What is Masterbatch?

Masterbatch is a concentrated mixture of pigments and/or additives encapsulated during a heat process into a carrier resin which is then cooled and cut into a granular shape. Masterbatch allows the processor to colour raw polymer economically during the plastics manufacturing process.

The polymers
There are two polymer resins to be considered:

Carrier Resin
The resin in which the pigments and/or additives are carried and which forms the masterbatch.

Dilution Resin
This is the polymer or polymers which make up the bulk of the plastic processor's finished product.

The Colourants
There are three main types of colourant:

Inorganic Pigments
This type of pigment is manufactured from natural raw materials and includes pigments such as titanium dioxide, iron oxides and ultramarine blue. Heat resistance and opacity is usually high but the colours tend to be dull and lack tinting strength. Pigments based on lead chromes and cadmium are unsuitable for food packaging and toys due to their toxicity.

Organic Pigments
Organic pigment systems are synthetically produced and tend to have lower heat stability and poor opacity compared to inorganics. The big advantages of this type of pigment are the bright colours, high tint strength, and conformation to legislation relating to food contact and safety.

Dyestuffs
These are man-made polymer-soluble dyes with properties similar to organic pigments except that many have high heat resistance. Their general use is limited due to their unsuitability with polyolefins, but they can be very effective in styrenics and engineering polymers.

The additives
Different types include:

Performance Additives:
To enhance the performance of the end product.

Processing Additives:
To aid the efficiency of manufacture.