DMD electrical insulation material characteristics and applications

DMD introduction

DMD is a flexible three-layer insulation made from polyester film covered on both sides with a layer of impregnated wool.In the electrical field, DMD commonly refers to "Dacron-Mylar-Dacron," DMD is a laminated structure composed of two layers of polyester film (often referred to as Mylar) sandwiching a layer of Dacron polyester fiber paper.

 

 

DMD Size:

Thickness: 0.10/0.13/0.15/0.18/0.2/0.22/0.25/0.30/0.35 mm, width: 980 and customized

Total thickness (μm):100,130, 150, 180, 200, 230, 280, 340, 450

 

Features and Applications:

1,Electrical Insulation Properties:

DMD exhibits excellent electrical insulation properties, making it suitable for use in electrical equipment such as motors and transformers.

Electrical Properties：

Property Unit of measure Typical Value

Breakdown Voltage (normal) kV ≥11.0

Breakdown Voltage (155±2 ℃) kV ≥10.0

Property Unit of measure Typical Value

Nominal Weight g/m2 260

Nominal Weight Tolerance g/m2 ±39

 

2,Mechanical Strength:

The DMD structure provides good mechanical strength and dimensional stability, making it a reliable material for insulation structures.

Mechanical Properties：

Property Unit of measure Typical Value

Tensile Strength MD (Before Bending) N/10mm ≥150

Tensile Strength TD (Before Bending) N/10mm ≥130

Stiffness TD N ≥30

Elongation MD % ≥10

Elongation TD % ≥15

Thermal Properties 

 

3,Heat Resistance:

DMD materials typically have a certain degree of heat resistance, allowing them to withstand elevated temperatures. This makes them suitable for use in motors and transformers.DMD is a Class F (155 °C) insulating material with high dielectric strength and high mechanical strength. It is tough and flexible.

This allows for easy insertion into the slot, and the unfolding effect ensures a secure grip. The smooth surface makes DMD ideal for automatic insulation and insertion machines. Additionally, it has excellent adhesion in combination with impregnated materials.External cured resin impregnation protects the polyester film from oxidation and hydrolysis.

 

4,Moisture Resistance:

The polyester film in DMD offers good moisture barrier properties, providing the material with a degree of moisture resistance, suitable for applications in humid environments.

 

5,Flexibility:

The laminated structure of DMD gives it some flexibility, facilitating its use in packaging and applications that require flexibility.

 

6,Applications:

DMD is commonly used in electrical equipment such as motors, transformers, and generators. It serves as insulation pads, insulating shims, and coil insulation components.

Typical Applications： 

Class F motor

Dry type transformers

 

 

7,Laminated Structure:

The laminated structure of DMD combines the electrical insulation properties of the double-layer polyester film with the mechanical strength of the Dacron polyester fiber paper, making it a versatile electrical insulation material.