its in raw materials 筹备, for equipment and mold 请求, injection molding process and material raw materials 措置几方面, 谈谈应 positive 视 事项.
　　（一） raw materials and drying due to in plastics in has 任何一点杂质, can can effect/influence material transparent degree, is and 储存, 运输, add material process in, must positive 视密封, raw materials dry 净. is raw materials in has water separation, add hot rear 会激发 raw materials 变质, therefore need drying, in injection molding 时, add material must as drying material 斗. also need positive 视一点 is drying process in, 输入 空 gas most good 应经 滤, remove wet, 以便保障不会传染 raw materials.
　　（二） machine 筒, screw and its parts dry 净
　　 is anti raw materials and in screw and parts 凹陷处存 has material or 杂质, hot property resin in, is in as front, machine rear as screw agent dry parts, make its viscous has 杂质, has screw agent 时, can use PE, PS and other resin screw. 当姑且停 machine 时, is anti raw materials in low temperature lower 勾留时刻 long, understanding drop, will drying machine and machine temperature degree drop 落, 如 PC, PMMA and other machine temperature degree need drop 至 160℃ below/following. （ material temperature degree for/regarding PC应 drop 至100℃ below/following ）
　　（三） in mold design upper positive issues issues （搜罗产 material design ）
　　 is 不闪现回勾当不畅, or cooling 不均造 formed plastics molding defect, generate 概况毛病舛误 and 变质, in mold design 时, positive below/following 几点.
　　a）壁 thick can can uniform 一致, demolding degree need large;
　　b） 渡部 separation 应逐步. slip 渡, anti has 尖角. generate, is PC产 material 必定不 need has 缺口;
　　c） gate. runner can can 恢弘, coarse short, 且应遵守 shrink short cold process gate 位, need add cold material 井;
　　d） mold 概况应 light 洁, coarse degree low （ most good low 于0.8）;
　　e）排 gas 孔. must 足够, 以实时排出空 gas and 熔 体 in gas 体;
　　f） remove PET outer, thick need thin, small 于lmm.
　　（四） injection molding process 方面应 positive issues issues (搜罗 injection molding machine 请求）
　　 is decrease internal stress and quality 毛病舛误, in injection molding process 方面应 positive below/following 几方面 issues issues.
　　a）应 selection specialized screw, belt/tape temperature 控射咀 injection molding machine;
　　b) injection temperature degree in plastics resin separation conditions lower, use relatively high injection wet degree;
　　c） injection pressure: relatively high, 以克服熔 material viscosity large 毛病舛误, pressure high generate internal stress formed demolding difficult and deformation;
　　d） injection speed degree: in meet/satisfy 充模 景象 lower, low, most good can using/adopting slow - fast - slow more grade 注 射;
　　e） holding pressure and molding cycle: in meet/satisfy material 充模, generate 凹陷, bubbles lower; can can short, can can decrease low material in machine 筒勾留时刻;
　　f） screw speed and back pressure: in meet/satisfy quality conditions lower, can can low, anti generate understanding drop can can;
　　g） mold temperature degree: products cooling 吵嘴, for quality effect/influence large, therefore mold temperature need can 切确节 made its process, has can can 话, mold temperature high good.
　　（五） other issues issues
　　 due to is need anti upper quality good 转, injection molding can can less use demolding agent; use use material large 20％.
　　 for/regarding remove PET outer, products 都应进行 rear 措置, 以消弭 internal stress, PMMA应 in 70－80T hot ring drying 4 small 时; PC应 in dry gas, 甘油. liquid 体石腊 and other add hot 110－135℃, 时刻按产 material 而定, most high need 10 more small 时. 而PET必 must di toward tensile 工序, dry obtain mechanical properties.
　　3, transparent plastics injection molding process
　　（一） transparent plastics process features: remove above combined issues issues, transparent plastics has process features, separation below/following:
　　1, PMMA process features
　　PMMA viscosity large, property 稍差, is must high material temperature, high injection pressure injection molding 才行, its in injection temperature degree effect/influence large injection pressure, injection pressure front 进, has 益于改良产 material shrink short rate. injection temperature degree relatively wide, melt temperature degree is 160℃, separation temperature degree 达270℃, is material temperature agent wide, process property relatively good. 故改良勾当 property, can from injection temperature degree 手. impact property 差, wear resistance good, easy 划花, easy 脆裂, front mold temperature, cold process, this 毛病舛误.
　　2, PC process features
　　PC viscosity large, melt material temperature degree high, property 差, 回此必 must relatively low temperature degree injection molding （270－320T之 间）, versus for material temperature agent relatively narrow, process property 不如PMMA. injection pressure for property effect/influence relatively small, viscosity large, still need relatively large injection pressure, is internal stress generate, holding pressure need can can short. shrink short rate large, dimensions 不变, material internal stress large, easy cracking, therefore use front temperature degree is pressure 改良勾当 property, but also 夙昔进 mold temperature degree, mold structure and rear 措置 削 decrease cracking can can. injection speed degree low 时, gate easy 生波纹 and other 毛病舛误, 放射咀 temperature degree need 孤立节 made, mold temperature degree need high, runner, gate retardant force need small.
　　3, PET process features
　　PET molding temperature degree high, material temperature agent narrow （260－300℃）, melt rear, property good, process property 差, 且常常 in in need add anti 延流拆卸. machine strong/high degree and property can injection rear high, must process tensile and modified dry property can. mold temperature degree 切确节 made, is anti warpage. deformation important formed separation, is 以倡议 using/adopting hot runner mold. mold temperature degree high, 否则会激发概况 gloss and demolding 坚苦.
　　4, transparent plastics parts 毛病舛误
　　 due to 篇幅关系, this 里 构 and effect/influence material transparent degree 毛病舛误, other 毛病舛误请参考产 material 申明书 or other material. its 毛病舛误概况 has below/following 几项:
　　 transparent material 毛病舛误 and 克服编 made:
　　（一）银纹: 由充模 and cold process in, internal stress toward property effect/influence, 垂直标 方针 generate force, make resin generate upper orientation, and non orientation generate light rate separation 歧而生闪 light filament 纹, its expand large rear, can can make material cracks. remove in injection molding process and mold upper positive outer （见 table/sheet, most good material as 退火措置. 如pc material can add hot to 160℃ above 连结3～5 separation 钟, again cooling can.
　　（二） bubbles: resin inner water gas and other gas 体排不出, （ in mold cold process in ） or 因充模不足, cold 凝概况 also fast cold 凝而组 formed “ true 空泡”.
　　（三）概况 gloss 差: mold coarse degree large, in addition 一方面 cold 凝 早, make resin can mold 概况 状态, has this make its 概况产牛藐 small 凹凸不服, make material 失墓庠蟆
　　（四）震纹: is from gate is core formed 密集波纹, its 启事因 melt viscosity large, front material already in type cold 凝, rear material also 攻破此 cold 凝面, make 概况闪现震纹.
　　（五）泛白. 雾晕: important due to in gas in 尘埃落入 raw materials or raw materials water amount large 而激发.
　　（六）白烟. 斑点: important due to plastics in machine inner, separation hot make machine resin generate separation or 变质而组 formed.

GF40% 直链 type PPS C-1040SC Idemitsu