Causes of Screw and Barrel Failure and Factors Affecting Service Life
Mar 04, 2026
The screw and barrel are critical components of an injection molding machine, and many people are concerned about the causes of their failure and the factors affecting their service life. During injection molding, the raw material enters the barrel from the tip, and the screw rotates inside. Through continuous rotation, the material is mixed and plasticized before being injected into the mold cavity from the screw head. It is evident that the barrel and screw must withstand high temperatures and pressures during operation, inevitably leading to wear and failure over time.
Most screw and barrel failures are due to wear, resulting in excessive clearance and inability to function properly, thus causing them to be scrapped. Wear increases the clearance between the screw and the barrel, further reducing the melting rate and decreasing the uniformity of raw material temperature, leading to a decline in the quality of the finished product and even increased energy consumption.
Plastic particles exist between the screw and the barrel. Under force, the screw needs to withstand cutting action. At high temperatures, these plastic particles plasticize, and this plasticization decomposes into corrosive media. These corrosive substances adhere to the surfaces of the barrel and screw, causing corrosion and accelerating their failure.
The factors affecting the service life of the screw and barrel, as seen from their failure causes, include:
1. Screw design and material selection.
2. Surface treatment processes, such as electroplating, spraying, or welding hardening alloys.
3. Barrel material selection and surface treatment process selection.
4. Material conditions and operating parameter settings.
To extend the service life of the barrel and screw, besides proper use, regular maintenance is essential to reduce wear and tear from high temperatures and raw materials.
