Friday, March 27, 2009

Clean Room Concepts

Our environment contains large amounts of contamination, both gaseous and particulate. However, the application of clean rooms pertains primarily to the problem of airborne particulate contamination control. Thus, the removal and elimination of these contaminants within clean areas has become critical to ensure high-yield and efficient production for many advanced precision manufacturing processes and technologies.
Such operations are performed in clean spaces where:
Airborne particulate generation is limited
Air flow patterns are selected
Temperature and humidity are controlled
Air pressure is regulated
Special construction materials and equipment are utilized
Operating procedures are regulated.
These spaces may be rooms, workstations, process enclosures, mini-environments or designated classified areas within a room or existing clean environment.
If any of the controlled conditions described above are relative to your manufacturing, assembly or laboratory operation, a controlled envir
Federal standards have been established for room air cleanliness which describe how clean the air is in a given area. Per Federal Standard 209E, numeric classification means how many particles larger than 0.5 microns are acceptable within a classified clean environment. Hence, a Class 100 environment would mean that no more than 100 particles larger than 0.5 microns would exist in any given cubic foot of air, Class 1,000 would mean 1,000 particles and so on.
Air Crafters clean rooms, enclosures and laminar flow work stations will remove airborne particles through HEPA or ULPA filtration of air entering an environment. Our standard HEPA filter will intercept and trap 99.99% of all particles 0.3 microns or larger, to meet or exceed Class 100 standards for particulate control. The use of ULPA filtration will boost your environment classification to Class 10. The required level of cleanliness will vary from process to process.
When the total air volume within a space moves in one direction at a uniform speed of between 70 - 120 FPM, its individual molecules assume parallel paths, or streamlines. The physics of this phenomenon allow for these streamlines of air to bend around objects and obstacles without losing laminarity or losing the particles which they carry.
Maintaining air flow laminarity within clean areas -and around and over your processes- will keep airborne contaminants (emanating from workers, nearby shedding processes and products) from fouling your critical process. The principle of laminar air flow is vital in contamination control. Air flow laminarity is a major component in the design and maintenance of clean environments.
A micron (micrometer) is one-millionth of a meter, (10-6m). In the English system, a micron equals approximately 0.000003937 inch.
Some examples of relative size might be useful for comparison purposes. Typically, the naked eye can see particles only as small as 40 microns; a human hair is approximately 100 microns in diameter; milled flour can contain particles as small as 1 micron; tobacco smoke is composed of particles as minute as .01 microns and as
Airborne particulate matter can be of organic or inorganic origin. Most contamination-control problems concern the total contamination within the air. Airborne particles range in size from 0.001 microns to several hundred microns.
Before any methods of contamination control of airborne particles can be successfully applied, a decision must be made as to how critical this particulate matter is to the process or operation in question. At the same time, consideration must be given to the quantity of particles of a given size that might be present at a specific point within an area.
Since a definite relationship exists between the size of a particle and the time in which it may be airborne, it is most meaningful to discuss particles by quantity of a given size. Both Fed. Std. 209-E and AF Technical Order T.O.00-25-203 show typical relationships.
To further analyze your contamination control requirements, the source of contamination should be considered. Basically, this is divided into external sources and internal sources.
For any given space there exists the external influence of atmospheric contamination, which inevitably finds its way into all areas of our working environment. This external contamination is generally introduced through air-conditioning systems which supply the workspace. In addition, external contamination can infiltrate through doors, penetrations or cracks within the enclosure. This contamination can generally be controlled by the level of filtration utilized in conjunction with clean-area pressurization.
Internal sources of contamination are caused through the introduction of equipment, material and personnel within an area. Contamination is created by every activity involving friction between surfaces. For example, the simple act of writing with a pencil on a piece of paper creates a cloud of very fine carbon particles and paper fibers. Even the movement of two pieces of metal together can generate very small particulate matter which can become airborne to form a very fine metallic dust. However, the greatest source of internal contamination is people. We continually shed particles. Flakes of dry skin, fabric fibers or loose hair are only some the sources that could destroy your critical manufacturing process. The amount generated can vary from as few as several hundred particles per hour to several thousand.
large as 1 micron; bacteria range in size from 0.3 microns to 30 microns.
onment may be needed to impr

With Air Crafters Clean Room Products

Air Crafters manufactures a full line of equipment and easy to assemble modular panelized enclosures, along with ceiling systems, clean room specific lighting, motorized and non-motorized ceiling-mounted filtration modules and environmental control components. These modular enclosures effectively control, reduce and eliminate the effects of particulate contamination on your critical processes.
Air Crafters also manufactures a complete line of furniture and casework specifically designed for clean room applications. All Air Crafters equipment is manufactured of steel or stainless steel to prevent the generation of particulate contamination by installed work pieces.
Principles of contamination control can be applied to a simple tabletop workstation to produce Class 100 levels of cleanliness, permitting the most sensitive operations to be performed within a particulate-free environment. When larger areas are required, Air Crafters also offers a complete line of modular clean rooms and enclosures to fit your specific needs and budgetary requirements that produce and ensure up to a Class 10 environment.
A question that must be addressed by users of clean spaces is: "What type of clean environment is required to produce or enhance my product or process?"
One approach is to convert an existing area into a clean room via retrofit. If a convenient sized space exists within a facility, it is often sensible to convert it, thereby realizing a substantial cost reduction.
A second approach is to purchase a pre-packaged modular clean room that can be adapted to the requirements of the process or facility within which it is to be installed.
A third appro

With Air Crafters Clean Room Products

1.) ROOM CLEANLINESS: Expressed as a classification per Fed.Std. 209E (e.g., Class 10, Class 100, Class 1,000, Class 10,000, Class 100,000), room cleanliness levels are the basis of any clean room design. It is important to know what classification you require, since an over-designed room can be costly to build and costly to operate.
2.)ROOM TEMPERATURE/HUMIDITY: If the process is not affected by temperature/humidity conditions which fall outside of human comfort ranges, do not specify tight tolerances. A typical specification is 70ยบ F±2 and 30-70% RH. Tighter tolerance will result in unnecessarily escalated costs.
3.) LIGHTING LEVEL: A level of 100 footcandles at the work surface is more than adequate for close assembly work. Higher lighting levels are costly in terms of energy consumption and initial cost. Lower levels can be maintained by control switching.
4.) PROCESS FLOW: This deals with the process being carried out within the room. The process will dictate the materials of construction as well as the layout of the facility. If the process is general in nature, a more flexible layout is recommended. The process should be defined as completely as possible before any clean room is laid out. This sounds elementary, but a poorly defined process will result in an unsatisfactory clean room, or one in which modifications are being made before the paint is dry. A knowledgeable clean room consultant will have experience in process flow and will be able to offer valuable assistance.
Now let us investigate some of the solutions offered by Air Craftersach is to analyze the process to be housed and define all specific parameters required in developing a mini-environment specifically designed to isolate your process under controlled conditions within your ambient environment, thereby reducing your facility’s operating cost and the risk of operator-introduced contamination.ove your process.

Air Crafters, Inc. has designed and engineered the SWCR Series with careful attention to user needs. This product’s development has been guided by the results of our extensive market research and industry expertise. Its modular component system makes it highly adaptable to your specific soft wall clean room requirements at low cost. Our SWCR Series offers easy assembly, operational efficiency and rugged, long-lasting construction. Its frame structure can be erected within the tightest spaces, due to our innovative drop lock assembly system. This system is easily customized and can be designed and engineered to fit your specific process or space requirements. Utilizing our structural rafter and header adapters we can create a free structural span of up to 24 ft. Our cell tight ceiling system creates an impervious barrier against particulate infiltration. Combined with our seal track curtain enclosure, you are assured a contaminant-free environment. Our standard kit assemblies will be shipped within ten days of receipt of your purchase order. Our soft wall clean room system is available in room classification ratings of Class 100,000, 10,000, 1,000, 100 and 10 (ULPA).

The CRW Series is the next step up in Air Crafters’ clean room enclosure line. Its modular assembly makes its installation extremely cost-effective. The structural frame is constructed of clear anodized architectural aluminum glazed with 1/4 inch full-light clear acrylic panels. This system provides permanent aesthetic appeal while enabling full visual monitoring of the activities or processes enclosed within.
Highly versatile, this modular system can be configured to create either entire room environments or adapted to create specific process or equipment mini-environments.
HEPA filtered air is provided by our BFM series (Motorized Blower Filter Module). You can choose from a complete line of light fixtures and ceiling systems to complete this clean envelope.
This system is available in all clean room classifications and can be designed and developed to fit your specific requirements.

Air Crafters has developed this innovative pre-engineered clean room system that allows specification, purchase and installation of a complete hard wall modular clean environment in less than six weeks. The MCRS series modular clean envelope system features versatile modular construction allowing for easy expansion or relocation if required.
Structural load-bearing six inch wall panels are manufactured in standard 2 & 3 ft. wide sections that are 10 ft. high. Panels feature fully insulated 16ga formed steel construction, and coated with a variety of non-particulating clean room certifiable finishes on both sides. Wall panels are connected via an exclusive concealed fastening system allowing for quick installation and providing smooth flush joints where wall sections meet. This system is non progressive, allowing for easy panel removal. Return air ducting is integral to each wall panel. Return air grilles and floor mounting tracks are made from type 304 #4 stainless steel and both feature a sloped transition.
Air Crafters also offers several clean room rated ceiling grid systems into which our complete line of clean room class rated luminaires and filtration systems are mounted.
To provide up to a Class 10 environment, our BFM series (Motorized Blower Filter Module) is an integral part of this clean room system. When these components are set into place they provide a complete envelope seal, forming a totally leak-free environment.
This modular sys
Air Crafters has designed and engineered the ASET Series (Air Shower Entry System) with careful attention to user needs. This product has been specially designed to meet customer requirements for ease of installation, rugged construction and long lasting aesthetic appeal. It has been engineered for modularity offering lightweight cold roll steel or stainless steel interlocking panelized construction. Unidirectional air jet nozzles providing 6000 fpm at nozzle outputs insure complete occupant blow-off. Our specially designed and engineered programmable logic controller activates all system functions and allows for user interface in modification of functions. Our system can be assembled in half the time of traditional systems.
The development of our Modular Power Head High Pressure Air Delivery System allows our basic unit to be easily adapted for any custom configuration (tunnel assemblies, low-profile side mounted power head, left and right turn orientations, and remotely located power head) at low customer cost. We believe, and are sure you will agree, ours is the finest engineered entry system in the industry.
This system has been designed and engineered to provide basic vertical laminar flow protection through full overhead HEPA coverage (Class 100). Its modular component system makes it highly adaptable to your specific vertical laminar flow requirements at low cost. Though offered in standard product-line configurations, this system is easily customized to fit your specific process needs.

Since cost is typically a factor in evaluating any effort to improve the quality of the product or process, the initial investment is usually in laminar flow work stations. These may be vertical or horizontal flow units. Perhaps the most popular style is the horizontal laminar flow unit, where the air is drawn from ambient space and directed by a centrifugal blower through a HEPA filter, horizontally toward the operator seated at the front of the work station. The clean air is continually passing over the work surface and then out into the ambient atmosphere of the room. The operator is outside the work space, although the operator’s hands, suitably gloved, do extend into the clean area. The air moving into the room at a velocity of 90 fpm tends to keep any outside contamination from moving into the work area.
In a vertical laminar flow station the air is introduced from above and moves vertically downward over the work area. The air leaving the HEPA filter is quite clean; however, a shortcoming of this type of station is that an operator, leaning over the work, would tend to "shed" onto the surface. As mentioned earlier, this shedding will contaminate. Vertical work stations are used in recirculating applications, or where fumes are generated and must be removed and exhausted. It would be wise to be aware of the possible source of contamination and insure that the operator using this type of station is well trained.

Air Crafters also offers a complete line of clean room and laboratory specific designed and engineered case work through our sister company, Lab Crafters. This high quality line is manufactured in all steel or stainless steel to provide a rugged, non-shedding storage and work area within your clean suite.
Air Crafters customers can be assured that we are dedicated to providing a full spectrum of contamination control technologies, services and equipment to meet your ever-expanding needs. Our substantial design and engineering capabilities can be brought to bear in solving the most complex clean room, clean process, custom equipment design requirements or special performance specifications. With over 45,000 square feet of manufacturing space (soon to be expanding) and fully automated production capabilities including CAD-CAM, robotics and laser technology, we can produce high-quality products at low cost ..... and deliver on time.tem is offered in sizes varying from 100 square feet to in excess of 1000 square feet. With Air Crafters’ MCRS recirculating clean rooms you purchase both the performance and aesthetics of a permanently built structure at half the price.

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