Using these six classifications can help food companies make better judgments about the best ways to invest in conveying equipment. In addition, they can establish a benchmark from which to be judged during customer audits.

Dry level

Dry level refers to areas of the plant where sanitation isn’t required. Typically, this would be a warehouse or case-handling line dealing with packaged goods. This conveyor design level can be cleaned using compressed air or a dry cloth. 

The focus would centre on a rugged, durable design, as opposed to anti-bacterial considerations that would add to the cost. In this economical conveyor design, 12-gauge coated mild steel material is used with bolted construction. Formed angle or pedestal supports will be common, as these bacteria-hiding crevices are not an area of concern in this setting.

Instead of stainless steel components and enclosures, NEMA 12 motors, junction boxes and disconnects are used. Money is saved as less expensive equipment is used for an environment where cleanliness isn’t a priority.

Wipe down

Wipe down conveyor designs typically are used for handling sealed containers when they’re conveyed to secondary level packaging operations, such as cartoning or case packing. This design also may be used to transport empty containers travelling to, but not in, the filling area. Equipment is wiped down or washed with mild detergents in the event of a packaging leak.

The focus is on conveyor durability and economy. The wipe-down level has the same basic construction as the dry level. However, investment in stainless steel belt pulleys and other supporting components can offer better service to cleaning for bacterial resistance due to occasional packaging defects. 

One significant upgrade is the use of NEMA 4 stainless steel motor and control enclosures.

Washdown

A shift into more demanding cleaning environments is the base washdown conveyor design. In processing basic, noncultured food items such as bakery items or snack foods, the base washdown design can tolerate low-pressure washing with moderate use of corrosive chemicals for cleaning.

Food-grade polymer bearings and housings and stainless steel frames now are part of this conveyor’s design and construction. Use of stainless steel frames and NEMA 4X enclosures for the motor and motor controls significantly improve sanitation levels. Sanitary channel or square tube supports also eliminate hiding places for debris and bacteria. Corrosion-resistant coatings are used on reducers, instead of paint.

Sanitary Level I

Sanitary level I conveyors handle more sensitive food products, such as ice cream. These applications demand more extreme caustic washdown procedures, such as antibacterial foams and demand significant component and construction investments, such as:

• Use of bolted stand-offs for improved cleaning capabilities between areas of guide-rail brackets, supports, bearings, splice plates, drop-out covers, electrical disconnects, photo-eye mounts and junction terminal boxes

• Continuous non-pitted welds 

• Heavy washdown duty motors, reducers and chain

Features may include cleaning-in-place/sterilisation-in-place systems.

Sanitary level II

Heavily caustic cleaning agents will be part of standard operating procedures at this level, as well as clean out-of place/removable (COP) components. This level further validates the quality assurances necessary for these types of food production capabilities.

All conveyor frame surfaces and components are stainless steel in the Sanitary level II design. Also, more welded surfaces translate to fewer fasteners and spacers that could potentially serve as hiding places for contaminants. Even the finished surfaces will demand a bead-blast finish, in preventing against the formation of small divots or scratches that could serve as bacteria breeding grounds. 

Sanitary Level III

The Sanitary Level III is an all-welded, sealed tube design also using bead-blasted stainless steel material. This construction level can be used to convey starched food products or other raw food, with extreme high-pressure caustic washdown requirements. This design is evidence of the trend toward increased cleaning efficiencies, and the prospects of even greater sanitation with the option of homogeneous belting.

This belting features an endless solid polyurethane composition with low tension. A sprocket and gear drive without hinge points provides optimal sanitation levels in handling raw foods, and also reduces maintenance.

Streamlined approach

Defining and positioning six levels of conveyor construction allows the OEM to streamline engineering processes and create better price points for universal components. The six levels of conveyor construction described in this article are designed to help food manufacturers match the right equipment with the right production application when investing in food-plant automation equipment.

Nercon Engineering & Manufacturing is a machine builder partner in the Rockwell Automation PartnerNetwork.