Melinex® 238 Low-oligomer Polyester PET film

Melinex® 238 PET Film - Low-Oligomer Polyester Film for Hermetic Compressor Motor Insulation

Melinex® 238 PET Film is a translucent white polyester film developed for electrical insulation in rotating electrical machines, especially hermetic compressor motors used in refrigeration and air-conditioning systems.

Compared with regular polyester insulation film, Melinex® 238 has low oligomer extraction properties. This makes it more suitable for motor insulation applications exposed to refrigerant, compressor oil, chemical stress and long-term thermal aging.

Chengrui supplies Melinex® 238 PET Film in rolls, sheets and custom slit widths for slot insulation, phase insulation, wedges, closures and punched electrical insulation parts.

What Is Melinex® 238 PET Film?

Melinex® 238 is a low-oligomer polyester PET film used for electrical insulation.

In hermetic compressor motors, insulation materials may work in a sealed system together with refrigerant and compressor oil. Under heat and chemical exposure, ordinary polyester film may not always provide the same long-term stability required by this environment.

Melinex® 238 is a more specific polyester insulation film for motor applications where low oligomer content and thermal aging performance are important.

Main Specifications

Available Thickness Range:

The film is supplied in a comprehensive range to suit various design needs:

300 gauge (0.075 mm)

500 gauge (0.125 mm)

760 gauge (0.190 mm)

900 gauge (0.225 mm)

1000 gauge (0.25 mm)

1200 gauge (0.30 mm)

1400 gauge (0.35 mm)

Features of Melinex® 238

1. Low Oligomer Extraction

The most important feature of Melinex® 238 is its low oligomer extraction property.

In hermetic compressor motors, insulation materials may be exposed to refrigerant, oil and heat for a long time. A low-oligomer PET film helps reduce extractable low-molecular substances and supports better long-term insulation stability in this environment.

2. Suitable for Hermetic Compressor Motors

Melinex® 238 is widely used in hermetic compressor motor insulation.

Typical equipment includes:

• refrigerator compressor motors;

• air-conditioning compressor motors;

• HVAC compressor motors;

• refrigeration motor insulation systems;

• motors working with refrigerants and compressor oil.

3. Good Dielectric Properties

As a PET polyester insulation film, Melinex® 238 provides good dielectric performance for motor insulation systems.

It can be used between the winding and stator core, between different phases, or in punched insulation parts that require thin and stable electrical insulation.

Applications of Melinex® 238 Film:

1. Hermetic Compressor Motor Insulation

This is the main application of Melinex® 238.

Hermetic compressor motors are commonly used in refrigeration and air-conditioning systems. Because these motors operate in sealed environments with refrigerants and compressor oil, their insulation materials must be selected more carefully than for standard open motors.

Melinex® 238 is suitable for this application because of its low oligomer extraction and stable electrical insulation performance.

2. Slot Insulation

Melinex® 238 can be used as slot insulation between the winding and stator core.

In this position, the material helps provide electrical separation and mechanical protection for the winding system.

The selected thickness depends on slot design, voltage level and required insulation distance.

3. Phase Insulation

Melinex® 238 can also be processed into phase insulation pieces for motor windings.

Phase insulation separates different winding phases and helps maintain insulation reliability during motor operation.

For compressor motors and refrigeration motors, low-oligomer film is often preferred when the insulation system is exposed to refrigerants or oil.

Approvals & Typical Properties:

Melinex® Film 238 holds key safety certifications and is available in a standardized range of thicknesses:

UL Recognized Component:

For 300 gauge (0.075 mm): RTI is 140°C (Electrical) and 125°C (Mechanical - STR).

For 1000 gauge (0.25 mm): RTI is 140°C (Electrical) and 130°C (Mechanical - STR).

Melinex® 238 vs Regular 6021 Polyester Film

Both Melinex® 238 and 6021 polyester film are PET-based electrical insulation films, but their application focus is different.

Melinex® 238 PET Film is a trusted polyester film used worldwide in electrical insulation, motor manufacturing, transformer production and precision industrial converting applications.

With excellent dielectric performance, dimensional stability and processing reliability, Melinex 238 remains a preferred material for demanding insulation applications.

Chengrui Insulation supplies original Melinex® 238 PET Film in rolls, sheets and custom-converted formats for customers worldwide.