Accession Number : AD0712137

Title :   EFFECT OF REFINING ON STRENGTH PROPERTIES OF PRESS DRIED HARD AND SEMI-HARD FIBRE BUILDING BOARDS. STUDIES IN PLANE PRESSING 5,

Corporate Author : SVENSKA TRAFORSKNINGSINSTITUTET STOCKHOLM

Personal Author(s) : Norberg,K. Gunnar ; Back,Ernst L.

Report Date : 09 MAY 1969

Pagination or Media Count : 9

Abstract : Sheets of Masonite pulp, which was refined at a consistency of 20% to pulp freeness values between 15 and 100 Defibrator seconds (DS) (780-645 CSF) were press dried at 200, 240 and 290C using distance bars to densities between 0.6 and 1.0 g/cu cm. The strength properties compared at equal densities were improved with increased refining, especially in the range of 15 to 30 DS. Thus, the modulus of elasticity, the breaking elongation and the specific impact strength were increased simultaneously. These effects were more pronounced at higher sheet density and normally most pronounced at a press temperature of 240C. Some of the strength properties were reduced when refining increased above 60 DS, probably due to network dislocations in the wet sheet during dewatering in the plane press. (Author)

Descriptors :   (*FIBERBOARD, MECHANICAL PROPERTIES), SHEETS, HOT PRESSING, WOOD PULP, PURIFICATION, PROCESSING, SWEDEN

Subject Categories : Wood, Paper and Related Forestry Products

Distribution Statement : APPROVED FOR PUBLIC RELEASE