IEC 60667-3-1: 2020 gives requirements for vulcanized fibre sheets for electrical purposes. Materials made by combining with an adhesive several thicknesses of vulcanized fibre are not covered by this document. Materials that conform to this specification meet established levels of performance. However, the selection of a material by a user for a specific application is based on the actual requirements necessary for adequate performance in that application and not based on this specification alone. Safety warning: it is the responsibility of the user of the methods contained or referred to in this document to ensure that they are used in a safe manner. This second edition cancels and replaces the first edition published in 1986. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
change to the range of thickness deviation in Table 1;
addition of apparent density in Table 1;
change to the range of thickness for tensile strength in Table 1;
addition of flexibility and shrinkage in Table 1;
change test method and property value of internal ply adhesion on Table 1.