We are familiar with TPE materials as formula materials, which are composed of SEBS, plastics, filling oil, fillers, and other additives. Based on SEBS and other related materials, they all have good processing performance and an important processing process called "granulation". The granulation process (factory) can be said to be a crucial link, serving as a link between upstream raw materials and downstream product manufacturers, and serving as a connecting link between the preceding and the following.
In addition, seeing that many enterprise users still have doubts about TPE granulation and related issues, today I will take you to have a deeper understanding of the relevant information.
SEBS and other raw materials are mostly in powder form, with small pellet sizes that are inconvenient for molding and processing. Additionally, various additives need to be added to meet product requirements. Therefore, it is necessary to mix the raw materials with additives to make pellets, which is called "granulation".
1. Advantages of TPE Granulation
1) Pellets feeding is more convenient than powder feeding and there is no need for a forced feeder;
2) Granular materials have a higher density than powder materials, resulting in better product quality;
3) The volatile matter and air content are relatively low, and the product is not easy to produce bubbles;
4) It is easier to disperse using functional masterbatches than directly adding functional additives.
2. TPE Granulation Process
1) Mix SEBS with processed oil and let it stand for a period of time to allow the oil to fully swell.
2) Weigh the SEBS, PP, fillers, and other components of the mixed oil, mix them in a horizontal mixer or high speed mixer for a certain period of time, and discharge them for standby.
3) Set the temperature of the twin screw extruder, with a general temperature range of 190-230 ℃ and a screw speed of 200-500rpm. Select the appropriate pelletizing method in advance.
4) For mass-produced TPE pellets, batch mixing is also necessary.
5) Detection. Process and prepare samples using injection molding and other processes. Test the hardness and mechanical properties of the sample.
6) Packaging. Pack as needed.
3. Granulation Method
According to different granulation methods, TPE granulation can be divided into the following three types:
1) Water strand pelletizing line
The pellets are generally cylindrical in shape, and the water strand pelletizing equipment consists of a granulator head, a cooling water tank, a granulator, a fan, and so on.
Features:
The equipment has a simple structure, convenient operation and maintenance, neat and beautiful pellets shapes, and a wide range of applications;
The power consumption is high, and the tool wear is severe. When cutting materials with different hardness, different cutting tools need to be used, which is not suitable for the anti-static requirements;
Before cutting, it needs to be cooled by a water tank, which is not suitable for situations with high water content requirements. The capacity is not high.
2) The underwater pelletizing line
The pellets are round or oval. When extrusion is just extruded, the phenomenon of extrusion expansion occurs, and the pelletizing begins, mainly composed of underwater pelletizer head, warm water circulation system, separation system, screening device, etc.
Features:
The pellet shape is neat, beautiful, and not easy to adhere;
Closed operation, good pellets quality, no dust or impurities mixed in, large production capacity;
Pellets can be transported to any place by water, with low noise;
There are many auxiliary equipment, which require a lot of maintenance and heat consumption.
3) The water ring pelletizing line
The pellets are in the shape of discs, which are composed of water ring pelletizer head, warm water circulation system, separation system, screening system and other parts, similar to the previous underwater pelletizing.
Features:
The pellet shape is beautiful, uniform, not easy to stick, and has a high capacity; Cutting pellets can be transported to any place by water, with low operating noise;
Closed operation, good pellet quality, no dust or debris mixed in;
There are many and complex auxiliary equipment, with high maintenance and heat consumption.
Nanjing Haisi Extrusion supply plastic extrusion granulation line for plastic reinforcement.
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