The impact of a strength grading process on sawmill profitability and product quality
2009 (English)In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 4, no 4, 1430-1454 p.Article in journal (Refereed) Published
A strength grading process, starting with log grading, was studied with respect to grading yield, impact on quality, and economic efficiency when visual grades according to Nordic grading rules were used for alternate product comparison. Pine (Pinus sylvestris) and spruce (Picea abies) logs and boards were graded with several varieties of commercial grading and strength-grading equipment. The boards were destructively tested, and the European grade-determining properties strength, stiffness, and density were measured. Models for these were made by partial least squares and validated. A method for the derivation of settings for multiple indicating properties, which increased yield in some cases, was proposed and evaluated. Grading to grade combinations of C40, C30, and C18 was done. The impact of visual override based on deformations was also studied. A simplified economic and sensitivity analysis was done. The outcome was that log grading can be used for strength grading with good economic and quality results. Strength pregrading on logs improves sawmill economy, depending on the species and market situation. Drying quality greatly influences the yield through visual override grading on deformations. Market prices of high grades (>C30) must improve in order to stimulate supply, as it is more economical to produce lower grades.
Place, publisher, year, edition, pages
2009. Vol. 4, no 4, 1430-1454 p.
Manufacturing engineering and work sciences - Manufacturing engineering
Produktion och arbetsvetenskap - Produktionsteknik
Research subject Wood Technology
IdentifiersURN: urn:nbn:se:ltu:diva-2729Local ID: 06a013a0-9c7e-11de-a77c-000ea68e967bOAI: oai:DiVA.org:ltu-2729DiVA: diva2:975582
Validerad; 2009; 20090908 (ysko)2016-09-292016-09-29Bibliographically approved