It is also known as DDP. The use of this B-stage resin coated paper increases the short circuit strength of distribution transformer coils.
It is produced by coating modified epoxy resin in diamond dot patterns on electrical insulating paper. The size of the dots are carefully designed to avoid interfering with vacuum drying and oil impregnation.
This type of presspaper is treated chemically and included nitrogen content to get a upgraded thermo performance.
• Insulation class A (105 °C)
• Presspaper (in rolls), 100 % sulphate wood pulp
• High purity and mechanical strength
• Thermosetting coating of expoxi-phenolic resin (B-stage), put in rhombic pattern on one or both sides.
• Good compatibility with transformer impregnants after curing of the coating.
Note: The surfaces to be bonded must remain tightly pressed together during curing
• Layer insulation in liquid-immersed transformers
• In rolls. 1000 mm, 1220mm, 1320mm, 1500mm, 1700mm, 1900mm
• In strips minimum width 4 mm
• Available thickness: 0.05 - 1.0 mm (presspaper thickness)
|Curing Temperature and Time||90℃±5℃/3h or 130℃±5℃/6h|
|Storage Life||month||6 months, room temperature, dry and well-ventilated environment|