Lumber Quality Research Articles

The impact of site on tree form, wood properties, and lumber quality of plantation-grown Pinus patula

Abstract South Africa is a water scarce country with minimal natural forests. Plantation forest species such as the Mexican tropical hard pine, Pinus patula Schiede & Deppe ex Schltdl. & Cham., was introduced into the country to satisfy local fibre demand. Today, the majority of pine plantations in South Africa are found in the Mpumalanga province. The province has diverse growing conditions in relation to climate and soil properties. Sample plots were established in even-aged P. patula plantations and stratified according to soil parent material and altitude. Growing conditions of each sample plot were characterised according to climate and soil properties. A total of 540 sample trees were measured for height, diameter, density, and latewood content. The sample trees were harvested to produce 2690 logs. The logs were milled, and the resultant lumber was graded according to density, dynamic modulus of elasticity, and modulus of rupture. Annual maximum temperature had the most significant impact on tree growth, while rainfall correlated with wood density and latewood content of standing trees. However, annual maximum temperature and tree height had a negative relationship with the recovered lumber properties and dimensional stability. Spring rainfall appeared to be the most important factor influencing lumber twist and this was possibly due to the associated larger juvenile core present in the trees.

STRENGTHENING AND RESTORATION OF THE GEOMETRIC PARAMETERS OF WOOD-CUTTING SAWS USING THE METHOD OF PLASMA DEPOSITION OF WEAR-RESISTANT ALLOYS

The article covers the issues related to wear and blunting of the teeth of wood-cutting tools, which leads to the loss of the tool's cutting capacity, a decrease in the productivity of the wood sawing process, the quality of lumber and blanks, and an increase in energy costs. It is shown that the process of wear of a wood-cutting tool is a rather complex complex of interrelated phenomena. The types of wear of the tool are given and it is indicated that the degree of wear of the cutting part of the saw teeth and the nature of the change in their microgeometry depends on a number of factors. Methods of increasing the wear resistance of wood-cutting saws are considered. It is shown that the method of strengthening saw teeth by surfacing wear-resistant alloys is the most promising. The purpose of the research is to increase the wear resistance and efficiency of the use of saws due to their strengthening by the method of plasma application of wear-resistant alloys. The method of experimental research with a circular saw of a special design is presented, the geometric parameters of the experimental samples of the tool are determined. Saws with inserted teeth made of P6M5, 8X6НФT, 9ХФ steels, cast hard alloy ВЗКР and hard metal-ceramic alloy ВK15 were studied. The analysis of the obtained results showed that the dulling intensity is the lowest with the use of the ВЗКР alloy. Wear-resistant ВЗКР alloy can be welded using various methods on automated equipment, provides high wear resistance of the tool and is cheaper than metal-ceramic hard alloys. The characteristics of the equipment for surfacing wear-resistant alloys on saw teeth and the technology of their strengthening are given. Tests of saws with teeth strengthened by ВЗКР alloy deposited in production conditions showed high wear resistance of saws, increased productivity of the sawing process, reduction of roughness of processing surfaces, and reduction of saw dust consumption in the sawing process.

Building resiliency in conifer forests: Interior spruce crosses among weevil resistant and susceptible parents produce hybrids appropriate for multi-trait selection.

Tree planting programs now need to consider climate change increasingly, therefore, the resistance to pests plays an essential role in enabling tree adaptation to new ranges through tree population movement. The weevil Pissodes strobi (Peck) is a major pest of spruces and substantially reduces lumber quality. We revisited a large Interior spruce provenance/progeny trial (2,964 genotypes, 42 families) of varying susceptibility, established in British Columbia. We employed multivariate mixed linear models to estimate covariances between, and genetic control of, juvenile height growth and resistance traits. We performed linear regressions and ordinal logistic regressions to test for impact of parental origin on growth and susceptibility to the pest, respectively. A significant environmental component affected the correlations between resistance and height, with outcomes dependent on families. Parents sourced from above 950 m a.s.l. elevation negatively influenced host resistance to attacks, probably due to higher P. engelmannii proportion. For the genetic contribution of parents sourced from above 1,200 m a.s.l., however, we found less attack severity, probably due to a marked mismatch in phenologies. This clearly highlights that interspecific hybrid status might be a good predictor for weevil attacks and delineates the boundaries of successful spruce population movement. Families resulting from crossing susceptible parents generally showed fast-growing trees were the most affected by weevil attacks. Such results indicate that interspecific 'hybrids' with a higher P. glauca ancestry might be genetically better equipped with an optimized resource allocation between defence and growth and might provide the solution for concurrent improvement in resistance against weevil attacks, whilst maintaining tree productivity.

Translocating seed sources to new geoclimatic environments has limited effect on lumber quality of eastern Canadian white spruce

Assisted gene flow according to expected climate gradients is considered as a forest management strategy to mitigate impacts of environmental change on forest growth. However, the effects of seed translocation on wood properties and lumber quality remain unknown. This study evaluated the effect of provenance origin on lumber production and quality at rotation age in two white spruce provenance trials established in contrasting environments in eastern Canada. Based on 108 sample trees, which resulted in 943 pieces of lumber, average volume production per tree at the southernmost site was twice that of the production at the northern site. Provenance had a significant influence on growth and lumber strength in the first sawlog but had no effect on lumber stiffness and wood density. Although visual grade yields of No. 2 and better were high in both trials (over 86%), the machine stress rated (MSR) grade potential and percentage of lumber that met the bending stiffness design values of the visual grades were generally low (12%–26%). Hence, plantation-grown lumber should preferably be machine stress rated to ensure its fitness for structural applications in buildings. Management strategies aiming to efficiently sequester carbon should primarily maximize volume productivity in northern sites, as moving seed sources north still reduces provenance productivity, while breeding programs should aim to prevent decrease in lumber stiffness due to augmented productivity and shortened rotation cycles.

REDUCTION OF EFFECT OF GROWTH STRESS PRESENCE USING ENDLESS SCREW DURING KILN DRYING AND STEAMING AND HEATING TREATMENT IN LOG BEFORE SAWING

The relaxation of growth stress in trees growing in fast-growth conditions, as plantation in tropical areas, affects lumber quality during of sawing or drying process. It was evaluated two pretreatments (heating and steaming application) before sawing process and endless screw use to maintain the boards pressed during drying ofDipteryx panamensisand Hieronyma alchorneoideswood with objective to reduce the effects of relaxation of growth stress. Theresults showed endless screw is used to maintain the boards pressed, the moisture content (MC) or drying rate did not vary. The use of endless screws with daily adjustment during drying produced a reduction of cup, check and split defects in lumber and this treatment is accompanied with a pre-treatment before sawing (heating or steaming treatment) decreased theincidence of drying defects. Then the use of both treatments is an opportunity to reduce theeffects of relaxation of growth stress on the quality of the wood of D. panamensisand H.alchorneoidesfrom fast-growth plantation conditions.

Application of the steaming step during kiln drying of lumber of two tropical species with high growth stress presence

The relaxation of growth stress in trees from plantation forests of tropical areas is manifested in the quality of wood after the sawing and the relaxation of drying stress is expressed during the drying process, producing low wood quality. The present study aims to evaluate the lumber quality in logs by heating and steaming application before sawing as pretreatment to reduce growth stress and the application of steaming step during drying of Dipteryx panamensis (almendro) and Hieronyma alchorneoides (pilón) wood. The results showed that the variation of moisture content and drying rate concerning drying time in wood from logs steamed before or during drying led to a quick increase in the drying rate and a decrease in the moisture content. The steaming application to the logs or during drying decreased the incidence and magnitude of drying defects and increased the quality of dried lumber, especially bow, split, crook, and check defects.

Reduction of growth stresses in logs of Hieronyma alchorneoides Allemão from fast-growth plantations using steaming and heating: effects on the quality of lumber

Key messageGrowth stresses are usually present in the fast-growing trees of forest plantations and can be evaluated along stem diameter. Growth stresses are relaxed after tree felling and during sawing and drying, and are manifested in the lumber quality. Different methods have been employed to reduce the effect of growth stresses, such as steaming and heating treatments. Excellent growth and yield in forest plantations of Hyeronima alchorneoides were observed, but they showed difficulties in the primary sawing process and a high incidence of wood warping during the drying process. Steam and heat treatments on the log were used to study their effects on H. alchorneoides sawlog and to evaluate lumber quality.ContextGrowth stresses in Hieronyma alchorneoides Allemão trees growing under fast-growth conditions show high and negative effects on the lumber quality (increased warps and splits or checks). Therefore, steaming and heating treatments have been applied to reduce these effects on the lumber.AimsThe main objective of the present work was to evaluate the effects of steaming and heating treatments on sawlogs of Hieronyma alchorneoides from the fast-growth plantations to reduce the longitudinal surface growth stress.MethodsTwenty-six trees ready for felling in the third thinning were sampled and commercial logs measuring 2.5 m long were extracted from them at different heights. These logs were used to investigate the effect of steaming and heating treatments and the growth stresses were measured before and after treatment. Crooking due to sawing, colour and wards, splits and checks were measured.ResultsThe results showed that the internal temperature of the logs was approximately 85 °C after the heating treatment, and it was nearly 90 °C after the steaming treatment. It resulted in a reduction of 1500 με (micro-deformations) before the treatment to 1000 με after the treatment. Therefore, crooking due to sawing decreased significantly in logs or semi-logs. The parameters such as colour, luminosity (L*), redness (a*) and lightness (b*) decreased in heartwood while L* increased and a* and b* decreased in sapwood, which led to the decrease in quality of the lumber, the magnitude and incidence of the defects in treated logs.ConclusionAs compared to untreated logs, the best performance was obtained with steaming treatment, followed by the heating treatment. The difference found between steaming and heating can be attributed to the temperature in the internal part of the log, which was more than 90 °C in steaming treatment; meanwhile, in the heating treatment, the internal temperature of the log was slightly lower (80–85 °C). Therefore, glass transition can be more easily reached by steaming treatment than by the heating treatment.

An Investigation of the Duration of Load of Structural Timber and the Clear Wood

In this study, DOL of structural timber and the clear wood and DOL of modulus of elasticity of wood were investigated. The dimension lumber of Spruce-Pine-Fir of Grade No. 2 and Grade No. 3 and the small clear specimens of the same species of the dimension lumber were used to conduct the short-term and the long-term bending test. The short-term strength distributions of the dimension lumber and the small clear specimens were obtained. The long-term tests were conducted under constant environmental conditions for 18 months. The sample matching technique was used to estimate the short-term strength of the specimens that underwent long-term tests. It was found out that there is virtually no difference in DOL between different grades or quality of lumber and no difference between structural timber and clear wood, and DOL obtained from the test of this study is more in agreement with Wood’s curve. A threshold stress ratio of about 0.55, loaded above which the wood began to experience strength loss, was revealed from the test. Making use of the threshold ratio concept, the DOL of wood can be obtained not only from failed specimens under load in the process of the long-term loading, but also from the ramp loading test of the specimens that survived the long-term test. Sustained load also poses DOL on the modulus of elasticity of wood, though to less degree than DOL of strength of wood.

Effect of sawn zone on the quality of lumber in the evaluation of selected pine wood defects

Effect of sawn zone on the quality of lumber in the evaluation of selected pine wood defects. In the course of research on the sawn pine raw material with defined distribution of the defects, a variable level of change in the presence of knots was assessed. Initially, the experimental material was classified in terms of the general-purpose timber, and then the strength classes of wood for structural applications were assigned. The proportion of sound knots increased in case of wood obtained from the middle and top zones. In the case of butt-end logs, an increase in the share of the rotten knots having an average diameter of 2-4 cm was observed. The intensity of the defect’s occurrence corresponded with the zone of origin along the large-sized roundwood length.

Steaming and Heating Dipteryx panamensis Logs from Fast-Grown Plantations: Reduction of Growth Strain and Effects on Quality

Abstract Steaming and heating as pretreatments before log sawing reduce the negative effects of growth strain (GS). The object of this work was to study the reduction of GS in logs of Dipteryx panamensis from a fast-growth plantation using steaming and heating treatments and evaluate the effects on the lumber quality. According to the results, the maximum temperature in the center of the log was approximately 90°C after 24 hours for both treatments. GS decreased after heating and steaming. The average value of GS for three treatments was 2,085.61 microdeformation units (με) before the treatment, decreasing to average value to1,692.14 με after the treatments. This reduction in turn produced a reduction of crook due to sawing measured in logs and semilogs and a decrease in the values and incidence of crook, bow, twist, and split. Similarly, color parameters (L*, a*, and b*) were statistically affected by the treatment, except for parameter L* in sapwood. In general, wood darkening was observed. Lastly, both treatments applied to D. panamensis logs showed few differences in GS, in crook due to sawing measured in logs and semilogs, and in the values and incidence of crook, bow, twist, and split. Therefore, both treatments achieved GS reduction in D. panamensis lumber.

К ВОПРОСУ ПОДГОТОВКИ РЕЖУЩЕГО ИНСТРУМЕНТА ПРИ РАСПИЛОВКЕ ЛЕСОМАТЕРИАЛОВ НА ЛЕНТОЧНОПИЛЬНОМ ОБОРУДОВАНИИ

the main drawback of circular sawing machines is the presence of broken teeth in the cut. In case of vibrations, violation of the saw plane, mismatch of the feed direction with the saw planes, and rebasing, these teeth spoil the processing surface. Belt sawing allows you to ensure high quality of lumber on the roughness of their surface at high feed rates; increase productivity by 1.5-2 times due to mechanization and automation of technological operations. One of the most important advantages of band saws is the small width of the cut, which is 1.5-2 times smaller than that of the sawmill; the small thickness of the saw ensures low consumption of wood in sawdust and high volume output of lumber. Sawing wood on band saws, in the vast majority of cases, is characterized by face cutting. Of the 3 forms of chip formation when cutting into the end, for band saws, the most characteristic is the formation of the chip element by chipping it with the stratification of wood along the bottom of the cut. The quality of the surface, in terms of its roughness, in addition to the formation of the chip element, is affected by its location in the interdental space, the presence and degree of compression and transportation of the chip element. The quality of the surface, in terms of its roughness, in addition to the formation of the chip element, is affected by its location in the interdental space, the presence and degree of compression and transportation of the chip element. As a result of studies of the initial conditions for the development of the teeth sharpening scheme, the orientation of the active elements of the blade relative to the middle plane of the saw can be identified as the main ones.

Preliminary evaluation for quality of dimension lumber in four common softwoods in Mongolia

The quality of dimension lumber (2 by 4 lumber) was preliminarily investigated in four common Mongolian softwoods: Pinus sylvestris L., Pinus sibirica Du Tour, Picea obovata Ledeb., and Larix sibirica Ledeb. to produce high quality dimension lumber for structural use. In total 61, 39, 67, and 37 pieces of lumber were prepared for Pinus sylvestris, Pinus sibirica, Picea obovata, and L. sibirica, respectively. The lumber was visually graded and then tested in static bending to obtain the 5% lower tolerance limits at 75% confidence level (f0.05) of the modulus of elasticity (MOE) and the modulus of rupture (MOR). In addition, the effects of sawing patterns on bending properties were also analyzed. The f0.05 of the MOE and MOR were 4.75 GPa and 15.6 MPa, 3.39 GPa and 11.0 MPa, 3.78 GPa and 11.7 MPa, and 6.07 GPa and 22.3 MPa for Pinus sylvestris, Pinus sibirica, Picea obovata, and L. sibirica, respectively. These results suggested that with a few exceptions, characteristic values of MOR in the four common Mongolian softwoods resembled those in similar commercial species already used. In visual grading, over 80% of total lumber was assigned to select structural and No. 1 grades in Pinus sylvestris and Pinus sibirica, whereas approximately 40% of total lumber in L. sibirica was No. 3 and out of grades. Sawing patterns affected bending properties in Pinus sylvestris and L. sibirica, but did not affect Pinus sibirica and Picea obovata. Dynamic Young's modulus was significantly correlated with bending properties of dimension lumber for the four species. Based on the results, it was concluded that dimension lumber for structural use can be produced from the four common Mongolian softwoods.

Salvage harvest planning for spruce budworm outbreak using multistage stochastic programming

Forest supply chain planning must deal with many natural disturbance uncertainties such as fires, insects, and windthrow. One important consideration is wood infestation by invasive insects, as it causes environmental and economic harm. An example of invasive insects in Eastern Canada is the spruce budworm (Choristoneura fumiferana (Clemens)), which is the most destructive insect in North America’s conifer stands. In 2017, more than 5 million ha of forest were defoliated by spruce budworm in Quebec. Repeated defoliation causes tree mortality, reduction of growth rates, and reduced lumber quality. Consequently, different wood qualities with greatly varied values are found in the forest. Changes in the outbreak intensity impact wood values throughout the forest. One of the common actions to mitigate the economic and environmental damages is salvage harvesting. However, because of the large uncertainties and lack of detailed information, it is a difficult problem to model. We propose a multistage stochastic mixed-integer programming model for harvest scheduling under various outbreak intensities. The objective is to maximize revenues of wood value minus logistic costs while satisfying demand for wood in the industry. The results show that when there is an outbreak throughout the forest, the priority for salvage harvesting is to focus on forest areas with the lowest level of infestation.

The Usefulness of Pine Timber (Pinus sylvestris L.) for the Production of Structural Elements. Part I: Evaluation of the Quality of the Pine Timber in the Bending Test.

The study assessed the quality of pine lumber by marking the modulus of elasticity in the horizontal system. The research material was a plank with the following dimensions: 137 mm wide × 39.50 mm thick × 3485 mm long. The pine wood was obtained by sawing timber in the form of logs with round cross sections and originating from the Forest Division Olesno (50°52′30″ N, 18°25′00″ E). Each long log was sawn to provide four logs of about 3.5 m, which were marked as butt-end logs (O), middle logs (S)—2 items, and top logs (W). The origin of the logs from the trunk (Pinus sylvestris L.) has a significant impact on the physical and mechanical properties of the wood from which they are made. Only butt-end logs (log type O) allows for the production of high-quality timber elements. The pine timber that was evaluated in this paper had a high density of about 570 kg/m3 and a high percentage of timber items were assigned to class C24 and higher (above 50%). The adopted horizontal model of evaluation of the modulus of elasticity gave similar results to those obtained in an evaluation according to the EN-408.

The flexural lumber properties of Pinus patula Schiede ex Schltdl. & Cham. improve with decreasing initial tree spacing

An increase in the stiffness of lumber with a decrease in initial tree spacing was confirmed for Pinus patula Schiede ex Schltdl. & Cham. The underlying properties of microfibril angle, wood density and knot frequency explained 71% of the variation in lumber stiffness. Tree spacing also influenced wood properties independent of radial growth rate. Rapid growth rates and reduced harvesting ages of South African-grown pine plantations have caused a reduction in the stiffness of structural lumber, which accounts for about 75% of all sawn wood. Microfibril angle and wood density are known to influence wood stiffness, which may be manipulated by the growing space of trees. The objective of this study was to evaluate the effect of slower growth rates, caused by narrow tree spacing, on the suitability of Pinus patula Schiede ex Schltdl. & Cham. wood for structural lumber. An 18- and a 19-year-old spacing experiment with four levels of initial tree spacing (1.83 m × 1.83 m, 2.35 m × 2.35 m, 3.02 m × 3.02 m and 4.98 m × 4.98 m) were sampled. Linear and non-linear mixed-effects models were developed to examine the effect of tree spacing on the quality of wood and lumber as defined by the modulus of elasticity, modulus of rupture and knot frequency of 208 boards and the ring-level microfibril angle and wood density of 86 radial strips. Wood and lumber quality improved with decreasing spacing, and only the narrowest spacing had lumber that conformed to the requirements of the lowest South African structural grade. Microfibril angle, wood density and knot frequency explained 71% of the variation of lumber stiffness. After accounting for ring width differences, there remained a significant effect of initial spacing on the parameters of models predicting microfibril angle and wood density. Wide initial spacing is discouraged if higher strength grades are desired for Pinus patula lumber.

Microfibril Angle Characteristics of Korean Pine Trees from Depending on Provinces

This study investigated the characteristics of microfibril angle(MFA) in order to see if there was any difference in pine tree lumber quality among the three mountain areas surrounding the Taebaek Mountains in Korea – Yeongdong (Goseong-gun), Yeongseo (Hongcheon-gun) and Yeongnam (Bonghwa-gun). Pine trees of each mountain area were divided into earlywood and latewood in relation to heartwood part (1959 ~ 1961, 3 annual rings) and sapwood part (2002 ~ 2004, 3annual rings), and measured at tangential section. The microfibril angle showed significant differences between mountain areas. In general, Goseong Mountain was found to have 37.35°, followed by Hongcheon Mountain 32.42° and Bonghwa Mountain 25.75°, in order. The sapwood part had larger angle than heartwood part; and earlywood, than latewood. Variation within a single annual ring tended to be smaller from earlywood toward latewood.

Clonal variations and effects of juvenile wood on lumber quality in Japanese larch

ABSTRACT Wood properties, including Young’s modulus, differ among clones in Larix kaempferi; however, available information is still limited on among-clonal variations of lumber qualities in L. kaempferi. The objectives of this study were to clarify the clonal variations in lumber quality and to identify the effects of juvenile wood on lumber quality in L. kaempferi. A total of 21 logs of 2.5 m in length were obtained from the trees of nine different plus clones of 57-year-old L. kaempferi trees. The logs were sawn into lumber, and the lumber was kiln-dried and planed into 38 × 89 mm in a cross-section. Lumber quality, such as bending properties, was determined. Significant differences were found in wood density, dynamic Young’s modulus, modulus of elasticity, and modulus of rupture of the lumber among the nine clones. The highest repeatability was recorded in wood density. The lumber consisting of juvenile wood showed a lower lumber quality compared to the lumber consisting of mature wood. To produce lumber with a high quality from L. kaempferi, the clonal variation of lumber quality and the existence of juvenile wood should be considered.

Automation of the process and increasing the effectiveness of multi-saw equipment with circular translational movement of blades

Design solutions for the automation of wood sawing aimed at improving the quality of lumber and increasing productivity are proposed. For these purposes, it is proposed to use robotic multi-sawing equipment with circular translational movement of saw blades. Keywords: saw module, saw block, automation, repositioning, stability, blade, productivity. hornet10@yandex.ru

Stress-strain condition of reinforced timber structures with artificially created weakenings

About 20% of the world’s timber grows in Russia, but the huge forest-raw material potential is used inefficiently. The forest industry is modestly represented and the Russian economy brings minimal income. In recent decades, more serious requirements have been placed on building structures, but the quality of lumber has been steadily declining throughout the world. The modern woodworking industry improves the quality of lumber by removing unacceptable wood defects, followed by end gluing of boards to a “mustache” or “toothed joint”. Of all types of joints of wooden elements, the notched adhesive or “toothed joint” provides the best use of their bearing capacity, since it causes less weakening of the cross-section of the elements, which is characteristic of other methods of joining (nailing, bolting, etc.). But along with this, the results of numerous tests showed that in conditions of mass production, the main place of destruction is the “toothed joint” or gear joints (about 50%) in the layers of the structures of the stretched zone. The presence in the most stressed layers of the stretched zone of the bent glued elements of the gear joints leads, as a rule, to the destruction of the elements precisely because of these weaknesses. As a result, there is a need for a more detailed and indepth study of the effect of artificially created weakenings on the work of wooden structures. One of the methods for improving the performance of structures made of low-grade wood is their reinforcement. The purpose of the research is to determine the degree of influence of some artificially created types of attenuation on the stress-strain state of reinforced wooden beams. The main research methods: mathematical calculations, computer modeling in the PC “COSMOS / M”, experiment. The experimental design technique is given [27]. The results are presented in the form of graphs and tables. The main conclusions made after the work: deformability in reinforced beams is 15-20% lower than in unreinforced ones; the destruction of reinforced beams with a weakened cross section occurs without a sharp collapse, due to the supporting effect of the reinforcement in the stretched zone and the reliable connection of the reinforcement with the wood, which provides an adhesive joint up to the destruction of the wood. The safety factor of reinforced wooden structures varies from 3.00 to 5.00.

Computed tomography (CT) scanning of internal log attributes prior to sawing increases lumber value in white spruce (Picea glauca) and jack pine (Pinus banksiana)

The increased pressure on timber supply due to a reduced forest land base urges the development of new approaches to fully capture the value of forest products. This paper investigates the effects of knowing the position of knots on lumber volume, value, and grade recoveries in curve sawing of 31 white spruce (Picea glauca (Moench) Voss) and 22 jack pine (Pinus banksiana Lamb.) trees. Internal knot position was evidenced by X-ray computed tomography (CT) imaging, followed by the application of a knot-detection algorithm allowing log reconstruction for use as input in the Optitek sawing simulation software. Comparisons of the three levels of sawing optimization (sweep up, shape optimized, and knot optimized) revealed that considering internal knots before log sawing (e.g., knot optimized) generated 23% more lumber value for jack pine and 15% more for white spruce compared with the traditional sweep-up sawing strategy. In terms of lumber quality, the knot-optimized strategy produced 38% more pieces of grade No. 2 and better in jack pine and 15% more such pieces in white spruce compared with the sweep-up strategy. These results indicate a great potential to increase manufacturing efficiency and profitability by implementing the CT scanning technology, which should aid in developing a strong bioeconomy based on an optimized use of wood.