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Scots pine blister rust fungi (Cronartium pini) is expected to become an increasing problem for both forest owners and sawmills in the Nordic region, and there is great uncertainty about the economic consequences. There is also a lack of knowledge about the biology of Scots pine blister rust, as well as the tree's response and defence against ongoing infection. The tree is known to defend itself by enriching resin at the infected area, creating a damaged area of resin-wood. There is currently no reliable way to detect and assess the degree of damage in sawn timber, which leads to waste, as entire sawlogs are usually downgraded when parts or most of the timber could possibly be used. The objectives of this preliminary study were to: (1) investigate whether X-ray computed tomography (CT scanning) can detect blister rust damage in pine timber, in order to optimise sawing and save the value of the sawn timber; (2) to compare the 3-dimensional CT image description of the fungal attack with how the damage looks on the outside, to enable recommendations for external assessment of the damage attack, for example during felling; and (3) to assess the possibilities for describing the course of the damage and the tree's defence against the fungal attack. Eight rust-infested and two non-infested trees (Scots pine) were collected from a thinning stand and a mature stand outside Bjurselet, Norsjö municipality in Västerbotten. The trees were felled in January 2022. After felling, the stems were visually inspected, and infected parts were marked with paint on the mantle surface. The stems were cut into logs of suitable length for transport and scanning. Cuts through fungal-infested regions were avoided. The wood was transported to LTU’s Wood Science and Engineering facility in Skellefteå for CT scanning. The CT scan of the sample trees showed that damage due to pine blister rust can be detected in a way that enables further development of an industrial detection method and optimisation of the wood decomposition. However, one difficulty discovered was that fungal-infested sapwood areas have similar image intensity as non-infested heartwood. It could also be established that the distribution of damage inside the volume of the stem is greater than can be detected visually on the mantle, especially in the longitudinal direction. In this study the temporal development of the infection from the time of infestation to the time of CT scanning could not be analysed. However, annual rings could be distinguished in both damaged and undamaged wood, making it possible to monitor the evolution of the damage from year to year. DNA analysis detected the presence of blister rust fungus in the wood, both in and outside resin-rich areas. The highest amount of fungus-specific DNA was measured outside the resin-rich area in the outer parts of the sapwood. Törskateangrepp på tall förväntas bli ett allt större problem för både skogsägare och sågverk i Norden. Det finns samtidigt stora kunskapsluckor om törskate generellt och om hur man ska hantera angripet timmer för att minska de ekonomiska konsekvenserna av angreppen. Det finns exempelvis inget tillförlitligt sätt att detektera och bedöma skadegraden hos sågtimmer, vilket leder till ökat spill vid sågning då hela stockar oftast nedklassas där man eventuellt skulle kunna använda delar eller merparten av timret. Osäkerheten om de ekonomiska konsekvenserna är stor. Det saknas även kunskaper kring törskatesvampens biologi, samt trädets respons och försvar mot pågående infektion. Syftet med denna förstudie var att (1) undersöka om röntgenbaserad datortomografi (CT-skanning) kan detektera törskateangrepp hos talltimmer, för att därmed kunna optimera sågningen och “rädda” det sågade virkets värde, (2) att jämföra CT-bildernas 3-dimensionella beskrivning av törskateangreppet med hur skadorna ser på utsidan, för att kunna ta fram rekommendationer för yttre bedömning av skadeangrepp till exempel vid avverkning, samt (3) att bedöma möjligheterna att beskriva skadeförloppet och trädets försvar mot svampangreppet. Åtta törskateangripna och två icke angripna träd (tall) insamlades från ett gallringsbestånd och ett slutavverkningsbestånd utanför Bjurselet, Norsjö kommun i Västerbotten. Träden avverkades under januari månad 2022. Efter fällningen gjordes en okulär besiktning av trädstammarna, där de törskateskadade delarna märktes med färg på mantelytan. Stammarna apterades i lämpliga längder för transport, samtidigt som det undveks att utföra apteringen i de törskateskadade områdena. Virket transporterades till LTU Träteknik i Skellefteå för CT-skanning. CT-skanningen av provträden visade att törskate kan detekteras på ett sätt som möjliggör fortsatt utveckling av en industriell detektering av törskate och optimering av timrets sönderdelning. En svårighet som dock uppdagades var att törskateangripna områden i splintveden har snarlika bildanalystekniska egenskaper som icke angripen kärnved. Det kunde även konstateras att törskatens utbredning i stammens volym är större än vad som kan detekteras okulärt på stammens mantelyta, framför allt i stammens längdriktning. I de preliminära analyser som ligger till grund för denna rapport är det dock inte möjligt att urskilja svampens tidsmässiga utbredning från angrepp till tidpunkten då CT-skanningen genomfördes. Däremot kan det konstateras att årsringar går att urskilja både i skadad och oskadad ved vilket ger möjligheten att från år till år följa skadeutvecklingen. DNA-analys detekterade förekomst av törskatesvamp i veden, både i och utanför kådrika områden. Den högsta mängden av törskatespecifikt DNA uppmättes utanför det kådrika området i splintvedens yttre delar. Sammanfattningsvis visar studien att de tekniska förutsättningarna för att detektera de inre skadorna av törskate med CT-skanning är goda och att utveckling av algoritmer för bildbehandling är ett viktigt nästa steg för automatiserad detektion av törskate i tall.

Timber utilisation and wood construction are fundamental components of Europe's strategy on progressing towards a sustainable bio-based economy. Both components require optimised strength grading procedures in Europe's sawmills. To further improve the current procedures, quality assessment and segregation of the raw material need to start already at the roundwood stage. Furthermore, the quality information should be made accessible throughout the production process to leverage the full potential for optimisation. This paper discusses the current state of research on combined log and board strength grading with a focus on the situation in Europe. It highlights limitations due to technology and current standardisation and identifies knowledge gaps and research opportunities. The European research project READiStrength (resource-efficient and data-driven integrated log and board strength grading) has been initiated to address these issues. Funder: ERANET Cofund Call "ForestValue – Innovating the forestbased bioeconomy"; Fachagentur Nachwachsende Rohstoffe e.V; Austrian Federal Ministry for Agriculture, Regions and Tourism; Microtec Srl GmbH; RemaSawco AB, Schilliger Bois SAS; Wiehag GmbH; Österreichische Bundesforste AG; Austrian Chamber of Agriculture;ISBN for host publication: 978-1-7138-4097-8; 978-1-7138-4111-1 READiStrength

Engineered wood products of today's construction industry require predictable mechanical properties of the used structural timber. At sawmills, automated strength grading is used to assess the stiffness and strength of sawn and dried timber boards. This process can be based on various technologies, e.g. surface scanning, dynamic excitation, flat-wise bending, which are used to derive so-called indicating properties, i.e. simplified numerical values. Heuristically derived statistical models can then be used to predict the stiffness and strength based on indicating properties. However, statistical strength grading can only exploit a small fraction of the potential strength of a single board, since it assesses the properties of a board in relation to its population. A growing number of sawmills in Sweden use computed tomography (CT) scanners to assess the incoming logs to optimise their positioning prior to sawing. CT scans provide high-quality data of the cross-sectional density distribution along the length of a log, which could also be used to derive continuum mechanical models of the yet unsawn boards and with that assess their mechanical properties. If the stiffness and strength of a virtual board can be predicted before it is sawn, then it could be pre-classified into a strength class or its specific use as a specific construction part could be predetermined already at the log stage, which would lead to a more efficient material usage. Additionally, the predictive power of the existing statistical strength grading processes could be improved for the final boards. The goals of this study were to i) derive 3D quasi-continuum and finite element (FE) models of CT scanned timber boards using different material laws for local stiffness based on measured density and ii) compare their capabilities for predicting stiffness and strength of the boards. The experimental material consisted of dried softwood boards (12% moisture content) of nominal cross-sectional dimensions 50x100mm with different lengths, scanned with a medical high-resolution CT scanner. The boards underwent an eigenfrequency measurement by dynamic excitation and were tested until failure in a four-point bending test, where both the local and global displacement were recorded. A previously developed algorithm was used to derive 3D quasi-continuum reconstructions from the CT scans and subsequently finite element (FE) models. The algorithm reconstructed the board geometry, pith, knots and local fibre directions (material coordinate system) on a volume grid of material points spaced 0.68mm apart. The stiffness tensor in each material point was made locally dependent on the measured density by different mathematical laws, e.g. constant, linear or power laws. Furthermore, material laws which scaled the stiffness tensor based on the ratio between the simulated and measured eigenfrequency were tested for comparison. The bending stiffness profile was calculated for each board along its length and different indicating properties for predicting stiffness and strength were derived and compared with respect to the experimental results. With the FE model, strain distributions in the cross-sections were studied and local stress states around the experimentally observed points of initial failure were investigated to determine whether similar dominant failure stress states existed among boards. The results showed high coefficients of determination between predicted stiffness and strength for material laws based on power laws and low values for linear laws. Nevertheless, the four-point bending tests only provided point-wise data (mid points) that could be used to validate the numerical model. It is therefore recommended to use field-based evaluations in the future, e.g. the surface strain obtained with DIC under four-point testing. ReadIStrength

Engineered wood products of today's construction industry require predictable mechanical properties of the used structural timber. At sawmills, automated strength grading is used to assess the stiffness and strength of sawn and dried timber boards. This process can be based on various technologies, e.g. surface scanning, dynamic excitation, flat-wise bending, which are used to derive so-called indicating properties, i.e. simplified numerical values. Heuristically derived statistical models can then be used to predict the stiffness and strength based on indicating properties. However, statistical strength grading can only exploit a small fraction of the potential strength of a single board, since it assesses the properties of a board in relation to its population. A growing number of sawmills in Sweden use computed tomography (CT) scanners to assess the incoming logs to optimise their positioning prior to sawing. CT scans provide high-quality data of the cross-sectional density distribution along the length of a log, which could also be used to derive continuum mechanical models of the yet unsawn boards and with that assess their mechanical properties. If the stiffness and strength of a virtual board can be predicted before it is sawn, then it could be pre-classified into a strength class or its specific use as a specific construction part could be predetermined already at the log stage, which would lead to a more efficient material usage. Additionally, the predictive power of the existing statistical strength grading processes could be improved for the final boards. The goals of this study were to i) derive 3D quasi-continuum and finite element (FE) models of CT scanned timber boards using different material laws for local stiffness based on measured density and ii) compare their capabilities for predicting stiffness and strength of the boards. The experimental material consisted of dried softwood boards (12% moisture content) of nominal cross-sectional dimensions 50x100mm with different lengths, scanned with a medical high-resolution CT scanner. The boards underwent an eigenfrequency measurement by dynamic excitation and were tested until failure in a four-point bending test, where both the local and global displacement were recorded. A previously developed algorithm was used to derive 3D quasi-continuum reconstructions from the CT scans and subsequently finite element (FE) models. The algorithm reconstructed the board geometry, pith, knots and local fibre directions (material coordinate system) on a volume grid of material points spaced 0.68mm apart. The stiffness tensor in each material point was made locally dependent on the measured density by different mathematical laws, e.g. constant, linear or power laws. Furthermore, material laws which scaled the stiffness tensor based on the ratio between the simulated and measured eigenfrequency were tested for comparison. The bending stiffness profile was calculated for each board along its length and different indicating properties for predicting stiffness and strength were derived and compared with respect to the experimental results. With the FE model, strain distributions in the cross-sections were studied and local stress states around the experimentally observed points of initial failure were investigated to determine whether similar dominant failure stress states existed among boards. The results showed high coefficients of determination between predicted stiffness and strength for material laws based on power laws and low values for linear laws. Nevertheless, the four-point bending tests only provided point-wise data (mid points) that could be used to validate the numerical model. It is therefore recommended to use field-based evaluations in the future, e.g. the surface strain obtained with DIC under four-point testing. ReadIStrength

Industrial high-resolution X-ray computed tomography (CT) scanners have recently been installed at several sawmills worldwide for the description of roundwood interior features and external log shape. These CT scanners represent a technological advancement for sawmill businesses that open a way to higher volume and value yields and new production planning strategies. This paper will present an indicative study of innovative use of non-destructive CT log data in a Swedish softwood sawmill, linking high-quality information of the wood material along the wood-value chain. Sawn timber was observed throughout the sawmill process line, i.e. from the log yard through the sawmill process until grading after the timber was dried. Before sawing, the CT scanner scanned the logs and calculated knot measurements from the 3D CT log data of simulated value-optimized center yield. A corresponding set of knot measurements were later calculated from the camera-based grading of the dried timber. Only considering knots from the two sets of measurements, the sawn timber was automatically given a quality assessment based on CT data, by camera-based scanning data, and by manual visual grading for reference. Partial least squares regression was used to create prediction models by correlating the two sets of knot measurements with the automatically determined grade from the dry-sorting. The prediction models tested increased the grading consistency between the grading based on CT data of virtual planks and based on camera data of the same planks. Furthermore, a traceability algorithm was tested as a tool to generate large data sets for future studies.

Crowdfunding är en ny metod för att finansiera företag och projekt som under senare år börjat få momentum. Genom att använda kunskapen och kapitalet hos ”crowden” finansieras idag projekt som tidigare inte ansetts hållbara. Centralt inom alla finansieringsformer är förtroendeskapandet mellan intressenterna, dock finns inga tidigare studier kring hur crowdfundingföretag skapar förtroende till entreprenörer och finansiärer. Syftet med vår uppsats är följaktligen att utröna hur crowdfundingföretag hanterar och arbetar med förtroende mot entreprenörer och finansiärer. Totalt har sju intervjuer genomförts varav fyra var med grundare till ledande aktörer på den svenska marknaden för crowdfunding. Resultatet i studien visar på att crowdfundingföretagen arbetar med att överkomma den informationsasymmetrin som råder gentemot finansiärer och entreprenörer genom ett aktivt arbete med relationsskapande och transparens gentemot dessa. Samtidigt slås även fast att användandet av legala och tekniska strukturer för att uppnå ett förtroende inte är genomgående för de undersökta aktörerna.

Tack vare Sveriges bibehållet starka inhemska ekonomi i kölvattnet av finanskrisen 2008-2010 har en diskussion angående svenska kronans eventuella övergång från en procyklisk tillgång till en säker tillgång förts. Samtidigt har det inom populärvetenskap och bland yrkesmän även uttryckts åsikter mot detta påstående. Tidigare studier har gjorts på den amerikanska dollarns roll som safe haven, både genom analys av dess trend före jämfört med efter signifikanta globala händelser men även genom att undersöka dess betingade kovarians gentemot andra valutor. Liknande studier har dock inte genomförts lika grundligt för den svenska kronan efter finanskrisen. Denna uppsats syftar därmed att utröna om någon signifikant förändring i svenska kronans karaktär kan ses före och efter centrala händelser under finanskrisen. Detta genom applicering av multivariat GARCH BEKK för att undersöka den betingade variansen och kovariansen mellan svenska kronan och procykliska valutor, samt mellan svenska kronan och safe haven valutor. Detta kompletteras sedan med en korrelationsanalys mellan kronan och CBOE’s volatility index (VIX) för att vidare stärka resultatet. Studien visar på en statistiskt signifikant men ekonomiskt försumbar skillnad i kronans variansstruktur före och efter de undersökta brytpunkterna. Dock kan ingen statistisk eller ekonomiskt signifikant förändring bekräftas i den betingande kovariansen mellan undersökta valutor. Vidare hittas även att korrelationen ökar mellan kronan och VIX-index vilket kan ses som en indikator på ökade procykliska tendenser. Sammanfattningsvis kan därmed ingen slutsats dras om kronans karaktär gått mot en safe haven efter den finansiella krisen.

Norrfog AB i Malå tillverkar limfogskivor i olika kvaliteter, bland annat till gör-det-själv- (GDS)-limfog, möbelfog och IKEAs hyllkoncept Ivar. Då Norrfog planerar att öka sin producerade volym av limfog ökar behovet av en effektiv styrning av rätt råvara till rätt slutprodukt. Samtidigt stiger råvarupriserna och det blir allt viktigare att maximera volyms- och värdeutbytet. Vid tidpunkten för studien: Norrfog AB köper klena furustockar och försorterar stockarna i diameterklasser med hjälp av en 2D-mätram. Ingen sortering sker på stocktyp och därmed blandas rotstockar, svartkviststockar och friskkviststockar. Stockarna sågas med en 2ex postning till plankor som efter torkning kapas upp till komponentlängder som därefter klyvs till färdiga lameller för limfogsproduktion. Huvudsyftet med detta projekt var att undersöka möjligheterna att styra rätt kvalitet av timmer till rätt slutprodukt; Ivarhyllan, GDS-limfog och möbelfog samt för- och nackdelar med att införa ett alternativt sågsätt – genomsågning. Inom ramen för studien fanns följande forsknings- och utvecklingsfrågor: •Stocklängdens betydelse för volymutbytet av limfog? •Stocktypens betydelse för kvaliteten på producerad limfog? •Går det att hitta rätt typ av stockar till en specifik produkt redan vid timmerplanen med hjälp av befintlig 2D-mätram och förbättrar 3D eller röntgen-skanning denna klassificering av stockar? •Finns det ett motstånd till fingerskarv bland konsumenter och vad anses vara ett önskvärt utseende på en träyta av limfog? Studien visar att den stocktyp som gav den bästa kvaliteten var friskkviststockarna, men även de stockar som sorterades som svartkvistiga visade sig innehålla mestadels friska kvistar i de aktuella timmerdimensionerna. Ett tydligt resultat var att rotstockar innehöll den lägsta kvaliteten med för många och/eller för stora svarta kvistar och det visade sig vara lämpligt att om möjligt sortera bort dessa stockar för att såga dessa separat till produkter med lägre krav på kvalitet. Sorteringsalgoritmer för olika mättekniker för timmer speciellt anpassade för att maximera utbytet kvalitet 1 i den färdiga limfogen testades. Med befintlig 2D-mätram sorterades 81 % av rotstockarna bort och med röntgenmätning ökade andelen bortsorterade rotstockar till 98 %. Ett viktigt resultat var att genomsågning gav i snitt 13 % högre volymutbyte än 2ex-sågning och att korta stockar gav ökat volymutbyte jämfört med fullängdsstockar. En separat undersökning angående skivornas utseende visar att fingerskarvade limfogskivor är något konsumenten kan tänka sig, så länge färgskiftningarna mellan lamellerna är små. Stora färgskiftningar och små svarta kvistar var det som respondenterna rankade som minst tilltalande för alla skivor oavsett fingerskarv eller inte. Godkänd; 2011; 20110511 (olof)

Wood industry of today deals with large volumes in an almost automatic process, which is not fully adapted tothe variability of the raw material. Consequently, it is crucial to sort the wood according to material properties inorder to process the wood efficiently and to obtain high quality end products. One material property which could beused for sorting is the moisture content of the sapwood, an important parameter for both the processing and the endproducts.Most large Swedish sawmills are using 3D scanners for quality sorting of Scots pine (Pinus sylvestris L.)sawlogs based on outer shape. Recently, some sawmills have also invested in X-ray log scanners in order to sort thesawlogs based on inner properties. It has previously been shown that, by combining raw data from industrial 3D andX-ray log scanners using path length compensation, green sapwood density and dry heartwood density can beestimated.In this study, the dry heartwood density was used to find an estimate of the dry sapwood density, thus allowingthe calculation of the sapwood moisture content. The log scanner data used in this study was simulated from 560Scots pine sawlogs which had previously been scanned in a computed tomography (CT) scanner. The estimatedsapwood moisture contents were then compared to reference values calculated by drying samples to 9% moisturecontent.It was found that the moisture content estimate could be used to separate the logs into two groups with high andlow moisture content, correctly identifying all logs with very low moisture content as dry logs. Out of all logs, 70%were correctly classified. The moisture content estimate could also be compared to the dry density dependentmaximum moisture content and used to identify logs that have actually started to dry. Godkänd; 2010; 20100302 (ysko)

An industrial laser light scattering scanner, designed to detect the spiral grain angle of logs by the light scattering along the grain, was used on two large samples of Norway spruce (Picea abies (var. Karst)) in various sawn dimensions (approximately 750 pieces). Additional measurements were made by other techniques, such as X-ray scanning, resonance frequency measurement, and various manual measurements. The strength properties of the boards were measured by destructive testing in four-point bending according to European standard. Multivariate methods (PLS) were used to model the relationship between the bending strength of the board (MOR) and the measurements. Based only on the output from the simple tracheid scattering equipment, a model for MOR achieved an R² exceeding 0.3. Combinations with average density or outer shape parameters from log scanning resulted in R² 0.4 and 0.3 respectively, although these parameters alone only accounted for R² 0.2. The results can be used to increase the understanding of strength in wood and in an improved industrial strength-grading process. Validerad; 2008; 20090115 (ysko)

Trä används i många tillämpningar där träet är synligt och där råvarans estetiska egenskaper därför är mycket. Exempel på sådana tillämpningar är produkter är golv och paneler. I detta projekt har produktionsprocessen för solida furugolv studerats, det vill säga hela kedjan från sortering av stockar till slutkonsumenters preferenser. Samarbetspartners i detta FoU- projekt har varit SCA -Bollsta sågverk, Norrlands Trä AB, SP Trätek och LTU - Träteknologi, Skellefteå. Syftet med projektet har varit att demonstrera hur man med hjälp av modern marknadsanalys, modern, industriellt implementerad mätteknik och avancerade sorteringsalgoritmer kan effektivisera produktionen av kundanpassade produkter med krav på estetiska egenskaper. Ett delmål var att undersöka alternativa utseendekvaliteter till dagens produktion av golvträ. Den genomgående metoden har varit att mäta och dokumentera råvarans egenskaper genom hela processen från stock till färdig produkt. En lättanvänd interaktiv databas har utvecklats inom ramen för projektet och använts för simulering av alternativa sorteringar av råvara avsedd för golvproduktion. Kopplat till databasen har även ett visualiseringsverktyg utvecklats. Detta gör det möjligt att direkt kunna se resultatet av simuleringarna i form av digitala golvytor. Utöver resultat i form av utvecklad databasgränssnitt, visualiseringsverktyg och verktyg för konsumentudersökningar så har projektet visat på intressanta resultat vad gäller både produktions och marknad. Resultatet av databassimuleringarna visar att man genom att förändra sorteringsstrategin och sortera stockarna baserat på information från en röntgenmätram helt kan undvika utsortering i råsorteringen, minska utsorteringen i justerverket med 25% (från tolv till nio procentenheter) och ändå producera en golvråvara med samma estetiska egenskaper som tidigare. Som ett alternativ till den ursprungliga golvråvaran har även en ny golvråvara definierats. Preferensstudier i både Sverige och Norge visade att konsumenternas tyckte bättre om den nya kvaliteten än den utsprungliga. Samtidigt gjorde denna nya golvråvara det möjligt att helt undvika utsortering i både råsortering och justerverk och samtidigt öka den tillgängliga golvråvaran med 27% (från 30 till 38 procentenheter). Godkänd; 2007; 20070823 (olof)

Quality sorting of sawlogs is becoming more and more common. This is the result of increasing production of customer specific products in combination with high raw material prices. Today, log quality sorting is being based on either 3D or X-ray scanning techniques. Previous research has shown that sorting accuracy is improved when using multivariate models to combine variables from both 3D and X-ray scanners. There is however a potential of further improving the sorting if 3D and X-ray data are combined at an earlier stage; from the measured 3D shape a better estimate of the X-ray path lengths through the log may be found, thus enabling the calculation of a log density profile from the measured X-ray attenuation. The development and evaluation of such a technique is the topic of current research at SP Trätek and Luleå University of Technology in Skellefteå. Preliminary results show that the method is good at calculating large scale properties such as heartwood content and heartwood and sapwood densities. When looking for smaller geometric objects, e. g., knot whorls, extra care must be taken so that observational errors from the 3D scanner do not compromise the X-ray data. Software simulating industrial X-ray scanner data from CT-scanned logs has also been developed. A very good agreement was found between simulated data and actual data from an industrial installation. This underlines that such a simulation tool is very valuable when developing algorithms for industrial X-ray scanners. Godkänd; 2007; 20081203 (ysko)

Traceability in the sawmilling industry is a concept that could be used to more effectively control the production processand the utilization of the raw material. The fingerprint approach is a traceability concept that rests on the idea that everypiece of wood is a unique individual with unique properties and hence can be identified and separated if a sufficientnumber of these properties are measured accurately enough. This study was hosted by a sawmill in northern Sweden andwas aimed at making the fingerprint connection between logs and the center yield sawn from those logs using length andknot information. The 140 logs involved in the study were of Scots pine with top diameters spanning the range from 153 to213 millimeters. The center yield sawn from these logs was of two dimensions. The smaller logs (153-187 mm) were sawnwith a 2 ex pattern to 50 by 100 mm, and the larger logs (174-213 mm) were sawn to 50 by 125 mm with a 2 ex pattern.The data from the logs were collected at the log sorting station by an industrial one-directional x-ray log scanner incombination with a 3-D optical scanner. The data from the sawn center yield were collected by an industrial cross-fedsurface scanning system situated in the sawmill's green sorting station. Both systems are used in the sawmill's normalcontinuous production. The results show that over 90% of all planks could be matched to the right log, which bespeaksa great potential for further development and realization of fingerprint tracing as a tool for process control and processimprovement. Godkänd; 2007; 20081203 (ysko)

In this study, 90 boards of Norway spruce (Picea abies (L.) Karst.) sized 48 x 148 mm in cross-section, have been examined using different scanning and measurement techniques. All of the boards originated from a sawmill located in southern Finland. Planar X-ray scanning, microwave scanning, and grain-angle measurement have been performed. In addition, strength and elastic properties were assessed for eachpiece by four point bending. The purpose of the study was to relate the potential of microwave scanning compared to other, industrially available techniques and to explain the physiological background of the microwave responses. The results show that the microwave signal, after transmission through wood, contains information about the bending strength and the modulus of elasticity. The correlation to densityis a key factor. Annual ring width was also found to be correlated both to microwave measurements and strength properties. Validerad; 2007; 20070516 (nillun)

The aim of the project has been to integrate technology for measuring fibre angle and heartwood content into an equipment that measures both properties during transverse feed in the green sorting. The results show that technology based on laser and image analysis makes this possible. The project has also proved that it is possible to produce straighter lumber by sorting out the part that is most prone to skewness and put these boards in the bottom of the stack during drying. The results were very clear and when following up the results in the secondary processing, the yield was improved in both cross-cutting and planing.The next step should be to verify that the technology works also on spruce and to study the potential in combining measurement technology with improved drying technology.Key words: Fibre angel, spiral grain, Scots pine, heartwood, drying, skewness

A nondestructive method of measuring knot parameters for research purposes has been compared to alternative, destructive methods. The method is based on automatic analysis of CT-images. The image analysis algorithms were adjusted to and evaluated on Norway spruce. The possibilities of measuring resin pockets in CT-images have been studied and stereological methods have been applied on volume estimation of resin pockets in saw logs. For research purposes the study showed that compared to destructive methods, both accuracy and speed of the CT-method were competitive. It was also shown that resin pockets can be detected and measured in CT-images of Norway spruce. Data from the CT-scanned logs was used to simulate an industrial X-ray LogScanner. The X-ray LogScanner was based on two X-ray sources and designed for scanning at 3 m/s. The possibility of using this X-ray LogScanner to make nondestructive measurements of properties of saw logs has been investigated. The study showed that the X-ray LogScanner measures minimum shadow diameter under bark before debarking with an accuracy comparable to a 3D-scanner and that the sawing position could be controlled based on X-ray LogScanner measurements of the best half of the logs. The X-ray LogScanner could also be used to measure percentage of heartwood and green heartwood density. Based on the X-ray LogScanner measurements it was possible to calibrate PLS-models for prediction of the bending stiffness of the centerboards. Godkänd; 1999; 20061117 (haneit)

Godkänd; 1997; 20070418 (ysko)