In this article, we will suggest 3 actionable ways for your screws and barrels maintenance.
The screw and barrel are the core component of the injection molding machine. The screw works for a long time in high temperature, high pressure, high mechanical torque and high friction. Wear problems are inevitable. The general screw is a surface nitriding treatment to improve the surface hardness, that is, to improve the ability to resist wear.
But if you ignore the causes of wear and tear, do not try to minimize the wear and tear will inevitably significantly reduce the working life of the screw.
Set the right temperature for different materials
Each plastic, having an ideal plasticization temperature range, should control the barrel processing temperature to close to this temperature range.
Granular plastic will reach the filling section from the hopper into the barrel. In this section, there will inevitably appear dry friction. When these plastics are underheated, uneven melting, it is easy to cause the inner wall of the barrel and screw surface wear increases.
Similarly, in the compression section and homogenization section, if the molten state of the plastic is disorderly uneven, it will also cause increased wear.
Set the reasonable screw speed
Some plastics with reinforcing agents, such as glass fiber, minerals or other fillers. These substances are often much greater than the friction of molten plastic on metal materials.
In the injection molding of these plastics, if a high rotational speed is used, it will increase the shear force on the plastic. At the same time, the reinforcement will also produce more torn fibers. The torn fibers contain sharp ends so that the abrasive pressure is significantly increased.
Inorganic minerals in the metal surface at high-speed glide, its scraping effect is not small. So the speed should not be adjusted too high.
Remove impurities in pellets
Production with pure raw materials may be a relatively small risk. But now, to reduce costs, some factories generally mix with some water mouth material in raw materials. While crushing, it is easy to mix some metal chips into water mouth materials. It is very harmful to the screw, so generally installed in the barrel of the magnet frame, strict feeding management and monitoring.
Conclusion
There are three ways to protect injection machine screws and barrels.
- Set the right temperature for different materials
- Set the reasonable screw speed
- Remove impurities in pellets