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Vietnamese In injection mold manufacturing, ensuring that molds are made to the required dimensions is fundamental. However, even with fixed mold dimensions, the actual size of the product can vary due to differences in shrinkage rates. Controlling shrinkage is particularly crucial in precision injection molding processes.
Factors Affecting Shrinkage
The design of the mold plays a key role in determining the shrinkage rate, and variations in resin batches can also lead to changes in shrinkage. Additionally, changes in pigments can affect the shrinkage rate. Differences in molding machines, the settings of molding conditions, their reproducibility, and fluctuations in actions during molding cycles further complicate the control of actual shrinkage rates.
Runner and Gate Balancing
As mentioned, shrinkage can vary with changes in resin pressure. In multi-gate single-cavity molds or multi-cavity molds, achieving gate balance is necessary to ensure consistent filling. The resin flow is closely related to the resistance within the runners, so ensuring runner balance should be the first step before balancing the gates.
Cavity Arrangement
To simplify the setting of molding conditions, special attention must be given to the arrangement of mold cavities. Molten resin transfers heat within the mold, and typically, the mold’s temperature distribution forms concentric circles centered around the gate. Therefore, when arranging cavities in a multi-cavity mold, it is essential to ensure both runner balance and a concentric cavity arrangement to achieve optimal results.
DAYIN Plastic Products Co., Ltd. specializes in home appliance mold manufacturing and provides OEM/ODM services, aiming to be a comprehensive solution provider for both R&D and manufacturing. Our product portfolio includes robotic vacuums, plastic tableware, and electronic dartboards. With 30 years of mold development experience, over 50 R&D professionals, and more than 100 injection molding machines, we are committed to delivering high-quality manufacturing services and creating greater value for our customers.