1. Flow marks or wavy lines appear on the surface of TPE/TPR injection molded products.

　　Causes.

　　(1) Insufficient pressure-holding. It can be solved by increasing the injection pressure, holding pressure, holding time, melt glue amount, etc.

　　(2) Low mold temperature and material temperature. Can be solved by increasing the mold temperature and barrel temperature.

　　2. TPE/TPR injection molding products are prone to bubbles

　　Reasons.

　　(1) The air wrapped in the melt, the injection pressure is too small or the time is too short, the air wrapped in the injection process is not completely discharged and remains in the product. This situation can be solved by increasing the back pressure, injection pressure, holding pressure and holding time.

　　(2) The raw materials contain moisture or small molecule impurities, which are heated into gas residue in the products during the injection process and form bubbles. This can be solved by thoroughly drying the material.

　　(3) The mold design is not reasonable, such as incorrect gate position or too small gate, long and narrow main flow and manifold. It is necessary to design the mold structure reasonably.

　　(4) Process reasons: the molding temperature is too high or the molding cycle is too long. The molding temperature and molding cycle can be reduced appropriately.

　　3.TPE/TPR injection molding products warp and deformation

　　Reasons.

　　(1) The mold filling speed is too slow and the orientation is too large, so the mold filling should be accelerated.

　　(2) The injection pressure is too small and the holding time is too short.

　　(3) The molecular weight distribution of the material is too wide, and the anisotropy is large when cooling and shrinking.

　　(4) The thickness of the product itself is uneven and heterogeneous.

　　(5) Defective cooling system of the mold, uneven cooling or cooling is not in place.

　　(6) Uneven force during demoulding.

　　(7) The location of the mold gate is not reasonable, for example, the gate is opened in a thin place, causing a high internal stress, resulting in warpage.

　　(8) The processing temperature is too high, and there is still a large thermal shrinkage after demolding.