There may be one or more reasons for the shrinkage of plastic barrels, including processing methods, the shape of parts, selection of materials, and mold design. Some of these shapes and data selection are usually determined by the original data provider and are not easily changed. But there are still many factors about mold design that can affect shortening. Cooling runner design, gate type, and gate size can have multiple effects. For example, small gates such as tube gates cool much faster than tapered gates. Premature cooling at the gate will reduce the filling time in the cavity and increase the chance of shrink marks. Regarding molding workers, adjusting processing conditions is one way to solve the shortening problem.
In addition, the filling pressure and time of the plastic bucket also affect the shortening. After the part is filled, the excess data is continuously filled into the cavity to compensate for the shortening of the data. This method may not reduce the shrinkage mark to a satisfactory level, but the molding worker can adjust the filling conditions to improve the shrinkage mark.https://www.fhpails.com/