Injection pressure: The melt overcomes the resistance needed to advance, which directly affects the size, weight and deformation of the product. Different plastic products require different injection pressures. For materials such as PA and PP, increasing the pressure will significantly improve its fluidity The injection pressure determines the density of the product, that is, the appearance of gloss. It does not have a fixed value, and the more difficult it is to fill the mold, the higher the pressure of the injection molded part.