PNEUMATICS 30 HYDRAULICS & PNEUMATICS June 2022 www.hpmag.co.uk the number of components required. Tip 5: take advantage of new technologies There are new opportunities for achieving both the benefits of on-machine mounting The new ability to move the manifold from the control panel to the machine in the food zone cylinder delivers advantages, not the least of which is energy savings. Figure 1 shows the dramatic energy cost saving of moving a manifold out of the panel and closer to the cylinder: 50% in this example. The shorter the tubing length between valve and cylinder, the faster and more repeatable the cylinder’s cycles. Faster cycles improve performance (see Figure 2). In many applications, such as filling, more precise cycles achieve better control of the process leading to higher consistency in product volume and weight and less waste. The trend today is for smaller machines. Mounting valve manifolds on the machine allows control cabinets to be smaller or eliminated altogether, which can significantly reduce both cost and footprint. Moving the valve manifold outside of the control cabinet also eliminates pneumatic connections installed into the wall of the control cabinet, lowering machining costs in materials and labour as well as reducing '1.*),#/! B)*#8/5+! #*!)! $)*.5! B)1<#*.! B/2*(.+! B)*#8/5+! "2@#*7!5.*7(<! `^!;/! Z!;/! "2@#*7!=/520.! a]!64!! `b!64!! C35#*+.,!=/520.! `]!64!! `]!64!! "/()5!=/520.D1315.!! `^^!64!! [Z!64!! E**2)5!.*.,73!1/-(F! cd]Feb! ceVF^V! > Y A Y7 7 Y < c *Assumptions: 20 cycles/min, 16 hours/day, 300 days/year, 6 bar pressure, $0.35/1000 SCF Figure 1: Energy cost comparison between panel-mount and machine-mount manifolds Figure 2: Relationship between tube length and cycle rates – shorter tubing results in higher cycle rates and greater control flexibility. The Festo MPA-C IP69K-rated manifold, for example, can be configured with supply and exhaust ports on each valve slice. All ports for every position can be completely independent of the valve next to it. For complex pneumatic situations where several different pressure zones are used, this can be one of the most cost-effective solutions. For some applications, the designer may face the choice of either locating an adjustment point for easy access in a panel or on the machine where it may be difficult to adjust. The latter means losing all the advantages of machine mounting. The MPA-C allows the OEM to plumb each valve slice to a pressure regulator. This solution achieves both objectives: easy adjustment and machine mounting. Final thoughts There are other design considerations for food and beverage packaging applications such as selecting tubing materials that withstand harsh chemicals and resist plastic transfer to food. Hydrolysis-resistant polyurethane (PUNH) and Polytetrafluoroethylene (PTFEN) tubing are ideally suited for use in the food and beverage industries. Both resist cleaning agents, microbes, and hydrolysis and are FDA compliant. PUNH is more flexible and economical, while PTFEN is ideal for the harshest environments. Designers can use one of the many free online tools offered by Festo to size the pneumatic system appropriately so that the system runs as energy efficiently as possible. And of course, specifying air filtration units to achieve 0.01 µm filter with 99.9999% efficiency is a must. It is the five tips, however, that lay the foundation for compliance, utilisation, and performance in food and beverage packaging applications. The MPA-C manifold, top centre, is installed in a difficult to adjust position. Proportional pressure regulators, lower left, plumbed to the manifold, solve the adjustment problem.
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