Problem1: Striped pigment strips in the product under sunlight
Considering both physical and mechanical properties of plastics and plastic molding processes:
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 add 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 debugged as follows:
1. Increase the temperature of the mixing chamber by the drop port portion
2. Apply a certain back pressure to the injection molding machine.
If it is still not good after the above debugging, it may be the dispersibility or matching problem of the color masterbatch and the resin, and should be solved by contacting the masterbatch manufacturer.
2 After using a certain color masterbatch, the product appears to be more susceptible to cracking.
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.
Problem2: After using the ratio on the color masterbatch specification, the color is too dark (too light)
Although this problem is simple, there are many possibilities, specifically:
1. The color of masterbatch has not been adjusted carefully, and the pigment is too little or too much.
2. Inaccurate measurement at the time of use, the phenomenon of random measurement by domestic enterprises, especially small and medium-sized enterprises.
3. There is a problem with the matching of the color masterbatch and the resin. This may be due to improper selection of the carrier of the masterbatch, or it may be that the manufacturer randomly changes the resin variety.
4. The temperature of the machine is not good, 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.
Problem3: Using the same color masterbatch, resin and formula, why do the products by different injection molding machines have color difference ?
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.
Problem4: After changing the resin of another brand, the same color masterbatch and formula, the color has changed, why?
Different grades of resin will have different density and melt index, so the properties of the resin will be different, and the compatibility with the color masterbatch will be different, resulting in color change. Generally speaking, as long as the density and melt index are not much different, then the difference in color will not be too large, you can correct the color by adjusting the amount of color masterbatch.
Problem5: Does the color shift of the 5 color masterbatch during storage affect the quality of the product?
Some color masterbatches have 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.