The problems occurred after adding color masterbatch to injection molding is that there are stripe-like pigment strips in the product under the sun. This problem needs to be considered from two aspects: plastic physical and mechanical properties and plastic molding process:
1. The temperature of the injection molding equipment is not well controlled, and the color masterbatch cannot be thoroughly mixed with the resin after entering the mixing chamber.
2. The injection molding machine does not apply a certain back pressure, and the screw mixing effect is not good.
3. The dispersibility of the color masterbatch is not good or the resin is not plasticized.
The process can be adjusted as follows:
1. Increase the temperature of the mixing chamber near the drop port portion
2. Apply a certain back pressure to the injection molding machine.
If it is still not good after the above adjusting, it may be the dispersibility or matching problem of the color masterbatch and the resin, and should be solved by contacting the masterbatch manufacturer. After using a certain color masterbatch, the product appears to be more easily broken. This may be due to poor diffusion and miscibility caused by the poor quality of the dispersant or auxiliary agent selected by the manufacturer, which affects the physical and mechanical properties of the product. Although the problem after using the ratio on the color masterbatch specification the color is too deep (too shallow) is simple, there are many possibilities, specifically:
1. The color masterbatch has not been carefully tested, and the pigment is too little or too much. 2. The measurement is inaccurate when used. The domestic enterprises, especially small and medium-sized enterprises randomly measured the amount, which is normal phenomenon. 3. There is a problem in the matching of color masterbatch and resin. This may be the carrier of the color masterbatch is not properly selected, or the manufacturer may arbitrarily change the resin type. 4. The temperature of the machine is improper, and the color masterbatch stays in the machine for too long.
Processing procedure: First check whether the resin type matches the color masterbatch, whether the metering is accurate, and then adjust the machine temperature or speed. If there is still a problem, contact the masterbatch manufacturer. The same color masterbatch, resin and formula, why are the products have different color when molded by different injection molding machines?
This is often caused by the injection molding machine. Different injection molding machines have different mechanical conditions due to different manufacturing, use time or maintenance conditions, especially the difference in the degree of adhesion between the heating element and the barrel, so that the dispersion state of the color masterbatch in the barrel is also different. A phenomenon will appear. After changing the resin of another brand, the same color masterbatch and formula, the color has changed, why?
Different models of resin will have different density and melt index, so the properties of the resin will be different, and the compatibility with the masterbatch will be different, so that color change occurs. Generally speaking, as long as the density and melt index are not big different, then the difference in color will not be too large, you can correct the color by adjusting the amount of color masterbatch. Does the color shift of the color masterbatch during storage affect the quality of the product?
Some color masterbathes have a high pigment content (or dye), and in this case, migration is normal. Especially the color masterbatch with dye added, serious migration will occur. However, this does not affect the quality of the product, because after the color masterbatch is injected into the product, the pigment is in a normal color development concentration in the product. Why are some injection products not looking good?
There are several possibilities:
1. The nozzle temperature of the injection molding machine is too low
2. The mold finish of the injection molding machine is not good.
3. The molding cycle of the product is too long
4. Excessive titanium dioxide contained in the color masterbatch
5. Dispersion of the masterbatch is not good for a period of time, some plastic products will fade. The quality of the basic pigment used by the manufacturer is not good, and drift occurs.
Why is ABS color masterbatch particularly prone to color differences? Different brands of ABS produced by different countries have large color difference. Even if the same brand of ABS, there may be chromatic aberration in each batch. Of course, color difference will also occur after coloring. This is due to the characteristics of ABS, and there is no thorough solution in the world.
However, this color difference is generally not serious, and users must pay attention to this characteristic of ABS when using ABS color masterbatch.