Transformer Winding Insulation Material DDM

It is also known as DPF. The use of this B-stage resin coated film increase the mechanical strength of transformer coils. It is produced by coating modified epoxy resin in diamond dot patterns on electrical insulating film. The size of the dots are carefully designed and arranged to cover only 36% of the surface, remaining 64% free for optimum SF6 gas distribution.

Product Details


After curing, the prepreg resin cures from stage B (prepreg) to satge C (cured), adhering to any metallic surface and creating micro channels for optimal gas distribution. The bonding strength is adequate to support effective gluing in unsupported coil design.


* Dry type transformer layer insulation 

* Oil filled transformer layer insulation

* SF6 high current voltage transformer wire winding insulation or layer insulation film

* Motor slot insulation, or phase insulation film

* Also suitable for Automobile, electronic application

DDM Technical Data:

Nominal thickness


Thickness tolerancemm±0.005±0.01±0.01
Standard widthmm1000mm



Breakdown voltagekv≥6≥8≥9
Bond strengthkpa≥350
Curing temperature and time
90℃±5℃/16h or 130℃±5℃/6h
Storage life
6 months, room temperature, dry and well-vetilated environment

Packaging & Shipping:

 Roll packing in requested meter, protected by PP bag and carton, put on fumigation-free pallets, wrapped with shirinking film.

transformer resin epoxy isnulation materials ddm diamond dotted paper/film


companycompanyhechin company



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