How Does Auto Lamp Cover Plastic Injection Molds Control Product Color Difference?

The color difference of auto lamp cover plastic injection moulds is a common defect in injection molding, and it is not uncommon for auto lamp cover plastic injection molds injection molding machines to be scrapped in batches due to different colors of matching parts. There are many factors affecting color difference, involving resin, masterbatch, masterbatch mixture, injection molded products, injection molding machine, mold, and other raw materials. Due to the wide range of aspects involved, color difference control skills are also recognized as one of the more difficult skills in injection molding. The following auto lamp cover plastic injection molds manufacturers introduce in detail.

1. Eliminate the influence of injection molding machine and mold elements.

It is necessary to select an injection molding machine with a suitable capacity for the main products processed by auto lamp cover plastic injection molds. Assuming that the injection molding machine has a title such as material dead angle, replace the equipment. If the color difference is caused by the pouring system and exhaust groove of the mold, it can be dealt with by repairing the corresponding parts of the mold. It is necessary to deal with the injection molding machine and mold problems before organizing production.

Eliminating the influence of raw resin and color masterbatch, and controlling raw materials is the key to dealing with the color differences. Therefore, especially when producing light-colored products, the significant impact of different thermal stability of the material resin on the luster and jitter of the product cannot be ignored.

2. Eliminate the influence of uneven mixing of masterbatch and masterbatch.

Poor mixing of plastic masterbatch and masterbatch will also make auto lamp cover plastic injection moulds discolored and unstable. After the masterbatch and the masterbatch are mechanically mixed when they are fed into the hopper through downward suction, the masterbatch is separated from the masterbatch due to electrostatic action and is easily adsorbed on the wall of the hopper, which will inevitably lead to changes in the amount of masterbatch in the injection cycle, and then Chromatic aberration occurs. This situation can be handled by sucking the ingredients into the hopper and then mixing them by hand. Now many companies choose Feeder to add masterbatch, which saves a lot of manpower. And it provides great help for color difference control, but many companies often have unsatisfactory results due to improper use. The amount of masterbatch added by the feeder at a fixed speed depends on the plasticizing time, and the plasticizing time itself is unstable, sometimes even greater. Therefore, to ensure a stable feeding amount, it is necessary to fix the feeding time of the feeder, and the setting time should be less than the plasticizing time.

3. Reduce the influence of barrel temperature on the color difference.

In the production of auto lamp cover plastic injection moulds processing plants, it is often encountered that the temperature of the barrel changes sharply due to the damage and failure of the heating ring, or the uncontrolled combustion of the heating control parts, and then the color difference occurs. The chromatic aberration caused by this reason is easy to determine. The damage and failure of the heating ring are generally accompanied by uneven plasticization, while the uncontrolled burning of the heating control part is often accompanied by gas spots, severe discoloration and even coking. Therefore, in production, it is necessary to check the heating components frequently and replace and repair them in time when the heating components are found to be damaged or out of control, so as to reduce the probability of such chromatic aberration.

4. Reduce the impact of injection molding process adjustments.

When the injection process parameters need to be adjusted due to non-chromatic aberration, try not to change the injection temperature, back pressure, injection cycle, and masterbatch dosage. After the adjustment, it is also necessary to examine the impact of changes in process parameters on Honor. If a color difference is found, it should be adjusted in time. Try to avoid high injection speed, high back pressure, and other strong shear injection processes, and avoid color differences caused by local overheating or thermal differentiation. Strictly control the temperature of each heating section of the barrel, especially the nozzle and the heating part near the nozzle.

5. Grasp the influence of barrel temperature and masterbatch on product color change.

Before adjusting the color difference, it is necessary to understand the trend of the color of auto lamp cover plastic injection moulds changing with temperature and color masterbatch. Different color masterbatches change with temperature or color masterbatches, and their color change rules are also different. You can confirm the variation rules through the color testing process. Unless you already know the color change law of this masterbatch, it is impossible to quickly adjust the color difference, especially when choosing a new masterbatch.