Polymer Additives and Additive Masterbatch

Additive masterbatches are concentrated functional additives carried in a polymer matrix, pelletised for easy addition to the injection moulding or extrusion process. They are used to modify the processing characteristics of a polymer, add specific functional properties to a moulded part, improve product durability or appearance, or reduce production costs — without requiring a change of base material or grade.

Yes, in several ways. Process aid masterbatches can reduce cycle times and energy consumption. Blowing agents reduce part weight and polymer consumption. Purge compounds reduce material waste and machine downtime during colour or material changes. Mould release agents reduce cycle times and the risk of part damage during ejection. Contact us to discuss your specific process and we can suggest the most appropriate additive for your situation.

Not necessarily. Depending on the requirement and production volume, an additive masterbatch can often be the more cost-effective solution. For example, UV stabiliser masterbatch can be added to a standard grade polymer for outdoor applications, avoiding the need to buy a UV-stabilised grade. Anti-microbial, anti-static, and anti-slip properties can all be introduced via masterbatch into material grades you may already have in stock.

Blowing agent masterbatch is widely used to prevent sinkage in thick-walled parts. Blowing agents introduce gas into the polymer melt, which compensates for volumetric shrinkage during cooling. They also reduce part weight, which reduces polymer consumption and can lower your material cost per part.

Yes. Multifunction masterbatches can be formulated to include two or more additives — and can also incorporate colour — so that you only need to dose a single masterbatch. This simplifies your process and reduces the number of materials you need to handle. These are made to order to your specific requirements. See also our Combi-Batch offering on the Masterbatch page.

Not always. Some additives can interact with or partially cancel out the effect of others when dosed simultaneously. We have extensive experience in additive formulation and can advise on compatibility before you commit to a combination. Contact us with your requirements and we’ll guide you through the options.

We don’t hold flame retardant masterbatch as a standard stock item, but we can source it on request. FR requirements vary significantly by application, polymer, and the specific standard you need to meet — UL94, BS EN, FMVSS, and others. Contact us with your polymer, wall section, and target classification and we’ll identify suitable options from our supply network.

An additive masterbatch is a concentrate — you dose it into your base polymer at a low addition rate, typically 1–5%. A functional compound has the additive pre-dispersed into the polymer itself, which you then process directly. Compounds offer better consistency and are more suitable for high-volume applications or where precise additive loading is critical. We supply both — see our Polymers page for information on functional compounds.

Yes. We supply additive masterbatch for a wide range of engineering polymers including PA6, PA66, PC, ABS, POM, PBT, and TPU. Some additives — particularly UV stabilisers and anti-static grades — have specific carrier and chemistry requirements for engineering polymers. Contact us with your polymer and application and we’ll confirm suitability.

Minimum order quantities vary by product. Some stock items have no MOQ. Made-to-order and specialist grades typically start from 5–25kg depending on the formulation. We will always confirm any quantity requirement before you commit. Contact us with your requirement and we’ll advise.