Nowadays, cleanrooms are one of the main indicators of high-tech production and a guarantee of quality products. Let’s talk about them in details. From a technical point of view, a cleanroom is a room designed and equipped with special equipment, where there are a certain number of various particles and substances (dust, microbes, aerosol particles and chemical vapors, etc.) in the air per cubic meter and this quantity is supported constantly. In some cases, cleanrooms are equipped with special devices capable of controlling the other parameters such as humidity, pressure and temperature. The main purpose of using cleanrooms is minimizing the possible flow, generation and accumulation of various particles.
Cleanroom can solve the following tasks:
- minimize the flow and selection of various substances and particles from the environment into the cleanroom
- control air pollution environmental parameters such as air temperature, humidity and pressure
- maintain established hygienic parameters
- allows to set the desired air flow
- ensures the maintenance of the necessary ergonomic parameters of the premises, including the lighting and noise level
The most important role of a cleanroom is to keep environment clean. Besides, correct design is of a key role to maintain purity. If designing done properly, cleanroom occurs overpressure against other rooms, and this we call the main principle of purity. This is achieved by properly selected aircraft systems that create cleanroom air certain imbalance (the difference between its supply and exhaust). It should be noted that while designing cleanrooms, the location of the rooms within the building should be taken into consideration. For example, if cleanroom located in the center of the building, the number of incoming clean air should exceed the hood for at least 20%. If cleanroom contains windows with glazing and infiltration, the air inflow must be higher at least 30%.
From written above it can be seen that cleanroom designing is a long and laborious process, where small details of a big importance. It also should be noted, that sterile rooms designed in accordance with certain standards and technologies, which allows minimizing the concentration of contaminants. However, it is worth remembering that, depending on the scope use of a cleanroom, there are certain standards and regulations defining permissible limits of particle concentration. That is why the design of cleanrooms in every certain object is unique, carried out individually with taking into account all its nuances. However, cleanrooms design, regardless of their purpose, must take place in accordance with a number of general rules:
- Provide an accurate calculation to ensure the necessary air, the allowable level of temperature, pressure and humidity, maximum permissible dust concentration of different substances and microorganisms
- Imply the mandatory creation and installation of a high-quality indoor air purification system (special filters), allowing rational and efficient allocation of air masses between the modules
- Necessary project and design works involving the separation of the cleanroom’s modules not only from each other but also from the building structure
Upon completion of cleanroom designing and planning, the construction and commissioning must take place. However, it is worth remembering that the design features will depend on cleanrooms’ functionality and size of equipment in it. Besides, cleanroom design assumes that, regardless of its parameters, there are following systems have to be installed:
- Sealing system
- System of treatment and distribution of air mass
- Installation and maintenance of optimal indoor climate
Installation of mentioned systems allows the movement of air masses from one room with a high level of purity to another room with a lower purity class. After the completion of cleanroom design, SUNBEL develops general layout of wall and ceiling panels, cleanroom doors, inspection and transfer windows ,HEPA, filter housings and so on.
Basic design of cleanrooms includes the following elements:
- Enclosing wall construction (deaf and glazed wall panels, doors, windows)
- Airtight ceiling, regardless of a purity class
- Antistatic flooring
- Air preparation system, including intake, exhaust and recirculating ventilation systems, air intake equipment, air distribution equipment with a final filter, air adjustment devices
- Filter-fan modules, creating a clean zone within a room
- System of airlocks premises and transfer windows
- Cleanroom system’s management
Further, depending on the scope of use, cleanroom can be equipped with different equipment and additional devices, including water treatment equipment, AHU system, laminar cabinets, laminar covers and so on.
Ready premises are divided into classes based on the degree of air purity in them. Detailed classification of such facilities is shown in a specially established standards for the various application sectors.
Cleanroom creating is regulated by the Rules of the production of medicines of the European Union (EC Guide to Good Manufacturing Practice for Medicinal Products), the so-called Rules GMP (Rules of production and quality control of medicin).
GMP aimed at preventing conditions that might lead to production of poor-quality products and provides requirements for buildings, equipment and personnel, proper construction of the production process, staff training, monitoring, reporting, and production validation.
Industrial cleanrooms are required in many areas and there are some of them:
Cleanrooms in medicine
In health care institutions such premises are necessary at operating theater, intensive care therapy and maternity ward. Due to the air filtration, which provides a low content of harmful substances and dust, cleanroom allows to minimize the risk of postoperative complications and infections and playing an important role in preventing the occurrence of nosocomial infections.
Cleanroom in medicine allows to create:
Modular units for air cleaning and disinfection in small cleanrooms (procedural, dressings, preoperative, anesthetic)
Aseptic chamber with air laminar flow for intensive therapy of leukemia, care following bone marrow transplantation, nursing with extensive burns.
Operating aseptic air laminar flow to create a medium with a low level of microbial contamination in the area of an open wound during the surgery.
Aseptic resuscitation rooms and intensive care patients undergoing complex surgery, prematurity and injured at birth of children, burn patients and so on
Clean room complexes;
Local clean areas;
Supporting clean rooms (close changing rooms, washing, sterilizing, corridors)
Sterile laminar flow cabinets
Cleanrooms in pharmaceutical industry
While manufacturing medicine the manufacturer should fully protect the production departments of the three major sources of pollution: biological organisms, aerosol particles and chemical contaminants. Only the cleanroom can solve these problems.
Lighting, temperature, humidity and balance of supply and exhaust air must comply with cleanroom purpose and did not have a direct or indirect negative impact on drugs during manufacturing process. The pharmaceutical industry uses a system of cleanrooms, including rooms of different cleanliness classes designed for different stages of the production process. Disposition of the premises must comply with the logical sequence of production operations and cleanliness requirements, to minimize the possibility of mixing different drugs or their components and cross-contamination. The most important indicator of cleanroom ‘ technical level is the level of intelligence management system.
Cleanrooms in electronic industry
Production in electronic industry requires particular precision and accuracy. That is why there are very strict requirements to the cleanliness level, grounding system to ensure the absence of static electricity in this sector of industrial production.
The main idea of this approach is to create insulation technologies, meaning physical separation of a certain clean air amount from the environment. This separation allows to exclude the influence of one of the most intense sources of pollution – human. Application of isolation technology entails the widespread introduction of automation and robotics.
Microelectronics requires the creation of cleanrooms of the highest purity classes with perforated raised floor to improve air flow and increasing unidirectional flow.
Cleanrooms in food industry
As far as there are special sanitary and hygiene requirements to food production, the use of sterile space is the basis of the normal production process and a guarantee of quality products.
The main way of microbes’ penetration in foods during production is aerobic. The most viable option to eliminate microorganisms penetrating the products is to provide a clean air environment.
Clean rooms with well-designed sterile air filtration systems provide security technology for preservation of various products. Sterile environment with the laminar air flow in filling and sealing areas, provides long shelf life without usage of chemical preservatives.