Pump company develops bespoke dispensing equipment for plastics processing industry

ColorMatrix Europe is part of the larger ColorMatrix Corporation, a global leader in liquid colorant and additive technologies for the plastics industry, serving both the injection moulding and extruding sectors.

One of the latest products to be added to the ColorMatrix range is the CM500 dosing unit that can dispense up to 1.66 ml/s with injection moulding or extrusion machines. Commonly handling colorants, the unit can also handle a variety of additives such as scavengers which prevent packaging tainting the taste of foods and beverages, as well as enhancers to improve material processing properties, UV absorbers and slip additives.

Many of the colorants are based on mineral or vegetable oils and generally the fluids are neutral, but viscosities can be as high as 12000 centipoise (similar to corn syrup).

The only practical pumping, metering and dispensing method for such fluids is by peristaltic pump. So, rather than develop a pump from scratch, ColorMatrix decided to prepare a detailed specification and use a know manufacturer to design, develop and produce the unit. Watson-Marlow Bredel, the world's leading manufacturer of peristaltic pumps, was awarded this contract.

In a typical application, the unit may dispense 40 or 50 different colours in a day, so it is important to have quick changeovers with no need for cleaning. Watson-Marlow Bredel was able to offer a pumphead that allows the tubing to be changed without tools and with automatic tube tensioning. While most customers use 4.8mm bore silicone tubing, low-dose applications can utilise a smaller tube within the same pumphead. For aggressive fluids, Watson-Marlow Bredel's Marprene tubing can be specified.