Mylar: the versatile transparent polyester film for innovative applications
Mylar is a biaxially oriented polyethylene terephthalate film (BOPET) that is used worldwide in a wide range of applications due to its mechanical, thermal and electrical properties. This polyester film is a branded product of DuPont, developed in the 1950s, which has played a key role in industries such as electronics, packaging and audio technology ever since.
GOBA supplies Mylar and comparable polyester films in thicknesses from 12 to 350 µm, cut to custom widths.
How is Mylar used?
Applications of Mylar film in industry
Mylar is frequently used in environments that require high thermal stability and mechanical strength. The film can withstand peak temperatures up to 150 °C without losing its properties.
- Electronics: as an insulating material in transformers and capacitors
- Packaging: ideal for food packaging thanks to its low gas permeability
- Aerospace: used by NASA in experiments for its heat resistance and reflective properties
- Loudspeakers: Mylar is used as diaphragm material to ensure precise sound quality
- Printing: Mylar film is excellent for printing, which makes it versatile in graphic applications
Technically demanding sectors
Mylar is particularly widely used in electronics and electrical engineering as an insulating material, where it stands out for its high dielectric strength and chemical resistance.
The history and manufacturing process of Mylar
Development in the 1950s
Mylar was developed by DuPont in the mid-1950s. It is a biaxially oriented polyester film manufactured by stretching orthogonal to the roll direction. This processing gives Mylar exceptional strength, transparency and mechanical stability.
Significance of BOPET
BOPET films such as Mylar stand out for their excellent electrical properties, low water absorption and high tensile strength. These properties make them ideal for insulation applications in electrical engineering.
Which properties distinguish Mylar film?
- Mechanical and thermal stability: Mylar remains dimensionally stable and tear resistant even under extreme conditions.
- Electrical properties: Mylar is a good electrical insulator with high dielectric strength that safely withstands voltages.
- Chemical resistance: the film is resistant to many chemicals and contains no plasticisers, which keeps it durable and stable.
- Low gas permeability: Mylar offers significantly lower gas permeability, making it ideal for applications such as packaging.
The use of Mylar film in loudspeakers
Why is Mylar ideal for loudspeaker diaphragms?
- High tensile strength: Mylar remains stable under tension and delivers precise vibrations
- Thermal stability: the film does not deform at high temperatures, which improves sound quality
- Low mass: lightweight diaphragms enable accurate sound reproduction
How does Mylar improve sound quality?
Thanks to its stable and smooth surface, Mylar minimises distortion and delivers clear, natural sound.
Technical properties of Mylar
High tensile strength and thermal stability
Mylar exhibits exceptional tensile strength and remains functional at temperatures up to 150 °C.
Low gas permeability
This property is particularly important for applications in packaging and for technical coatings, for example in aerospace, where Mylar is often coated with aluminium.
Reflective properties
Mylar can be sputter-coated with aluminium, making it an ideal material for insulating and reflective applications.
GOBA Takeaway
Mylar is one of the most versatile polyester films on the market. Thanks to its outstanding electrical, thermal and mechanical properties it is used in countless industries, from electronics to audio technology. Whether as an insulating film in transformers or as diaphragm material in loudspeakers, the range of applications is virtually unlimited.