While processing lines dealing with fragile items such as electrical components have embraced the benefits of Non Contact Transfer systems, the food and beverage sector has lagged behind. However, Trevor Osborne of Bosch Rexroth says that may be about to change.
Non-Contact Transfer systems (NCTs) are a tried and tested method of efficiently processing fragile items of up to one kilogram. Using the Bernoulli principle, airflow under the NCT device creates a vacuum and lifting force. The product is lifted by this force and if it is in danger of coming too close to the hard surface of the NCT the streaming air can reject the product in order to protect it.
By this method, objects can be moved accurately with no need for any surface contact which, in addition, means that the product can remain sterile if required. Crucially, the non-contact nature of the method reduces the potential for contamination or damage, successfully reducing wastage costs.
The ability of NCTs to handle fragile items has been widely accepted in the electronics, printing, telecommunication and pharmaceutical industries. In theory, this same approach would seem ideal for easily breakable food items which would also benefit from minimal surface contact. However, most NCT units are made from aluminium – a material which is not approved in the food and beverage industry in keeping with the standards set by the European Union (EU) and the United States Food and Drug Administration (FDA).
Alternative methods currently used in food and beverage, such as suction cups, pose other challenges, including high levels of contamination which might be a particular issue in a powdery environment which is often the case when processing bakery products. This has exposed a requirement for an NCT solution to meet both the approved material and stringent hygiene standards which are demanded of the food processing sector.
The answer was a NCT unit made from Polyetheretherketone (PEEK), now known as NCT-PK which is functionally identical to the aluminium version of the NCT but has some crucially different characteristics. As an organic polymer thermoplastic, which is highly resistant to thermal degradation or contamination, PEEK passes all EU and FDA standards. This makes the NCT-PK the ideal solution for handling processes in a food and beverage environment.
The use of PEEK not only meets the right criteria in terms of material standards, but offers various performance benefits. The lifting force remains unaffected by soft, porous or dusty work pieces, ensuring its efficiency remains constant in environments where contamination of the system would result in costly down time. PEEK is also designed to withstand daily cleaning, making it compliant with all conventional CIP (Cleaning-In-Place) and SIP (Sterilisation-In-Place) practices. The NCT-PK can also be permanently marked which removes the need for unsecure labeling.
An NCT-PK has a minimum working press of 1 bar and a maximum of 7 bar with a typical working press of 5 bar. Lifting force is delivered by mounted friction pads in silicone which is an ideal substance for food handling, due to its hardness. The silicone is fixed to ensure that the pads cannot accidentally fall out.
The NCT-PK which is only available from Rexroth, is a unique solution for the food and beverage industry and one which can improve processing efficiency and save money through reduced waste. Thanks to the innovative application of PEEK in the place of aluminum, these benefits are now also being extended to solar, semiconductor and electronic industries.