book or notebook, book, or notebook covers or kansikirja or notebook, book, or notebook covers or file and method for book or notebook decks or kansioo and method book or notebook decks or file of n order

摘要

The invention relates to an insulation board (1), which is made of organic wood fiber pulp. According to the invention, the insulation board comprises a number of overlapping insulation board layers (2), which are made of some organic wood fiber pulp, such as heat fiberized wood fiber pulp or the like. The fiber length in the organic wood fiber pulp is within the range 1.0-5.0 mm, most advantageously 2.5-4.0 mm.