When it comes to plastics manufacturing, selecting the right pigment isn’t just about getting the color right. It’s about ensuring that the color stays right throughout the process and one of the most critical factors influencing color stability is processing temperature. Different pigments react differently under high-heat vs. low-heat conditions and understanding that behavior is essential for achieving consistent, high-quality results.

Plastics are processed across a wide range of temperatures depending on the resin type and the application. For example:

The higher the processing temperature, the more likely pigments are to degrade, shift in hue, or lose opacity—unless they’re carefully selected for thermal stability.

Color Shift or Fading: Organic pigments can break down under high heat, resulting in unexpected browning, yellowing, or dullness.

Decomposition Odor or Fumes: Thermal degradation of certain pigments can produce undesirable byproducts.

Loss of Strength or Coverage: Inorganics may maintain tone but lose tinting strength under prolonged heat exposure.

Use High-Heat-Stable Pigments: Iron oxides, certain carbon blacks, and specially engineered organics are better suited for high-heat applications.

Test Under Real Processing Conditions: Lab matches aren’t enough; pigments must be validated at true production temperatures.

Watch for Resin-Pigment Interactions: Some combinations can cause unforeseen chemical reactions at elevated temperatures.

Underdispersion: At lower temps, some pigments don’t fully wet out or disperse, leading to streaking or specks.

Carrier Compatibility: Pigments in concentrates may not flow well in cooler-running resins like PVC or LDPE.

Color Strength Overload: Low-heat systems often need less pigment loading, or the color can come out too strong or uneven.

Optimize Pigment Loading: Less is often more—reduce load to improve flow and appearance.

Select Easily Dispersible Pigments: Choose pre-treated pigments for improved flow at low shear and temperature.

Pair with Compatible Carriers: Use concentrates formulated for low-temperature compatibility.

Choosing the right pigment for the right processing environment helps minimize defects like color drift, blooming, plate-out, and opacity loss – saving manufacturers time, reducing scrap, and protecting brand integrity. By understanding and anticipating how pigments behave under different thermal stresses, processors can better collaborate with their color suppliers to develop formulas that perform reliably, batch after batch.

At the end of the day, smart pigment selection isn’t just about color — it’s about processability, consistency, and long-term success.