Masterbatches and colorants

Masterbatches and colorants for polymers

On its own, plastic often has a neutral appearance: it can be grayish-white, transparent, milky or simply white. To give polymer products the required color, a decorative appearance, shade stability and additional functional properties, manufacturers use masterbatches, colorants and modifying additives for polymers.

Masterbatches make it possible to color the polymer directly during processing — injection molding, extrusion, blow molding or film production. This is a convenient way to achieve uniform color, reduce dusting in production and control pigment dosing more precisely than with powder colorants.

What a masterbatch is

A masterbatch is a concentrate of pigments, colorants or functional additives uniformly dispersed in a polymer carrier. It usually takes the form of small pellets and is added to the base polymer during processing.

During production, the masterbatch is mixed with the base polymer melt, and the pigments, pre-dispersed within the pellets, give the finished product the required color. The quality of a masterbatch depends not only on the pigment itself, but also on its dispersion, compatibility with the polymer, concentration, heat resistance and color stability under real processing conditions.

Masterbatches from Material Wizard

Material Wizard works with polymer products, including additives for polymers, colorants, masterbatches and modifiers. These materials are used to color polyethylene, polypropylene and other thermoplastics, as well as to impart additional properties to finished products.

When selecting a masterbatch, it is important to consider not only the desired color but also the compatibility of the polymer carrier with the base material, the processing temperature, and requirements for UV stability, transparency, matte finish, strength, food contact or other service conditions of the product.

White masterbatches

White masterbatch is used to color polyethylene, polypropylene and other plastics white. The main pigment in such concentrates is often titanium dioxide, which provides high hiding power, brightness and a stable white shade. Some formulations may also use lithopone or other white pigments.

White masterbatches can play not only a decorative but also a functional role:

• giving the product a clean, bright and uniform white color;
• improving the appearance of the polymer product;
• providing a matte or semi-matte effect depending on the formulation;
• increasing the product's resistance to UV radiation when appropriate stabilizers are included;
• improving the thermal stability of the product through special additives.

Black masterbatches

Black masterbatch usually consists of carbon black, a polymer carrier and additional additives. Carbon black is produced under controlled conditions, which makes it possible to adjust its dispersion, color intensity, hiding power and functional properties.

Black masterbatches are widely used in the production of:

• packaging products;
• pipes and technical profiles;
• parts for the automotive industry;
• films, sheets and extruded products;
• technical parts requiring a stable black color and additional protection from light.

In some cases, oxide pigments or special formulations may be used instead of carbon black when the product requires not a classic deep black color but other optical or technological properties.

Advantages of using masterbatches

Masterbatches are convenient for series production, as they allow precise dosing of the colorant or additive and its uniform distribution in the polymer melt. The main advantages of using masterbatches:

• uniform and stable color of finished products;
• simple dosing during production;
• the ability to adjust color saturation;
• reduced dusting compared with powder pigments;
• a cleaner and more environmentally friendly production process;
• the ability to combine color with functional additives;
• improved stability of product properties depending on the concentrate composition.

Functional additives in masterbatches

In addition to pigments, masterbatches may contain special functional additives. These make it possible not only to give the product a color, but also to change its behavior during processing or in service.

Masterbatches may include:

• antioxidants;
• light stabilizers;
• antistatic agents;
• UV stabilizers;
• slip additives;
• antiblocking additives;
• processing modifiers;
• additives to improve heat resistance or color stability.

Thanks to such components, a masterbatch can serve not only as a colorant but also as a tool for adapting a polymer product to specific conditions of use: the outdoor environment, solar radiation, contact with dust, static electricity, thermal loads or surface requirements.

Selecting a masterbatch for a specific polymer

The correct choice of masterbatch depends on the base polymer, the processing method and the requirements for the finished product. Polyethylene, polypropylene, polystyrene, ABS, polyamides or other materials may require different polymer carriers, different pigments and different concentrations of the active substance.

Material Wizard helps select a masterbatch or modifying additive taking into account the material, the processing temperature, the required color, saturation, shade stability, UV resistance, surface requirements and the service conditions of the finished product.