The time required to complete an plastic injection molding process is called the molding cycle, also known as the molding cycle.It actually includes the following parts:
Molding cycle: The molding cycle directly affects labor productivity and equipment utilization.Therefore, in the production process, the relevant time in the molding cycle should be shortened as much as possible under the premise of ensuring quality.In the entire molding cycle, the injection time and cooling time are the most important, they all have a decisive impact on the quality of the product.The filling time in the injection time is directly inversely proportional to the filling rate, and the filling time in production is generally about 3-5 seconds.The holding pressure time in the injection time is the pressure time for the plastic in the cavity, and it accounts for a large proportion in the entire injection time, generally about 20-120 seconds (extra-thick parts can be as high as 5-10 minutes).
Before the melted material at the gate is sealed, the holding time has an impact on the accuracy of the product size, if it is later, it will have no impact.The holding time also has the most favorable value, which is known to depend on the material temperature, mold temperature, and the size of the main runner and gate.If the dimensions of the sprue and the gate and the process conditions are normal, usually the pressure value that obtains the smallest fluctuation range of the product shrinkage rate shall prevail.The cooling time is mainly determined by the thickness of the product, the thermal and crystalline properties of the plastic, and the mold temperature.The end of the cooling time should be based on the principle of ensuring that no changes are caused when the product is demolded. The cooling time is generally between 30 and 120 seconds. It is not necessary for the cooling time to be too long. It will not only reduce production efficiency, but also affect complex parts.It is difficult to demold, and demoulding stress may even occur when demolding forcefully.The other time in the molding cycle is related to whether the production process is continuous and automated, and the degree of continuity and automation.