A mylar bag is a type of plastic bag made from biaxially-oriented polyethylene terephthalate (BoPET), commonly referred to as Mylar. Mylar is a highly durable, flexible, and reflective plastic film that was first developed in the 1950s.

How are Mylar Bags Made?

Mylar bags go through a specialized manufacturing process:

• Polyethylene terephthalate (PET) plastic resin is heated, melted, and blown into a film.
• The PET film is then stretched and oriented biaxially along two axes, giving it strength.
• The oriented PET (BoPET) is bonded with a thin layer of aluminum to make it reflective.
• The material is kept under high tension at over 200°F to smooth the film into strong, flexible sheets of Mylar.

Key Benefits of Mylar Bags

There are several key advantages that make mylar an ideal material for bags and packaging:

• Moisture and Oxygen Barrier – The aluminized surface acts as an excellent barrier against moisture and oxygen. This helps preserve foods and prevent spoilage.
• Puncture and Tear Resistant – Mylar is highly durable and resistant to rips or punctures during packing, transport, and storage compared to other plastic films.
• Flexible Yet Strong – The biaxial orientation gives mylar bags both flexibility and tensile strength. Bags maintain integrity but can contour contents.
• Reflective Surface – The mirrored surface is able to reflect over 99% of radiant heat and light. This helps regulate temperatures.
• Transparent Viewing – Mylar allows contents to be clearly viewed while also blocking UV rays that can degrade contents.

Common Uses of Mylar Bags

Due to these useful properties, some popular uses of mylar bags include:

• Long Term Food Storage – For securely storing dry foods like grains, beans, coffee, and nuts to prevent spoilage.
• Cannabis Packaging – Provides excellent odor, moisture, and UV protection for cannabis products.
• Electronics Protection – Mylar bags create a moisture-free environment to store electronics safely.
• Document Preservation – Libraries and archives use mylar bags to protect rare records and documents.

Mylar bags are an indispensable product for securely storing and protecting all kinds of items. Their unique durable, reflective, transparent, and barrier properties make them ideal for a variety of packaging needs across many industries.