- Under sunlight, there are striped pigment bands in the product.
This issue needs to be considered from two aspects: plastic physical and mechanical properties and plastic molding process:
Nine common problems with masterbatch
Impact of plastic physical and mechanical properties:
1. The temperature of the injection molding equipment is not well controlled, and the color masterbatch cannot be fully mixed with the resin after entering the mixing chamber.
2. The injection molding machine does not add a certain amount of back pressure, and the mixing effect of the screw is not good.
- The dispersion of the color masterbatch is not good or the resin plasticization is not good. The process can be debugged as follows:
- Slightly increase the temperature of the mixing chamber near the discharge port
- Apply a certain back pressure to the injection molding machine. If it still does not improve after the above debugging, it may be a dispersion or matching problem with the masterbatch and resin, and you should contact the masterbatch manufacturer for resolution.
- After using a certain color masterbatch, the product appears to be more likely to break.
This may be due to poor diffusion and miscibility caused by the poor quality of the dispersants or additives selected by the manufacturer, which affects the physical and mechanical properties of the product. https://doi.org/10.1016/j.jmapro.2023.03.072
3. After using the masterbatch according to the proportion in the instruction manual, the color is too dark (too light)
Although this question is simple, there are many possibilities, specifically:
- The color masterbatch has not been carefully tested, and the pigment is too little or too much.
- Inaccurate measurement during use, and a large number of domestic enterprises, especially small and medium-sized enterprises, use arbitrary measurement.
- There is a problem with the matching of color masterbatch and resin. This may be due to improper selection of the color masterbatch carrier, or it may be that the manufacturer changes the resin variety at will.
- The machine temperature is improper and the color masterbatch stays in the machine for too long.https://solidcomould.com/product/armrest-8/
Processing procedures: First, check whether the resin type matches the masterbatch and whether the measurement is accurate. Secondly, adjust the machine temperature or speed. If there are still problems, please contact the masterbatch manufacturer.
4. Under the same conditions, the products injected by different injection molding machines have different colors.
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 close contact between the heating element and the barrel, resulting in different dispersion states of the color masterbatch in the barrel. As mentioned above, phenomenon will occur.
5. The color changed after changing to another brand of resin.
The density and melt index of different brands of resin will be different, so the performance of the resin will be different, and the compatibility with the masterbatch will also be different, resulting in color changes. Generally speaking, as long as the density and melt index are the same If the color is large, the color difference will not be too big. The color can be corrected by adjusting the amount of color masterbatch.
6. Does the pigment migration that occurs during the storage of masterbatch affect the quality of the product?
Some color masterbatches have a high pigment content (or dye). In this case, migration is normal. Especially when dye is added to the masterbatch, serious migration will occur. But this does not affect the quality of the product, because after the masterbatch is injected into the product, the pigment is at a normal color concentration in the product.
7. Why do some injection products have poor gloss?
There are many possibilities:
- The nozzle temperature of the injection molding machine is too low
- The mold finish of the injection molding machine is not good.
- Product molding cycle is too long
- The color masterbatch contains too much titanium
- The color masterbatch is not well dispersed
- Some plastic products will fade after a period of time.
The basic pigments used by the manufacturer are of poor quality and drift occurs.
9. Why is ABS masterbatch so prone to color difference?
Different brands of ABS produced in various countries have large color differences. Even if the same brand of ABS is used, the batch number may exist in each batch. However, this color difference is generally not serious. Users must pay attention to this characteristic of ABS when using ABS masterbatch.