Electrical Pressboard

Our Electrical Pressboard is a high-density insulation paperboard. It is made from 100% high-purity sulfate wood pulp. It is pressed under high temperature and high pressure. The density can reach 1.0 to 1.3 g/cm³. Ordinary paperboard has a density of only about 0.7. Why does density matter? Higher density means higher mechanical strength. It also means higher breakdown voltage. High-density paperboard also absorbs less moisture. Less moisture means more stable insulation performance. A transformer insulation parts processing factory came to us. They needed electrical pressboard to make shims, support strips, and angle rings. Before, they used imported paperboard. The price was very high. We sent them a sample of our Electrical Pressboard. Thicknesses ranged from 0.5 mm to 4 mm. They tested the compression strength. Our paperboard had a compression strength of 65 MPa. The imported product had 68 MPa. Very close. But our price was 40% cheaper. Now they buy 5 tons from us every month.

Our Electrical Pressboard has a breakdown voltage of 15 kV/mm in the vertical direction. In the parallel direction, it is 8 kV/mm. Bending strength is 100 MPa. Compression strength is 65 MPa. Water absorption is below 1.5%. All indicators meet national standards. We can also process our Electrical Pressboard into finished parts. You give us a drawing. We make a mold. We punch out the parts on our punching machine. Your customer can assemble them directly. No need to cut them in-house. That saves labor. Our Electrical Pressboard is used for transformer shims, support strips, angle rings, insulation cylinders, and clamp insulation. Below are the specifications.