There may be one or more reasons for forming a plastic hook to process shrinkage marks, including processing methods, component geometries, material selection, and mold design. The geometry and material selection is usually determined by the raw material supplier and is not easily changed. However, there are a lot of mold manufacturers on the mold design factors may affect the plastic hook processing contraction link. The cooling runner design, gate type, gate size can have a variety of effects. For example, a small gate, such as a tubular gate, cools much faster than a conical gate. Premature cooling at the gate reduces the filling time in the cavity, thus increasing the chance of shrinkage marks. For the molding workers, adjusting the processing conditions is a method to solve the shrinkage problem of plastic hook processing. Filling pressure and time significantly affect shrinkage. After the part is filled, the excess material continues to fill the cavity with the shrinkage of the compensating material. Too short a filling phase will cause shrinkage to intensify, resulting in more or larger shrinkage marks. This solution to the plastic shrinkage method itself may not reduce the shrinkage mark to a satisfactory level, but the molding worker can adjust the fill condition to improve the shrinkage mark.