The History of Paper Board as Electrical Insulation Paper

The use of paper board as electrical insulation paper started in the early-mid 20th century. Since the need for high voltage electrical transformers, there has been a need for an insulating material that could withstand the high electrical and physical stresses experienced around a core and windings. Pressboard, a board made by compressing layers of paper together and drying them, has been used for installation purposes in many of the first electrical machines. However, as electrical technology increased, the need for a higher density material that was capable of insulating larger and higher voltage transformers grew. In the late 1920s, Hans Tschudi-Faude became the director of H. Weidmann Limited and began developing a type of press board that would meet the higher standards needed for the newer, more powerful transformers.

Unlike older methods of press board production, Transformer board was not based on used paper or cotton waste but was made with high-grade sulfate cellulose. The new product was made purely out of cellulose without a resin or binder, improving electrical insulation capabilities and could be completely dried, degassed, and oil impregnated. The new product became famous under the name Transformer board. Throughout the 1930s, new methods of production and advances in understanding replaced almost all insulating parts of transformers with parts made from transformer board.