Why Durable Floors Matter in Food & Beverage Plants

Mechanical, Chemical and Thermal Shocks

Floor and wall finishes must be able to stand up to the demands of the space they are in. In slaughterhouses, it is not uncommon for heavy hooks to accidentally fall to the floor sometimes or for heavy equipment to get knocked over. In storage areas, freezers, and warehouses, flooring must possess adequate mechanical resistance and substrate adhesion to handle constant wear and abrasion from frequent forklift and other equipment traffic. Flooring systems with low impact-resistance are the ones most likely to need frequent repair or replacement.

Aggressive cleaning agents are another potential danger. Floors with low chemical resistance not only wear down faster, but can also create traps where bacteria and viruses can hide.

Further stresses are caused by temperature shock. Some occurrences may be accidental, such as hot grease falling to the floor during potato chip production. Other occurrences, such as wash downs, are intentional. These procedures use liquids that often can exceed 100° C or steam that can be a lot hotter. The flooring system in place must be able to withstand frequent, rapid and often extremely wide temperature changes.

Durable floors begin with quality materials, good design and sound workmanship. The whole floor structure and each of its components (sub-base, load-carrying slab, screed and upper protective layer) are independent and work together to provide the required levels of performance and durability. If the ground and sub-base fails, for instance, the concrete slab may crack under heavy loads. Meanwhile, if the coating has limited resistance against chemicals, it may not be able to protect the slab underneath against deterioration.

Some examples of the many stresses affecting floors in food processing plants include:

• mechanical shocks and impact
• wear and abrasion
• exposure to chemical agents
• thermal shocks and extreme temperature variations
  
• high point loads
• dragging and shifting pallets
• falls of heavy objects, knives, hooks or other sharp objects

When it comes to chemical resistance, different floor coatings react differently
to the type of chemical, concentration, temperature, and exposure duration, and should be assessed individually. Among the most challenging chemicals are phosphoric or nitric acids and caustic or chlorine solutions used to clean production equipment, floors, and walls.

Other hazards are elements that are part of normal production, including lactic, citric, and acetic acids, blood, wet sugar, oils, fats, grease and more. It is important to note that even if the amount of these compounds is relatively low, evaporation can increase their concentration and corrosive properties.

Temperatures in a food or beverage plant can often vary widely and rapidly. For instance, the temperature of the floor adjacent to a freezer may range from 0° C or below to an ambient 21° C or higher. The flooring system must be able to function in both conditions.

What is more difficult to deal with is the thermal shock, which is caused by a sudden and large change in temperature, up to 100° C or more and then back again, in a few minutes or even seconds. Thermal shocks can be caused by high temperature spills from cooking, washing and cleaning of vessels and pans. It can also occur from hot CIP (cleaning-in-place) fluids and hot water rinses that are drained from production equipment onto the floor after high temperature cleaning and sanitation.

Thermal shock can cause the flooring system to crack and in some cases de-laminate. To prevent this, the floor should have a thermal expansion coefficient close to that of the concrete substrate below, good cohesive strength, and a low modulus of elasticity.

Thickness of the floor also plays an important part. The top layer should be no less than nine millimeters thick for water or chemical discharge temperatures from 90° C and above.

The greater the thickness of the floor, the greater its ability is to provide good
resistance to the many stresses and factors causing deterioration.

The recommended thickness depends on a detailed assessment of the type and magnitude of specific stresses the floor will encounter. For resin-based flooring in a food processing facility, the minimum thickness is three millimeters, while a thickness of six millimeters or more is better, especially in wet areas. For tile, the thickness range is typically between 8.5 to 20 millimeters thick, but a minimum of 12 millimeters will especially protect high load areas.