There are three factors which are important to the injection molding process. These three factors are time, pressure and temperature. In this passage, we talk about time in injection molding process.

The time needed for one injection cycle is cycle time. The cycle time includes clamping time, injection time, holding time, cooling time in mould and other time.

1. Clamping time

Clamping time refers to the time for clamping mold in injection molding process. If the clamping time is too in injection molding, the mold temperature will be too low while molten plastic will stay in nozzle for too long time. If the clamping time is too short in injection molding, the mold temperature will be too high.

2.Injection time

Injection time means the time from when injection molding process begins to the time when melt plastic filling the cavity. 

In injection molding manufacturing, small plastic products only take about 3~5 seconds and large ones take about tens of seconds. The injection time has an inverse relationship with injection speed in injection molding process. Shorter injection time means faster injection speed.

3. Holding time 

Holding time refers to the time for continuing pressure on the plastic product ranging from 20 to 25 seconds or even 5~10 munities. If the holding time is too short in injection molding, plastic product will not be tight enough and cause dent and unstable size. But if the holding time is too long, the stress of product will be increased. It also will be more difficult to demoulded.

4. Cooling time in mould

Cooling time means the time from the finish of holding pressure to the time when mould is opened in injection molding process. Cooling time depends on the thickness of the product, thermal property of plastic and crystallization characteristics of plastic as well as mould temperature. The criterion of setting cooling time is to make sure it will not lead to distortion of products.

In injection molding process, many factors can influence the products. Temperature is just one of them. If you want to know more, please contact us (Dakuamr MAchinery Co., Ltd).

Edited by Cina Zhu

E-mail: dkm@dakumar.com;

Skype: sinomould-13