The key technical parameters of an injection molding machine serve as the core metrics for assessing equipment performance and its alignment with production requirements; they directly determine processing capacity, molding precision, and production efficiency, while also serving as a crucial basis for equipment selection and commissioning.
Clamping force is a critical parameter, measured in kilonewtons (KN); its function is to securely lock the mold during injection, thereby counteracting mold-expansion forces and preventing material overflow. Proper selection requires careful matching of the specific product and mold; insufficient clamping force can easily lead to flashing, whereas excessive force results in increased energy consumption and accelerated equipment wear.
Theoretical shot weight (unit: g/cm³) refers to the maximum amount of molten material that can be injected at one time, determining the maximum size and weight of processable products. The selection should be 1.1-1.3 times the product weight; insufficient shot weight will cause material shortage, while excessive shot weight is likely to cause raw material waste and melt decomposition.
Injection pressure (unit: MPa) has a range of 100-250 MPa (up to more than 300 MPa for precision models). It is used to overcome the flow resistance of molten material and ensure complete mold filling, especially suitable for thin-walled and precision products. Too low pressure is prone to material shortage, while too high pressure will increase internal stress and damage equipment, usually set in segments.
Injection speed (unit: mm/s) determines the speed of melt filling, affecting product quality and efficiency. High speed is suitable for thin-walled and complex products, but too fast speed is prone to bubbles; low speed is suitable for thick-walled products, but too slow speed is prone to material shortage, usually adopting "slow-fast-slow" segmental control.
Mold opening stroke and mold thickness are key parameters for mold adaptation. The mold opening stroke must meet the mold height and product ejection requirements, and the mold thickness must be within the allowable range of the equipment; otherwise, normal mold clamping and production cannot be carried out. The mold parameters must be confirmed in advance during selection.
Repeatability (usually ≤±0.1%, up to ±0.05% for high-end models) measures the consistency of batch molding, directly affecting product qualification rate, and is the key for selection in precision fields such as electronics and medical care.
In addition, parameters such as back pressure and screw speed also affect molding quality and need to be adjusted based on core parameters. During selection and commissioning, comprehensively matching products, plastics and molds can give full play to equipment performance.
