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Application of domestic spectrophotometer in solving the problem of ABS color difference

Author:Spectrophotometer

The domestic spectrophotometer can well meet the color measurement of plastic industry. Whether it is plane, particle or curved object, the domestic spectrophotometer of CHNSpec can solve it. Domestic spectrophotometer is helpful for enterprises to establish color data management system, improve product appearance quality and competitiveness.

ABS plastic is a terpolymer of acrylonitrile (a), butadiene (b) and styrene (s). As a general plastic with excellent comprehensive properties, ABS is widely used in electronics, electrical appliances, automobiles, construction and other fields. ABS is widely used in the field of household appliances because of its good surface gloss, chemical resistance, tenacity, hard quality and good processability.

ABS plastic injection molding products can be seen everywhere in our daily life. In order to use the products with good appearance and visual effect, the appearance parts are required to have different colors, and all parts constituting the appearance of the equipment are required to have consistent colors. Color difference is one of the common defects in colored ABS plastic injection molding products. Such defects will cause product color difference and seriously affect the quality of products.

Influencing factors of color difference
1.Different batches of ABS plastic raw materials have certain color difference, and the color difference between some batches has exceeded the control index of 0.8 required by cooperative users.
2. Adding different batches of ABS masterbatch with the same batch of ABS masterbatch will produce large color difference. When adding different batches of ABS masterbatch with the same batch of ABS masterbatch, it will also produce large color difference, and the color difference of adding the same batch of ABS masterbatch with the same batch of ABS masterbatch will be small. It shows that the batch difference between ABS and color masterbatch will have a great impact on the color difference of injection molded products.
3. The color difference of injection molded products with premix (through twin-screw granulation) is smaller than that of admixtures (mechanical mixing), and the mixing effect will affect the color difference.

4. Back pressure has little effect on color difference. Increasing the screw speed has little effect on the color difference, but if the screw speed is too low and the stopping time is prolonged, the color difference will be more serious.
5. Injection temperature and residence time have a great influence on the color difference.
6. The dilution ratio of color masterbatch has a certain influence on the color difference. Reducing the dilution ratio can improve the mixing effect of admixture.
7. Adding dispersant in color masterbatch can reduce the color difference of injection molded products.


Solution
1. Spot check the raw materials (ABS resin and color masterbatch). If the color difference between batches is large, mix the raw materials in batches.
2. Do not use small injection molding machine to make large products, so as to ensure that the materials have enough time to plasticize evenly in the barrel.
3. Reduce the stopping time of materials in the barrel, and do not use large machine as small parts; Control the temperature of the nozzle and the material pad thickness of the melt after injection molding. The material pad thickness is preferably 1 ~ 1.5 mm. In order to avoid the long-term heating of the melt affecting the color difference of the product.
4. Appropriately reduce the dilution ratio of color masterbatch.
5. In the manufacture of Color Masterbatch, the amount of dispersant can be appropriately increased to strengthen the dispersion of color masterbatch in matrix resin.
6. The amount of antioxidant is appropriately increased in ABS plastic raw materials and color masterbatch to improve thermal stability.
7. When coloring with color masterbatch, because the density of color masterbatch is greater than that of natural color masterbatch, the color masterbatch will be stored in the barrel for a long time and will gradually precipitate downward, resulting in color difference. Therefore, the feeding amount of hopper of injection molding machine should be controlled as much as possible each time.

According to experience, we know that in order to control the error, we can try our best to avoid color difference according to the above methods. But the key point is, how do we determine the direction and degree of color deviation? How much does our adjustment affect the color? We need an instrument that can assist us in accurate color difference regulation, rather than relying solely on human experience.

With the increasingly strict requirements of customers for color quality, more and more ABS plastic manufacturers choose CHNSpec spectrophotometer for color difference control. For each adjustment, the instrument can accurately record the corresponding change of color in the form of numerical value, so as to determine the amplitude of adjustment.

CHNSpec spectrophotometer ds-700d

The products developed and produced by Hangzhou Caipu Technology Co., Ltd., such as color difference meter, domestic spectrophotometer, gloss meter and Haze Meter, are widely used in domestic printing, coating, auto parts, metal, household appliances, food safety, medical inspection and other industries and scientific research institutions. The company unremittingly carries out technology research and development and improves brand service to ensure the stability of the company's products. CHNSpec is committed to providing users with high-quality products and services with leading technology. CHNSpec technology is willing to work with you for common development and win-win!

For the quality inspection of flat plastics, affordable color difference treasure, spectrophotometer and domestic spectrophotometer can be selected. Desktop domestic spectrophotometer is recommended for granular plastics, and 1 * 3 small aperture of spectrophotometer ds-700d can be used for curved plastics.

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