Cleanroom integrity is key to ensuring the efficient operation of ventilation systems and pressure maintenance. As with most forms of engineering, it is usually the moving parts which wear out first, and the leak sites will tend to manifest themselves around the doors and windows, which are opened and closed.
Cleanroom doors play a crucial role in ensuring production reliability. They are used to access cleanrooms or to separate different room classifications, with requirements for these doors depending upon the process or specific product within. Hence the need for frequent and regular inspection. Just as the Building Safety Act mandates that fire rated doors must be inspected every three months and flat entrance doors annually, so too is it important that leaks in cleanrooms are found, fixed, and sealed on a regular basis.
Biological and other contaminants can quickly build up in enclosed spaces, especially in those occupied by a disproportionate number of people. If just one person is infected with an airborne virus and they are freely exhaling, a hazardous toxic indoor environment is created. The airborne virus will spread rapidly, infecting other unprotected people, who, once infected, become another source of biological contamination.
It is vital to constantly replace the stale and possibly contaminated air with pure fresh filtered air, with possibly up to 15 air changes per hour, whilst simultaneously regulating the relative humidity. To do this efficiently and effectively, a very high level of airtightness must be achieved and maintained.
Airborne viruses can envelope particulate matter and can remain live and suspended in the air for hours. They can also travel and, as air flow is turbulent, it is difficult to predict exactly how these viruses might spread. Removing particulate matter, and biological contaminants, is an important aspect of airborne infection control. This process starts with airtightness tests to find the leaks with microscopic accuracy.
Efficiently seal cleanrooms with high-speed doors
Every cleanroom has its own individual application profile; whether that’s a cleanroom facility used in the semi-conductor industry, automotive sector, food production, or medicine manufacture, they all require precisely defined levels of air quality.
The CR Series (cleanroom) high-speed doors from EFAFLEX are tailored to each environment but share common characteristics throughout the range: fast action opening and closing speeds, airtightness, air cleanliness, and smooth, easy to clean surfaces.
They are perfectly aligned to the requirements in controlled production zones. They guarantee the airtightness of all accesses, which considerably contributes to saving costs, and, coupled with their fast-opening speeds, exposure between zones is minimised.
In the EFA-SRT CR Premium high-speed roll-up door, EFAFLEX has developed a door for the specific requirements of cleanrooms (GMP). Even with high pressure on the door curtain, the air exchange is constantly reduced to a minimum, which increases the service life of air filters. The door model offers an outstanding, hygienic design, with reduced surfaces to prevent particle deposits.
The EFA-SRT CR Efficient high-speed roll-up door was specially designed for use in cleanrooms with medium requirements. The particularly narrow door frames allow for a space-saving and visually appealing installation, even in confined spaces. Thanks to an integrated absolute encoder, the door can immediately return to automatic operation even after a power failure, without the need for a manual synchronisation run.
In the EFA-SRT CR C, EFAFLEX has developed a door for the specific requirements of the cleanroom industry, where efficient sealing and installation dimensions are critical factors. The door is TÜV-certified for use in cleanrooms of ISO Class 6 or 7. It is characterised by its compact design with minimal space requirement and slim frames, whilst the EFA-TRONIC control is fully integrated into the construction (version ISO Class 6).
If speed is of the essence, the EFA-STT CR transparent cleanroom door is the best solution. Thanks to the spiral, this high-speed door opens and closes reliably at a speed of up to 2.5 m/s. It is particularly useful when the exchange of pressure and atmosphere is to be minimised, for example during inertisation for dry fire prevention.
Built to last – EFAFLEX doors are manufactured using the highest quality materials, to ensure they are capable of up to 250,000 operating cycles per year. This means a better return on your investment with extended periods between service intervals and to minimise costly downtime.
EFAFLEX’s high-performing doors are being used within some of the world’s most prestigious, market leading pharmaceutical, and medical cleanroom environments, and other sectors in similarly demanding situations where their speed of opening and closing, combined with their innovative design minimises areas where dust can settle and surfaces are easy to clean.
Recently, a Staffordshire based university had an EFA-STR CR-C (ISO Class 6) door installed within their facility. This is a number of fabric roll-up design, classified to ISO Class 6 (Class 1000 cleanroom) to maintain air cleanliness levels of a maximum of 1,000 particles (≥0.5µm) per cubic metre of inside air.
The university had a specific requirement where air control and purity was essential.
The EFAFLEX edge:
- Industry-specific door solutions for use in clean rooms.
- High air tightness even with varying pressure differences.
- Certifications in accordance with ISO classes 5 and 6, which ensure air particle purity (ISO 14644-1).
- Long service life despite a high number of cycles.
- Designed to minimise flat surfaces, the door is easy to clean and simple to maintain.
Monitor controlled zones for airtightness
Airtight integrity is often compromised at the entry points. Doors and cleanrooms must be checked for air leaks regularly to comply with regulatory standards, and more frequently for peace of mind.
To maintain a cleanroom environment, therefore, it is most important to be able to locate and measure the physical size of leaks and to have some idea of the potential air flow rates and air permeability that might result.
Airtightness is NOT a constant. It is a variable, changing over time as a result of thermal stress and other factors. It is not just a high total airtightness that matters either; if a small but significant amount of airflow is concentrated in one area, that can also be a problem. Even assuming a known leak with a constant physical size, the air that moves through it over any time period will vary too due to temperature and pressure differences. It is not the current air flow rate that matters, per se, but the potential air flow under worst-case conditions.
Keep your cleanrooms airtight: intelligently, accurately, and prognostically with the Portascanner AIRTIGHT. The Portascanner AIRTIGHT is a world-first instrument that is able to:
- Non-disruptively identify leak sites with a microscopic level of accuracy.
- Measure and quantify their cross-sectional area.
- Determine the air flow rate through each leak under any range of conditions using sophisticated algorithms.
- Calculate the room’s overall air permeability.
- Storing photographic and quantitative data to generate traceable, exportable reports.
In January 2023 the world-first Portascanner AIRTIGHT was tested in a UK Clean Room Laboratory and the results were astounding.
The Portascanner AIRTIGHT non-disruptively identified substantial leakage around the latch on the secondary entrance door and across the top and right-hand side of the door to the equipment room. Minor leaks were also detected in the equipment hatch, including in the wall panel.
The Department Manager at the UK Laboratory states: “I think that the equipment you have used is quick, clean and causes minimal (if any) disruption. I think that given the level of accuracy it can provide coupled with images of the leak locations it is a very useful piece of equipment for anyone wanting to gather more information on the integrity of their facility and a cost-effective tool for any contractor.”
If a small but significant amount of airflow is concentrated in one area, this can cause a problem in the maintenance of a cleanroom environment. To maintain a cleanroom environment, it is crucial to locate and measure the physical size of leaks and to have some idea of the potential air flow rates and air permeability that result.
