The term masterbatch or color granules refers to plastic additives in the form of granules. They are also called "polymer-bound additives". The density is higher than pure LDPE granules. They are added to the natural plastic (raw polymer) to color it or to change its properties. Compared to pastes, powder or liquid additives, masterbatches increase process reliability and are very easy to process.
There are basically three groups of masterbatches:
These are used to color plastic products. Depending on the quantity added, translucent, transparently colored or opaque qualities can be produced.
Ensure certain properties of the end products. These are the most common properties:
Increases UV resistance. Different products and concentrations result in the product desired by the customer.
Depending on the film thickness, different concentrations are used to create fire protection class B1 or B2 according to DIN 4102 and EN 13501-1.
To improve the natural surface electrical resistance of PE.
The addition of antiblock masterbatch in extruded film prevents blocking during take-up, regulates the slip and antistatic properties of additive films, enables smooth unwind from the roll and improves the film converting process at the converter and end user.
Added to achieve excellent gliding effect. It can be combined with anti-blocking masterbatches to reduce adhesion between surfaces and the film itself.
Used for high performance polyethylene bag applications that require good anti-blocking properties combined with a high coefficient of friction and anti-slip properties.
These contain both colorants and additives.
The term "masterbatch" probably originated from a generalization of the process used in rubber production. In the past, only the master was allowed to produce highly concentrated and therefore expensive mixtures (=batches) for later dilution. They were the mixtures of the master (= masterbatches). They are also called color/additive/combi concentrates in the German industry colloquial language.