Simulation of the yield of knot free boards from Scots pine (Pinus sylvestris L): a comparative study between square-sawing and star-sawing.
2005 (English)Report (Other academic)
This work describes a simulation of the removal of knots from square-sawn wood and from wood sawn with the star-sawing pattern. The efficiency of the two methods is compared according to the length of the received boards and the volume exchange. The production of wood free from knots is important since the market demands wood without knots for reasons of both appearance and material properties.
The simulation is done with data for trees and logs taken from The Swedish Stem Bank. The data is then used to simulate the sawmill process in a computer program called the Virtual Sawmill. Data related to the received boards are then used in a MATLAB model simulating the cross cutting of knots.
The simulation gave a mean knot-free board length of 263 ±100 mm and a spillage of 15.9 % when logs with a top diameter of 100-370 mm are square sawn. Star sawing simulated for logs with a top diameter exceeding 230 mm gave a mean knot-free board length of 417 ±321 mm, while the mean length of knot-free boards was 298 ±122 mm for square sawing when simulating sawing of the same logs. Under these conditions the volume losses for cross cutting is 9 % for star sawing and 13 % for square sawing. This shows that star sawing has a potential for the production of knot-free wood.
Place, publisher, year, edition, pages
Växjö: Växjö universitet , 2005. , 12 p.
, Växjö universitet, TD, Submitted paper, 2004:16
sawing, wood, simulation, volume yield, blanks, finger-jointing, pine
Research subject Technology (byts ev till Engineering), Forestry and Wood Technology
IdentifiersURN: urn:nbn:se:lnu:diva-20915OAI: oai:DiVA.org:lnu-20915DiVA: diva2:542079