Modern Development in Swedish Fiberboards

In the search for a cheaper raw material in the Swedish fiberboard industry, changes from 100 percent stone groundwood to additions of 20 to 30 percent refiner groundwood from sawdust are described. The Asplund process is used in the manufacture of hardboard with unbarked wood as the furnish Laboratory results show satisfactory properties for bark contents up to 50 percent. Large amounts of bark tended to decrease surface smoothness, slightly increase dimensional changes, but improved the workability of the board. Sawdust greatly improved surface smoothness, but other properties remained unchanged. From a hardboard quality standpoint, the use of up to 40 percent bark or almost 100 percent saw dust is probably quite permissible and even desirable. Fiberboard with a density of 0.4 to 0.8 grams per cc. is classified as medium density hardboard. Flexibility in dimensional changes make this board suited to wall paneling and exterior siding after heat treatment for water resistance and dimensional stability. A more refined pulp is used for this process, put into operation in 1958.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member