Why do PU pigments expand?

PU pigments may swell under certain circumstances, which is usually related to the following factors:

Water absorption: PU pigments have a certain degree of water absorption. When exposed to high humidity environments, the water in the pigments will be absorbed, causing the pigments to swell.

Chemical reaction: The components in PU pigments may react chemically with other substances to produce gases or products, causing the pigment to expand. For example, reactions with gases create bubbles that cause the pigment to expand.

Temperature effects: Temperature changes may also affect the expansion of PU pigments. At high temperatures, components in the pigment may expand or become more reactive, causing the pigment to swell overall.

Fillers and Additives: Pigments may contain fillers or certain additives that may cause the pigment to swell under certain conditions.

Processing conditions: The processing conditions of PU pigments (such as heating, mixing, extrusion, etc.) may also affect its expansion. For example, the heat generated during processing may cause the pigment to expand.

To reduce the expansion of PU pigments, you can take the following measures:

Control processing conditions and try to avoid excessive temperature or humidity.

Choose the right ingredients and additives to reduce factors that can cause bloating.

Increase the stability and weather resistance of pigments to reduce the impact on the external environment.