Author Archives: Liberty Industries

  1. Understanding the Design & Construction of Cleanrooms

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    Cleanrooms are specialized workspaces for critical processes and operations. They are designed to maintain strict standards of cleanliness for certain types of manufacturing and product preparation. Cleanrooms are commonly used for some applications in the manufacture of electronics, semiconductors, pharmaceuticals, medical devices, and aerospace equipment, as well as in labs and research settings.

    Here, we’ll look at the major goals of cleanroom design, how they are constructed to meet those goals, and some of the standards cleanrooms must meet.

    Click to ExpandCleanroom Design Considerations

    Understanding the Design & Construction of Cleanrooms

    Cleanroom design is focused on controlling the environmental conditions in an enclosed space, as well as the size and number of particles (i.e., contaminants) in the area. Strict guidelines and classifications are set by international standards for cleanrooms. For these reasons, when constructing a new cleanroom, it is critical to consider environmental conditions and requirements like temperature, ventilation and filtration, airflow, and air pressure. 

    Working with an experienced cleanroom contractor is the best way to ensure all systems are designed and installed correctly and that they function as intended. 

    Begin by analyzing workflow and patterns of movement within and into and out of the room (this includes people and equipment). These impact airflow, temperature and humidity, and particle or contaminant levels. Materials used for ceilings, walls, and flooring can also have an effect on airflow, dust accumulation, and moisture levels. All of this information is used to plan HVAC and filtration systems that create and maintain the right conditions when the room is at rest and in use.

    Many systems and equipment can be used in a cleanroom to achieve the required conditions, and not all cleanrooms are designed and built identically. Some examples of the components that may be used in a cleanroom include: 

    • Air showers
    • Air pressure monitoring equipment
    • Airlock entry and exit systems
    • Gown rooms, donning/doffing space, and storage for protective equipment
    • HVAC systems
    • Fans equipped with high-efficiency particulate air (HEPA) filters
    • Sticky mats to trap particles on shoes or that fall from above

    A new cleanroom is evaluated at three points during construction to ensure proper conditions can be maintained: 

    1. As built, when construction is complete but equipment and machinery are not moved in yet.
    2. At rest, when all equipment and systems are installed but not yet operational.
    3. In operation, when employees and equipment occupy and use the room for regular operations.

    Cleanroom Classifications

    The current international cleanroom design standards are ISO Standard 14644-1. It sets nine classifications (i.e., ISO 1 through ISO 9), each designating positive pressure requirements and the allowable number of particles of different sizes per cubic meter within the room. Particle sizes are grouped into six ranges from ≥ 0.1µ to ≥5µ. 

    For example, an ISO class 1 cleanroom, the most “clean” environment, requires that there be no more than 10 particles ≥ 0.1µ per cubic meter and no particles larger than that at all. In contrast, an ISO class 7 cleanroom allows more particles of different sizes per cubic meter, resulting in a slightly less “clean” setting:

    • No requirements for particles ≥ 0.1µ to ≥ 0.3µ 
    • Up to 352,000 particles ≥ 0.5µ 
    • Up to 83,200 particles ≥ 1µ
    • Up to 2,930 particles ≥ 5µ

    ISO 14644-1 standards are very similar to the former US Standard 209 requirements, which have not been in use since 2001.

    Different applications and manufacturing processes must comply with different cleanroom classifications, and this plays a major role in the design and construction of the room. Some applications may have additional requirements, such as sterile drug compounding. This process is subject to USP chapter 797 requirements, which include limits on particle sizes and counts and sets air pressure requirements, along with guidance for equipment and personnel procedures.

    Cleanroom Supplies from Liberty Industries

    To learn more about the design and construction of cleanrooms, please download our free in-depth Understanding the Design & Construction of Cleanrooms guide here

    Since 1953, Liberty Industries has specialized in cleanroom equipment, supplies, and construction services for customers in a range of industries. We provide everything required for your cleanroom or contamination control applications from cleanroom design engineering to protective garments, and from airflow equipment to particle counters. 

    Contact us today to learn more about our capabilities or to discuss the requirements of your cleanroom application.

  2. A Guide to Essential Cleanroom Equipment

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    Cleanroom environments are ideal for safely handling specimens, conducting tests, and manufacturing and assembling sensitive goods. Properly maintaining air purity and protecting workers, devices, and products within the space, however, requires a combination of essential cleanroom equipment and protective garments to achieve. In this guide, we’ll review air handling and filtration, PPE, and cleaning equipment solutions to help ensure your cleanroom remains compliant with industry standards.

    A Guide to Essential Cleanroom Equipment

    Air Handling and Filtration Systems

    Supplying and maintaining clean air within a cleanroom is a top priority. Four common types of air handling and filtration equipment that make this possible include the following:

    • High-Efficiency Particulate Air (HEPA) Filters. HEPA filters are a critical component of a successful cleanroom for reliably purifying the air. These filters remove 99.99% or more of particles sized 0.3 microns and up.
    • Air Handling Units (AHUs). These systems help ensure the consistent circulation of purified air while carefully controlling cleanroom conditions. Based on the needs of your application, AHUs effectively manage certain aspects of the air within the space, such as its flow, humidity level, and temperature.
    • Laminar Flow Equipment. Managing air’s flow direction and velocity can be just as important as controlling its humidity and temperature. Laminar flow equipment creates continuous streams of filtered air through a space and across surfaces in a particular direction, such as away from equipment for sterile operations.
    • Pass Thrus. Also called pass-through airlocks or communicators and package transfer units, cleanroom pass thrus allow you to safely transfer items from an exterior space to your controlled interior environment to limit contamination.

    Personal Protective Equipment (PPE)

    Head and face coverings, clothing, and other equipment help protect workers from breathing in or coming into contact with harmful substances. At the same time, PPE minimizes the chance of cleanroom contamination from dirt, fibers, hair, or skin cells. Some common examples of PPE include:

    • Caps, Hoods, and Related Coverings. These garments keep loose hair from falling onto equipment and work surfaces.
    • Safety Goggles or Glasses. This eye protection keeps airborne particles from entering your eyes, along with any splashed substances.
    • Face Masks. Fully covering your mouth and nose, these masks serve a dual purpose. Face masks protect a cleanroom environment from contaminants you exhale while preventing you from inhaling harmful particles into your respiratory system.
    • Coveralls. These cleanroom garments will provide full-body coverage, from your neck to your wrists and ankles. Usually consisting of materials that develop and shed minimal lint, they protect you and your clothes while reducing fiber and particle contamination in the cleanroom.
    • Gloves. Gloves are another example of PPE offering dual protection. They provide you with a layer of protection between your hands and harmful substances, and gloves lessen the chance of particle transfer onto handled materials.
    • Booties and Overboots. This PPE prevents you from tracking dirt and other contaminants into a cleanroom on the soles of your shoes.

    Maintenance and Cleaning Equipment

    Proper air filtration and strict PPE use will prevent many potential sources of contamination from compromising your cleanroom. However, additional equipment options are available to help you maintain your cleanroom space.

    For example, you can place shoe brush machines near a cleanroom entrance. These units scrape dust and dirt off the bottom of shoes using stiff bristles to reduce the risk of contamination from footwear. Sticky mats, or tacky mats, supplement shoe brush machines, their sticky surfaces pulling contaminants from the bottom of your shoes as you cross over the mat. Wipes, disinfectant solutions, and roll mops also allow your cleaning teams to wipe away and remove contaminants that made their way to surfaces within the cleanroom.

    Essential Cleanroom Equipment From Liberty Industries

    For a reliable cleanroom environment that meets or exceeds your required standards, Liberty Industries is here to help. We have numerous guides on subject matter related to the above, please feel free to download our free eBook on essential cleanroom equipment here.

    Since 1953, we’ve been manufacturing and distributing contamination control equipment and accessories to clients worldwide. We aim to be your one-stop shop for customizable cleanroom product solutions, offering everything from Tacky Mats® and shoe brush machines to air showers and laminar flow benches. Our engineering team can even help you with the cleanroom itself, providing modular, hard- and soft-wall, and mini-micro cleanroom options.

    Contact us to learn more about our extensive cleanroom equipment selections or request a quote today.

  3. How Do Cleanrooms Differ by Industry?

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    Click to ExpandHow Do Cleanrooms Differ by Industry?

    Not all cleanrooms are created equally. Depending on the particular industry, cleanroom classifications and specifications vary, as different manufacturing processes have unique standards and sterility requirements. Here, we’ll take a look at the various industries that rely on cleanrooms and how each one differs.

    Pharmaceutical and Biotechnology Cleanrooms

    In the biotechnology and pharmaceutical industries, cleanrooms are specified at ISO Class 5 through Class 8. ISO, or the International Organization for Standardization, is responsible for providing the requirements, guidelines, characteristics, and specifications that are used to ensure services, products, and processes are suitable for the intended purpose.

    Particulate matter is the primary concern for any cleanroom, specifically when it comes to viable particulate contamination. It’s possible to prevent viable particulate contamination by installing cleanrooms with cove corners, cove ceilings, and cove bases in stick-built or modular designs, all of which help to maintain cleanable surface conditions. These design elements are especially crucial for meeting cleanroom standards for biotechnology and pharmaceutical applications.

    Cleanrooms in the pharmaceutical and biotechnology industries prioritize the prevention of cross-contamination,  filtration of indoor and outdoor air, and pressurization control. Because these cleanrooms are used to produce drugs and other pharmaceutical products, they must meet stringent guidelines and comply with regulations set forth by the FDA, including Current Good Manufacturing Practice (CGMP) requirements.

    According to the CGMP requirements under the FDA, cleanrooms facilitating aseptic processing must include:

    • Controls for temperature and humidity
    • Highly cleanable walls, flooring, and ceilings with hard and smooth surfaces
    • Filtered air supplies using high-efficiency particulate air (HEPA) filters under positive pressure for both nonlaminar and laminar flows

    Medical/Hospital Cleanrooms

    Cleanrooms in medical and hospital applications must meet many of the same requirements as those in the biotechnology and pharmaceutical industries to avoid contamination. Medical and hospital cleanrooms are specifically designed with cross-contamination in mind, incorporating cleanable surfaces and filters that prevent particulates from entering. In addition, professionals working in these cleanrooms must wear the proper apparel, including gloves, plastic clothing, hairnets, and shoe coverings. This protective gear can help maintain a safe environment that prevents bacteria from infecting patients.

    Many cleanrooms in the medical industry function as isolation rooms for patients. These spaces require negative pressure that prevents the spread of contaminants between rooms caused by breathing, coughing, or sneezing. To avoid contamination, medical cleanrooms don’t allow for circulating air, and they utilize HEPA filters, alarms that detect any loss of pressure, and hands-free toilets and showers. The HEPA filters in these applications can remove dust and other particles as small as 0.3 µm.

    Some specific applications for medical and hospital cleanrooms include the following:

    • RNA / MRNA research
    • Laboratory, veterinary, and hospital pharmacies
    • Isolation wards
    • T-cell and gene
    • Medical equipment, devices, and tooling

    Aerospace & Automotive Industry

    The automotive and aerospace industry uses various manufacturing processes to produce parts and components, many of which require the use of cleanrooms to maintain better quality and prevent defects. These industries utilize cleanrooms to perform processes such as glass coating, painting, and the production of various electrical components. Because humidity, pressure, and temperature control are especially important for these processes, cleanrooms are typically specified at ISO Class 7 or Class 8.

    Many vehicle components require specialized manufacturing processes that can’t be performed on factory lines. As vehicles become more technologically advanced, their components become increasingly delicate and small. These tiny components are critical to vehicle safety and operation; therefore, defective parts can lead to costly and dangerous accidents. As such, the need for automotive and aerospace cleanrooms has grown.

    Cleanrooms in these industries not only can reduce errors but also allow for temperature and humidity control as well as the reduction in particulate, pressure, and static levels. Reliable cleanrooms also maintain foreign object debris (FOD) control, which has become increasingly critical in this industry.

    Compliant Cleanrooms from Liberty

    If you need dependable, high-quality cleanroom products and contamination control supplies for your application, Liberty Industries offers numerous solutions to meet the needs of nearly any industry. As contamination control experts, we provide various products to solve your critical environmental challenges. We offer softwall cleanrooms and modular cleanrooms as well as a wide range of cleanroom supplies and accessories.

    Contact us today to get started with the ideal cleanroom solution for your industry.

  4. What Is an Air Shower?

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    Air showers are an essential part of any cleanroom operation, addressing the biggest potential containment breach at its source. These chambers or tunnels are a key preventative measure that any cleanroom manager should consider. In this blog, you’ll learn more about air showers and why they’re integral to critical cleanroom applications across many industries.

    How Do Air Showers Work?

    Air showers are tunnels or chambers containing air jets that blow off personnel entering or departing a cleanroom. The pressured jet nozzle air streams drive dirt and dust particles away from the people or objects in the chamber. It then filters out contaminants and redirects them out of the chamber.

    Air showers are positioned at the entrances and exits to cleanrooms or other highly controlled environments. As entrances and exits can be the biggest source of containment breach or contamination, having air showers as an extra layer of security for products and workers is a worthy investment.

    A one-person air shower has two doors that cannot open simultaneously. When the employee enters the air shower chamber from the outside, both doors lock, and then the air jets blow air in high-velocity streams for 4 to 8 seconds. This process blows potential contaminants to a low-pressure section of the chamber. After waiting another 2 to 4 seconds for the room to be cleared of contaminants, the second door leading to the cleanroom will be unlocked and allow the employee to enter.

    Why Air Showers for Cleanrooms

    Cleanroom entrances and the people entering through them pose the greatest risk of contamination and must be managed accordingly. Air showers reduce pollutants that stick onto personnel and equipment despite prior gowning or disinfection procedures. Entrances and pass-throughs with an air shower act as a barrier between critical and non-critical regions.

    By dislodging particulates before they get into the cleanroom, air showers also minimize particle accumulation to reduce cleanroom maintenance needs. They help to decrease energy consumption because HEPA filters do not have to work so hard. In fact, the filters last considerably longer when personnel utilize air showers.

    Applications of Air Showers

    When utilized correctly, an air shower can eliminate the majority of harmful contaminants before they even enter your cleanroom, ensuring your product stays safe and uncontaminated. Here are examples of where air showers can be applied.

    • Aerospace Cleanrooms: The aerospace industry consists of complex aircraft that require failproof components made to the highest standards. Excess particles may degrade an aerospace sensor or cause electrical equipment to malfunction. To guarantee worker safety and project success, all equipment must be made in optimal cleanroom conditions. Aerospace cleanrooms utilize large air showers at the entry and exit to remove particles from people and components, keeping the production area clean and free of contaminants.
    • Pharmaceutical Cleanrooms: Pharmaceutical cleanrooms are essential for developing, testing, and manufacturing life-saving drugs. Contamination in pharmaceutical processes might influence test results or consumer health. Since these cleanrooms must meet stringent cleaning standards, they frequently rely on air showers. The extra degree of security guarantees that individuals passing from outside to inside the compounding room do not bring in potentially harmful contaminants.
    • Medical Research Cleanrooms: Air showers are often found in medical research cleanroom applications involving sensitive equipment. In research studies involving toxic fumes or biohazards like infectious diseases, the inside of the cleanroom may pose more of a threat than the outside. In addition to negative pressurization, air showers are key to removing particles from workers as they exit the cleanroom.
    • Precision Manufacturing Cleanrooms: Although not all production environments have strict particle control specifications, sensitive products like sensors, radar systems, and computer hardware must be produced in a controlled environment. For example, producing defense industry components like weapons, security devices, and other complex equipment requires a highly controlled cleanroom environment.

    Air Showers From Liberty Industries

    Air showers are worth the investment in safeguarding your cleanroom operation. The method is highly effective at addressing the source of the most major potential containment breach—the entrance to the cleanroom. Liberty Industries offers a comprehensive selection of air showers made of different materials and for various cleanroom applications. Our air showers are optimized for low traffic areas, high traffic areas, height restricted areas, and other operational conditions.

    Contact us or request information today to learn more about our high-performance solutions.

    What is an Air Shower?
  5. Product Spotlight Page – Tacky Mats®

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    Dirt and other contaminants carried on the bottom of workers’ footwear can build up on floors and eventually transfer onto work surfaces, equipment, and products. Tacky Mats®, also known as cleanroom sticky mats and tack mats, clean shoe soles as people walk overtop them to prevent such particles from entering sterile or cleanroom environments.

    Utilizing Tacky Mats® at the entrance of your facility or cleanroom improves the efficiency of daily operations since employees won’t need to change into disposable shoes or booties before passing into a workroom. Read on to learn about other benefits and applications of these adhesive mats.

    Benefits of Tacky Mats®

    In appearance, Tacky Mats® may be similar to welcome mats you might find outside any typical doorway. You should place your mat in an area with high foot traffic for best results. Tacky Mats® use peelable layers of sticky adhesive that easily remove dirt and other contaminants as they come in contact with footwear to safeguard against polluting a sterile or cleanroom environment.

    By trapping particles in the adhesive as people walk over the mat, the mat’s surface minimizes potential contaminants as part of a two-step process. First, the adhesive holds dirt in place, preventing workers from tracking it into a room or facility. Then, once the sticky mat surface has collected a large amount of dirt and becomes ineffective—typically at around 50 walkthroughs—you can peel away the saturated layer to uncover a fresh one.

    These mats offer economical dirt control and come in varied sizes, making them applicable in different spaces and situations. Typically, the ideal size requires workers to take at least two to three steps across the mat in order to make contact with both shoes and achieve a comprehensive clean. Given their light weight and compact size, these adhesive mats are easy to position and install on tile, vinyl or concrete surfaces.

    Tacky Mats® Applications and Uses

    Tacky Mats® are best suited for areas where cleanliness is important, or for locations containing sensitive materials and equipment. Some common applications include:

    • Cleanrooms and other sterile environments
    • Research laboratories
    • Medical buildings
    • Hospitals & Pharmacies
    • Pharmaceutical applications
    • Foodservice facilities
    • Factories and other industrial or manufacturing facilities for healthcare devices, aerospace components, etc.

    Tacky Mats® From Liberty Industries, USA Made product

    Tacky Mat® is a registered trademark to Liberty Industries Inc. Our company invented the Tacky Mat® and has been manufacturing and distributing high-performance contamination control products since 1953 for cleanrooms and other related applications. We have a wide range of USA made Tacky Mats® for industrial, manufacturing, and commercial environments. Our company designs our Tacky Mats® to ensure that products and processes stay clean and free of contamination. Liberty Industries couples top-quality products with the superior customer service that only an industry leader can provide.

    Browse our catalog of Tacky Mats® to see our available offerings, or contact us today for more information and to request a quote.

  6. The Role of Stainless Steel in Cleanroom Equipment

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    Click to ExpandStainless Steel in Cleanroom What to Know

    Since 1953, Liberty Industries has been manufacturing and distributing high-quality cleanroom and contamination control supplies and accessories across the globe. We are your one-stop source for all your cleanroom needs, offering products designed to meet the requirements of various critical environments.

    Stainless steel offers a range of properties that are specifically beneficial to cleanroom environments, making it an ideal material for various equipment. We offer stainless steel air showers, pass thrus, and laminar flow equipment that can be customized to fit your specific cleanroom needs.

    Why Stainless Steel?

    Stainless steel equipment and furniture are mostly preferred for cleanroom environments because they meet stringent hygienic requirements and safety standards. Stainless steel is not only robust and sturdy, but it can also withstand even the most rigorous cleaning processes. Some of the advantages of stainless steel equipment in cleanroom environments include:

    • Versatility. Stainless steel is versatile when it comes to design, allowing stainless steel equipment manufacturers to provide tailor-made solutions complying with various regulatory criteria.
    • Corrosion resistance. High-grade austenitic stainless steel, such as Grade 304, offers unmatched corrosion resistance to various chemicals, acids, and alkali.
    • Easy to clean. Stainless steel is easy to clean and disinfect without the risk of losing its robustness and other properties. Grade 304 steel has no pores or cracks that could house dirt, grime, or bacteria. It cleans easily with soap and water, and it can also withstand more rigorous cleaning processes without corroding.

    Which Stainless Steel Grades Are Used for Cleanrooms?

    Some of the grades of steel often used for cleanroom equipment include:

    Grade 304

    Grade 304 is arguably the most common type of stainless steel used for cleanroom equipment, as it offers a cost-effective option that resists oxidation and corrosion. It contains 18% chromium and 8% nickel but no molybdenum. Cleanroom furniture and equipment made from this material can withstand rigorous cleaning processes without wearing away. Grade 304 stainless steel is known to maintain structural integrity even when exposed to high temperatures of 870° C. It also holds up well when exposed to chloride content up to 200/mg/l.

    Grade 316

    Grade 316 stainless steel is the second most common type of stainless steel in cleanroom equipment. It contains 16% chromium, 10% nickel, and 2% molybdenum. Molybdenum protects against specific forms of corrosion and pitting that result from industrial solvents and cleaners. The big difference between Grade 316 and grade 304 stainless steel is that 316 stainless steel resists chloride corrosion and other harsh chemicals.

    Cleaning Stainless Steel in a Cleanroom

    Some of the tips for cleaning and caring for stainless steel in cleanrooms include:

    • Use warm water and a soft cloth or non-abrasive sponge to clean normal spills and small stains.
    • Where necessary, use a mild soap or detergent to clean stainless steel surfaces.
    • Use recommended solvents such as non-sterile or sterile 70% isopropyl alcohol to clean more stubborn messes such as grease, oil, stains, and fingerprints.
    • Use a clean cloth over all surfaces to prevent water spots.

    Stainless Steel Equipment Available from Liberty Industries

    Liberty Industries provides various stainless steel cleanroom equipment designed to meet your specific needs. These include:

    • Pass Thrus. Our stainless steel pass thrus are constructed of 304-#4 stainless steel. They also feature stainless steel hinges and acrylic doors. Our engineers can tailor-make your product to include custom sizes, an optional interlock system, fire-rated doors, and more.
    • Laminar Flow Equipment. We offer stainless steel peripheral laminar flow cleanroom hoods and table top laminar flow fume hoods to protect against harmful fumes and contamination.
    • Air showers. Our air showers are constructed from 304 #4 – 16 gauge stainless steel and come with heavy-duty anodized aluminum doors featuring 3/16″ safety glass. The doors are equipped with magnetic interlocks, and you can choose either left or right door swings.

    Stainless Steel Cleanroom Equipment from Liberty Industries

    Stainless steel is a very popular material option for various cleanroom equipment due to its many desirable properties and ability to withstand rigorous cleaning processes. At Liberty Industries, we offer durable stainless steel air showers, pass thrus, and laminar flow equipment that can be tailor-made for your specific cleanroom application. To learn more about our stainless steel cleanroom equipment, contact us today. You can also view our full catalog for more information about our other products.

  7. Our Product Spotlight: Shoe Cleaners

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    As one of the leading contamination control experts, Liberty Industries has been known for providing high quality cleanroom and contamination control supplies to companies across the globe since 1953. We offer a large selection of products for many industries, including manufacturing facilities, pharmaceutical companies and healthcare companies.

    John J, Nappi, Sr, founder of Liberty Industries, invented the shoe brush cleaner in the late 1960’s. It continues to be one of our most popular products since it can be used outside of cleanrooms as well as industrial applications. We were able to streamline the production process because we only source parts from US manufacturers instead of offshore suppliers. We proudly manufacture the shoe brush cleaner in the United States inside our state-of-the-art Connecticut facility.

    Shoe Brush Cleaners for Your Cleanrooms & Controlled Environments

    Labs, cleanrooms, and similar facilities require a clean environment that is free from contaminants. They are designed to maintain extremely low levels of particulates, including dust and airborne particles. Cleanrooms also usually have a level of cleanliness based on the number of particles per cubic meter at a predetermined molecule measure.

    Facilities must follow certain protocols and buy multiple products to ensure that a specific room is clean enough. A motorized shoe cleaner for cleanrooms is an excellent investment, because it can remove dirt, dust, and other foreign substances from the soles of a worker’s shoes so that potentially dangerous contaminants can’t enter a cleanroom or laboratory environment. The innovative machine can also be placed either inside the gowning room or just outside of the cleanroom entrance. Many companies prefer shoe brush cleaners because they can efficiently clean the bottoms, sides, and tops of a person’s shoes.

    Liberty Industries offers three primary models of shoe brush cleaners:

    1. Shoe Brush 2010SC

      The Shoe Brush 2010SC model, which includes an optional Tacky Mat®, is a fully self-contained system that uses a timing belt between the gear motor and bottom brush assembly. The unit includes a HEPA filter exhaust system that allows it to operate at a 99.99% efficiency rate and is best used prior to entering a cleanroom area. It features an enclosed fan-cooled gear motor and a floating, weight-loaded top brush with a round belt drive and four motor-driven brushes. Workers are notified whenever the HEPA filters are dirty and the easily accessible contamination bag, pull-out dust drawers and filters make them easy to empty or replace.

    2. Shoe Brush 2001 – TB

      The Shoe Brush 2001-TB model has four motor-driven brushes that allow it to clean both the sides, top, and bottom of a worker’s shoes. The 132-pound item, which can be used in a variety of settings both on and off-site, uses a transmission drive and an enclosed, fan-cooled motor.

    3. Shoe Brush 351 Bull Dog

      The Shoe Brush 351 Bull Dog is a heavy duty machine that can quickly and efficiently clean mud, leaves, sand, and other debris that may stick to the bottom of someone’s shoes after they have walked around outside. Visitors and anyone else can use this machine when they come in and before they enter the facility’s office area.

    4. Follow the Proper Maintenance Protocols

      The Cleanroom Classification system is based on the number and size of contaminants within a room or space. The cleanrooms are ranked according to their level of sanitation as determined by the International Standards Organization (ISO), with Class 1 being the most sanitary, to Class 9, which is the least. The ISO standards have strict allowances for particles between 1μm and 5μm. The standards for a cleanroom will vary depending on the industry.

      Facilities can reduce contamination and better maintain a controlled environment by maintaining strict hygiene measures, using protective equipment, using cleanroom supplies and ensuring that workers cautiously enter and exit the area. For this reason, products like a high quality shoe brush machine are important, because they can help reduce the risk of contaminants entering the work area.

      Order High Quality Shoe Brush Machines From Liberty Industries!

      Shoe brush cleaners are a smart investment for facilities in various industries. As one of the largest manufacturers and distributors of top quality cleanroom and contamination control supplies and accessories, Liberty Industries can be your main source for all your cleanroom needs. Feel free to view our product catalog, download our free eBook, and contact us for additional information about our high quality shoe brush machines.

  8. The History & Innovation of the Cleanroom

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    Liberty Industries is a leading provider of cleanroom and contamination control supplies for laboratories, healthcare providers, manufacturing facilities, and more. Our innovative solutions are designed to deliver the best results across a wide spectrum of industries and have been a primary contributor to cleanroom history and innovation.

    The legacy of the cleanroom can be initially traced back to French chemist, Louis Pasteur, one of the originators of medical microbiology. His research throughout the mid- to late-1800s revealed the effects of microbes on organic tissue. Through his tireless study, Pasteur discovered that boiling water and air exclusion would prevent meat from decomposing, establishing his namesake process of pasteurization. From this discovery, he also posited that the exclusion of microbes could reduce or prevent the spread of disease, which led to the development of the first cleanrooms.

    Based on Pasteur’s germ theory, British surgeon Joseph Lister first used antiseptics in surgery to create sterile operating rooms. In 1867, he began to use carbolic acid to clean his hands and instruments and found that this significantly reduced bacterial infection in his patients. This successful attempt to control microbial spread in a targeted environment gave rise to the concept of cleanrooms, and in the 1960s the idea truly took root.

    cleanroom diagram

    The Forefather(s) of the Modern Cleanroom

    In the 1960s, scientist Willis Whitfield worked at Sandia National Laboratories, a federally funded scientific research facility in Albuquerque, New Mexico. Whitfield developed the first forced-air filtration system to control the number of airborne particles within an enclosed space. He filed this as the first cleanroom design, called Ultra Clean Room, under U.S. Patent No. 3158457 in 1964, an accomplishment that saw him inducted into the U.S. National Inventors Hall of Fame.

    Whitfield used gravity and forced air circulation to create a controlled space with extremely low levels of particulate matter. The circulation initiated at the top of the room, where incoming air was forced into the enclosure through HEPA filters in the ceiling. Particulate matter was forced to the ground and drawn out at the bottom of the room. Though the first cleanroom was only able to hold a single adult male, cleanroom technology has since evolved rapidly and now sees broad usage across a variety of large-scale operations, from medical research facilities to electronics manufacturing.

    liberty industries facility 1960s

    John Nappi, Sr. & the Evolution of Liberty Industries

    In 1953, Liberty was founded by John Nappi, Sr. under the name Liberty Machine Company. A visionary entrepreneur and inventor, John Nappi designed and manufactured tooling and machinery for companies throughout Connecticut. With the advent of cleanrooms in the 1960s, the company was uniquely suited to provide innovative contamination control solutions for a wide range of cleanroom applications.

    As cleanroom technology advanced, John Nappi continued to develop useful and practical products, including Tacky Mats®, Shoe Brush Cleaners, air showers, and laminar flow devices. In the 1960s, he updated the company’s name to Liberty Industries, Inc. to reflect its new mission and diversified specialization.

    John Nappi’s son, John J. Nappi, Jr., followed in his father’s footsteps by acquiring the business in 1973.  The company has continued to develop advanced cleanroom and contamination control technology for a wide range of industries, including pharmaceutical, medical, nuclear power, electronics manufacturing, aerospace, and precision manufacturing.

    Over the course of many decades, Liberty has evolved from a small machine shop manned by an intrepid entrepreneur to a world-class manufacturer of state-of-the-art cleanroom technology. Our company continues to push the boundaries of the industry, acquiring the latest manufacturing technology and continuously developing new products and processes. No matter how advanced our technology has become, we hold to the values our company was founded under in 1953: honesty, integrity, commitment, and reliability.

    As Liberty Industries has grown, so has the Nappi family. As a family-owned and operated company, Liberty has seen the introduction of a third generation in John J. Nappi, Jr.’s son, Giovanni J. Nappi III. Giovanni has been around the business his entire life and understands every aspect from the ground up. He initially founded Liberty Coatings in 2006, a subsidiary of Liberty Industries Inc. which provides Cerakote® finishes to industry-leading manufacturers in the sectors of firearms, automotive, and industrial coatings.  Liberty Coatings operates with the philosophy that when high-quality services are offered, delivered on time, and at a competitive price, the company will exceed clients’ expectations.  The coatings division has contributed to the range of diversity in the Liberty Industries customer base. Due to John J. Nappi Jr. and his son Giovanni’s direction, the company continues to grow and prosper through quality product manufacturing and innovation.Nappi family Liberty Industries

    Liberty Industries for All Your Cleanroom Needs

    With a firm foundation in the fundamental science of cleanroom technology, Liberty Industries has scaled the heights of cleanroom and contamination control technology. As a world-class leader in the development and manufacture of cleanroom products, we employ some of the finest minds in the industry to help our customers find the ideal cleanroom setup and supplies for any project. Contact our experts today to learn more about our cleanroom and contamination control products and services.


  9. The Importance of Differential Pressure in Cleanrooms

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    At Liberty Industries, we serve as a one-stop source for all cleanroom needs. For over six decades, we have supplied superior cleanroom and contamination control supplies to customers across the globe. Equipped with extensive industry experience, our team has the knowledge and skills to design and develop a standard or custom cleanroom solution suitable for any critical environment.

    In the following article, we provide an overview of one of the key operating principles of cleanrooms—differential pressure. We outline what it is, how we measure it, and how it affects other conditions in a cleanroom.

    Differential Pressure in Cleanrooms

    Differential pressure refers to the difference in air pressure from one location to another within a system. In cleanrooms, maintaining the right amount of differential pressure—either positive or negative—is essential to preventing contamination.

    • In positive differential pressure cleanrooms, the internal pressure is greater than the external pressure to prevent the ingress of any contaminants through any opening—whether intended or accidental—in the cleanroom.
    • In negative differential pressure cleanrooms, the external pressure is greater than the internal pressure to prevent the egress of any potentially harmful compounds contained within the cleanroom.

    Combined with appropriate temperature, humidity, and airflow level, proper differential pressure levels ensure both cleanroom designs work as intended. As such, it is essential to carefully measure and monitor pressure inside and outside of the cleanroom to confirm the differential remains within the acceptable range.

    Industry professionals often employ visual gauges or meters to facilitate the identification of current pressure levels inside and outside of cleanrooms. The devices are designed to automatically calculate and output the difference between two pressure points in the cleanroom (typically two inlet points), eliminating the need for operators to manually monitor separate gauges and calculate the difference between the results. More advanced measuring instruments may offer additional capabilities for monitoring temperature, humidity, and other cleanroom parameters.

    At Liberty Industries, we offer Magnehelic gauges for these applications. They provide accurate measurement of pressure, pressure differential, and vacuum to 2% of full scale. In addition to cleanrooms, typical use cases include automatic valves, control equipment, and gas-air ratio controls.

    Cleanroom Standards

    The level of cleanliness required from a cleanroom depends on the industry and industrial application. For this reason, cleanrooms are available in numerous classifications, each of which denotes a specific level attainable based on the number and size of contaminants with the given space.

    The International Organization for Standardization (ISO) categorizes cleanrooms from ISO 1 to ISO 9, with ISO 1 having the fewest contaminants per square meter. In addition to the number of particulates, the size of particulates also plays a crucial role in ISO classification. Contaminants are measured in microns, from 1μm to 5μm, with different cleanrooms offering different filtration capacities for each size. For example, cleanrooms with HEPA filters remove particulates as small as 0.3μm with 99.99% efficiency rates, while cleanrooms with ultra-low particulate filters remove particulates as small as 0.12μm with an efficiency rate of 99.999%.

    The effectiveness of the mechanisms that facilitate cleanroom operations—including the filters—depend on many factors remaining within tolerable levels. These factors include pressure, temperature, humidity, and airflow, all of which can help or hinder the attainment and maintenance of proper cleanliness levels.

    Quality Cleanroom Solutions From Liberty Industries

    Cleanrooms play a critical role in many sensitive industries and industrial applications. For these instruments to work correctly, maintaining proper differential pressures (among other factors) is essential. To learn more about cleanrooms and the role differential pressure plays in their operation, contact us today. For assistance selecting and sourcing a cleanroom solution for your facility, request a quote.

  10. Cleanroom HVAC Systems 101

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    Founded in 1953, Liberty Industries has since established itself as a premier manufacturer and distributor of cleanroom and contamination control supplies and accessories. Equipped with almost seven decades of industry experience, we can design, build, and install some of the highest quality cleanrooms with top-of-the-line components, including cleanroom HVAC systems.

    The following blog post provides an overview of HVAC systems for cleanrooms, outlining design basics and key design considerations.

    HVAC systems for cleanrooms

    The Basics of HVAC Design

    Heating, ventilation, and air conditioning (HVAC) is an umbrella term for the systems used to maintain conditions—e.g., temperature, airflow, and humidity—within indoor areas. They are used in industrial, commercial, and residential facilities to ensure environmental conditions are comfortable and optimal for the necessary operations. When integrated into cleanrooms, they are critical to the maintenance of air quality levels for applications involving sensitive materials or requiring the containment of potentially hazardous materials.

    Conventional and cleanroom HVAC systems have some overlapping functions—i.e., enabling industry professionals to control temperature, humidity, and airflow to achieve comfortable living and working conditions. However, the HVAC systems for cleanrooms also perform more advanced functions—such as monitoring and maintaining air supply and flow patterns, filtering out contaminations, and preserving pressure differentials—to ensure the enclosed area is suitable for sensitive and/or dangerous material operations.

    The design of a cleanroom HVAC system changes depending on the requirements and restriction of the application, including  ISO classification , temperature, humidity, and pressure specifications.  Some of the key components include:

    • Air handling units (AHUs)
    • Air ducts
    • High-efficiency particulate air (HEPA) filters
    • Air diffusers
    • Air return pathways and equipment
    • Air quality monitoring and control systems

    Considerations During the Design Phase

    When designing and planning a cleanroom, there are several factors to keep in mind to ensure the finished structure meets the needs of the application. While designs may vary depending on the operations performed within the cleanroom some of the key considerations include:

    Airflow Capacity

    The airflow capacity of a cleanroom (indicated in cubic feet per minute) affects how many air changes are performed per hour. This characteristic, in turn, depends on several factors, such as the cleanliness level required, the number of personnel and equipment/supplies, the size and number of rooms, and the movement of the people and materials into and out of the cleanroom. While commercial HVAC systems perform less than two air changes per hour, cleanroom HVAC systems generally do 10 to 600 air changes per hour. The higher air change frequency is necessary to prevent particles from settling in the cleanroom.

    Airflow Pattern

    Airflow patterns within cleanrooms generally take one of three forms: laminar (unidirectional), turbulent (non-directional), or mixed-flow. The pattern appropriate for a cleanroom depends on the design and application.

    Pressure Differential

    Cleanrooms are available in positive pressure or negative pressure variations. Positive pressure cleanrooms are used to keep contaminants out, while negative pressure cleanrooms are designed to keep potentially hazardous materials in.

    Employees and Equipment

    Both employees and equipment are sources of contamination for cleanrooms. When brought in or out, they may allow particulates and pollutants to come into the controlled environment or hazardous materials to escape into the outside environment. With this in mind, cleanroom personnel must commit to rigorous health and safety protocols such as wearing the correct personal protective equipment (PPE), going through decontamination areas and bringing in or out only cleared supplies and materials.

    Other factors that employees influence include the number of air changes required per hour (more employees mean more air changes) and the temperature levels (cleanroom temperature must be within comfortable levels for human operators).

    Cleanroom Layout

    The layout of a cleanroom affects the efficiency and effectiveness of the HVAC system. For example, the positioning of equipment and air input/output points can help or hinder the filtration of particulates.

    Design Considerations for Cleanrooms

    Design and Construct Your Cleanroom With Liberty Industries

    For all your cleanroom needs, turn to the experts at Liberty Industries. We provide cleanroom design, construction, and installation services as well as all related supplies and accessories to deliver a complete solution.

    For additional information about our cleanroom capabilities, download our eBook or contact us today. To receive pricing details, request a quote with your cleanroom requirements.



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