First, the two-color injection molding machine consists of two sets of plastic injection devices with the same structure and specifications. The nozzles need to have a special structure according to the production method, or two sets of molding dies having the same structure that can be rotated and transposed.
When plasticizing injection, the process parameters such as melt temperature, injection pressure and injection melt amount in the two sets of plasticizing injection devices are required to be the same, and the fluctuation of process parameters in the two sets of devices should be minimized.
Second, the two-color injection molded plastic products have higher parameter values for the melt temperature and the injection pressure at the time of injection than the conventional injection molded plastic products. The main reason is that the mold flow path in the two-color injection molding is relatively long, the structure is relatively complicated, and the flow resistance of the injection melt is large.
Third, the two-color injection molding plastic products should use raw materials with good thermal stability and low melt viscosity to avoid decomposition due to high temperature of the melt and long residence time in the flow channel. The plastics used in many applications are polyolefin resins, polystyrene and ABS materials.
Fourth, in the injection molding, in order to make the melt of two different colors can be well welded in the mold during molding, and to ensure the molding quality of the injection molded product, a higher melt temperature and a higher temperature should be adopted. Mold temperature, high injection pressure and injection rate.