Food processing machinery requires daily cleaning with chemicals. Even the smallest blind spot can collect moisture and can lead to contamination in the machine. More and more machine builders are therefore designing parts with a more hygienic design. igus is a member of the European Hygienic and Design Group (EHEDG) and has now developed the first linear guide system that is based on EHEDG hygienic design guidelines.
Using FDA-compliant materials such as the high-performance polymer iglidur A160 and a high-alloy stainless steel, and carriage design with a washable interior, means the design adheres to hygienic standards.
Special rules for hygiene in machines apply in the food, pharmaceutical and cosmetics industries. It is important to ensure that contamination on products is eliminated. Therefore, machine builders and plant operators ensure they design and use parts with the best materials for the components. Best case, these comply with the FDA (US Food & Drug Administration) and EU regulations.
"More and more customers want an optimised design based on hygienic design principles, looking for parts with an open design that can withstand regular cleaning processes with chemicals, steam and high pressure water," says Rob Dumayne, drytech director at igus UK. Companies are now demanding lubrication-free components that can be cleaned quickly, ensuring downtime is reduced. Plastics specialist igus has now developed a drylin W linear guide which meets specific hygienic design guidelines. It has joined design group the EHEDG, an association of suppliers to the food industry, universities, health authorities and research institutes
Trap-free design for cleaning, with the right materials
The main challenge was how to construct a trap-free design.
The focus was on designing a self-draining carriage and rail that would allow liquids to drain freely without trapping water. "This is a brand-new innovation for the linear technology market,” says Dumayne. “So far, most hygienic design solutions have been based on a completely enclosed unit – a design that is sub-optimal for cleaning." The new self-draining carriage is made entirely of the high-performance polymer iglidur A160, one of the FDA- and EU10/2011-compliant igus materials.
The lubrication-free solution has already proved itself as a plain bearing material in numerous applications in the food industry. Hygienic lead screws and large grooves are also used to prevent water from accumulating and bevelled edges allow cleaning solutions to run off easily. The bottom seal protects the space under the rail from dirt accumulation, ensuring that no particles of food can be caught.
The shafts are also sealed to prevent any gaps from collecting debris. A corrosion-free 316 stainless steel is used for the linear rail to avoid microscopic surface structures developing, preventing dirt from adhering.
