Exclusive article for BRITISH PLASTICS & RUBBER

Custom masterbatch formulations produced and delivered in less time than it takes to source a standard off-the-shelf product could signal the end of stock colours and the compounding of certain polymers, argues Tony Gaukroger, Managing Director of ColourTone Masterbatch Limited.Many factors have contributed to this fundamental change in market position. Driven by pressure to reduce stock holding of materials, the advent of JIT (Just in Time) and demands to get products into the retail chain as fast as is humanly possible, processors are seeking greater levels of service. Fortunately the latest polymers, additives, equipment and processing technology have provided the tools to meet these needs by enabling the formulation and manufacture of bespoke masterbatches that can be introduced to an increasing range of base polymers at dosages unheard of 20 years ago.

Even the difficulties of colouring polymers with a strong base colour, e.g. ABS and filled materials, can now be overcome as developments in polymer technology have created materials that can accept higher loadings of additives and advancements in processing machinery allow them to be made and converted into products. Processors no longer have to purchase a stock universal masterbatch that yields a different colour in every polymer.

Too many colours
How often have processors been offered a choice of 250 colours and still not found the one they want? And why so many colours?

To understand why so many stock colours are offered you have to look at the market back in the 1970s and 1980s. At this time there was less focus on colour and therefore not so much demand for bespoke shades. Hence, manufacturers enjoyed the freedom to produce a selection of colours in universal carriers for use across a wide range of polymers. They would run yellow first, then orange, red and brown colours etc. to opitimise efficiency by minimising cleaning downtimes. Lead times for custom colours were, as a result, determined by their position in this manufacturing cycle.

Often production was geared to meet output targets set by accountants preoccupied with performance based on capacity and plant utilisation rather than earnings per machine and overall profitability. Market conditions allowed this situation to prevail and as pressure on delivery increased, in tandem with demands for fresh, new, colours, manufacturers responded by producing more stock colours.

Long term this strategy is doomed to failure. Just how many colours should be produced to meet customer requirements for a particular shade? What is the cost of stocking a minimum quantity of 25kgs of each of 250 shades, i.e. 6.5 tonnes of premium priced material? The whole idea simply does not make economic sense.

Perhaps this is why some markets avoid the issue altogether and tell customers what they can have. For example the motor industry generally offers a fastidiously researched, but severely limited, choice of colours when it introduces a new model. But then when it comes to colour matching within the vehicle itself, plastics producers and processors find themselves up against some of the most stringent standards for colour control and consistency.

Colour and marketing success go hand in hand. Colour adds value. These days colour consultants work with designers to create unique combinations of colour and shading that will appeal to customers. A decade ago you chose from a colour card. Now, virtually any colour can be matched and achieved in plastic, paint or fabric. Products are now marketed with built-in obsolescence that is directly influenced by colour.

Production efficiency

As masterbatch production efficiency has improved, mainly through developments in machinery and electronic process control, as well as polymer and additive technology, it has become easier to incorporate more pigment into base polymers and so produce stronger (more highly concentrated) masterbatches. Modern compounding extruders distribute and develop additives more efficiently than earlier models. They also enable faster cleaning and so reduce downtime during colour and material changes.
Conversion plant - injection moulding, extrusion machines etc - is now designed to process these sophisticated materials and to run masterbatches down to 1 per cent dosage or less.
Then there is the advancement in logistics. Virtually any polymer or pigment can now be sourced within hours and deliveries can be geared to match. Overnight, next day deliveries are now the norm across the UK as well as overseas.

Taking these factors into account it is now possible to produce masterbatches in a wider range of polymers and for more users to benefit from them.

ColourTone has successfully produced polymer specific and engineering polymer masterbatches in many materials including ABS, PA, PC, PE, PET/PBT, PMMA, POM (acetal), PS, PVC and TPR.
Two notable developments include a polymer-specific colour masterbatch for rigid PVC that makes it as easy to colour PVC as any other plastic material. Thought to be a world first, this material (patent applied for) has the potential to turn the PVC processing market inside out by allowing processors to cash-in on the benefits of lower polymer costs, reduced stock holding and the production flexibility offered through using masterbatch.

An acetal masterbatch for use in copolymer and homopolymer injection moulding grades, produced to meet demands from trade moulders, serves as another example of what can be achieved. Colour matched to customers' requirements this polymer specific acetal product can be made as special blends that include additives such as molybdenum disulphide. Dosage rates fall within 1-5 % depending on colour, properties, and intended application.

However, continuing high demand for certain colours proves that the market for universal stock colours remains active for the time being. The question is, how long can it compete against colour matched material, in a base polymer of choice, delivered in the same time-frame?

Tony Gaukroger
Managing Director
Colour Tone Masterbatch Limited
Pant Glas Farm Industrial Estate
Newport Road
Telephone: +44 (0) 2920 888910
Fax: +44 (0) 2920 868487

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