mylarfoil

Mylar foil, also known as BoPET (biaxially-oriented polyethylene terephthalate) or PET film, is a polyester film used for its strength, stability, and reflective properties. It is produced by stretching polyethylene terephthalate film in both the machine and transverse directions, which aligns the polymer chains and enhances its mechanical properties. This biaxial orientation results in a material that is resistant to tearing, stretching, and most chemicals.

The most recognizable characteristic of Mylar foil is its shiny, metallic appearance, often silver. This is achieved by coating the PET film with a thin layer of aluminum. This metallic coating significantly increases its reflectivity, making it useful for thermal insulation and light reflection. Mylar foil is also a good barrier against moisture and gases, though not as effective as true foils made entirely of metal.

Common applications for Mylar foil include food packaging, where its barrier properties help preserve freshness. It is also used in electrical insulation due to its dielectric strength. In the horticultural industry, reflective Mylar is used in grow tents and on walls to maximize light exposure for plants. Its lightweight and durable nature also makes it a popular choice for emergency blankets and kites. While often referred to as "foil," it is important to note that Mylar is a plastic film with a metallic coating, not pure metal foil.