Wood-fiber board |
Wood-fiber boards (abbreviation WFB) of general-purpose produced by the wet method are a sheet material manufactured in process of hot pressing of wood fiber mass, which is formed as a carpet. These fibers are obtained by steaming and milling of wood raw material. |
Raw materials are waste of lumbering and woodworking, pulpchips and fuelwood for technological needs. The phenol-formaldehyde resins and paraffin are used to increase strength of the WFB. |
Commercial production of WFB began in the USA in 1922. In 1931 the Swedish patent was obtained on introduction of a new technology, which is most widely spread in the world, the main technological stages remain unchanged until now: wood raw material is milled to the state of wet cotton-like mass, under relative humidity of 60-70% it is fed to pressing. According to their intended use the boards are divided into types: hard (T, quality group A or B) and soft (Ì-3). |
At present the Open JSC “Nelidovskiy DOK” produces hard wood-fiber boards (WFB) State Standard 4598-86 of the following types and sizes: :
grade T quality group A
density from 850 to 1100kg/m
thickness 3.2mm; 4.0 mm
width 1220 mm
length of sheets from 1740 to 3050 mm (according to customer’s order) |
Due to increased strength and water resistance the hard WFB is indispensable for furniture production; it is also widely used in construction.
An example of reference designation of a hard board of quality group A, sort 1, nominal dimensions 3050õ1220õ3,2 mm: T gr. A I s 3050õ1220õ3.2 State Standard 4598-86
|