Color Standards for Plastics — Plastic Colorants and Color Concentrates

Plastic is a widespread medium for various applications, from children’s toys to kitchen tools. Coloring plastics can take on many different forms, and it’s vital to meet industry standards for safety and performance. At HunterLab, our spectrophotometers help plastic manufacturers create ideal color concentrates for their products.

ASTM Color Standards for Plastic

The American Society for Testing and Materials (ASTM) provides a series of standards for plastic production. While plastic is easy to mold and ideal for many applications, it’s a synthetic material that may be poorly made or unsafe for use.

ASTM standards provide rules and guidance for plastic production to ensure products last and stay safe throughout their lifespan. The organization’s website offers extensive documentation for you to follow these standards in your operation. Criteria include descriptions like:

• Specifications for materials
• Testing methods
• Production procedures

Color is an essential feature of plastic standards because plastic colorants can affect the quality of the material. Plastic producers use color charts to compare their colors, and the best way to handle this comparison is with color measuring devices. Machines like spectrophotometers quantify color based on the light it absorbs and reflects, so manufacturers can create a match to a color on the chart.

What Are Color Concentrates for Plastics?

Color concentrates are plastic colorants in a pellet or grain that manufacturers form into plastic. Rather than adding a colored layer to the outside of a plastic product, concentrates make up the product.

To create a concentrate, a pigment is mixed with a polymer or carrier resin. For concentrates to work, the polymer must work with the base resin that the concentrate mixes with. The challenging aspect of concentrates is the lack of a universal polymer. Developers must identify the best polymer and base resin for production.

The ASTM standards provide testing methods that can help manufacturers determine the quality of their color.

Pigments for Plastic

Pigments are the physical color mixed with a polymer to create a concentrate. They can be organic or inorganic, both of which offer positives and negatives. While pigments give plastics brilliant colors, they also support product performance. A manufacturer’s choice of pigment can determine:

• Transparency: If you’re looking to create a plastic color with low opacity, you need to make smaller particles for better dispersion.
• Weathering: Some pigments perform better in outdoor environments than others, and it’s critical to consider this when creating an outdoor product.
• Light fastness: This factor measures performance in indoor environments. Typically, inorganic pigments are better at producing high light fastness.
• Warping: Some pigments may cause plastic products to warp or shrink during the manufacturing process. Developers should consider this factor when working with organic pigments.

Create Precise Colors With HunterLab

Our spectrophotometers allow plastic manufacturers to quantify colors for matching industry color charts. Create concentrates and stick to ASTM standards with ease. Explore our full inventory of spectrophotometers and reach out to our team to find out how we can support your operation.