A high-tech coating system is delivering a monolithic surface that is ‘shaped’ to facilitate plant wash downs and eliminate the cracks, voids and seams where Listeria and other contaminants thrive. By Doug Commette
With increasing amounts of news stories on food processing facilities pulling product off the market and being temporarily shuttered due to potential contamination from Listeria Monocytogenes, the issues of plant sanitation, design and construction are at the forefront of the industry.
At issue are food and meat processing plants in ageing industrial buildings with endless nooks and crannies, as well as right-angled construction. In these plants, walls and ceilings are often constructed with angled steel, i-beams, concrete block, interlocking metal and fibreglass panels, double-t ceilings and tiles with concrete grout.
This provides a virtual breeding ground for standing water, dirt, dust, mould, and pathogens such as Listeria, E. Coli and Salmonella. With so many cracks, pits, and seams, plants are at risk despite aggressive power washing and chemical sanitation techniques.
Product recalls from Listeria
The fallout from a public recall due to Listeria extends well beyond the lost revenue from an extended shutdown and loss of inventory. Litigation due to consumer illness (and even death), as well as the devastating impact to the brand’s reputation can literally put a processor out of business.
In the US market, on April 20, 2015, frozen desert maker Blue Bell Creameries voluntarily recalled all of its products on the market made at all of its facilities due to potential contamination from Listeria. The difficulty with Listeria is that it is good at evading detection. It can aerosolise or attach to equipment and people, and will thrive in cold temperatures. As a result, it is difficult to control in the processing environment.
To combat this pathogen, many facilities rely on a robust sanitation programme to prevent Listeria from entering or contaminating the environment. In addition, many processors engage in ongoing environmental sampling programmes to monitor the efficacy of those efforts.
If any bacteria or contamination is detected, called “testing hot,” it can result in an immediate shutdown. Closing a food processing plant that is running 24 hours a day, seven days a week, can cost the processor millions in lost revenues. There is also the risk of fines by the USDA for repeat violations.
In most instances, companies simply respond to a positive test by performing intensified cleaning and sanitisation. Once the company’s follow-up sampling of the affected sites is negative, the issue is typically considered to be resolved.
In addition to concerns about bacteria, contamination also comes from facility maintenance issues, such as chipping paint, spalled and cracked concrete, and areas in the walls and ceilings that can collect dust, dirt, mould and other contaminants.
Until now, the costly and labour-heavy solution was simply to clean more often and mitigate the problems using FRP panels or layer upon layer of paint to attempt create a cleanable surface.
However, the aggressive cleaning agents such as bleach and detergents and heavy high pressure power washing cycles take a heavy toll on the paints, epoxies, concrete, fibreglass and metal surfaces, eventually wearing them away until they need complete replacement, or even worse, they jeopardise a plant shutdown and/or fines. This is a very costly, labour-intensive programme that repeats itself in perpetuity at the majority of food processing plant across the world.
To address this issue, new techniques are being used to deliver a complete rehabilitation of the walls and ceilings, often during planned maintenance weekends. At the forefront is Fixxus Rehabilitation Systems, a company that performs this type of work for well-known Fortune 500 food processors.
Through a process of structural rehabilitation, precise surface preparation, retrofit design modifications, and a high tech food-grade protective polyurea coating and topcoat, Fixxus delivers a monolithic liner that eliminates all existing chips, seams and gaps. Furthermore, the space is “reshaped” through this process so only smooth, curved lines remain to eliminate areas where water, dirt, grime or pathogens can accumulate.
“We prep the surfaces and fill in all the joints, protrusions and seams,” says Danny Cook, CEO of Fixxus. “Our goal is to deliver a monolithic system so that when staff wash down there’s nowhere for water to stand.”
One of the key elements of the Fixxus process is application of an extremely fast curing, pure polyurea coating designed for use in food processing plants. Since the material is spray applied, it can be applied quickly by trained applicators and built up to any required thickness and shaped into the modified wall and ceiling design.
According to Cook, polyurea is the only coating system that can create a monolithic surface in the short time frame required to minimise plant downtime. “Most other coatings take one to four days just to cure, which is too long when you need to get the plant back on line. Polyurea cures within minutes,” he explains.
Fixxus Systems uses a private label formulation of pure polyurea for food contact facilities from VersaFlex, a global supplier of high-performance polyurea coatings, liners and joint sealants for a variety of industrial environments. The company offers two systems that are third-party rated for FDA Direct Food contact.
“VersaFlex designed a formulation for our use and this type of application,” says Cook. “The company worked with us to make adjustments on the cure time, the gel time and the topcoat.”
Due to the aggressive nature of plant wash downs, a custom polyurea topcoat is required to complete the process. The final topcoat creates a very slick surface, making it difficult for standing water, dust, dirt or bacteria to take hold. To complete all this work, Fixxus works with the food facilities to plan and optimally time rehabilitation operations. This keeps plant, or area, downtime to a minimum.
“These plants typically have only two to four days to get the work done,” says Cook. According to Cook, completing the work in as little as a weekend or even four days is no small task. Most jobs require 15-20 workers, including a trained spray applicator.
Having worked in hundreds of food processing, cleanroom and pharmaceutical-grade facilities, the company is experienced in the details and standards for cleanliness and sanitising. The entire workforce is fully trained on the smallest of details from wearing hairnets to wash down procedures.
Before any coatings are applied, there are multiple steps to rehabilitate an ageing food facility. No amount of cleaning will properly prepare a surface that requires repair. So the first step is to address any areas with spalled or cracked concrete, chipping and peeling paint, or heavy corrosion.
The next step is an intensive cleaning process to remove grease and grime and other surface contaminants that build up as a result of meat processing, cooking and general facility maintenance. This involves using specially approved wash down solutions and self contained high powered water blasting techniques.
Then all holes, voids, seams and penetrations are filled, along with additional modifications for the reshaping. For example, a combination of concrete and moulded foam materials are used to transition any flat surfaces from 90° to 45° degree to prevent standing water from accumulating.
These areas typically include the cove joint from wall to floor, steel I beam bases, welded and frame bolted angle iron, and gaps in the current construction or wall/ceiling fascia. Standing water is one of the many contributing factors for Listeria and other pathogens, along with mould and corrosion.
Finally, every piece of equipment, pipe, flooring and other exposed areas must be wrapped in plastic or covered before spraying begins. “It’s a lot of prep work and a little bit of spraying,” says Cook. “But the good news is we can get the plant back up and running by the time the managers need it.”
Fixxus also pays special attention to ensure the final monolithic liner is applied so the end result is cosmetically appealing. “In many applications, such as the inside of large tanks, sprayed polyurea is not required to be cosmetically appealing,” explains Cook. “With a processing plant, everything needs to be trimmed out and the polyurea applied very evenly so the plant has a nice, clean look.”
For food processors in ageing facilities this type of complete interior wall and ceiling rehabilitation – regardless of the surface or substrate and level of disrepair – may be the quickest way to break the cycle of constant deterioration and ongoing repair, while minimising risk of pathogen-based product recalls.
Doug Commette is with Versaflex.
Caption: Listeria and other contaminants thrive in nooks and crannies found within plants
Caption: The application involves a little bit of spraying and a lot of preparation
Caption: Fixxus Systems uses a formulation of pure polyurea from VersaFlex in its coating systems