SYNTETIC RESIN-BONDED PAPER by Bulgarian State Standard /BSS/ 5326-76

The following brands are produced from electroinsulating paper and high-quality phenol resins with thickness from 0.5 mm to 100 mm and size (1450 x 950) mm.:
E - with good mechanical qualities for normal electric load, applicable as a constructional material in equipment and machinery construction industry, as an insulating material in low voltage range of electrical industry;
AE - same as brand E with better die-stamping qualities;
E2 - with insubstantial water-absorbing capacity and good electroinsulating qualities remaining in high humidity conditions as well, making this type of paper applicable in high-frequency and communication equipment operating in humid climate;
E2.A - good die-stamping quality at normal temperature, high electroinsulating resistance and low dielectric strength under very hard humidity conditions;
E3 - good mechanical qualities as well as high electric strength, applicable in high-voltage machinery for function in transformer oil at temperatures up to 1200C;
E4 - because of its increased electric strength parallel with the layers, it is applicable in high-voltage machinery;
Synthetic resin-bonded paper pads with thickness from 0.5 mm to 3.0 mm –subsidiary material for drilling of printed-circuit boards according to Branch Standard /BS/ 04 78187-85; Synthetic resin-bonded paper pads on phenol base; Synthetic resin-bonded paper pads with covering sheets on melamine base.