Masterbatch is a solid or liquid additive used for coloring or imparting other properties to plastics. It is a concentrated mixture of an additive encapsulated in a carrier material, such as PE or PP. The carrier material is compatible with the main plastic in which it will be blended during molding, whereby the final plastic product obtains the color or properties from the masterbatch. Masterbatches are already premixed compositions, which can alleviate issues of insufficient dispersion of the additive or colorant when compounding with raw materials. The concentration of the additive in the masterbatch is much higher than in the end-use polymer, but the additive is already properly dispersed in the host resin. The use of masterbatches allows the factory to keep stock of fewer grades of the polymer and to buy cheaper natural polymer in bulk. Some advantages of using masterbatches in plastic manufacturing include:

• Easier incorporation of additives: Masterbatches allow for less complex addition by pellet-to-pellet mixing or adding in the extruder. A special dosing device is not required for the smallest dust quantities. It also reduces the accuracy of the addition required to achieve the same addition rate in the final product.

• Improved product consistency: Predetermined ratios of additive ingredients are included in masterbatch, which means there is minimal chance of variance during the manufacturing process. Masterbatching gives users better color consistency when working with large orders. Melting processes are improved because binding agents in masterbatch are matched with polymers being used.

• Increased productivity: Masterbatch can increase volumetric output (as a result of thermal conductivity and volumetric expansion at a given temperature). In addition, it has the ability to downgauge due to its higher concentration.

• Cleaner and safer production: Masterbatch additives are cleaner and safer to handle. There is no color pigment or other powdered additive to waft, spill or statically attach to surfaces. The result is a cleaner production area, reduced cross-contamination, and potentially quicker transitions between different products. The encapsulation of the additive in the masterbatch provides benefits to the additive as well. The masterbatch can help protect the additive from degradation, which increases its shelf life.