Pressboard and presspaper for electrical purposes - Part 3: Specifications for individual materials - Sheet 2: Requirements for presspaper, types P.2.1, P.4.1, P.4.2, P.4.3 and P.6.1

This part of IEC 60641 gives the requirements for presspaper for electrical purposes comprised of 100 % sulphate wood pulp, 100 % cotton or a mixture of sulphate wood pulp and cotton. The main changes with respect to the previous edition are: type P.6 has been replaced with a new type, but the designation has been kept, type P.7 has been deleted, the thickness relation of the properties has been simplified and the values were adjusted to today's needs of users.