Diane here, focusing on the topic of how to design machinery for clean room applications. If a machine is to be used for food processing, medical use, or other sanitary applications, there are a lot of things to consider in the design. And of course, that means making sure the components utilized are appropriate for sanitary use as well.
The American Meat Institute has prepared an excellent checklist of things to consider when designing equipment of this nature.
1. Cleanable to a microbiological level: Food equipment must be constructed to ensure effective and efficient cleaning over the life of the equipment. The equipment should be designed as to prevent bacterial ingress, survival, growth and reproduction on both product and non-product contact surfaces of the equipment.
Our GN 5339.5 stainless steel triangular knobs were specially designed for use on machinery in the food industry. The smooth and enclosed areas as well as the corner radii comply with the requirements of hygiene standards.
2. Made of compatible materials: Construction materials used for equipment must be completely compatible with the product, environment, cleaning and sanitizing chemicals and the methods of cleaning and sanitation.
Our LWKX-TPA casters are corrosion-resistant and can withstand up to 110°C (230°F) sterilization by pressure steam cleaning, so they are perfect for medical, dental, instrumentation, hospital, food service and laboratory equipment.
3. Accessible for inspection, maintenance, cleaning and sanitation: All parts of the equipment shall be readily accessible for inspection, maintenance, cleaning and sanitation without the use of tools.
4. No product or liquid collection: Equipment should be self-draining to assure that liquid, which can harbor and promote the growth of bacteria, does not accumulate, pool or condense on the equipment.
The design of our GN 565.5 stainless steel handle is without hollows or other places that debris might collect.
Of similar material and design is our GN 949 stainless steel handwheel, also appropriate for sanitary applications.
5. Hollow areas should be hermetically sealed: Hollow areas of equipment such as frames and rollers must be eliminated wherever possible or permanently sealed. Bolts, studs, mounting plates, brackets, junction boxes, nameplates, end caps, sleeves and other such items must be continuously welded to the surface not attached via drilled and tapped holes.
Our GN 341.1 leveling feet are designed with a convex bolt head seat on the base to reduce the formation of deposits and simplify cleaning. The adjustable height sleeve shrouds the thread to resist accumulation of impurities.
6. No niches: Equipment parts should be free of niches such as pits, cracks, corrosion, recesses, open seams, gaps, lap seams, protruding ledges, inside threads, bolt rivets and dead ends.
7. Sanitary operational performance: During normal operations, the equipment must perform so it does not contribute to unsanitary conditions or the harborage and growth of bacteria.
Obviously one way to achieve this is the use of stainless steel components. Yet another example of our many all-stainless steel parts is the GN 300.5 adjustable lever.
8. Hygienic design of maintenance enclosures: Maintenance enclosures and human machine interfaces such as push buttons, valve handles, switches and touchscreens, must be designed, to ensure food product, water or product liquid does not penetrate or accumulate in and on the enclosure or interface. Also, physical design of the enclosures should be sloped or pitched to avoid use as storage area.
9. Hygienic compatibility with other plant systems: Equipment design must ensure hygienic compatibility with other equipment and systems, such as electrical, hydraulics, steam, air and water.
10. Validated cleaning and sanitizing protocols: Procedures for cleaning and sanitation must be clearly written, designed and proven effective and efficient. Chemicals recommended for cleaning and sanitation must be compatible with the equipment and the manufacturing environment.
“Keeping it clean” can be painstaking when you’re designing equipment. We’re here, as always, to advise and assist with your cleanroom machinery project.