How much do you know about the working principle of plastic granulator?

According to different material characteristics, different screw combinations should be selected to achieve the best results. For example, 1: EPDM/PP-TPV should choose a high shear configuration consisting of many kneading blocks and components such as reverse rotation and gear disc, in order to achieve the internal relationship and optimal balance of EPDM vulcanization 

1, unit parameters.

A. The parameters are: main engine speed, main engine current, feed speed, pellet cutting speed, melt pressure, melt temperature, section temperature and so on.

B. There is no direct relationship between the speed and current of the main engine, but the higher the speed, the lower the power loss.

C. Feeding generally uses semi-starvation feeding, so the size of feeding directly affects the extrusion productivity.

D. The melt temperature is basically the actual temperature of the material; there is a difference between the section temperature and the actual material temperature, generally 5-20 degrees. This is due to the difference between temperature probe and material contact.

E, the best matching and balance of the main engine speed, feed speed and section temperature setting, in order to maximize the extrusion efficiency and achieve high quality and high output products. (Considering screw element combination at the same time).

2. The difference between small-scale and large-scale.

Small machine screw has small diameter, small wall chamber between screw and cylinder, high heat transfer and heat dissipation efficiency, and good material dispersion. That's why the laboratory can produce very good products, but the same scale up to large units can not be achieved.

3. The inherent relationship between material properties and process characteristics and twin screw extrusion.

A. Modification of plastics is ever-changing: rubber-plastic blending, plastic alloy, filling modification, toughening modification, glass fiber reinforcement, reactive extrusion and so on.

B. Technological characteristics: to achieve simple physical melt blending or physical reaction extrusion of several raw materials? Will raw materials be premixed together or fed separately in stages?

C. Design reasonable screw element combination and parameter setting according to material performance and process characteristics.

4. Organic arrangement and combination of building block screw elements to realize the special efficiency of physical and chemical reactions of materials.

A. Components include: conveyor block, kneading block, gear disc, counter-rotating element, internal mixing rotor, Mitsubishi and so on.

B. According to different material characteristics, different screw combinations should be selected to achieve the best results. For example, 1:EPDM/PP-TPV should choose a high shear configuration consisting of many kneading blocks and components such as reverse rotation and gear disc to realize vulcanization of EPDM and a special macromolecule alloy TPV with micro-island structure formed by shearing particles uniformly dispersed in PP phase; for example, 2:SBS toughening HIPS should choose fewer kneading blocks, No. Weak shear configurations consisting of counter-rotating and gear disc components are combined to achieve simple physical melt blending, toughening of SBS rubber phase and avoiding degradation of components.

5. The extrusion quality of blended materials can be judged directly from the extrusion strip or granulated particles.

The quality of extruded products can be visually characterized by smooth strips or particles with uniform color. The toughness of particles can also reflect the toughening effect or the vulcanization degree of rubber in dynamic vulcanization products.

6. Parabolic section temperature design + head temperature specialization design to control material melting reaction process.

Twin-screw extruder is generally composed of 7 to 12 barrels, each barrel has an independent temperature control system. The temperature is set to be low at both ends and high in the middle, and the machine head is cooled and pelleted to achieve low temperature extrusion as far as possible to achieve a good extrusion appearance.