Selection of ABS granulation filter screen changer

ABS is a long-chain copolymer composed of styrene, butadiene and acrylonitrile. This styrene-based material combines the hardness and toughness of san with the good resistance of butadiene monomers or copolymers. Impact performance. The vast majority of ABS is used in the production of injection molded parts for household appliances components and auto parts, others are used in thermoforming extruded sheets, and a smaller part is used in the production of drainage pipes. ABS can be blended with PC to make ABS/pc alloy which can be used for injection molding parts of electrical component products. In general applications, flame retardants will be added to ABS during the blending process.

In recent years, both consumer electronics and auto parts have shown a trend of strong demand. Of course, these beautiful accessory products are becoming smaller, lighter and thinner, with higher surface requirements (ABS  often requires surface painting), and more stringent requirements for chromatic aberration.

One of the processing characteristics of ABS materials is that both the natural color and the ivory color will turn yellow after being heated, and the shear force will cause the melt temperature to rise, the raw material is relatively sensitive to the processing residence time, and the poor fluidity will also cause the color to change. If there are strict requirements on the color of the product, these issues should be carefully considered during processing.

Process technical requirements for ABS filtration screen changer

According to the characteristics of ABS material and the characteristics of its production process, the ideal ABS  filter should meet the following requirements:

1. Strictly control pressure fluctuations when changing the network

In view of the sensitivity of ABS to shear force, whether the filter is installed at the outlet of the extruder or the melt pump, the back pressure must be stable. This is very important, otherwise it will cause product quality changes (such as color changes, product yellowing, etc.). Therefore, the melt pressure can only be changed within a small range.

2. Best fluid mechanics

ABS is very sensitive to residence time, so the best melt flow channel should be as short as possible. Any dead angle will cause color changes and reduce product quality. At the same time, too long material residence time will also cause material degradation. In addition, flame retardants are also particularly sensitive to residence time.

3. Fully automatic operation

Most ABS is produced by large manufacturers, and most of the equipment is fully automated. Any interruption of the processing process is not conducive to production (such as manually adjusting the speed of the extruder to compensate for pressure changes due to the replacement of the filter), and will cause fluctuations in product quality.

4. The product quality is stable when changing the screen

The output of ABS manufacturers is usually between 5000Kg/h-14000Kg/h , which requires a high degree of automation. Obviously, if low-priced foreign products are produced in the process of replacing the filter, it will reduce profits and increase costs. In addition, it is difficult to determine whether the production can reach the normal state within 15 minutes after replacing the filter, because it also depends on whether the operating procedures of the equipment are correct.

5. Possibility of finer filtering

The increasing requirements for the processing quality of ABS products (such as electrical components and auto parts) make ABS manufacturers not only have to achieve 160 or 200mm (80 or 100 mesh), but also have some production The quotient found that when the filtration fineness is finer than 60mm  (250 mesh), the quality of ABS  will be further improved.