Clean rooms are enclosures designed to facilitate sensitive research, fabrication and other operations that must take place in the absence of dust, moisture and other airborne contaminants. Clean rooms systems were first developed in response to the needs of the aerospace and microtechnology industries in the early 1960s. As those and other high-tech disciplines like bio-technology and medical research developed, and as products and research subjects became smaller, airborne contaminants became increasingly disruptive. The rigidly controlled environments with which these professionals began to surround their work came to be known as clean rooms.
All clean room designs are intended to provide a workspace in which factors like airborne dust, variable air temperature and pressures, moisture and other atmospheric conditions can be carefully controlled. All of the different possible clean room constructions allow professionals a range of workspace possibilities. They range from strict Class 100 clean rooms to less rigidly controlled portable clean rooms and modular clean rooms. As more and more operations came to rely on clean rooms, regulatory authorities and standards-setting organizations classified clean rooms according to their capacity for removing contaminants. Class 1,000 clean rooms, for example, employ clean room supplies that are unlikely to release fibrous contaminants. The standards for clean room equipment used in Class 10,000 clean rooms are less strict; they can often feature soft walls and are used for less sensitive applications.
The measure of clean room cleanliness is the number of air pollutants that can be found in an air sample. Many clean rooms are not intended to be completely sterile environments. More typically, professionals concern themselves with the amount of dust floating in the air or that can be kicked up from the floor when stepped on. This dust is microscopic and can sometimes only be measured by specialized machinery. There are some cases in which sterility is a requirement; many medical research operations and testing procedures must be conducted in a sterile environment. Pharmacological studies, infectious disease testing and other highly sensitive medical research-related procedures often require the complete evacuation of any microbes that may be present in their surrounding environments. Clean room cleanliness is determined based on the presence of contaminants over 0.5 micrometers in size. A human hair is usually around 100 micrometers wide, and humans shed dead skin cells at a rapid rate of 100,000 particles per minute while standing still. For these reasons, very little skin or hair, if any, is allowed to be exposed in clean room settings; they are both usually covered by protective clothing. Also, most clean rooms are equipped with some kind of air quality control system, many of which involve air filters and fans that remove air from within the clean room and pump filtered air in.
Clean room designs range in terms of size, material and their intended standard of cleanliness. Clean rooms used by major manufacturers of microelectronics, pharmaceutical products or circuitry can be as large as warehouses; these large clean rooms are sometimes referred to as "ballrooms." Other clean rooms can be as small as household ovens; these are used in small scale medical testing procedures as well as specialized, limited or exclusive-run manufacturing operations. They can also be used for repairs and for small experiments. Permanent clean rooms are usually built into the structures of the buildings that house them, as are the machines that regulate their conditions. However, some permanent clean rooms can be enclosed by glass or clear plastic walls. Soft walls, which are most commonly used in clean rooms with lower decontamination standards, are often made of flexible acrylic materials or other plastics. All of the materials used in the construction of clean rooms must be carefully chosen for their non-fibrous, non static electricity-generating and non-corrosive qualities. Any material that could contribute to air contamination must be avoided during the construction of clean rooms. Even stainless steel can corrode when exposed to bleach, which is sometimes used as a disinfectant.
There are two main standards systems against which the cleanliness of a clean room is measured. US FED STD 209E is the system of standards set by the United States government; clean room models are assigned a class number based on the number of 0.5 micrometer-sized particles found in every cubic foot of atmosphere within the clean room. The class numbers correspond with the particle per cubic foot number. Class 1 clean rooms can be expected to contain one 0.5 micrometer-sized particle per square foot, Class 100 can be expected to contain 100 particles, and so on. If regular, unfiltered air were assigned a classification, it would be Class 1,000,000. The International Organization for Standardization also assigns standards to clean rooms based on their anticipated contaminant levels, though the ISO standards are assigned on a scale of three to eight, with three being assigned to the most effective clean room systems. The British Standard system is also recognized by some industries; their system measures contaminants in cubic meters instead of feet.
Clean Rooms - Pacific Environmental Technologies, Inc.
Modular Hardwall Clean Rooms - Modular Cleanrooms, Inc.
Positive Pressure Clean Rooms - Clean Air Technology, Inc.
Negative Pressure Clean Rooms - Clean Air Technology, Inc.
Hardwall Modular Clean Rooms - Cleanrooms by United
Custom Clean Rooms - Allied Cleanrooms
Given the requirements of modern-day equipment and devices, it is imperative for the manufacturing industry to get sophisticated. The cleanrooms that at one time had application in medical and scientific research industry, have become a norm in an array of industries. Cleanrooms now are a common sight in many manufacturing operations that process materials, which are sensitive to static electricity, dust, a multitude of micro-particles, and microorganisms. An industry that extensively uses cleanrooms is the semiconductor industry; semiconductors are sensitive to dust, and if a product is contaminated by dust, it can be rendered useless; therefore, the industry follows ISO cleanroom standards.
A cleanroom facility has a number of preventative devices, clean room equipment and materials to give a controlled environment that is free from dust and microorganisms. The equipment can be either for personal protection, or to have a germ- or dust-free air in the facility. The cost of personal gear and supplementary devices, such as highly efficient particulate air filters, air showers, and anti-static devices, is quite high.
Here, we will discuss all the important information that you may need to make an informed decision about your cleanroom purchase.
How many types of cleanrooms are there?
Cleanrooms most commonly have applications in short-run production jobs and emergency work. For temporary means, cleanrooms are usually modular. It has a structure that can be assembled relatively in a small span of time for a specific work with suitable equipment, and when the structure had served its purpose, it is disassembled. Depending on the need, they can be assembled in existing facilities, like warehouses, as a separate work unit, and even outdoors, if it becomes necessary.
Most of the portable or temporary cleanrooms are softwall cleanrooms, which means they do not have rigid walls; instead, the walls are constructed from transparent polymers. Generally, modular cleanrooms are equipped with all the equipment that are found in permanent facilities, such as anti-static devices, small and portable HEPA filters, and garment change facilities.
They provide the same degree of sterility with almost half of the investment. However, they are designed to last for a minor period.
How cleanrooms are graded?
International Organization for Standardization (ISO) grades cleanrooms; the classification or grading is based on the number of particles, 0.1 micrometers or larger, permitted per cubic meter of air. There is a table standardized by ISO that defines various grading; for instance, an ISO 3 cleanrooms has maximum of 103 particles per meter cubed, or 1,000 particles. They are commonly known as Class 10000 Clean Rooms and Class 100 Clean Rooms, among others.
There are nine ISO classes, each having different permitted contaminant in the air, the lowest being, ISO Class 1, and the highest, ISO Class 9.
ISO has written standards that you can access under following name:
Accessories for cleanrooms
Depending on the types of materials manufactured in a cleanroom, there is an array of accessories that are required for labor and other uses. In a computer parts manufacturing unit, all the workers in cleanroom need to wear anti-static garments and bracelet or anklet to prevent static current. Additional cleaning devices, cleanroom supplies and work benches are also installed, and standard equipment of laboratory and manufacturing must comply to clean standards.
Clean rooms are especially designed enclosed area where the presence of airborne particles are regulated or controlled. Clean room equipment minimizes the generation, introduction, and retention of particles inside the room; moreover, controlled environment has specific temperature, humidity and pressure.
Maintaining a clean room can be a daunting task, therefore, here we are discussing the several areas of concern that gives insight into the overall picture of controlling contaminants.
The following factors should be considered while deciding a contamination control program.
Architecture of clean rooms are designed while keeping in mind the needs of a facility. The principal aim is to achieve and maintain an airflow that has uniform velocity that follows a parallel flow lines throughout the enclosed space-a uniform laminar flow.
The thumb rule is: the more restriction to air flow, the more turbulence it causes. Turbulence has been attributed to many contamination problems. According to ISO clean room standards, all clean room should have a well-designed space where airflow is not restricted in any way.
Almost all standards specify High-Efficiency Particulate Air (HEPA) filters as must equipment in clean rooms. These are indeed important, however, for low-grade clean rooms, like class 100 clean rooms a HVAC unit can be used as an alternative. Nevertheless, in Class 10000 Clean Rooms, HEPA air filters are necessary, as they filter very small particles with 99.97% efficiency.
Other than HEPA, there are a wide numbers of filtration mechanisms available; weigh in the price, advantages and installation cost before choosing an alternative to standard filtration system.
In most clean rooms, cleaning is daily practice to maintain a degree of cleanliness based on the requirement. It is an important element of contamination control. Owners need to make decisions about maintenance, cleanroom supplies, and cleaning schedule.
There are questions, compiled below, that will help you to make an effective cleaning program:
Maintaining a clean environment is a big task, it includes other factors too, such as garments, behavior of human in room, instruments, and physical structure. There are set standards for cleaning everything, visit ISO website to get the guidelines.
Clean rooms are commonly used for laboratory, medical, or software engineering applications. These clean rooms are designed to protect against dust, chemical vapors, airborne particles and other low level pollutants while maintaining a controlled temperature. The trick to a proper clean room is to control the air flow with the use of directional air filters that allow for a laminar air flow. By utilizing laminar flow it continuously cycles new filtered air into the clean environment to ensure no contaminates are lingering.
There are four styles for measuring and classifying clean room cleanliness: US FED STD 209E, ISO 14644-1, BS 5295 and EMP EU. However the US FED STD 209E and ISO are the most commonly used. Classification of a clean room is based on the number of particles allowed in a particular amount of air. The amount of particles in a specific area is determined through the use of a discrete particle counting device. The standards are broken up into different "classes" and the larger the class number refers to a greater amount of particles permitted. For example an ISO Class 5 clean room allows for 100,000 particles per cubic meter. Also, an ISO Class 5 room is the equivalent of a Class 100 US FED STD 209E clean room.
Only certain items are usually allowed into strict clean room environments. Personnel will typically wear clean room apparel that will not bring unwanted particles into the clean room. Items like face masks, bouffant caps, beard covers, shoe covers and even approved cleaning wipes are required for clean rooms with limited permitted particles. Soft wall clean rooms can be utilized for applications that do have as sensitive materials. Clean rooms range in sizes as small as household ovens or as big as warehouses.
- A room located between a clean room and outside area that acts as a buffer during the transportation of materials into and out of the clean room.
- A small room in which
high-speed air jets rid personnel of contaminants prior to entering the
- Represents the number of particles 0.5 microns in size or larger per cubic foot of air in the clean room. The smaller the class number, the higher the air purity.
- Structure that secures lights and filters into the ceiling.
Clean Room Construction - Custom or pre-designed clean rooms that fit industry-specific standards and come in many different forms.
Clean Room Equipment - Any movable furniture, machinery tool or storage systems made specifically for use in clean rooms.
- Walls that create multiple clean areas to meet a variety of cleanliness requirements inside a single clean room.
- Also called "bunny suits," they are worn over regular clothing and made from a special non-linting, anti-static fabric.
- Tables that come with either a perforated or solid top and meet clean room requirements.
- Harmful or unnecessary substances that decrease the purity of the environment in which they are found.
- An uncontrolled dissipation of electricity, also called a "shock," which can easily destroy semiconductor products.
- A summary of the clean room and other functional areas, which articulates the areas necessary for functioning and support.
- Text that dictates air cleanliness standards in clean rooms.
- Unit containing either HEPA or ULPA filter located in clean room ceilings or walls.
- Air filter capable of trapping
a minimum of 99.97% of particles at least 0.3 microns in size.
- The equipment responsible for providing and maintaining heating, cooling and air conditioning to a building or facility.
- Airflow within a confined area traveling with consistent speed and direction.
- Measurement unit equivalent to one-millionth of a meter.
- Microscopic, living organisms. They can be released from human skin during skin cell shedding.
- Represents the measurement or dimensions of a particle.
- An object, either solid or liquid, ranging from 0.001 to 1,000 microns.
- A body of matter consisting of distinct particles.
- Additional filter used in conjunction with the main filter to collect large particles and protect the main filter from excess contamination.
- Substance often consisting of plastic or silicone used to secure HEPA filters into ceiling grids.
located at clean room and shower entrances that utilizes adhesive film
to clean the shoes of personnel.
- Services responsible for the testing and maintenance of clean room components, including HEPA filters, HVAC systems and other equipment. Tests on HEPA filters include particle count surveys, air condition measurement, vibration measurement and airflow consistency.
- Airflow within an enclosure that does not travel in one direction.
- Air filter capable of trapping 99.9999% of particles at least 0.12 microns in size.
- Also called "process utility summary," "tool matrix" or "utility requirement spreadsheet," it is the summary of the analysis of the services of each piece of equipment needed to plan the construction of a clean room.
- Also called a "slice," it is a very thin piece of silicon that is the base material for microchips.