How To Reduce Injection Molding Cycle Time?

The injection molding cycle directly affects labor productivity and equipment utilization. Therefore, in the injection molding manufacturing, on the premise of ensuring the quality of plastic parts, the relevant time in the molding cycle should be shortened as much as possible. Injection time and cooling time are critical throughout the injection molding cycle and they have a decisive influence on the quality of injection molded parts.

Injection time: injection time includes feed time and hold time. The feeding time refers to the time for the screw to advance rapidly to push the plasticized molten material into the mold. The time required to fill the cavity is usually 3 to 5 seconds. For plastic parts with high melt viscosities and fast cooling rates, fast injection should be used to reduce the melt feed time. The holding time refers to the residence time after the screw advances and is injected, that is, the cooling time of the molten material entering the cavity and the supply time of the injection pressure. During this injection time, the proportion of time is relatively large, usually about 20 to 120 s. Plastic parts are simple in shape, small in size, and short in holding time. If the larger plastic part and wall thickness are larger, the holding time is longer.

Cooling time: Cooling time refers to the cooling and solidification time of plastic parts after filling the melt. The cooling time is related to the thickness of plastic parts, material properties and mold temperature. In general, the shorter the time, the better the plastic parts are not deformed during demolding. The cooling time of plastic parts is usually in the range of 30 to 120 s.

Reducing the cycle time of injection molding can help reduce the cost of manufacturing plastic parts. It enables injection molding machines to produce more products simultaneously with the same energy consumption. But how can we reduce the cycle time of injection molding?

1. Use high-speed injection molding machine

The injection molding machine has the following steps: melting plastic, injection molding, mold opening, mold clamping and demolding. The function of the injection molding machine itself is one of the main reasons affecting the cycle time of injection molding. High-speed injection molding machines have many advantages in terms of speed.

Make sure the mold structure is simple and easy to process, in other words, make the mold design as difficult as possible. Most molds can be designed in different ways, and there are many ways to demold. Simplified mold design reduces cycle time for injection molding.

2. Use a good cooling system.

Cool the mold with cold water. In addition to wasting time during the injection molding process, cooling also takes up a significant amount of injection molding cycle time. Therefore, the use of low-temperature cooling water and the rapid passage of cooling water through the cooling system help reduce the cycle time during the injection molding process.