A pass box is a widely used transfer device in cleanrooms, designed for transferring items between the cleanroom and external areas or between areas within the cleanroom with different cleanliness levels. Its purpose is to prevent contaminants from entering the cleanroom, thus ensuring the stability of the clean environment. Below is a technical article on pass boxes, detailing their functions and working principles.   Technical Analysis of Pass Boxes   1. Definition and Function of Pass Boxes A pass box, also known as a transfer hatch, is a critical component in cleanrooms. It serves as an isolated passage for transferring items between different areas of varying cleanliness levels, or between clean and non-clean areas. The primary function of a pass box is to minimize contamination risks during transfers, ensuring a stable clean environment inside the cleanroom. The key functions of a pass box include: Contamination Prevention: Cleanroom Pass boxes prevent contaminants from entering or exiting the cleanroom by isolating the transfer process. Air Filtration: Many pass boxes are equipped with air filters, such as HEPA or ULPA, to ensure clean air circulation within the pass box. Separation of Personnel and Material Flow: By allowing only materials to be passed through, pass boxes separate human traffic from material flow, improving the efficiency of cleanroom operations.   2. Types of Pass Boxes Pass boxes come in several types, tailored to different applications and structural needs: Mechanical Interlock Pass Boxes: These use a mechanical system to ensure that only one door can open at a time, preventing direct air exchange between the cleanroom and non-cleanroom areas. Electronic Interlock Pass Boxes: An electronic system controls the interlocking doors for higher precision and security, suitable for high-demand environments. Air Shower Pass Boxes: These contain a built-in air shower system that removes dust and contaminants from items’ surfaces during the transfer process, making them ideal for ultra-clean environments.   3. Working Principles of Pass Boxes The pass box operates on an interlock mechanism and includes an air filtration system to ensure cleanliness during the transfer process. The working process includes the following steps: Interlock Door Control: Pass boxes typically have two doors: one facing the cleanroom and one facing the external area. An interlock system—either mechanical or electronic—ensures only one door opens at a time, which prevents cross-contamination. Air Filtration: The pass box may include HEPA or ULPA filters to purify the air inside. Some models also feature an air shower system that blows air onto items to remove dust or other particles. Transfer Procedure: During transfer, one door opens for the item to be placed in the pass box. The first door is then closed before the opposite door can be opened, allowing items to enter or exit without compromising the cleanroom's air quality.   4. Installation and Maintenance of Pass Boxes Pass boxes should be installed in high-traffic transfer points according to cleanroom layout requirements. Regular inspections and maintenance of interlock mechanisms, air filtration systems, and air shower units are essential for optimal operation.   5. Applications of Pass Boxes Pass boxes are widely used in several industries to control contamination and ensure product quality: Semiconductor Manufacturing: Used to transfer delicate components like wafers, reducing the risk of particle contamination. Pharmaceutical Industry: Ensures aseptic conditions by transferring drugs and instruments without introducing contaminants. Food Processing: Prevents dust and microbial contamination of raw materials during transfer.

Today, Pharma United Co., Ltd. had the pleasure of welcoming several industry peers to our factory. The company leadership was on hand to receive the guests and personally guide them through our facilities. The visit started with a tour of our state-of-the-art cleanroom showroom, where visitors had the opportunity to observe some of our key products up close. Following that, we moved on to the sandwich panel production line, providing a comprehensive overview of our manufacturing process and demonstrating the high standards we adhere to in production. After the tour, we held a productive discussion session, exchanging insights and ideas on industry trends, challenges, and future developments. The day was both informative and enjoyable for everyone involved, and we look forward to more such collaborations and exchanges in the future. We are grateful to our visitors for making this day a great success!

A cleanroom is a specially designed environment where the concentration of airborne particles is controlled to ensure a contamination-free space. Cleanrooms are commonly used in industries that require strict control over environmental pollutants, such as dust, airborne microbes, aerosol particles, and chemical vapors. These environments are essential in sectors like pharmaceuticals, biotechnology, electronics, aerospace, and food processing, where even the smallest contaminant can compromise product quality or pose a safety risk. Key Features of a Cleanroom   1. Air Filtration    Cleanrooms use High-Efficiency Particulate Air (HEPA) or Ultra-Low Penetration Air (ULPA) filters to remove contaminants from the air. These filters capture particles as small as 0.3 microns or even smaller, ensuring that only clean air circulates within the room. The filtration system is often designed with positive pressure to prevent unfiltered air from entering. 2. Temperature and Humidity Control    Temperature and humidity levels are carefully controlled to meet specific requirements for different industries. For example, in the pharmaceutical industry, humidity control is critical to prevent moisture-sensitive materials from degrading. 3. Controlled Access    To minimize contamination, access to a cleanroom is highly restricted. Personnel must wear special garments, including gloves, masks, and coveralls, which prevent particles from their bodies from contaminating the air. Some cleanrooms also have air showers at the entrance to remove any dust particles from people before they enter. 4. Surface Materials    All surfaces within a cleanroom, such as walls, ceilings, and floors, are made from materials that do not shed particles and are easy to clean. The goal is to ensure that the room remains as sterile as possible during operation.   Cleanroom Classifications Cleanrooms are classified based on the number and size of particles allowed per cubic meter of air. The most widely used classification system is the ISO 14644-1 standard, which divides cleanrooms into nine different classes, ranging from ISO Class 1 (the cleanest) to ISO Class 9 (least clean). The classification depends on the specific industry and product requirements. For instance: - ISO Class 1 is used for manufacturing sensitive products like semiconductors. - ISO Class 5 is common in pharmaceutical production.   Applications of Cleanrooms   1. Pharmaceutical Industry    In drug manufacturing, cleanrooms prevent contamination of medicines, ensuring safety and efficacy. Sterile manufacturing environments are critical for injectable drugs and biologics.   2. Biotechnology    Laboratories dealing with cell cultures, DNA sequencing, and tissue engineering require cleanrooms to avoid contamination that could disrupt experiments or research outcomes.   3. Semiconductor Manufacturing    The production of microchips and electronic components takes place in ultra-clean environments to avoid defects caused by particles or impurities, which can affect the functionality of the devices.   4. Medical Devices    Cleanrooms ensure that surgical tools, implants, and other medical equipment are sterile, reducing the risk of infections when these devices are used in healthcare settings.   Why Are Cleanrooms Important?   Cleanrooms are critical for maintaining product integrity and ensuring that the manufacturing process meets regulatory standards. They prevent contamination, improve product quality, and protect end-users from potential health risks. Cleanrooms also contribute to research and development by providing a controlled environment where experiments can yield accurate and reliable results.   Conclusion Cleanrooms are essential in industries that require the highest levels of cleanliness and contamination control. Through advanced air filtration, environmental monitoring, and strict protocols, they help manufacturers meet stringent quality and safety standards. Whether in pharmaceuticals, biotechnology, electronics, or other fields, cleanrooms play a pivotal role in delivering safe, effective, and high-quality products.

PHARMA UNITED (Kunshan) Co., Ltd. is a company mainly engages in develop, manufacture, sale and service for clean room products. We manufacture SS304 equipment, sandwich panel, clean room doors and windows for pharmaceutical, electronics, food and chemical industry. Our factory covers an area of more than 20,000 sqms, with advanced manufacturing equipment such as CNC laser cutting machine, CNC bending machine, CNC punching machine, etc. Design - manufacturing - installation - commissioning - validation - after-sales services is our working schedule. Every product can customized with high standard & high quality. Try our best to make you satisfy. Business scope: Cleanroom wall & ceiling panel, patition wall, false ceiling Cleanroom doors & windows, steel door, HPL door, aluminum frame door, emergency door HVAC System turnkey project, cleanroom gerneral contractor Cleanroom equipments (passbox, hatch, weighing booth, LAF, air shower, SS304 furniture) Indoor & outdoor PODs (modular cleanroom) Company photo: Warehouse Working area Bending Maching Laser cutting Punching Machine Office building