Shanghai Daoqin Plastics Co., Ltd.

        发脆 is made parts in certain 部位出现容 easy cracking or 折断. main/primary is due to material degradation 而导致 large separation 子断链, reduce large separation versus for separation quality, from make polymer overall physical properties decline.

         products very large separation is due to internal stress formed. formed products causes very more, main/primary has:

        1, equipment 方面

        (1) machine inner has understanding or material, easy 引起熔 material degradation.

        (2) machine 塑化容 amount small, plastics in machine inner 塑化不充 separation; machine 塑化容 amount large, plastics in machine inner hot and 受剪切 function time long, plastics easy aging, make products 发脆.

        (3) ejection plant/unit or balanced, 顶杆截面积 or distribution 不当.

        2, mold 方面

        (1) gate small, 应考虑 adjustment gate dimensions or increase 设辅助 gate.

        (2) separation runner small or 配置不当, amount balanced combined combined or increase separation runner dimensions.

        (3) mold structure defect formed injection molding cycle 反常.

        3, process 方面

        (1) machine 筒, nozzle temperature degree low, high. if material material easy degradation, improve/increase machine 筒, nozzle temperature degree.

        (2) reduce screw back pressure pressure and speed, make material is hydrophobic 松, decrease/reduce plastics 因剪切 hot formed degradation.

        (3) mold temperature high, demolding difficult; mold temperature low, plastics cooling, 熔接缝 melt combined defect, easy cracking, especially is high melting point plastics polycarbonate (PC) and other more is 如此.

        (4) type type need has demolding degree. type difficult demolding 时, need improve/increase type temperature degree, shrink short cooling time 爱你; type difficult demolding 时, need reduce type temperature degree, long cooling time.

        (5) amount less use metal parts, polystyrene (PS) this category of property cold hot ratio large plastics, more can add parts injection molding.

        4, raw materials 方面

        (1) raw materials mixed has other or 者掺杂 不适当 or amount solvent agent or other additives.

        (2) has plastics 如ABS and other, in 受潮 情况 lower add hot and water gas catalytic reaction, make made parts large 应变.

        (3) plastics recycled 次数太 more or recycled material content high, or in machine inner add hot time long, 都会促 make made parts 脆裂.

        (4) plastics quality 不佳, versus for separation quality distribution large, has rigid property separation and other non-uniform structure formed separation has amount large; or other plastics 掺杂污染, defect additives 污染, 灰尘杂质污染 and other is formed causes.

        5, products design 方面

        (1) products belt/tape has easy 出现应 force cracking 尖角, or thick degree versus very large 部位.

        (2) products design thin or 镂空太 more.

        改进 methods

        材 material -- injection molding front 设置适当 drying conditions; plastics if drying active drying temperature degree high, tube/pipe can remove volatile content and other material 质, meanwhile easy 导致材 material degradation, especially is hot property material.

         decrease/reduce use recycling material, increase material ratio/proportion; selection high strength plastics, mold design, add large runner, separation runner and gate dimensions, small runner, separation runner or gate easy more hot, from 而导致 polymer separation understanding;

         injection molding machine -- selection design good screw, make 塑化时 temperature degree separation more add uniform. if material temperature degree 不均, in local easy poly more hot amount, 导致材 material degradation.

         process conditions -- reduce material and nozzle temperature degree;

         reduce back pressure, screw speed and injection molding speed degree, decrease/reduce more hot generate, polymer separation understanding; if is understanding strong/high degree 不足导致 发脆, can through increase melt temperature degree, add large injection molding pressure methods, improve/increase understanding strong/high degree.