DMD insulation paper: Introduction, Features, Manufacturing Process

What is DMD?

DMD is a high temperature laminated insulation material, composed by two layers of non woven polyester and one central layer of polyester. The temperature resistance grade is F, that is, 155℃. The executive standard for ‌DMD insulation paper is JB/T 4060-1991 and the product color is usually white. Its thickness is between 0.10mm and 0.50mm and its width is between 980mm and 990mm.

What are features of DMD?

1. Excellent insulation performance: DMD insulation paper has good electrical insulation performance, which can effectively isolate the conductive part of electrical equipment to prevent leakage or breakdown.

2. Chemical corrosion resistance: DMD insulation paper has good chemical resistance and can maintain stable performance in a certain corrosive medium.
3. Good mechanical strength: DMD insulation paper has good mechanical strength and wear resistance and can withstand certain mechanical stress and wear.
4. High temperature resistance: DMD insulation paper has high temperature resistance. It usually can withstand temperatures above 130 ° C and is suitable for electrical equipment in high temperature environment.

How is DMD insulation paper made?

Preparation of polyimide fiber paper:

·First, a polyimide resin is mixed with a solvent to form a polyimide resin solution.
·Impregnate the polyimide resin solution into the cellulose paper substrate so that the paper substrate is fully impregnated.
·The impregnated paper substrate is dried and cured so that the polyimide resin can be cured into fiber paper.

Preparation of DMD insulating paper:

·The prepared polyimide fiber paper is laminated with two pieces of polyester film.
·By hot pressing process, polyester film and polyimide fiber paper are bonded together to form DMD insulation paper with double layer structure.
·After cooling and finishing treatment, the DMD insulation paper product with double-layer structure is finally formed.

Quality inspection and packaging:

·Conduct quality inspection on the prepared DMD insulation paper and check whether its appearance, size, insulation performance and other indicators meet the requirements.
·Qualified DMD insulation paper products are packaged, which is usually in roll or sheet packaging to facilitate transportation and use.

Does DMD insulation paper rust?

It won't. DMD is mainly composed of polymer materials such as polyester film and polyimide fiber paper, which have excellent corrosion resistance and are not easily attacked by oxygen and water. So rust does not occur.

Drawbacks of using DMD insulation paper

1.Not easy to adjust thickness: The thickness of DMD is usually fixed and not easy to adjust, which may limit its use in some specific application scenarios.

2.Non-easy stripping: DMD is usually not easy to peel off. Once bonded, it may be difficult to separate, which may increase the difficulty of repair and replacement.
3.Sensitive to ambient humidity: DMD is sensitive to ambient humidity. And prolonged exposure of DMD in high humidity environment may affect its insulation performance.
4.Limited thermal stability: Although DMD has a high temperature resistance, a certain degree of thermal stability problems may occur under extreme high temperature conditions.
5.Limited flexibility: DMD is relatively thin and has limited flexibility. It may not be suitable for some application scenarios that require a high degree of flexibility.

What is DMD insulation paper used for?

It is used for motors, generators and electric appliances in the slot insulation, liner insulation and turn to turn insulation.

DMD is typically used on low and medium voltage electric machines. Specific applications include:
—Slot liner for electric motors.

—Phase insulation.

—Interlayer insulation material for transformers.

Where to find DMD?

Ztelec Group is a professional manufacturer of high-quality electrical insulation materials with more than sixty-five years of manufacturing experience. If you need more product information and quotes, please contact us.