Shanghai Daoqin Plastics Co., Ltd.

         cracking, made parts surface filament cracks, micro 裂, 顶白, cracking and made parts mold sticking, runner mold sticking formed or 创伤危 machine, cracking time separation demolding cracking and application cracking. main/primary has below/following several causes formed:

        1． processing 方面:

        (1) processing pressure large, speed degree fast, material more, injection, holding pressure time long, 都会造 formed internal stress large cracking.

        (2) adjustment mold opening speed degree and pressure anti fast speed strong/high made parts formed demolding cracking.

        (3)适当调 high mold temperature degree, make made parts easy demolding, 适当调 low material temperature anti separation understanding.

        (4)预 anti due to 熔接痕, plastics degradation formed machine strong/high degree low 而出现 cracking.

        (5)适当 use demolding agent, attention/notes 经常消 remove 模面附 gas and other material 质.

        (6) made parts residual stress, can through in molding rear 立即进行退火 hot 处理 消 remove internal stress decrease/reduce cracks formed.

        2． mold 方面:

        (1) ejection need balanced, 如顶杆数 amount, 截面积 need 足够, demolding degree need 足够, type need has light slip, this anti due to outer force ejection residual stress in cracking.

        (2) made parts structure can thin, 渡部份应尽 amount using/adopting 圆弧 渡, 避免尖角, 倒角造 formed force in.

        (3)尽 amount less use metal parts, anti parts and made parts shrinkage rate different formed internal stress add large.

        (4) for deep made parts 应设置适当 demolding gas 孔道, anti formed true negative pressure.

        (5)主 runner large make gate material future and solid demolding, this easy demolding.

        (6)主 runner sleeve/set and nozzle combined anti cold hard material 拖拉而 make made parts viscous in upper.

        3．材 material 方面:

        (1) recycled material content high, formed made parts strong/high degree low.

        (2) wet degree large, formed plastics and water 汽发生 chemical reaction, reduce strong/high degree 而出现 ejection cracking.

        (3)材 material 本身不适宜 positive in processing ring or quality 欠佳, to 污染都会造 formed cracking.

        4． machine 台方面:

         injection molding machine 塑化容 amount need 适当, small 塑化不充 separation can full mixed combined 而变脆, large degradation.