Shanghai Daoqin Plastics Co., Ltd.

         injection molding products surface can defect dark 斑, gloss or 者雾化区, and surface or by as orange peel. usually this defect in gate or 者远离 gate 区域 尖锐转角 rear 面. from mold and molding process 两方面 手, can 够找出 generate this defect causes.

         products upper dark 斑

         dark 斑出现 in gate 附近, 就像昏 dark day 晕. in production high viscosity, low flow property material products 时, 如PC, PMMA or 者ABS时尤 is obvious. in cooling surface resin by in flow resin belt/tape 走时, products surface can can this type of can defect.

        人们 usually this type of defect frequency 繁发生 in and holding pressure stage/phase. upper, dark 斑出现 in gate 附近, usually in injection cycle stage/phase. experiment/testing table/sheet 明, table/sheet slip 移 发生实际 upper need 归因于 injection speed degree, more 确切 说 is melt front flow speed degree.

         gate dark and in 尖锐 转角形 formed rear dark 斑, is due to injection speed degree high, cooling surface by internal belt/tape 动发生移位而 generate. increase injection speed degree separation injection can 够客服此 defect.

        即 make melt mold injection speed degree is 恒定, it flow speed degree 也会发生变化. in mold gate 区域时, melt speed very high, is mold cavity rear 即充模 stage/phase, melt speed decline. melt front speed this type of 变化会 belt/tape products surface defects.

         decrease small injection speed degree is solution this issues types methods. is reduce gate melt front speed degree, can will injection separation formed several steps 进行, 并逐渐 increase injection speed degree, its is in 整 充模 stage/phase obtain melt speed.

         low melt temperature degree is products generate dark 斑 另一 causes. improve/increase machine temperature degree, improve/increase screw back pressure can decrease/reduce this type of phenomenon 发生 几 rate. another, mold temperature degree low generate surface defects, therefore improve/increase mold temperature degree is products surface defects can 行 办 method.

         mold design defect in gate generate dark 斑. gate 处尖锐 转角 can through semi 径 避免, in design need gate and 直径, gate design is combined 适.

         dark 斑不但会发生 in gate 位置, but also 也经常会 in products 尖锐 转角形 formed rear 出现. 例如, products 尖锐转角 surface generally non light slip, is in its rear non dark coarse 糙. this is due to high speed and injection speed degree make cooling surface by internal 流体取代发生 sliding formed.

         again recommendation using/adopting separation injection 并逐渐 increase injection speed degree. most methods is melt is in 流 锐角边缘 rear its speed degree 才开始 increase.

         in gate 区域, products 发生角 degree 尖锐变化也会造 formed this type of defect. therefore design products need in that use more is slip 圆角 渡.

         improvement gloss 差异

         for/regarding injection molding products 说, in has products surface, its gloss different is most is obvious. make mold surface separation uniform, 不规则 gloss can can in products upper. is 说, products certain mold surface 效果没 has very good heavy 现.

        随 melt gate 距离逐渐 increase, melt injection pressure reduce. if products gate 远端不 can by 充满, that 么该处 pressure is most low, from make mold surface 纹理不 can by positive 确 复 made to products surface upper. therefore, in mold cavity pressure most large 区域(from gate 开始 流体路径 一 semi) is most less gloss 差异 区域.

         need this type of 状况, can improve/increase melt and mold temperature degree or improve/increase pressure, meanwhile increase holding pressure time can decrease/reduce gloss generate.

         products good design can decrease/reduce gloss 差异出现 几 rate. 例如, products thick 剧烈变化 can formed melt 不规则 flow, from formed mold surface difficult by made to products surface. therefore, design uniform thick can decrease/reduce this type of 状况 发生, large thick or large 肋筋会 increase gloss generate rate. another, melt separation gas is formed defect causes.

         orange peel 起源

        “ orange peel ” or surface defect generally in use high viscosity material molding thick products runner 末端. in injection process in, melt flow speed degree low, products surface speed solid 化. flow retardant force add large, melt front will non-uniform, make solid outer material can and type 腔壁充 separation 接触, from generate 皱褶.

         this 皱褶经 solid and holding pressure rear 就会变 formed can remove defect. for/regarding defect, solution methods is improve/increase melt temperature degree and improve/increase injection speed degree.