Patented USIT® components revolutionize hygiene-sensitive production areas

Iso view: relaxed and tense screw connections (Image Novox KG)

Isometric view: Loss safety of the screw (left) and alternative loss safety of the screw (right).

Special hygienic screws according to Hygienic USIT® for use in hygiene-sensitive areas represent a breakthrough in process technology. The components of NovoNox KG, equipped with sealing and washer discs from Freudenberg, ensure high hygiene standards and significantly facilitate cleaning procedures. For even greater safety, the company is now entering the market with an extension of the patented USIT® line.

Innovative system compensates for weaknesses

According to Machinery Directive (MD), fastening parts on machines must be tamper-proof. To reliably prevent contamination with germs and bacteria in hygiene-sensitive production areas, the components used here also feature tightness and smooth surfaces. Based on the high requirements for hygiene standards and the goal of making cleaning processes easier and more efficient, NovoNox developed patented hygienic USIT® screws in cooperation with Freudenberg Sealing Technologies.

Proven success: The innovative NovoNox system with rounded edges, chamfers, low head, and the screw collar for use with the USIT® disc offers absolute tightness and thus resistance to contamination. Additionally, it enables easy cleaning processes and a chip-free security against loosening. Removing or replacing damaged screws can also be achieved by simply unscrewing the safety disc: cleanly, quickly, and without any chip formation.

Conventional systems are inadequate

Conventional screw systems do not provide this. Although screws can be fixed to machines with a safety band to prevent loss, such a solution is unthinkable for use in hygiene-sensitive production environments. As a result, open penetrations and too many gaps hinder easy yet thorough cleaning. Cleaning processes such as CIP (Cleaning in Place), SIP (Sterilization in Place), or WIP (Wash in Place) are impossible under such conditions.

Components currently available on the market also possess other properties that are unsuitable for use in hygiene-sensitive areas. While EU regulations can be met here, for example through the retrofitting of standard screws with a tapered disc over the shank, this is only possible with a conical disc that can be slipped over the shank. The pressure generated during tightening causes such a strong tapering that removing the conical disc from the remaining threaded part becomes impossible or only possible with damage—undesirable chip formation included.

Issue: tightness and security against loosening

Another problem arises from sheet metal covers that do not sit properly on the machine body. Since the safety disc acts as a spacer, a gap forms between the cover plate and the machine. Using sealing strips is ineffective here, especially since thin sheets often lie wavy due to internal stresses. Overflowing milk, porridge, drinks, cleaners, or water from rinsing can pass through the gap and reach the internal screws, leading to dangerous contamination.

These dangers are eliminated with the new safety components. The system guarantees absolute tightness and has no dead spaces. At the same time, it accounts for the necessary security against loosening. The key feature is vulcanized wedge segments made of EPDM, which sit in the inner bore of the integrated sealing disc. When slipping onto the screw shank, the wedge segments are pushed aside. When the thin shank is reached, these elements automatically fold back into their original position. As a result, the sealing disc and security against loosening are 100 percent centered on the thin shank.

More safety and options

Since their market launch, the existing USIT® range has enjoyed high demand. With the new system and extensions to screw head variants with high head, ball head, low head, and ball head with safety drive, even more individual customer requirements can be realized. Whether functional criteria, space requirements, or safety aspects: with the current expansion of the USIT® offering, users are better protected against germs and particles and are on the especially safe side in hygiene-sensitive manufacturing areas.