Polyurethane Resin Dispensing

Watson-Marlow Bredel Pumps case study: Polyurethane resin pumped using OEM peristaltic technology

A company that produces machines for applying distinctive resin ‘domes’ to labels is using Watson-Marlow Bredel’s OEM pumps for the dispensing process. The machines are also sold to other label producers in Europe and across the US.

Peristaltic Polyurethane Pumps

Based at Ashton-Under-Lyne in Lancashire, Mockridge Doming Systems is a division of Mockridge Labels and Nameplates Ltd and, for the past five years, has been manufacturing machines for dispensing polyurethane resin on to printed and cut labels. When cured the resin provides a decorative and durable clear lens coating to the printed image, commonly referred to as a dome. When looking for a reliable and cost effective solution to pumping the resin from the delivery containers in the machines, Mockridge selected peristaltic polyurethane pumps from Watson-Marlow.

“The main reason for this choice was the fact that this type of pump does not come into direct contact with the resin,” says Divisional Manager Stuart Lord, “which is important as polyurethane resin is affected by moisture and this can damage the finished product by introducing small bubbles of air into the surface of the finished dome.”

Mockridge uses two 501FAC/RL fixed speed OEM pumps on each machine for the two products that make up the curable dome (resin and hardener). The two should not be brought into contact with each other until being applied to the label. Mockridge also selected Marprene tubing, which in combination with the pump provides a closed loop delivery system.

Resin Dispensing

Peristaltic pumps have no valves, seals or glands. Nothing but the hose or tube touches the fluid, eliminating the risk of the pump contaminating the fluid or the fluid contaminating the pump. The 501 FAC/RL is a single channel OEM pump and is made up of a 501RL spring-loaded pumphead, an induction motor, Watson-Marlow’s purpose designed gearbox and a faceplate. The pumps are available in a choice of two voltages and four speeds, providing flow rates up to 2700ml/min from 8.0mm bore tubing (3240ml/min when used at 60Hz). The pumphead features rapid and simple tube loading, accepting seven tube sizes without adjustment.

“Mockridge chose Watson-Marlow both on reputation and customer support,” continues Mr Lord. “In the early days of development the support received from the sales engineers was invaluable and, together with the loan of different pumps for evaluation, made the decision easy to choose Watson Marlow as the preferred supplier. We have now installed 36 peristaltic pumps into various systems and they have proved to be very reliable and virtually maintenance-free in operation.”

The company has been so impressed with peristaltic technology that it is now considering Watson-Marlow OEM pumps as the complete solution to polyurethane resin dispensing from container to dispense point, as well as a possible pumping solution for a lower-budget unit.