Plastics replace metals in pneumatics

Paul Boughton
Festo is introducing a family of technopolymer-based products for the high-volume, cost-conscious industrial control markets. The new product line includes air preparation units, compact and ISO cylinders, one-way flow control valves and a series of solenoid-operated valves and valve terminals. All of these products are said to offer significant cost savings over their traditional counterparts.

Festo's new DSNUP series of pneumatic cylinders, for example, feature end caps made from a technopolymer (IXEF 1022, a 50 per cent glass-fibre reinforced polyarylamide compound), stainless steel piston rods and aluminium barrels, and have a list price that is some 30 per cent lower than their interchangeable all-metal DSNU counterparts. Available with piston diameters of 16, 20 and 25mm, the DSNUP cylinders feature ISO swivel mounting and threaded end and bearing caps to simplify installation.

The company is also introducing compact cylinders with technopolymer end caps incorporating push-in tube fittings. These ADNP cylinders cost 20 per cent less than their equivalent all-metal versions. The cylinders are suitable for simple automation tasks such as controlling gates and flaps, and for simple clamping and holding functions. Their high resistance to chemicals makes them suitable for food processing and packaging applications, and their low weight will prove particularly advantageous to OEMs developing automated handling systems.

Festo is also launching a series of technopolymer-based valves that are available as individual components or as fully assembled and tested valve manifolds. The new VB12 valves feature a body moulded entirely from IXEF 1022, resulting in a very cost-effective, low-weight design. Complementing the existing 20mm wide-bodied range, the valves accommodate air flow rates from 200-1000 litres per minute. Festo performed extensive analysis of the valves to determine the optimum design that provides a similar rigidity to metal vales, as well as ensuring good leakage values and preventing any misalignment of embedded contacts. This analysis included forensic materials science techniques using dynamic x-ray analysis. Detailed thermal analysis – using worst-case scenarios of overdriven co-located solenoids and elevated ambient temperatures – confirmed that the valves provide 100 per cent reliability at ambient temperatures of up to 50 degrees C.

Steve Sands, Festo's Product Manager, comments: "The shape of the pneumatics market is changing. 'Fit for purpose' has been spoken about for a long time but, as credit and cost squeezes continue, the focus is becoming very clear. The market is becoming increasingly polarised by the demand for higher technology or highly adapted products at one end, and basic low-cost products at the other. And despite the obvious sales potential for low-cost products, this is not Festo's traditional market strength, and we have not entered this market lightly. Festo has conducted a rigorous materials research and development programme to develop the necessary computer-based modelling and analysis tools to ensure that we can utilise the right materials in the optimum way. With our manufacturing experience and volumes we now consider it technically and commercially viable to replace more metal parts in pneumatic valves and cylinders with injection moulded components. The use of polymer materials achieves only a part of the potential savings; equally important are the ongoing innovations in manufacturing, assembly and logistic processes to help hone down the total production costs."

Sands also points out that these new products from Festo are likely to enjoy rapid market take-up: "We believe that the introduction of these high-quality, low-cost pneumatics products represents a major opportunity for UK-based OEMs and systems integrators who, until now, have struggled to compete with companies that use unbranded low-cost imports."


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