Analysis of plastic injection molding conditions

In injection mold design and production, injection molding has the following three points:

1, mold temperature. Mold temperature is one of the key factors affecting the molding. Generally, the mold temperature is higher than that of micro-filling. Unbalanced mold temperature will seriously affect filling. Therefore, it is necessary to periodically change the cooling water and clean the mold waterway in mass production.

2, molding time. If the holding pressure is too high and the holding time is too long, it will cause whitening, cracking, and surface inequality defects when the through-hole region of the product is demolded.

3, the material is warmed up. Dry before injection, especially the glossy plastic parts should require long-term preheating and drying.

Since the mold temperature has a great influence on the mold shrinkage, and it also directly affects the mechanical properties of the injection molded product, the mold must be kept within the specified temperature range, and the mold temperature must not change with time. The temperature difference between the cavities of the multi-cavity mold must not change. To this end, temperature control measures must be taken in the mold design to heat or cool the mold, and in order to minimize the temperature difference between the mold cavities, the design of the cooling circuit must be taken into consideration. Generally, a cooling water circuit can be separately provided for each cavity, and a flow control device can be provided at the outlet of each cavity cooling water circuit.