产品造型与模具设计

1） 产品造型

K料是无定型聚合物，不会结晶，因此，收缩率较小，而实际收缩率取决于产品设计和加工参数，厚的截面收缩率大于薄的截面，沿流动方向的收缩率大于垂直方向。此外，大部分注塑制品的翘曲现象是由于相邻截面的收缩率不同而引起。所以，在产品造型设计时，要综合考虑这些因素。在允许的前提下，制品壁厚尽可能取大些，各处壁厚尽可能均匀，不要相差太大。这样有利于注塑加工，并能得到良好的制品质量。

2） 脱模斜度与顶出系统

K料制品的表面较光滑，容易粘附在高度抛光的模具上，特别是深模的模芯。因此，在模具设计时脱模斜度应取较大值，一般大于3°，由于K料制品的粘模性，生产过程会出现脱模困难，故模具设计时，尽量使顶出力均匀分布在整个制品上，对于几何形状规则或大面积平整的制品，如杯、瓶、盒子等好采用脱模板或脱模环。对于形状不规则的制品，尽可能采用直径较大的顶针或采用数量较多的顶针，以增加有效顶出面积。

3） 流道

K料的注塑加工，可采用各种冷流道和热流道，流道设计时，必须避免死角位，流道截面可取较大值，热流道的加热器必须安装能控制的温度控制器，以免胶料因滞留、剪切过量、温度失控而引起的降解，影响制品的质量。

Product Modeling and die design 1) product modeling k material is an amorphous polymer, will not crystallize, therefore, the shrinkage rate is small, and the actual shrinkage rate depends on the product design and processing parameters, the thick section shrinkage rate is greater than the thin section, along the flow direction shrinkage rate is greater than the vertical direction. In addition, most of the warpage phenomenon of injection molding products is due to the shrinkage of adjacent cross-sections caused by different. Therefore, in product modeling design, we should consider these factors. Under the premise of allowing, the product wall thickness as large as possible, wall thickness as uniform as possible, do not vary too much. This is conducive to injection molding, and can get good product 2) the slant of demoulding and the surface of ejecting system K products are smooth and easy to adhere to highly polished molds, especially the core of deep molds. Therefore, in the mold design, the release angle should take a larger value, generally greater than 3 ° , because of the stickiness of K material products, the production process will be difficult to release the mold, so when the mold design, try to make the ejection force evenly distributed in the entire product, for the geometric shape of regular or large area of flat products, such as cups, bottles, boxes and so on to use the release plate or release ring. For products with irregular shape, larger diameter ejector pins or larger number of ejector pins should be used as far as possible to increase the effective ejector area. 3) all kinds of cold runner and hot runner can be used in the injection molding of runner K material. When the runner is designed, the dead angle must be avoided, and the section of the runner can be larger. The heater of the hot runner must be installed with a temperature controller that can be controlled, so as to avoid the degradation of the rubber material caused by retention, excessive shear and out of control of temperature, which will affect the of the products.