Shanghai Daoqin Plastics Co., Ltd.

        当 melt in high speed, high pressure conditions lower 注入容积 relatively large type 腔时, easy generate melt phenomenon, 此时, melt surface 出现横 toward fracture, fracture is coarse 糙 夹杂 in parts table/sheet formed 糊斑. especially is a small amount of material 直接注入容 easy large type 腔时, melt more is heavy, 呈现 糊斑也就越 large.

         melt essence is due to high poly material material elastic property is generate, material in material in flow 时, material 筒附近 熔 material to abrasion scratch, anionic force relatively large, material flow speed degree relatively small, material from nozzle 注出, tube/pipe function anionic force 消失, material in 部 熔 material speed high, 筒壁处 熔 material by in 心处 熔 material belt/tape accelerated, due to material flow is versus for 连续, inner outer material flow speed degree will heavy new 排列, 趋于平均 speed degree.

         in process in, material will 发生急剧 应 force will generate 应变, injection speed degree fast, to force especially large, large material can force, melt 破裂.

         if material in runner in has 突然 形状变化, 如直径 shrinkage, expand large and 出现死角 and other, material in 死角处停留 and ring, it and positive material force different, 剪切形变 relatively large, its mixed positive material in 注出时, due to 两者 形变恢复不一致, can combined, 若悬殊 very large, 则发生 fracture 破裂, its performance 形式也 is melt 破裂.

        由 upper can 知, need 克服困 melt 破裂, generate 糊斑:

        一 is need attention/notes remove runner in 死角, make runner amount 流线化;

        二 is improve/increase material temperature, decrease/reduce material time, make its 形变容 easy and combined;

        三 is in raw materials in add low separation material, is material molecular weight low, distribution wide, has decrease light elastic property 效应;

        四 is control injection speed degree and screw speed;

        五 is combined 理设置 gate and selection positive gate 形式, this versus important, table/sheet 明, using/adopting expand large type gate, gate (隧道 gate) relatively is 理想. gate most good selection in material 先注入 渡腔 rear again relatively large 容腔, need make material 直接进入 relatively large 容腔.