If the material contains foreign objects such as plastic fragments, it may indeed cause blockages, poor operation, or product quality issues in the injection machine. The following is a specific breakdown explanation:
1. Block the screw channel
Plastic fragments may have varying sizes and irregular shapes, making them difficult to be smoothly pushed forward by the screw, especially at the feeding port and the front end of the screw, which can easily accumulate and form blockages, leading to unstable material supply and, in severe cases, causing downtime.
2. Uneven melting
The melting characteristics of plastic fragments may be different from those of the raw materials, with melting points that are either too high or too low. After entering the heating zone, they may not be fully melted, forming solid lumps and causing a decrease in the flowability of the molten material, which can block the nozzle or hot runner.
3. nozzle or hot runner blockage
Incomplete melted fragments are prone to accumulate in the flow channels of nozzles or molds, forming hard blocks that hinder normal injection flow, resulting in insufficient filling of the mold cavity or abnormal pressure fluctuations.
4. Increase screw and barrel wear
If the fragments contain impurities (such as fiberglass, dust, or other fillers), they will cause irregular friction on the screw and barrel under high-speed rotation and high pressure, shortening their service life.
5. Impact on product quality
Plastic fragments may differ from the main raw material components, causing uneven melting and resulting in black spots, bubbles, inconsistent colors, or decreased mechanical properties in the finished product.
6. Increase the frequency of equipment maintenance
Material blockage will increase the downtime and cleaning cycle of injection machines, requiring frequent disassembly of nozzles, cleaning of material barrels and flow channels, affecting production efficiency and stability.