Causes and solutions of extrusion in injection molding

Extrusion means that during the injection molding process, the plastic material does not flow smoothly in the mold cavity, resulting in defects or inability to form the product. The main reasons for the extrusion of glue are as follows:

1.Mold temperature is too high: mold temperature is too high will reduce the fluidity of plastic materials, resulting in its flow in the cavity difficult.

2. The barrel temperature is too low: the barrel temperature is too low, which will affect the plasticization quality of the plastic material, resulting in uneven flow in the cavity.

3. Excessive pressure: During the injection molding process, excessive pressure may cause the plastic material to flow unsmoothly in the cavity, resulting in extrusion.

4. Unreasonable mold design: Unreasonable mold design, such as the gate size is too small or the flow path is too tortuous, may lead to plastic material flow in the cavity is difficult.

For the above reasons, we can take the following measures to prevent and solve the problem of gluing:

1. Reduce the mold temperature: under the premise of ensuring the molding quality, reduce the mold temperature appropriately to improve the fluidity of plastic materials. According to the actual production situation, the cooling water can be added to the mold to achieve a better cooling effect.

2. Adjust the cylinder temperature: according to the characteristics of the plastic material and product requirements, set the cylinder temperature reasonably to ensure that the plastic material is fully plasticized to ensure the uniformity of its flow in the cavity.

3. Reduce the pressure: under the premise of ensuring the quality of the product, the injection molding pressure is appropriately reduced to reduce the resistance of the plastic material flowing in the cavity. The pressure of the injection molding machine can be adjusted according to the actual production situation.

4. Optimize the mold design: Optimize the mold design, such as expanding the size of the gate and reducing the twists and turns of the flow channel, in order to improve the smoothness of the flow of plastic materials in the cavity. According to the actual production situation, the mold structure can be adjusted or more advanced mold design technology can be adopted.

In actual production, we can also take the following measures to deal with the problem of gluing:

1. Improve the fluidity of plastic materials: choose plastic materials with better fluidity to improve the smoothness of their flow in the cavity. Plastic materials can be modified or replaced with more suitable materials according to actual production needs.

2. Reduce the wall thickness of the product: excessive wall thickness of the product may lead to difficulties in the flow of plastic materials in the cavity. By reducing the wall thickness of the product, the fluidity of the plastic material can be improved and the risk of extrusion can be reduced.

3. Adjust the injection speed and time: according to the characteristics of plastic materials and product requirements, reasonably set the injection speed and time to ensure the full flow of plastic materials in the cavity. You can try to gradually adjust the injection speed to find the most suitable injection parameters.

4. Regular maintenance and maintenance of the equipment: regular maintenance and maintenance of the injection molding machine to ensure that the equipment is in good working condition. For example, grind the injection screw and replace the parts with more serious wear to improve the working efficiency of the equipment.

There are many reasons for the extrusion problem in injection molding, but it is mainly due to the influence of factors such as mold temperature, barrel temperature, pressure and mold design. In order to solve the problem of gluing, we can start from the above aspects and take corresponding measures to prevent and cope with it. In the actual production process, we can also flexibly apply the above measures according to the specific situation to ensure the maximum product quality and production efficiency.