PECM Issue 44 2020 | Page 82

PROCESS TECHNOLOGIES THE PERFECT BLEND BROANMAIN PLASTICS Well colour me pink! That’s how Masterbatch works If you’re looking to achieve a splash of colour, texture or even anti-bacterial into your plastic components, chances are your moulder is using masterbatch in the mix. With the global masterbatch market set to increase in value to USD 15 billion by 2026i, Thomas Catinat, Operations Manager at Broanmain Plastics explains why masterbatch is so popular and how as a moulder they go about achieving the perfect blend to ensure consistency batch- to-batch. Masterbatch is commonly divided into five segments - black, white, colour, additive and fillers. Each formulation offers different functions that when distributed evenly through the polymer mix give it its unique plastic fingerprint. Colour masterbatch is a highly concentrated pigment. Supplied in pellet form rather than powder or liquid, it is blended into plastics to create a range of end-use applications, for example food and beverage packaging, appliances, automotive and pharmaceutical packaging. Additive masterbatch offers improved performance of plastic products, for instance illumination, UV resistance, anti-oxidants, antimicrobials or anti-static. Filler masterbatch is used to create better properties such as stiffness or a lighter weight polymer. Chalk, for example, is used to bulk out the plastic. Specific fillers can also be added to make a component fire retardant. Black and white masterbatch are typically used in building and construction, automotive, consumer goods and domestic appliances. Achieving a special effect, such as chrome, wood grain, stone, marbling and even sparkle is also possible. These types of compounds are often used to boost consumer appeal and mimic heavier materials. READY MIXED OR CREATE ON DEMAND? Compounded mixes might be purchased in bulk when creating larger quantities of 82 PECM Issue 44 Masterbatch colour is a highly concentrated pigment which moulders blend with base polymer resins and additives to achieve a special formulation (iStock.com/Irina Vodneva) components. But for many end customers, masterbatch is often the most cost effective way for moulders to create the perfect recipe time and again. Blended in-house, moulders use volumetric dosing units to automatically mix the material ready for processing. Using granular masterbatch can be a lot less messy than powders or liquid, with fewer health and safety risks from dust or spillages. customer’s requirement for pigment colour, as well as special properties like heat stability. JET BLACKS AND BRIGHT WHITES The ability to maintain a low stock holding and call up a specific blend when required from an external supplier can be more economical, helping to keep production costs down on short runs. For a number of components, such as electronics, producing the deepest blacks and the purest whites can be more challenging that some think. It requires a high pigmentation concentration, especially to make contemporary products such as mobile phones really stand out. Achieving uniform colour is critical. And although there’s usually a standard range of around 40+, there can be over 1000 different masterbatch formulations. Universal masterbatch offers convenience, are more readily available from suppliers and work with most polymers. The downside is not all universal masterbatches are compatible with all base materials. Conversely, polymer specific masterbatches are formulated using the same base polymer that it will be blended with. These tend to be bespoke and customised to suit a specific Typically, a white masterbatch is used to add opaqueness or whiteness into plastic products. Different grades of titanium dioxide (TiO2) are applied to reflect or scatter light. As well as outdoor applications, some whites are suitable for food contact plastics. One of the key advantages of the white masterbatch is it has a high rate of dispersion, so can easily incorporate other colourants.