An ultracompact peristaltic pump made from a chemical and heat-resistant polysulphone material has been developed by Welco Company, Ltd.(Fuchu, Tokyo). The rigid, high-strength polymer enables the new WPM series pumps to be exposed to isopropyl alcohol and other chemicals and to withstand elevated temperatures.
Unlike conventional nylon peristaltic pumps that have a maximum operating temperature of 50°C, the new WPM-2 pump can operate efficiently and safely at temperatures reaching 80°C,” says Kenichi Ono of Welco’s Project Planning Div. “All of the parts are made from polysulphone, allowing the pump to be sterilised by autoclave at 0.1 MPa and 121°C for 20 minutes,” he adds. The company also plans to introduce a more-affordable alternative with some parts made from POM that will be able to withstand temperatures of 50°C. “The WPM-1, which will come in six colours, is designed for cost- and design-conscious customers, whilst the WPM-2 offers superior quality.
To facilitate pump assembly for a range of devices, the company has reduced the diameter of the WPM series pumps by more than 17% (from 46 to 38 mm) and made the pumps lighter (weight is approximately 83 g). Also, the top cassettes can be manually mounted and removed without tools, simplifying tubing replacement and maintenance. Even after it has been mounted, the top cassette can be adjusted freely in a 90º angle, increasing design flexibility, Ono says. The flow rates are 7 to 97 ml/min.
Welco has also designed and developed special gearmotors for the WPM series that feature silent operation. Operating at a 52 dB noise level, the machines are suitable for use at home and in the hospital, says Ono.
The new WPM series was developed in response to customer requests at the MD&M and Medica events in the United States and Germany, where the company often exhibits. Welco will present the new WPM series at this year’s Medica in Düsseldorf, Germany.
“To meet more diverse needs, we plan to add new variations to the WPM series by offering stepper motors or smaller motors, as needed,” Ono says. “A model with a flow rate under 1 ml/min is also under development.”
The WPM series pumps, which will be launched in September, are suited for dental and endoscopy sterilisation systems, drug testing, analysis and related applications. They are not intended for use with implantable devices, stents or similar products.
— Miki Anzai