"Self-funding" peristaltic pumps

"A self-funding investment - a Finance Director's dream" is how Colin Paine, MD of Casp Products describes the outcome of his company's decision to introduce Watson-Marlow peristaltic pumps into their production process. "Since the pumps were installed in March this year improved dosing accuracy has increased production yield by 5 to 8%."

Watson-Marlow pumps are used for high precision dispensing of viscous nutrient media at 50°C on to Dipslides - double-sided plastics paddles - with the nutrient dispensed to "wells" on each side. Manufacture, carried out entirely in-house in a cleanroom environment, is a continuous process with a typical shift involving more than 5000 individual 3.5 ml dispense operations, each of which must be completed in under one second.

A consistently high standard of volumetric accuracy, ease of maintenance and all-round reliability are crucial factors. The dosing cycle is part of a continuous mixing, blending and sterilising process and downtime will have a knock-on effect leading to loss of product. Inaccuracy is costly. If drift in volume occurs during a run, this leads to over/under filling of the wells, rendering the slide un-useable and consequently wasted.

Originally dosing was carried out by an analogue dispensing system, but factors such as ambient temperature and variations in gearbox grease viscosity during the operating cycle caused drift and loss of accuracy. On-site trials of a 505Di dispensing pump with twin 313 pumpheads operating in parallel were arranged to prove the pump's suitability. Colin Paine and his colleagues admit to initial reservations about the level of accuracy attainable, but now say the system "exceeds expectations, even on long term dispensing cycles".

More information on 500 Series pumps.