Unstable injection pressure: This situation is generally related to the nozzle hole of the injection molding machine being too small, because the nozzle is in long-term contact with the mold. The mold temperature is very low at 20-90 ℃, and the nozzle temperature is 240-280 ℃. There is a temperature difference between them, which inevitably leads to heat exchange. When the nozzle temperature drops below the melting point of nylon, the nozzle hole is frozen, and it will be pushed open by high pressure during the next injection, causing pressure loss and injection. However, after increasing the injection pressure, the mold will expand again after producing several molds. From the phenomenon, it appears that the injection molding machine is unstable, but in fact, the nozzle hole is too small. Increasing the nozzle hole will cause this phenomenon to disappear. PA POM ABS materials can cause problems.

Wave shaped flow marks: The mechanism of formation is that the flow rate of the adhesive material in the mold cavity is too slow, and the frozen adhesive material cannot adhere tightly to the mold. Solution: ⑴ Increase injection speed ⑵ Increase mold temperature ⑶ Increase barrel temperature ⑶ Increase nozzle aperture or gate appropriately

Silver wire: The mechanism of production is that there is gas in the plasticized material, which is forcibly pressed out on the surface of the mold during injection, resulting in white silk patterns on the surface of the product. Solution: ⑴ Check if the raw materials are damp or mixed with other materials ⑵ Check if the raw materials are decomposed in the barrel (barrel temperature is too high, screw speed is too fast) ⑶ Check if the nozzle hole is too small ⑶ Check if the mold temperature is too low ⑶ Check if the mold exhaust is poor ⑶ Check if the gate size is too small ⑶ Check if the back pressure is too low and if too much recycled material is used

Weld line: The mechanism of formation is that the temperature of the adhesive material at the end of the flow is very low, and the bonding is poor. The pressure transmission is weak, which makes the two streams of material not tightly bonded. Solution: ⑴ Increase injection pressure and speed ⑵ Increase mold temperature ⑶ Increase material temperature ⑶ Improve mold

Exhaust and shrinkage: The mechanism of production is the injection or shrinkage of the product. If it is a shrinkage, use the shrinkage method to solve it.

Focal spot: The mechanism of formation is that the rubber material occupies the mold cavity at high speed during injection. When the gas in the mold cavity cannot be eliminated in time, this part of the gas is compressed, and the compressed gas heats up, burning the product. Solution: ⑴ Reduce the injection speed or pressure ⑵ Reduce the melt temperature ⑶ Improve the mold exhaust ⑶ Reduce the clamping force ⑶ Increase the nozzle aperture

Poor demolding: Improper control of mold temperature leads to uneven shrinkage of various parts, resulting in uneven wrapping force. The residual stress caused by injection in the product is high, resulting in a large encapsulation force and making demolding difficult. The solution to this problem: ⑴ Reduce injection and holding pressure; ⑵ Reduce injection and holding time ⑶ Increase or decrease material temperature. ⑶ Raise or lower the mold temperature Check the draft angle of the mold

Warping deformation: The mechanism of occurrence is excessive internal stress and uneven shrinkage of the product.

Excessive internal stress in the product: ⑴ Reduce injection pressure, decrease injection time, decrease holding pressure, decrease holding time ⑵ Increase material temperature, increase mold temperature. Uneven shrinkage of products: ⑴ Reduce material temperature, lower mold temperature, and increase cooling time. ⑵ Increase injection pressure, increase injection time, increase holding pressure, and increase holding time.