August 19, 2026

Why Is Pigment Heat Resistance Important? Choosing Pigments for Plastic Processing Temperatures

In plastic manufacturing, the quality of a pigment is determined not only by its color performance but also by its ability to withstand processing conditions. Especially in applications involving injection molding, extrusion, blow molding and masterbatch production, pigment heat resistance is one of the key criteria for selecting the right pigment.

Plastic materials are processed at different temperatures depending on the polymer and production method. Therefore, a pigment must be evaluated not only for its color but also for its ability to maintain its stability and performance under the required processing temperature and residence time.

Using a pigment with insufficient thermal stability may result in color changes, shade shifts, reduced color strength or pigment degradation during processing. In continuous production, these problems can lead to batch-to-batch color differences and quality issues.

What Is Pigment Heat Resistance?

Pigment heat resistance refers to the ability of a pigment to maintain its physical and chemical properties when exposed to a specific temperature for a defined period of time. In plastic applications, this includes the pigment's ability to maintain its color, color strength and stability during thermal processing.

Temperature alone is not the only factor that matters. The duration of exposure is also important. Short-term exposure to a high temperature can affect a pigment differently from prolonged exposure to a lower temperature.

Why Is Plastic Processing Temperature Important?

The processing temperatures of polymers used in plastics manufacturing vary considerably. Materials such as PE, PP, PVC, ABS, PA and PC are processed under different thermal conditions. For this reason, pigment selection for plastics should consider not only the polymer but also the actual temperature conditions of the production process.

A pigment may perform well in a relatively low-temperature application but fail to deliver the same result in a higher-temperature injection molding or extrusion process.

When selecting pigments for plastic applications, the following factors should be evaluated together:

• Type of plastic polymer
• Processing temperature
• Pigment residence time in the process
• Injection molding or extrusion conditions
• Required shade and color strength
• Final product application
• Exposure to light, UV and environmental conditions

Choosing the right pigment helps prevent color-related production problems and supports consistent color performance from one production batch to another.

Which Pigments Offer High Heat Resistance in Plastics?

The heat resistance of a pigment used in plastic applications depends on its chemical structure and the polymer system in which it is applied. Therefore, there is no single temperature limit that can be applied to all pigments. The same pigment may show different performance depending on the carrier system, processing time and type of plastic.

In general, inorganic pigments can offer advantages in terms of thermal stability compared with many organic pigments. Certain iron oxide pigments, metal oxide pigments and other thermally stable inorganic pigments are commonly considered for plastic applications where higher processing temperatures are involved.

However, some high-performance organic pigments can also be suitable for demanding plastic applications. In these cases, the pigment's chemical structure, technical specifications and intended application conditions should be evaluated together.

Heat Resistance of Organic and Inorganic Pigments

Tüver Pigment supplies organic pigments and inorganic pigments for different plastic and industrial applications, supporting pigment selection according to application requirements.

Pigment Selection for Injection Molding and Extrusion

When selecting pigments for plastic injection molding, machine settings and the properties of the polymer should be taken into account. During injection molding, pigments can be exposed to high temperatures and shear forces within a relatively short period of time. Therefore, selecting a pigment based only on its color performance is not sufficient.

In extrusion processes, the pigment may remain exposed to elevated temperatures for a longer period. Particularly in masterbatch production, pigment compatibility with the carrier polymer, dispersion performance and thermal stability should be evaluated together.

Heat Resistance in Masterbatch Production

Pigment selection for masterbatch production requires careful consideration of thermal stability. The pigment must disperse uniformly within the carrier system while maintaining its color performance at the processing temperature.

Insufficient thermal stability can cause shade changes, reduced color strength or batch-to-batch color variations in the final product. For this reason, masterbatch manufacturers should evaluate the processing temperature of the target polymer together with the pigment's recommended application conditions.

How Is Pigment Heat Resistance Tested?

Pigment heat resistance should not be evaluated solely as a theoretical value. Testing under conditions that closely resemble the actual production process can provide more reliable results.

During a typical evaluation, the pigment is incorporated into the relevant plastic system and exposed to the target processing temperature. The resulting color is then compared with a reference sample.

• The initial color shade is established.
• The pigment is incorporated into the plastic at a defined dosage.
• The sample is processed at the target temperature.
• Color change is evaluated after thermal exposure.
• Where required, color measurements can be performed using a spectrophotometer.

This approach helps evaluate not only the theoretical thermal stability of the pigment but also its actual performance within a specific polymer and processing condition.

Common Mistakes When Using Pigments at High Temperatures

When a color problem occurs during plastic production, it is not always correct to assume that the pigment itself is the only cause. Processing conditions should also be reviewed.

• Selecting the wrong pigment class
• Processing above the pigment's recommended temperature range
• Excessive pigment residence time in the process
• Insufficient dispersion
• Incorrect pigment dosage
• Incompatibility with the carrier polymer
• Interaction with raw materials or additives

How to Select Pigments for Plastic Applications?

Pigment selection for plastics should not be based solely on achieving the desired color. Processing temperature, polymer type, pigment concentration, dispersion behavior and the environmental conditions that the final product will encounter should all be considered together.

For plastics processed at elevated temperatures, the following criteria should be evaluated in addition to thermal stability:

• Thermal stability: The ability of the pigment to maintain its color performance at the target processing temperature.
• Color strength: The pigment concentration required to achieve the desired color intensity.
• Dispersion: The ability of the pigment to distribute uniformly throughout the plastic.
• Polymer compatibility: Compatibility with polymer systems such as PP, PE, PVC, ABS, PA and PC.
• Lightfastness: Color stability when the final product is exposed to sunlight or UV radiation.
• Chemical resistance: Performance when the product comes into contact with oils, solvents, detergents or other chemicals.
• Migration and bleeding behavior: The tendency of the pigment to migrate within or out of the plastic system under specific application conditions.

How Should Processing Temperature Be Matched with Pigment Selection?

The first step is to determine the actual processing temperature of the plastic material. The pigment's technical documentation should then be reviewed to determine whether its recommended thermal stability and application conditions are suitable for the process.

Why Are Laboratory Trials Important in Pigment Selection?

Technical data sheets provide an important starting point for selecting a suitable pigment. However, the final selection should ideally be supported by trials under conditions that represent the actual production process.

When introducing a new pigment into an existing production system, a laboratory or pilot-scale trial can be performed. This makes it possible to evaluate color strength, dispersion, thermal behavior and overall performance within the selected polymer.

This approach helps identify potential color deviations and processing issues before moving to full-scale production.

Choosing Pigments for Plastic Applications with Tüver Pigment

Tüver Pigment supplies organic pigments and inorganic pigments for plastic, masterbatch and various industrial applications.

Rather than selecting a pigment based only on a color chart, a more reliable approach is to evaluate the plastic type, processing temperature, intended application, color strength, thermal stability and processing conditions together.

For injection molding, extrusion and masterbatch applications operating at elevated temperatures, pigment specifications should be matched carefully with the actual production conditions.

Conclusion

Pigment heat resistance is one of the key parameters affecting color stability and process reliability in plastic manufacturing. In high-temperature applications, selecting a pigment solely according to its color shade or color strength can lead to color changes and production problems later in the process.

The correct approach is to evaluate the polymer, processing temperature, pigment thermal stability, residence time and final product requirements together. For plastic and masterbatch manufacturers, pigment selection should therefore be based on technical data and, where necessary, trials under actual production conditions.

For technical information and pigment selection support for your plastic application, contact Tüver Pigment.