Masterbatch is the way most plastics get their colour and their performance. This guide explains what it is, the main types, how it is dosed and what to ask a masterbatch supplier.
Masterbatch is a concentrated mixture of pigments or additives dispersed in a carrier polymer and formed into pellets. Instead of adding fine powders directly to a plastics process, a converter adds a small percentage of masterbatch pellets to the main resin. The pellets melt and mix in the extruder or moulding machine, and the colour or additive ends up evenly spread through the finished film, sheet, pipe or part.
Masterbatch is used because it is cleaner, safer and more accurate than handling raw additives. Powders create dust, are hard to weigh in small amounts and can clump, which leads to specks, streaks and weak spots. In a masterbatch the additive is already dispersed in polymer by a compounder with the right equipment, so the converter only has to feed pellets at a set ratio, usually between 0.5% and 5%.
Masterbatch is made by compounding. The carrier polymer, typically polyethylene or polypropylene chosen to match the customer's resin, is melted in a twin-screw extruder together with a high loading of pigment or additive. The screws shear and mix the melt so the particles are fully wetted and broken down, then the strands are cooled and cut into pellets. Gravimetric feeders weigh each ingredient continuously, which keeps the concentration consistent from batch to batch.
The amount of masterbatch added to the main polymer is called the let-down ratio or dosage. A ratio of 1:50 means one part masterbatch to 50 parts resin, or 2%. The right ratio depends on how concentrated the masterbatch is, the active level needed in the final product and, for film, the thickness: thinner film usually needs a higher dose of additives such as UV stabilisers.
Choosing a masterbatch starts with the polymer and process, then the end use. The carrier must be compatible with your resin, the additive must survive your melt temperature, and the grade must meet the regulatory requirements of your market, such as food-contact, REACH or Halal. A good supplier will ask about your line, recommend a starting dose and support a trial rather than just sending a data sheet.
Aviura makes functional and additive masterbatch: the grades that change how a plastic performs rather than how it looks. Our range covers UV stabilisers, antioxidants, slip, antiblock, anti-fog, processing aids, antistatic, flame retardant, antimicrobial and specialty grades for PE and PP, compounded in Malaysia with formulation led from the UK.
UV protection for outdoor and general film.
PE / LLDPE / LDPE · Outdoor and general film
Long-life UV protection, with agrochemical-resistant options.
PE / LLDPE · Greenhouse, mulch and agricultural film
Prevents condensation droplets on agricultural and food film.
PE / LLDPE · Agricultural and food film
Removes melt fracture and cuts die build-up.
PE / LLDPE · Blown film and extrusion
Non-fluorinated processing aid for UK and EU markets.
PE / LLDPE · UK and EU film and extrusion
Absorbs moisture in recycled polymer during processing.
PE / PP · Recycled polymer and film
Pigments or dyes that give plastic its colour, matched to a shade standard.
Titanium dioxide for opacity and whiteness in film, sheet and moulded parts.
Carbon black for colour, opacity and UV protection in pipe, film and cable.
Functional additives such as UV, slip, anti-fog, antistatic or processing aids.
Calcium carbonate or talc to reduce cost or change stiffness and printability.
Several additives, or colour plus additives, in one pellet for a single dose.
A carrier polymer, usually PE or PP, plus a high concentration of pigment, additive or filler, and sometimes a dispersing aid. The carrier is chosen to be compatible with the polymer the masterbatch will be added to.
A masterbatch is a concentrate that is diluted with natural resin at the converter. A compound is a ready-to-use material that already contains the final level of additive or colour and is processed as it is.
Most masterbatch is added at 0.5% to 5%, but the right dose depends on the concentration of the grade, the active level you need and the product thickness. The supplier's data sheet gives a starting range, which you then confirm in a trial.
Functional or additive masterbatch adds a property to a plastic rather than a colour: UV resistance, lower friction, anti-fog, static control, easier processing, flame retardancy and so on.
Send us your polymer, process and the problem you want to solve. We recommend a grade and starting let-down, then ship a 1 kg lab sample, 5 kg pilot sample or 25 kg line trial with TDS, SDS and batch COA.
Masterbatch has to prove itself on your extruder, not ours. This is the route every new grade takes.
Polymer, process, the problem to solve, and your current product if you have one.
A grade and a starting let-down for your line, shared with you shortly.
A 1 kg lab sample, 5 kg pilot sample or 25 kg line trial, with TDS, SDS and batch COA.
We review the results with your team and adjust dosage or formulation.
Price, MOQ and lead time fixed against the approved grade.