What Is a Clean Bag?
A Clean Bag, also known as a cleanroom bag, is a polyethylene bag manufactured in cleanroom environments to ensure high cleanliness.
These bags, commonly referred to as cleanroom bags, are suitable for packaging components and products in fields where cleanliness is crucial, such as the medical, food, and electronics industries, due to their low susceptibility to foreign particle adhesion.
Taking into account the considerations for raw materials, Clean Bags not only prevent external contamination but also protect against pollution from outgassing (gas components released from organic materials and packaging materials constituting the product), adhesives, and additives.
Uses of Clean Bag
Clean Bags are primarily used in fields where high cleanliness is required, including the medical, food, and electronics/precision equipment sectors.
1. Medical
In the medical field, Clean Bags are predominantly used for packaging pharmaceuticals (including raw materials) and medical instruments. They are employed to prevent the introduction and adhesion of foreign particles and impurities. Specific use cases include:
- Prevention of impurity contamination in raw materials
- Packaging for transport within pharmaceutical manufacturing processes
- Shipment packaging for pharmaceutical raw materials and intermediates
- Storage and shipment packaging for pharmaceutical formulations (capsules, tablets, powders)
- Shipment packaging for medical instruments (syringes, tubes, etc.)
2. Food
In the food sector, Clean Bags are utilized for general food packaging and packaging for the shipment of food additives.
3. Electronics and Precision Equipment
Precision equipment and semiconductor devices may experience a decrease in yield due to gas emissions (outgassing) from packaging materials and contamination from additives. In the electronics and precision equipment sector, Clean Bags are crucial to preventing such contamination and maintaining the cleanliness of components. Specific use cases include:
- Packaging of LCD and precision equipment components
- Packaging of semiconductor devices and semiconductor device components
- Packaging of substrates (silicon, glass wafers, etc.)
- Packaging of HDD components
- Packaging of high-performance resin
- Precision cleaning and packaging of transport equipment (chip trays, carrier cases, wipes, etc.) and parts after cleaning
Principles of Clean Bag
1. Manufacturing Process
Clean Bags are fundamentally manufactured in cleanrooms where cleanliness is strictly controlled. The cleanliness of cleanrooms is meticulously managed and defined by ISO standards. Clean Bags are typically produced in cleanrooms with a cleanliness level of approximately ISO class 6 or class 7, equivalent to the cleanliness levels required in food factories, pharmaceutical factories, semiconductor factories, etc.
Regular tests, such as tests for falling microbes, airborne bacteria, and microbiological tests on products, are conducted. Workers wear dedicated dust-resistant work attire (cleanroom attire).
2. Components (Additives)
Regular low-density polyethylene bags contain additives to improve the manufacturing process, and these additives (such as BHT antioxidants, fatty acid-based lubricants, silica-based anti-blocking agents, etc.) may aggregate and powder on the inner and outer surfaces of the bag. This phenomenon, known as “breed-out,” poses a risk of additives adhering to or contaminating the products inside the bag.
Clean Bags are manufactured without such additives, preventing contamination from breed-out. Additionally, they are designed with consideration for preventing contamination from outgassing released by typical packaging materials, making them effective in preventing contamination from outgassing.
Types of Clean Bag
Clean Bags come in various shapes, including different thicknesses, widths, lengths, etc. Film structures range from single-layer films to 5-layer films, offering versatility for different applications. Colors include transparent, semi-transparent white, transparent blue, etc.
Especially when transporting electronic components, semiconductor-related components, etc., into clean environments (cleanrooms), double packaging is necessary. Double packaging involves repeating the process of product insertion, vacuuming, and sealing twice to hermetically seal the product inside. However, some products integrate the roles of the first and second bags to simplify packaging and opening procedures.
Moreover, some Clean Bags are equipped with functions such as anti-static and vacuum packaging. Anti-static bags are particularly suitable for packaging powders and precision equipment. There are standard cleanliness specifications, including the regulations of the U.S. Food and Drug Administration’s Drug Master File and the Japanese Pharmacopoeia. Depending on the application, it is essential to select products that meet these specifications.