Shanghai Daoqin Plastics Co., Ltd.

　 in injection molding processing upper, water control and molding processing conditions selection is effect/influence molding product quality most important factors, separation lower: water control

　　PC type plastics make to non low water 份亦会 generate hydrolysis 而断键, molecular weight reduce and material property strong/high degree reduce phenomenon. therefore in molding processing front, 应严格 control polycarbonate (PC) water in 0.02% below/following, 以避免 molding product machine strong/high degree reduce or surface generate bubbles, and other 之异常 appearance. is water generate 异常之情况, polycarbonate (PC) in processing front, 应先经 hot drying machine drying 三至五 small above, temperature degree setting is 120℃, or remove temperature drying machine water 份, remove wet gas in 漏斗入口处应 has -30℃之露点. 　　 injection molding

　　 is meet/satisfy various injection molding process demand, polycarbonate (PC) has different melt flow index specifications. usually melt flow index 介于5至25g/10min皆 can suitable for injection molding. is its most processing conditions injection molding machine types type, molding product 之形状以 and polycarbonate (PC) specifications different, has versus 当之差异, based on 实际情形 add adjustment.

　　 injection molding machine selection key points

　　锁模 pressure:

　　以 formed product 投影面积每平方公 separation 乘0.47至0.78吨（ or 每平方寸乘3至5吨）.

　　 machine large small:
　　 formed product weight is injection molding machine amount 40至60% is most 佳, machine polystyrene (PS) table/sheet its amount (盎斯)时, decrease/reduce 10%, is use GUANG DA之容 amount. 1盎斯=28.3公克.

　　 screw:
　　 screw long degree most less has 15 直径 long, its L/D is 20: 1 most 佳. pressure shrink ratio is 1.5: 1至30: 1. screw front 端之止　　流阀应 using/adopting sliding ring 式, its resin can flow most less has 3.2MM.

　　 nozzle:
　　尖端开口 most less has 4.5MM(直径), formed product weight is 5.5KG above, nozzle 直径应 has 9.5MM above. another, 尖端开口需 ratio gate less 0.5至1MM, 且段道愈 short good, is 5MM.

　　 molding conditions key points:
　　熔 melt temperature degree and mold temperature:

　　 most molding temperature degree setting and very more factors has 关, injection molding machine large small, screw 组态, mold and molding product design and molding cycle time and other. generally 而言, is let plastics 渐渐 熔 melt, in material tube/pipe rear 段/进 material setting relatively low temperature degree, in material tube/pipe front setting relatively high temperature degree. screw design or L/D value small, toward temperature degree setting can.

　　 mold temperature 方面, high temperature can provide relatively surface appearance, 残留应 force relatively small, for relatively thin or relatively long molding product easy 填满. low mold temperature can shrink short molding cycle.

　　 screw speed degree:
　　建议40至70rpm, 但需视乎 machine and screw design adjustment.
　　 injection molding pressure: most high is speed mold, injection molding pressure large good, generally is 850至1, 400KG/CM2, can 达2, 400KG/CM2.

　　 back pressure:
　　 generally setting low good, is material uniform, use 3至14KG/CM2.

　　 injection molding speed degree:
　　射 speed and gate design has very large 关系, use gate or gate 时, is anti day phenomenon and flow marks phenomenon, application relatively slow speed. another, formed product thick degree in 5MM above, is bubbles or 凹陷, slow speed injection shot has 帮助. generally 而言, speed is thin fast, thick slow.

　　 from injection molding is holding pressure 之保, holding pressure need amount low, molding product 发生残留应 force. 而残留应 force can use methods remove or decrease light; conditions is 120至130℃约三十 separation 钟至一 small 时.

　　 material 筒清扫

（1） in polycarbonate (PC) molding temperature degree lower, add 入清洗 material (general purpose grade polystyrene (PS) or 透苯), injection shot
　　　二十至三十次.
（2） will machine rear 退, will material 空射, injection shot material 开始膨胀起泡.
（3） will material temperature degree heavy new setting to 200至230℃.
（4） 继续 will material 空射, to material temperature degree 达260℃且 outer table/sheet very dry 净透.