What is injection molding barrel

Injection molding barrel, also known as barrel or barrel, is an important part of the injection molding machine.

1. Definition and function

The injection molding barrel is a device used in the injection molding machine to convey, compact, melt, stir and pressurize the plastic. It completes the plasticization process of the plastic by working in conjunction with the screw to ensure that the molten material can be injected into the mold cavity at a constant temperature, quantity and pressure.

2. Structure and characteristics

Structure: The injection molding barrel usually consists of multiple heating zones, which are heated and controlled in sections by electric heating wires, electromagnetic heating or microwave heating. The inner wall of the barrel is designed to be smooth and streamlined to prevent the molten material from being retained and ensure the quality of the molded workpiece. To ensure uniform heating and melting, the barrel usually has multiple heating zones along its length.

Cooling channel: Some barrels may also have cooling channels to control the temperature of the plastic material and prevent premature solidification.

Features: The injection molding barrel must be heat-resistant, pressure-resistant, corrosion-resistant, fatigue-resistant, and have good heat transfer. In order to meet these requirements, the barrel is often made of special alloy steel and nitrided to increase the surface hardness.

Materials: Barrels are typically made from hardened steel or bimetallic alloys to withstand the high temperatures and pressures involved in the process.

3. Working Principle

The working principle of the injection molding barrel is to use the heat source generated by the heating device and the mechanical shear generated by the rotation of the screw to melt the plastic particles evenly. During the melting process, the temperature control in the barrel is very important, which determines the melting state and molding quality of the plastic. Through the closed-loop control system composed of thermocouples and heating devices, the temperature of each section of the barrel can be accurately controlled.

4. Use and Maintenance

Precautions for use:

When installing and disassembling, protect the flange connection plane and the nozzle connection plane to avoid scratches and impact pits.

After the temperature reaches the process temperature, the connecting nut should be re-tightened to avoid deformation of parts and leakage of molten material.

When stopping production, highly corrosive raw materials are not allowed to remain in the barrel. After stopping, it needs to be cleaned and coated with a layer of protective oil.

The barrel should be disassembled in a hot state after cleaning the residual material. Use a copper brush or emery cloth when cleaning, and avoid scraping with hard tools.

5. Maintenance method:

When the inner surface of the barrel is not seriously worn or scratched, it can be polished with an oil stone or emery cloth.

Regularly check the heating device and thermocouple of the barrel to ensure that they are working properly.

For barrels with severe wear, they should be replaced in time to avoid affecting production efficiency and product quality.