by Katie Daniel | September 14, 2017 3:07 pm
By Jon Schumacher
Regulatory requirements have become increasingly stringent across nearly every industry in North America. Perhaps no sphere has felt the impact of these tightened standards more than pharmaceutical and food manufacturing. While some regulations are created in response to new technology, equipment and processes, these industries have often needed to become more sophisticated to keep up with regulations. A prime example of this can be seen in the ongoing improvements in door and wall products specified for cleanroom and wash-down applications.
Cleanrooms are essential in contamination control for processes in the pharmaceutical and food industries. In fact, planning for these particular spaces has evolved into a specific area of industrial design. The primary challenge for these designers is keeping contaminants generated by people, processes, facilities, and equipment from being suspended in the air. Since prevention is more effective than diminishing an existing problem, one of the best ways to minimize contamination is to stop contaminants from ever entering the room in the first place.
The function of cleanrooms is to create environments that maintain an extremely low level of environmental pollutants such as dust, airborne microbes, aerosol particles, and chemical vapours. Every cleanroom has a controlled level of contamination specified by the number of particles per cubic metre at a specified particle size.
To give perspective, the ambient outside air in a typical city contains 35 million particles per cubic metre in the range of 0.5 μm (0.02 mils) and larger in diameter, corresponding to an ISO 9 cleanroom (per ISO 14644-1, Cleanrooms and Associated Controlled Environments−Part 1: Classification of Air Cleanliness by Particle Concentration), while an ISO 1 cleanroom allows no particles in that size range and only 12 particles per cubic metre of 0.3 μm (0.01 mils) and smaller.
The pharmaceutical industry generally requires ISO 6 to 8. These levels of cleanrooms play a crucial role in the manufacturing of products required to be free from microbial and particulate contamination and protected from moisture. Regulations in the food industry are not quite as stringent as the pharmaceutical industry with respect to the particulates range, but clean areas and wash-down walls are equally important in the prevention of contamination.
In these industries, doors and walls play an essential role in maintaining clean operations and product integrity. High-performance fabric doors (also known as ‘industrial curtains’) fit virtually anywhere and are uniquely designed to address the need for environmental control, productivity, safety, and cleanliness. They are used not only to prevent cross-contamination, but also to aid in maintaining correct room pressures, air circulation rates, and ensuring optimal operating efficiency.
While anti-microbial walls have always been important in segmenting environments, there is a growing use of flexible, industrial fabric walls for applications subject to wash-down protocols. They are quicker, easier, and less expensive to install than traditional construction. The assemblies also offer an additional benefit in that they can be moved or reconfigured to satisfy future changes in the process or floor plan. (For more on these assemblies, see this author’s previous Construction Canada article in the June 2015 issue by visiting www.constructioncanada.net/understanding-high-speed-doors-and-industrial-curtains.)
Doors play an integral role
High-performance doors and flexible industrial fabric walls have evolved in recent years and are a viable option for various food and pharmaceutical applications.
The primary function of most industrial doors is to provide tight environmental separation, yet allow occupants and equipment to quickly and safely move from one area to another. In pharmaceutical manufacturing, doors assume an even larger role by allowing companies to achieve and maintain a specified level of cleanliness for a given cleanroom. High-speed fabric roll-up doors (also called upward-acting doors) are commonly used in cleanrooms. They are also an integral part of airlocks that form buffers between different classes of clean areas.
Cleanrooms are generally classified according to the number of particulates in the air. The cleanest allow for the fewest particulates. The goal in virtually all cleanrooms is to maintain an air pressure differential between rooms, pushing air from the opening’s cleaner side to the less-clean side. Occasionally, the goal is to keep particulates within a certain room to avoid cross-contamination with the processes in adjoining rooms. For these reasons, most facilities incorporate multiple pressure steps within the building’s structure. The steps typically range from 5 to 13 Pa (0.02 to 0.05 w.g.) between rooms, but can be as high as 50 Pa (0.2 w.g.).
A door capable of at least 50 Pa in pressure differential is needed to maintain a tight seal and minimize air leakage. Given the requirement to maintain pressure differentials, doors that seal tightly and cycle quickly are essential in pharmaceutical manufacturing. A properly designed door helps ensure the facility’s makeup fans can satisfy the required amount of makeup air needed to maintain pressure. Another prerequisite in overall door design is cleanliness, since doors must operate in a pristine manufacturing environment. Any high-speed door used in pharmaceutical manufacturing must also balance the need for productivity with operational safety.
Specifying high-speed roll-up doors
Bi-parting doors made from stainless steel or fibreglass are widely used in pharmaceutical manufacturing facilities. Many companies will use fabric roll-up doors to meet the needs of specific applications where bi-parting doors will not fit due to limited wall space in a plant.
A roll-up door uses little wall space because it is an upward-acting unit, where the ‘curtain’ of the fabric door collects in a head assembly at the top of the door when it is opened. By comparison, a rigid-panel door that opens from the centre requires considerable wall space on each side of the door in order to function. As an example, a door spanning a 1.8-m (6-ft) wide opening requires approximately 0.9 m (3 ft) of wall space on each side of the opening so each panel has a place to travel when opened.
A new generation of roll-up doors has come on the market in recent years featuring anti-microbial materials and other upgrades for cleanroom applications. These new features, coupled with their ability to operate at high cycle speeds and provide tight sealing capability, are reasons they are catching on with pharmaceutical and food manufacturers.
Choosing a cleanroom door
Commonly referenced in Canada, the U.S. Food and Drug Administration (FDA) cleanroom standards outline recommendations and requirements for manufacturers of pharmaceuticals and medical devices. The starting point is to look for doors compliant with Current Good Manufacturing Practices (CGMPs), the U.S. Food and Drug Administration (FDA), and United States Department of Agriculture (USDA).
Key considerations for any door configuration are ease of cleaning and durability. In all cases, these doors must be able to stand up to repeated cleaning with chemical solvents and have a smooth, hard, nonporous surface resistant to microbial and fungal growth. Doors should also have a tapered surface and edges that essentially eliminate the harbouring of dust or other contaminants, and possess no sharp angles to minimize harbourage of microbes. Additionally, they should:
It is also advisable to avoid doors with exposed fasteners and coils, as they will take longer to clean and could harbour various contaminants.
The ability of cleanroom doors to accommodate site-specific needs is another consideration for industrial designers. These could include features such as vision panels, push plates, or other activation devices, as well as magnetic locks and (perhaps most importantly) interlocking systems. Commonly known as airlocks, these systems are found in entrances and exits, gowning and de-gowning areas, and material transfer locations. In all these areas, it is important to keep two doors from being open simultaneously, thus preventing air infiltration from one space to the other.
The best door systems allow for wireless interlocking of air locks. Breakaway capability is another recent advancement in cleanroom doors, allowing employees to push through the curtain in the event of a power failure. While this feature is not needed on a frequent basis, it will be greatly appreciated on the rare occasion it is required. Finally, low-voltage remote controls should be specified if possible as they provide a cleaner look and are easier to install.
High-speed doors and fabric walls in the food industry
High-speed doors also play an important role in maintaining cleanliness in the food industry. New food industry-specific variations have been developed that meet USDA and FDA standards for cleanup. These types of doors are made of smooth polypropylene (PP), which provides higher resistance to acids and bases and a lower water absorption rate than vinyls and urethanes. This quality makes them highly resistant to mould and offers superior wash-down durability.
Other food-specific enhancements include:
Fabric walls or industrial curtain partitions also play key roles in maintaining sanitary conditions in the food industry, where they are increasingly being used for applications related to blending and mixing, or production operations involving powder or raw ingredients.
While USDA and FDA do not specify cleanroom regulations in the food industry, they do provide guidelines based on Hazard Analysis & Critical Control Points (HACCP) best practices. As such, designers should seek out products that specifically cite their compatibility with these protocols. One of the most common uses for industrial fabric walls in the food industry is for the isolation of production lines so they can be cleaned while other lines nearby continue to run at peak efficiency. Not only do these flexible fabric walls allow plant engineers to easily enclose areas and contain overspray from cleaning, but they can also help reduce potential for cross-contamination during production processes.
Some wash-down fabric walls are constructed of durable, cleanable, anti-microbial vinyl specifically designed for use in operations where compliance with federal food regulations is paramount. To eliminate the potential for harbourage concerns, fabric walls with manufactured panels with heat- or radio-frequency (RF)-welded seams and airtight/watertight panel-to-panel connections should be employed.
Wash-down fabric walls are typically suspended from existing ceiling structures or roof decks. Stainless steel components and hardware allow the walls to hold up to wet and harsh conditions that occur when production equipment is cleaned as part of HACCP best practices protocol. Should the ability to open and close the wall be needed, heavy-duty stainless steel track and trolley systems are available to ensure easy operation and durability in the wash-down environment.
Flexibility and potential cost savings are among the main benefits of fabric walls in any application. Since they are not rigid, they can easily be custom-designed to match a facility’s specific needs or workspace. Further, they can be moved or reconfigured if those needs change. When combined with anti-microbial wash-down features, this flexibility allows plant managers to achieve cleanliness protocols and production goals without the cost, permanence, or space requirements of rigid walls.
Pharmaceutical cleanrooms and food processing centres demand the most sanitary operations and equipment to ensure quality products. While the strictest FDA, USDA, and HACCP guidelines require the cleanest of processes, recent technology is up to the task.
From high-speed roll-up fabric doors to anti-microbial wash-down fabric walls, new products are changing the way these industries keep their facilities up to code and help provide the highest-quality products.
Jon Schumacher is the director of marketing for Rite-Hite Doors. He has been with the company for 20 years and is a former vice-chair of the Door and Access Systems Manufacturers Association (DASMA). Schumacher can be reached via e-mail by contacting email@example.com.
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