How to test the migration resistance of pigments in plastics?

Migration in plastic coloring refers to the migration of pigments from the inside of the plastic to the surface of the product (blooming) or from a plastic through the interface to the plastic and the solvent (bleeding). It has four manifestations in plastic molding coloring: Hua blue pigment

1. Migration: When a colored plastic product is attached to a white or light-colored plastic product, the pigment migrates from the colored product to another item.

2. Precipitation: contamination of molds and rollers during plastic molding.

3. Frosting: The colored plastic products will appear on the surface of the product over time, causing blooming and whitening.

4. Decolorization: The color will fall off from the surface of plastic products.