Lack of glue, also known as insufficient filling, is one of the common problems in the process of injection molding. The injection molding part is not full, and the existing bubbles, cavities, shrinkage holes, etc. are inconsistent with the standard template, which is called lack of glue. So how to solve itPlastic shellWhat about the lack of glue?

The following are the reasons for the lack of glue in the plastic shell and its improvement measures:

① Mold: a. the design of the gating system is unreasonable. The gating system is the channel for the melt to enter the mold cavity, which has a great impact on the molding quality of the plastic parts. The gate is not parallel and the gate is not located at the wall thickness; b. The exhaust structure of the mold is poor; c. Impurities or cold materials in the melt block the flow channel; d. Mold temperature does not meet the requirements. Improvement measures: improve the pouring system, increase the exhaust of the mold, remove the impurities of the compound, and increase the mold temperature.

② Raw materials: a. the water content of raw materials is too large; b. Volatile substances in raw materials exceed the standard; c. There are too many impurities or recycled materials in the raw materials. Improvement measures: barbecue raw materials and increase raw materials.

③ Injection molding machine: A. insufficient injection quantity: for example, 180t products are produced by 150t machines. b. The nozzle is blocked by foreign matters and the nozzle hole is too small; c. Insufficient supply of raw materials: if the barrel is blocked, the nozzle material will affect the blanking; d. Check valve failure; e. Insufficient injection stroke. Improvement measures: increase the injection volume and increase the injection stroke.

④ Molding operation: A. mold temperature is too low; b. The injection pressure is too low; c. The pressure holding time is too short; d. The injection speed is too slow; e. The melt temperature is too low. Improvement measures: increase the mold temperature, increase the injection pressure, maintain the pressure time, and improve the injection speed.