Author: MULAN -Plastic Molding Manufacturer
The plastic mold factory Xingye will introduce the product color difference of the plastic mold processing factory, which is a common shortcoming in injection molding. Due to the different colors of matching parts, it is not uncommon for injection molding machines to fail in batches. There are many factors affecting the color difference, involving the mixing of material resin, color masterbatch and color masterbatch homogeneous materials.
Injection molding products, injection molding machines, molds, etc. Due to its wide coverage, color difference control skills are recognized as one of the most difficult skills in injection molding. Next, the plastic mold factory Xingye Xiaobian will give you a detailed introduction.
1. Eliminate the influence of injection molding machine and mold elements. The plastic mold factory introduces the selection of an injection molding machine with a suitable capacity for the main products of plastic mold processing. If the injection molding machine has problems such as material dead ends, replace the equipment. For mold gating system.
If the color difference is formed by the exhaust groove, it can be dealt with by the maintenance mold of the corresponding part of the mold. It is necessary to deal with injection molding machine and mold problems before organizing production to reduce the complexity of problems. Eliminate material resin.
Effect of color masterbatch Control of raw materials is the key to deal with color difference. Therefore, especially when producing light-colored products, we cannot ignore the significant impact of the different thermal stability of the material resin on the product's glorious fluctuation. Given that most injection molding manufacturers do not produce plastic masterbatches or color masterbatches themselves, we can focus on production management and raw material inspection.
That is to strengthen the inspection of raw material warehouses; in the production process, the same product should choose the same manufacturer as much as possible. The same trademark base material. Color masterbatch production; as for color masterbatch, we should do sampling and testing before mass production, which should not only be the same as the previous calibration, but also should be compared in this time.
Assuming that the color difference is not large, it can be qualified. It seems that batches of color masterbatch have slight color difference, and the color masterbatch can be mixed from scratch before use to reduce the color difference caused by uneven mixing of color masterbatch. Together, we also need to check the material resin.
If the thermal stability of the color masterbatch is not safe, we advocate the manufacturer to exchange it. 2. Eliminate the influence of uneven mixing of color masterbatch and masterbatch. Poor mixing of plastic masterbatch and color masterbatch will also change the color of the product.
After the masterbatch and color masterbatch are mechanically mixed evenly, due to the electrostatic effect, the color masterbatch is separated from the masterbatch and is easily adsorbed on the wall of the hopper, which will inevitably cause a change in the amount of color masterbatch during the injection molding cycle, and then cause color difference. In this case, the material can be sucked into the hopper and then mixed manually. Now many companies choose feeder to add color masterbatch, which saves a lot of manpower and provides great help for color difference control, but many companies often have unsatisfactory results due to improper use.
At a fixed speed, the amount of color masterbatch added to the feeder depends on the plasticizing time. The plasticizing time itself fluctuates, and sometimes it is relatively large. In order to ensure a stable feeding amount, the feeding time of the feeder needs to be fixed. , the setting time is less than the plasticizing time. When using the feeder, due to the small outlet of the feeder, after a period of use, the mass powder particles accumulated in the screw of the feeder may be blocked, or even cause the feeder to stop, so regular cleaning is required. 3. Reduce the influence of barrel temperature on color difference.
The plastic mold factory tells everyone that during the production process, the plastic mold processing factory often encounters a drastic change in the temperature of the cylinder caused by a damaged heating ring or a long-term burning of the heating control part, and then there is a color difference. It is easy to determine the chromatic aberration caused by this reason. Generally, the color difference caused by the damage and failure of the heating ring will be accompanied by uneven plasticization, and the uncontrolled long-term burning of the heating control part is often accompanied by product gas spots, severe discoloration or even coking.
Therefore, in the production process, it is necessary to check the heating part frequently, and replace and repair it in time when it is found that the heating part is damaged or out of control, so as to reduce the incidence of this color difference. 4. Reduce the impact of injection molding process adjustments. When the injection molding process parameters need to be adjusted due to non-chromatic aberration, try not to change the injection molding temperature, back pressure, injection molding cycle and the amount of color masterbatch added.
The effect of changes in process parameters on glory also needs to be investigated. If color difference is found, it should be adjusted in time. Try to avoid using high injection speed, high back pressure and other injection molding processes that cause strong shear effects, and avoid color differences caused by factors such as partial overheating or thermal differentiation.
Strictly control the temperature of each heating section of the cylinder, especially the nozzle and the heating part near the nozzle. 5. Grasp the influence of cylinder temperature and color masterbatch quantity on product color change. According to the plastic mold factory, before adjusting the color difference, it is necessary to understand the change trend of product color with temperature and color masterbatch amount.
Different color masterbatches change with the change of production temperature or the amount of color masterbatch, and the color change rules of their products are also different. Its changing rules can be confirmed through the color test process. Unless you already know the color change rules of this color masterbatch, it is impossible to adjust the color difference quickly, especially when choosing a color change produced by a new color masterbatch.
For more information about plastic molds, please visit Xingye's official website: http://www.dgxingyesj.com.