Cause and Solution of Plastic Product Brittle
What are the reasons and solutions for product brittleness during injection molding? After injection molding, the impact performance of plastic parts has decreased significantly compared with that of raw materials, which is commonly known as brittleness. The direct cause of brittleness is the excessive internal stress of plastic parts.
Unscrewing Plastic Injection Mold
1. Material
Before injection molding, set appropriate drying conditions. If the materials are dried for several days or the drying temperature is too high, although volatile matter and other substances can be removed, it will also lead to material explanation, especially for thermosensitive plastics. Next, reduce the use of recycled materials, increase the proportion of raw materials, select appropriate materials, and make high-strength plastics.
2. Mold design
Increase the size of the main runner, splitter runner and gate. Sharp corners of the runner should be avoided. Too small runner, splitter runner or gate size and sharpness will lead to polymer decomposition.
3. Injection molding machine
The appropriate screw should be selected, so that the temperature distribution during plasticizing is more uniform. If the temperature of the material is uneven, it is easy to accumulate too much heat locally, leading to the degradation of the material.
4. Process conditions
plastic injection products
First, reduce the temperature of the barrel and nozzle, back pressure, injection pressure, screw speed and injection speed, reduce the generation of excessive shear heat, avoid polymer decomposition, and reduce the opening speed, ejection speed and ejection pressure.
5. Plastic design
During design, the part where the fluid in the middle of the plastic part will flow through shall not have too thin wall thickness, and the products shall be designed with sharp corners, inserts, notches or thicknesses that are prone to stress cracking.
