Diamond Dotted DMD Paper For Transformer

Diamond Dotted DMD Paper is a three-layer composite DMD insulation paper with a diamond adhesive grid, with F class 155℃, which is an advanced electrical insulation material engineered for heavy-duty industrial applications.

This high-performance laminate is manufactured by combining electrical-grade polyester film with polyester non-woven fabric on both sides using a premium Class F heat-resistant adhesive. The surface is then precisely coated with a specially modified epoxy resin in a distinct diamond grid pattern and processed into a semi-cured B-stage matrix.

When your wound coils undergo heat treatment, the diamond resin dots liquefy and cure, bonding the conductors into a rigid structural block while leaving sufficient open grid channels for optimal transformer oil circulation.

Technical Specifications (TDS)

As a leading global supplier of raw materials for power grids, we ensure that every batch of our composite insulation material strictly aligns with international IEC standards.

• Product Structure: Polyester Non-Woven Fabric + PET Film + Non-Woven Fabric (DMD)

• Adhesive Matrix: High-Performance Class F Heat-Resistant Adhesive

• Surface Coating: Specially Modified Epoxy Resin (Diamond Grid Pattern)

• Curing Stage: B-Stage (Semi-Curing for optimal shelf-life and thermal reactivity)

• Insulation Class: Class F (155°C)

Main Features

1. Excellent Mechanical Properties

The DMD composite structure provides good tensile strength and handling performance during transformer winding.

2. Reliable Dielectric Performance

The polyester film layer contributes stable electrical insulation, making the material suitable for transformer insulation systems.

3. Strong Bonding Performance

The diamond-pattern epoxy resin provides effective bonding after curing, helping improve coil integrity and reduce displacement.

5. Good Heat Resistance

The product uses F-class heat-resistant adhesive, making it suitable for transformer applications that require stronger thermal performance than ordinary bonding insulation paper.

Industrial Applications

This specialized three-layer composite DMD insulation paper with diamond adhesive grid is the definitive insulation choice for the following industrial manufacturing sectors:

• Oil-Immersed High-Overload Transformers: Specifically deployed for interlayer insulation and turn insulation in distribution and power grid transformers subjected to cyclic overload pressures.

• Transformer Component Assemblies: Extensively utilized for end insulation barriers to secure winding structures.

• Electromagnet Wire Protection: Ideal for the tight, continuous wrapping and insulation shielding of conductive flat wires (copper/aluminum flat conductors).

Curing Conditions

The curing conditions for this product are:

130°C ± 5°C for 5 hours

150°C ± 5°C for 3 hours

Under these conditions, the resin dots soften and cure to bond adjacent winding layers effectively.

This curing behavior is one of the key technical points of diamond dotted DMD insulation paper, because the final bonding performance depends on the correct winding and curing process.

Plain DMD Insulation Paper vs Diamond Dotted DMD

The main difference is the diamond dotted epoxy resin coating.

Plain DMD Insulation Paper mainly provides insulation, no bonding effect after heating

Diamond Dotted DMD Insulation Paper: provides insulation, provides bonding after curing, helps improve winding stability

For customers making transformer coils, this difference is important.

The product is not just an insulation layer. It becomes part of the winding structure after curing.

Frequently Asked Questions (FAQ)

Q1: What is diamond dotted DMD insulation paper?

A: It is a three-layer composite DMD insulation paper coated with modified epoxy resin in a diamond pattern for both insulation and bonding.

Q2: What is the main benefit of using Diamond Dotted DMD instead of standard fully coated films?

A: Fully coated films block the dissipation of heat. The diamond grid pattern leaves open spaces between the bonded dots. These open channels act as permanent micro-passages that allow transformer oil to flow smoothly, accelerating heat dissipation and preventing dangerous localized hot spots in high-overload systems.

Q3: Can we adjust the curing time if our industrial oven has specific heating curves?

A: For safety and consistency, we highly recommend adhering to either the 130°C for 5 hours or 150°C for 3 hours protocols. Deviations can result in an incomplete cure, reducing the mechanical bond strength under short-circuit stress.