What is the Difference Between Washdown Design and Sanitary Design?

Washdown machine design and sanitary machine design are not the same.

And the design you need depends on what type of product you are packaging and its accompanying health and safety requirements.

Understanding the difference between the two designs will not only help guarantee your line passes inspection and the delivery of a safe product to consumers, but also can save you money on your machine purchase.

Sanitary designed machines implement more intricate designs and materials than washdown designs to accommodate a variety of sanitary standards. Because of the intricacies and materials in a sanitary design, the cost will be higher than a washdown machine. Of course, every machine and situation is different.

“A customer once requested ‘a wash down, sanitary design infeed conveyor’ for a flow wrapper,” shares Hugh Crouch, Product Manager for Flow. “It was explained that we could do a sanitary design infeed conveyor, but we wanted to know if a sanitary design is actually what that customer needed. After learning the difference, the customer realized he simply needed a washdown design for the infeed conveyor, so it could be washed down if any product fell off the tray. The difference in price between washdown and sanitary design was significant.”

For a company looking to purchase a new machine, understanding the difference between the two designs will help you during consultation and negotiation with your OEM. So, what are the characteristics of each?

Sanitary design

To help OEM’s design sanitary machines up to industry standards, the AMI Foundation put together the Equipment Design Task Force (EDTF), which was comprised of meat and poultry industry leaders who have a significant interest in reducing the risk of contamination of food products by pathogens. The 10 principles they laid out for sanitary equipment design can be applied to all food industries.

These designs apply to not only production line equipment, but also packaging equipment.

1. Cleanable to a microbiological level. Construction design needs to prevent bacterial ingress, growth, survival and reproduction on product and non-product contact surfaces. Requirements for points of product contact and non-product contact can be different for sanitary vs. washdown designs.
2. Made of compatible materials. Materials must be compatible with their product, environment, and cleaning and sanitation practices. A general rule is to use stainless steel and avoid non-cleanable surfaces, enamelware, and uncoated aluminum, among other materials to avoid.
3. Designs should have parts that are easily accessible for cleaning, maintenance, and inspection without requiring tools to access the parts in question.
4. No product or liquid collection. Liquid build up can harbor and promote the growth of bacteria, so designs need to be self-draining to avoid liquid accumulation. Moisture can’t drip, drain, or draw into product zone areas.
5. Hollow areas, such as rollers and frames, should be hermetically sealed Items like studs, mounting plates, and brackets should be welded to surfaces.
6. Equipment shouldn’t have niches, cracks, pits, corrosion, open seams, bolt rivets, and more because of bacterial build up.
7. Equipment must perform as intended so faults don’t contribute to unsanitary conditions.
8. Hygienic design of maintenance enclosures. Push buttons, valve handles and touchscreens need to be designed so no product residue and water penetrates enclosed surfaces. Enclosures should be sloped or pitched to avoid water accumulation.
9. Hygienic compatibility with other plant systems. These systems could include exhaust, drainage, or automated cleaning systems. Evaluate any sanitation risks for the entire operation while they are in use, not just each system or machine individually.
10. Validated cleaning and sanitizing protocols. Clearly write out cleaning and sanitation protocols that are proven effective and efficient. Cleaning materials should be compatible with your equipment.

Sanitary design in use

The ULMA FlOW VAC 55 SD is an example of a sanitary designed machine. It automatically loads products inside vacuum bags, and this specific version is designed for the high hygiene requirements of the fresh food industry.

Below are several examples of sanitary designs and considerations that went into the design of the FLOW VAC 55 SD:

• Designed for quick and simple cleaning
• Protected from humidity, and uses stainless materials
• Hollow areas and niches have been avoided, product and liquid collection areas removed, and easily accessible for inspection, maintenance, cleaning, and sanitation.
• Has sloped cabinets and surfaces
• The cantilever design concept ensures that all the drive mechanisms are assembled in a frame that is isolated from the packaging process. This prevents any debris from the product or film scrap ending up in the drive mechanisms, thus reducing cleaning and extending the life of the components.
• The conveyor belt where the product is fed into is sealed on the sides and easily removable.
• USDA design criteria and FDA requirements are followed where necessary, including rubber components, the reel holder, and lubrication-free plastic.

If your product or industry requires sanitary designed machines, make sure the machine you purchase adheres to sanitary standards so it can pass inspections and helps ensure the delivery of a safe product to your consumers. In other applications sanitary design could be used, but consideration for washdown design is acceptable.

Washdown design

The main purpose of sanitary design is to prevent the pooling of water that causes growth of bacteria, which contaminates the product. However, what if your plant only uses water to wash off debris, and water that pools isn’t a concern? Or your plant doesn’t use water to clean its machines, and instead uses wipes to clean the surfaces? For these machines washdown design is acceptable.

What’s the difference between sanitary design and washdown design? It comes down to the level of detail. Here are several examples comparing the two:

• Sanitary design requires a specific stainless steel finish, while washdown design uses standard finishes.
• Hollowed areas and niches are minimized.
• Exposed threads are allowed, but should be minimized.
• Machine parts can be placed over the line and product.
• Slants for water runoff aren’t required, but are commonly added.
• Frames should all be welded shut.

The level of detail on a sanitary designed machine is so that water can’t get trapped or pooled and build bacteria, while also eliminating areas that can trap materials and harbor contaminants. The differences might not seem like much, but the more stringent requirements for sanitary design cost more to implement, and result in higher priced equipment.

Understanding the difference and identifying the correct design needed between sanitary and washdown design is critical, both for safety standards and for cost. If you’re looking into a new packaging machine and aren’t sure which to design to select, feel free to reach out to our team of packaging equipment experts. We’re here to help in any way we can.