Kvistars frekvens, form och beskaffenhet i trekantprofil av furu (Pinus silvestris L) och gran (Picea abies Karst).
1995 (Swedish)Report (Other academic)
Frequency and Character of Knots in Triangular Profiles of Pine (Pinus silvestris L) and Spruce (Picea abies Karst).
Holmberg Dick Sandberg
This report describes the structure and amount of knots in triangular profiles from StarSawing of pine (Pinus silvestris L) and spruce (Picea abies Karst). The yield of blanks is determined mainly with a defined knot structure and the fibre aberration around knots. In addition a minor investigation of the amount of pitch pockets has been carried out.
The specimens comprise of butt logs from three different areas in Sweden. The specimens are taken from normal grown pine, and both normal and fast grown spruce.
Large amounts of the knots found in triangular profiles from butt logs are unacceptable for further refinement. Thus, the knots have to be removed. When producing blanks free from knots there is a volume decrease of 8 and 21 percent in average for pine and spruce respectively, referring to the original volume. Further refinement including fibre aberration increases the volume loss by another 5 percent for pine and 6 percent for spruce. The length of the refined blanks varies between 2 and 500 centimetres for pine and between 2 and 400 centimetres for spruce.
Measurement results are included in the report for calculating the volume yield of blanks free from knots, with or without fibre aberration. The distributions of lengths of blanks and corresponding volume yields are shown in different graphs.
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 1995. , 26 p.
, TRITA-TRÄ R-95-12, ISSN 1104-2117 ; 12
knot, blank, sawing, StarSawing, pine, spruce, pitch pocket, fibre aberration, Picea abies Karst, Pinus silvestris L
gran, tall, trä, kvistar, kådlåpa, stjärnsågning, stående årsringar, sönderdelning
Research subject Technology (byts ev till Engineering), Forestry and Wood Technology
IdentifiersURN: urn:nbn:se:lnu:diva-20786ISRN: KTH/TRÄ/R--95/12--SEOAI: oai:DiVA.org:lnu-20786DiVA: diva2:540963