FLOORS: Fit For The Food Industry

In the US, industrial facilities of all kinds are required to adhere to numerous federal government standards, and the food-processing industry is certainly no exception.

In warehouses and light industrial areas, and in industries not involved with consumable products, having uncoated concrete floors may be a perfectly acceptable choice. But in food-and-beverage plants, where cleanliness and purity are paramount, it is non-negotiable that concrete floors be covered with an appropriate protective coating, very often provided by seamless, hygienic-floor coating systems.

The floor of a food-processing facility is typically exposed to many types of food byproducts—such as fats, hot oils, blood, sugar solutions, and natural food acids. Some of these corrosive substances can cause serious damage to concrete. Additionally, contaminants can infiltrate uncoated concrete, resulting in the uncontrolled growth of bacteria—a food-safety hazard.

Coatings selected for application on food- and beverage-processing facility floors must be durable enough and thick enough to create a protective barrier that prevents contaminants from permeating the concrete substrate and ensures a hygienic surface. Coating choices Processors of foodstuffs face demands for hygienic surfaces across a variety of plant areas, all with differing corrosive conditions, such as for dry storage areas, cold storage rooms, and mixing, canning and slaughtering areas. Floor-coating systems have been developed to meet this range of service conditions, So, the type of floor coating used is one of the most important product specifications a food-processing plant manager can make. Options Floor coatings are available in several formulations: a) epoxies High-solid epoxies provide outstanding protection against acids and alkalis. Fast-drying, odorless epoxy mastics, epoxy primer sealers and surfacers are among the formulations currently available. These coatings offer a number of key benefits including outstanding adhesion; an excellent ability to withstand abrasive cleaning procedures and cleaning chemicals; fast curing properties for minimized downtime of the area being treated; plus compatibility with textured, anti-slip additives. Additionally, high-solids formulations are low in Volatile Organic Compounds (VOCs). A popular choice suitable even for clean-room floors is a self-leveling epoxy system utilizing a 100-percent solids-binder resin with a blended aggregate, which is easily applied with a notched trowel or squeegee and back rolled with a texture roller. When a rapid return to service is one of the paramount factors in order to minimize plant downtime, 100-percent solid epoxies are a wise choice for coating floors. Many operators of meat-processing facilities select 100-percent epoxy coatings because these coatings offer strong bonding characteristics, resistance to thermal and mechanical shock, and the ability to endure frequent cleaning with hot water at high pressure. They also may be used in areas where highly-acidic products are processed. b) urethanes Polyurethane coatings continue to be popular for flooring applications in the food industry. These coatings typically come in slurry form and tend to be somewhat more costly up front, but their service life often outlasts other product categories. In fact, these systems are making significant gains on epoxy and vinyl-ester flooring systems in many meat and poultry plants. Urethane cement slurry and mortar systems provide superior resistance to thermal cycling when compared to epoxy and vinyl-ester coatings in addition to providing excellent long-lasting performance. They also have very low odor during application and have a seamless, easy-to-clean surface when dry. c) methyl methacrylate Methyl Methacrylate (MMA) coatings are also used for food-and-beverage facility floors because they can be applied at relatively low temperatures, cure quickly, and are low in odor, reducing the risk of imparting an unpleasant taste or odor to processed foodstuffs. As a result, MMA coatings are often used in cold-storage areas such as freezer rooms. d) polyureas When environments demand tough, flexible and impact-resistant floors, polyurea coatings are an excellent choice. There are 100-percent pure polyurea coatings available that are USDA-acceptable and even UL-approved to the ANSI-NSF 61 Standard, so they are increasingly being used by tanks for holding potable water, as well as floor coatings for food-and-beverage industry floors. All polyureas are formulated with no VOCs, have no odor, and dry tack- free in as little as 45 seconds. These coatings are especially useful in food-processing areas since they provide a seamless and flexible surface that can withstand temperatures as low as -6°C to 121°C. Because of their elasticity, polyurea coatings are ideal for substrates such as concrete, which tends to crack. As an elastomer, these coatings have the ability to stretch and bridge gaps up to 1/8-inch. Due to this flexibility, polyurea coatings are not limited by temperature extremes. More rigid coatings tend to crack as the substrate expands or contracts because of differences in the coefficient of linear expansion. Traffic The volume and type of traffic is another important criterion in selecting a floor coating for a food-processing facility. Personnel safety and potential liability issues compel food-processing plant managers to ensure skid-resistant floors by using textured or grit surfaces. The degree of texture is typically determined by the conditions of operation, frequency of cleaning and maintenance, and presence of oils, greases and other potentially slippery substances. A high-medium grade of texture for food processing makes sense since these environments are often ‘wet’ either from cleaning agents or from the inherent exposure to oils and grease. Where high-impact and heavy loads are part of the traffic pattern, a flexible membrane may be applied beneath the floor coating. Cleaning Food-processing operation pure and up to government standards. Consequently, food-processing facility floor coatings must be durable enough to handle vigorous cleaning procedures, which typically include very hot water, steam, and aggressive cleaning chemicals. It is clear that only high-performance floor coatings will withstand this kind of punishing maintenance. On a typical day, floors are exposed to a variety of process chemicals as well as corrosive cleaning chemicals, primarily detergents. If a floor is subjected to only minor chemical contact, a thin film coating may suffice; however, if a floor is exposed to the variety of moisture, temperature, and chemical conditions typically found in a food-processing area, it is essential that the plant manager select a thicker, more durable floor coating that can offer sufficient protection to meet those conditions. In addition to the corrosive nature of the cleaning chemicals, the very hot, high-pressure steam used in daily cleanings can take its toll. The pressure alone is often capable of removing a standard coating, much like what happens when a deteriorating concrete driveway is pressure-washed. Because the cleaning process is performed repeatedly and at very high temperatures, it is crucial that the coating be thick and durable. Application conditions Yet another factor in selecting a floor coating for a food-processing facility involves application conditions. While these issues are typically not relevant for installation of floors and coatings in new facilities, they are indeed germane when updating or retrofitting an existing facility. Food-processing facilities are often very damp,sometimes cool or even cold,and sometimes hot–all in a typical day. The selected coating must be able to be installed under any and all of these conditions. Urethane-modified cementitious flooring systems, for example, can perform in steam heat as well as freezing or below-zero temperatures. Some of these systems also offer a rapid return to service which could be critical to plant operations. Our thanks to our sister publication Food Manufacturing for this article.