How to solve the problem of broken products after adding color masterbatch in injection molding?

Under the sunlight, there are streaks of pigment bands in the products This problem needs to be considered from two aspects: the physical and mechanical properties of plastic and the plastic molding process.

- The temperature of injection molding equipment is not controlled well, and the color masterbatch cannot be fully mixed with resin after entering the mixing cavity.
- The injection molding machine does not add certain backpressure, and the mixing effect of the screw is not good.
- The dispersion of masterbatch is not good or the resin is not plasticized well.
- The process can be debugged as follows.
- Increase the temperature of the mixing cavity by the drop port slightly.
- Apply a certain back pressure to the injection molding machine.

If the above debugging is still not good, it may be the dispersion or matching problem of masterbatch and resin, which should be solved by contacting the masterbatch manufacturer.

After using a certain color masterbatch, the product appears to be easy to break, which may be due to the poor quality of dispersant or auxiliary agent selected by the manufacturer, resulting in poor diffusion and mutual solubility, affecting the physical and mechanical properties of the product. The color is too dark (too light) after using the color masterbatch according to the ratio on the instruction manual. Although this problem is simple, there are many possibilities, specifically.

- The color masterbatch is not carefully tested, the pigment is too little or too much
- Inaccurate measurement when using, the phenomenon of random measurement by small and medium-sized enterprises exists in large quantities
- There is a problem of matching color masterbatch with resin, which may be due to improper choice of the carrier of color masterbatch, or the manufacturer may change the resin variety at will.
- Improper machine temperature, the color masterbatch stays in the machine for too long.
- Handling procedure: Firstly, check whether the resin type matches the masterbatch and whether the measurement is accurate, secondly, adjust the machine temperature or speed, if there is still a problem, contact the masterbatch manufacturer.

The same masterbatch, resin, and formula, why do different injection machines inject products with different shades of color?

This is often caused by the injection molding machine. Different injection molding machines have different mechanical conditions due to different manufacturing, usage time or maintenance conditions, especially the difference in the degree of tightness between the heating element and the barrel so that the dispersion of the masterbatch in the barrel is not the same, and the above phenomenon will occur.

After changing another brand of resin, the color changes with the same masterbatch and formula, why?

The density and melt index of different resin grades will be different, so the performance of the resin will be different, and the compatibility with the masterbatch will be different, thus the color will change.

Does the pigment migration phenomenon during the storage of masterbatch affect the quality of products?

Some masterbatches have high pigment content (or dyestuff), in this case, the migration phenomenon is normal. Especially for the masterbatch with dyestuff, a serious migration phenomenon will occur. However, this does not affect the quality of the product, because after the masterbatch is injected into the product, the pigment in the product is at the normal concentration of color development.

Why do some injected products have bad gloss?

There are various possibilities as follows.

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. Too much titanium dioxide in the masterbatch
5. Poor dispersion of the masterbatch