IEC 60641-3-1:2008 gives the requirements for pressboard for electrical purposes comprised of 100 % sulphate wood pulp or a mixture of sulphate wood pulp and cotton. The main changes with respect to the previous edition are:
- Requirements for types B.0.3 and B.5.3 were added;
- The precompressed type B.3.1 was divided in B.3.1A and B.3.1B (higher flexibility);
- Types B.6.1 has been replaced with a new type, but the designation has been kept;
- Type B.7.1 has been deleted;
- The thickness relation of the properties has been simplified; and
- The values were adjusted to today's needs of users.