Polyester films (PET) by GOBA

Polyester Films: Versatile, Temperature-Stable and Custom-Cut

Custom Polyester Films

Polyester film as an electrical insulation film is made from linear polyethylene terephthalate (PETP) and obtains its special properties through a stretching process. A thin layer of molten PETP is applied to a roller and then stretched orthogonally to the roller rotation direction. After fixation at high temperature, a biaxially oriented PETP film is created.

Polyester film is used in the electrical insulation industry under various brand names (Hostaphan, Mylar etc.) as insulation film in insulation class B (continuous temperature up to 130 °C according to IEC 216). Through lamination, it can also be used in higher thermal classes.

Gotthardt Isolierteile GmbH has been working in close cooperation with all renowned European manufacturers for decades. We are, among other things, the largest European converter for Mitsubishi Hostaphan in the thick film segment.

Properties of Polyester Films

Mechanical Properties

With high tensile strength and stability, polyester films are particularly suitable for demanding applications. Due to their biaxial orientation, they are extremely resistant yet flexible at the same time.

Chemical Resistance

Polyester films are resistant to most chemicals and do not absorb moisture, making them ideal for environments where they come into contact with aggressive substances. The films are also free of plasticizers, which guarantees a longer service life.

Temperature Resistance

With temperature resistance up to 150 °C, polyester films are suitable for applications where they are exposed to extreme temperatures. This corresponds to insulation class B.

Application Areas

Industrial Applications

Polyester films are used in a wide variety of industrial applications, e.g. as separator films, protective films or packaging material. They provide an excellent barrier against moisture and chemicals.

Stator with polyester film insulation
Stator with polyester film insulation in an electric motor

Electrical Applications

In electronics and the electrical industry, polyester films serve as insulation material. They are not only temperature-resistant but also electrically insulating, which is why they are used in transformers, motors and other electrical equipment.

We offer slit rolls for virtually every application area. Precision slitting requires a high level of technical expertise and the use of state-of-the-art production machinery. According to your specifications, we produce slit rolls from 5 mm width with a width tolerance of +/- 0.1 mm.

Application Areas for GOBA Slit Rolls

  • Motor and transformer insulation
  • Wound capacitors
  • Cable manufacturing
  • Flexible printed circuits
  • Lamination and metallization
  • Adhesive tapes and embossing films
  • Separator films and labels
  • Packaging and printing

Custom Polyester Films Made to Order

GOBA GmbH offers custom polyester films specifically tailored to the needs of your application. Whether Mylar or Hostaphan, our high-quality films provide you with a tailored solution with optimal properties.

Do you have a specific requirement?

Contact us to find the optimal solution for your needs.

Knowledge from our glossary

Technical fundamentals and term explanations on this topic.

  • Polyester Film

    Polyester film is biaxially oriented PET film (BOPET) made from polyethylene terephthalate, used in electrical insulation as thermal class B with a continuous rating of 130 °C.

  • HOSTAPHAN

    HOSTAPHAN is the brand name of the biaxially oriented PET film made by Mitsubishi Polyester Film in Wiesbaden, which as RN and WN insulates electrically in thermal class B up to 130 °C and withstands a breakdown voltage of 12 kV at 50 µm.

  • Mylar

    Mylar is the brand name of Mylar Specialty Films (formerly DuPont Teijin Films) for biaxially oriented polyester film (BOPET) with high dielectric strength and low moisture absorption.

  • Polypropylene Films

    Polypropylene films are films made from the semi-crystalline thermoplastic polypropylene, produced as cast film (CPP) or biaxially oriented film (BOPP) and usable continuously up to 100 °C.

  • Electrical Insulating Films

    Electrical insulating films are thin plastic films that separate live parts, from polyester film in class B (130 °C) to polyimide film in class R (220 °C), with breakdown values per thickness defined in IEC 60674.

  • Laminating Film

    Laminating film is a film bonded across its full surface to paper, board, metal or an insulating material, by an adhesive, by heat or by its own adhesive layer, and in print finishing it is usually 12 to 30 µm thin.