How to improve the extrusion efficiency of TPE materials?

TPE materials can be directly injection molded, extruded, and poured without the need for vulcanization. Extrusion molding, as one of the main processing methods for TPE materials, has developed into a mature process for TPE tension tubes, TPE headphone cables, TPE sealing strips, TPE tension bands, TPE automotive sealing strips, TPE anisotropic plastic materials, and other products. So how to improve the extrusion efficiency of TPE materials? Below, the TPE editor from Shenzhen Zhongsu Wang will introduce it to you.

How to improve the extrusion efficiency of TPE materials?

1、 Optimize the configuration of extrusion equipment

Efficient extrusion begins with high-performance equipment. The screw is the core component of the extruder, and its design directly determines the plasticizing effect and conveying efficiency. Due to the sensitivity of TPE material viscosity to shear, a specially designed TPE screw should be selected. This type of screw usually has a large compression ratio (generally recommended between 2.5:1 and 3.5:1) to ensure that the material is fully compressed and plasticized. At the same time, the compression section of the screw should adopt a gradual design to provide stable pressure establishment and avoid material degradation caused by local overheating. In addition, adding mixing elements such as pins or barrier sections in the metering section (homogenization section) of the screw can effectively promote the uniform dispersion of TPE components, improve melt uniformity, and lay the foundation for stable extrusion.

2、 Fine tuned process parameter control

Process parameters are the direct factors affecting extrusion efficiency. In terms of temperature control, the processing temperature range of TPE is relatively narrow, requiring precise control of the temperature in each heating zone. Usually, the temperature from the hopper to the machine head should increase in a gradient. For example, the temperature in the feeding area can be set below the melting point of TPE to prevent premature melting of the material; The temperature in the compression zone and metering zone should reach the optimal processing window of the material (usually between 150 ° C-200 ° C); The temperature of the machine head and mold needs to be slightly lower than the temperature of the barrel to prevent overheating and degradation of the melt and maintain its strength. The screw speed is the key to determining production, but excessively high speeds can increase shear heat and cause instability in the melt. Therefore, the optimal speed balance point should be found through experiments while ensuring product quality. In addition, a stable feeding rate is a prerequisite for ensuring extrusion continuity. It is recommended to use a weight loss feeder to achieve precise and uniform material supply.

3、 Improve TPE material formula

For TPE manufacturers or downstream users, the performance of the material itself is an inherent determinant of extrusion efficiency. By adjusting the ratio of TPE matrix resin (such as SEBS, SBS, etc.) to rubber oil, the melt strength and flowability of the material can be adjusted within a certain range. Appropriately increasing the resin content or using a matrix resin with a narrower molecular weight distribution can help improve melt strength and reduce melt fracture. In addition, adding appropriate processing aids (such as external lubricants) to the formula can effectively reduce the friction between the melt and the barrel or screw, reduce energy consumption, and improve the surface smoothness of the extruded material.

4、 Optimize mold and cooling system design

The mold is the final stage of extrusion molding, and its design directly affects the molding efficiency and final quality of the product. A reasonable mold flow channel design should ensure that the material has a uniform flow velocity inside the mold cavity, avoiding defects caused by local flow velocities that are too fast or too slow. For elastomers such as TPE, the length of the molding section (parallel section) of the die is crucial. Adequate molding section length can provide the necessary pressure to ensure stable flow of the melt, thereby obtaining extruded products with precise dimensions and smooth surfaces. In addition, an efficient cooling system can quickly shape the extruded material, directly determining the speed of the production line. The design of sink cooling or air cooling systems should ensure uniform and efficient cooling, prevent deformation or warping of products due to uneven cooling, and allow for higher production traction speeds.

In summary, improving the extrusion efficiency of TPE materials requires collaborative optimization of equipment, processes, materials, and molds. By implementing refined management and technological innovation in the production process, enterprises can not only effectively increase output and reduce energy consumption, but also significantly improve product quality, thus occupying a more advantageous position in the fierce market competition.