In the production of injection molded products, how should we control the color difference of injection molded products?

I. Selection and control of raw materials

The quality and stability of raw materials is the basis for controlling color difference. First of all, we should choose the plastic raw material suppliers with reliable quality and stable color. Different batches of raw materials may have color differences, so when feeding, the color of each batch of raw materials should be strictly inspected and compared with standard samples. At the same time, for some products with very high color requirements, it is recommended to use the same batch of raw materials for production, in order to reduce the color difference caused by different batches of raw materials.

For example, the production of a brand of cell phone shell, in order to ensure the consistency of the color, the manufacturer will require the raw material supplier to provide a specific batch of plastic granules, and in the production process of each batch of incoming materials are subject to strict color testing.

Second, the optimization of color matching process

Accurate color matching is the key link to control color difference. In the color matching, according to the color requirements of the product, the use of professional color matching equipment and software, accurate calculation and deployment of the proportion of various pigments. At the same time, attention should be paid to the compatibility and dispersion of pigments to ensure the uniform distribution of colors.

For example, in the production of colorful plastic toys, color matching engineers will determine the best pigment formula through many tests and adjustments according to the color standard provided by customers, and will strictly follow the formula in the production process.

Third, the adjustment of injection molding process parameters

Process parameters in the injection molding process, such as temperature, pressure, injection speed and cooling time, etc., also have an important impact on the color difference of the product. Too high or too low temperature may lead to the decomposition or uneven distribution of pigments, thus producing color difference. Proper pressure and injection speed can ensure uniform filling of the plastic melt and avoid local color differences. Reasonable cooling time can make the product color stable during the cooling process.

Taking the production of plastic tableware as an example, if the injection temperature is not set properly, it may cause color inconsistency between the edges and the center of the tableware. This problem can be effectively solved by optimizing the temperature parameters.

Fourth, the design and maintenance of the mold

The structure and surface quality of the mold will also affect the color difference of the product. Good mold design should ensure that the plastic melt flows evenly in the mold to avoid stagnation and local overheating. Regular cleaning and maintenance of the molds should be carried out to prevent wear and tear and accumulation of dirt on the mold surface, which will affect the color uniformity of the products.

For example, long-term use of the mold if not cleaned in a timely manner, may form a layer of dirt on the surface, resulting in the production of injection molded products appear color spots.

Fifth, the control of the production environment

The stability of the production environment can not be ignored on the color difference control. Keep the temperature and humidity of the production workshop constant, can reduce the environmental factors on the raw materials and product color. In addition, to avoid the mixing of dust and impurities, but also to prevent the surface of the product stains and color differences.

For example, producing plastic parts for optical instruments in a clean room can effectively avoid dust adhering to the product surface, thus ensuring the purity of the product color.

Sixth, quality testing and monitoring

In the production process, we should establish a perfect quality testing system and regularly test the color of the product. You can use colorimeter and other professional equipment to quantitatively analyze the color of the product and compare it with the standard color. Once the color difference is found to be beyond the allowable range, adjust the production process or take corresponding corrective measures in a timely manner.