Can the PE foam have different colors?

04.10.2021

Polyethylene is basically translucent or milky-white in color, but almost any desired color can be achieved by using plastic colorants. Plastic coloring is useful in creating the image of a product, also can help improving usability and quality. Additionally, it plays a big role in decoration and identification.

Coloring of polyethylene foam

Plastic colorants are chemical compounds that can dye plastics.

There are two methods of coloring:

  • external coloring: coloring the surface of plastics (printing, coating, plating)
  • internal coloring: coloring plastics by kneading colorants into them (Plastic Colorants)

The colorants can be dyes or pigments depending on the type of polymer resin to be colored. Dyes are used in combination with polycarbonate, polystyrene and acrylic polymer. Pigments, on the other hand, can be used with polyolefins.

Pigments do not dissolve in plastic, while dyes do. They are used to color transparent plastics where strong coloring is required. Dye gives a brilliant color and don’t blur surface defects like pigments. Dyes generally do not perform well in outdoor applications.

The colorant must meet the criteria, for example, the compound must be chemically compatible with the base resin, meet the color standard, and be chemically stable.

Pigments

Pigments can be divided into the following categories:

  • Organic pigments
  • Inorganic pigments
  • Carbon black
  • White pigments
  • Special effect pigments
  • Aluminum pigments
  • Other pigments

The organic or inorganic particles added to the polymer base provide a particular color and functional benefits to plastics.

Organic pigments

In terms of coloring ability and color strength, organic pigments are more effective than inorganic ones and can also be used to color transparent plastics.

Inorganic pigments

They are used to color plastics that require a high degree of opacity. Inorganic pigments also have excellent heat resistance and weathering properties. However, some inorganic materials are perceived damaging health, so the industry is moving towards organic pigments.

The choice of color depends on the actual plastic and its final application, requires durability, influenced by environmental aspects and costs.