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Mellqvist, D., Buck, D. & Johansson, J. (2023). Experimental study of the effect of velocity on cutting forces for bevelled handsaw teeth. In: Gary S. Schajer (Ed.), Proceedings of the 25th International Wood Machining Seminar: . Paper presented at 25th International Wood Machining Seminar (IWMS-25), Nagoya, Japan, October 4-7, 2023. , Article ID 2.
Open this publication in new window or tab >>Experimental study of the effect of velocity on cutting forces for bevelled handsaw teeth
2023 (English)In: Proceedings of the 25th International Wood Machining Seminar / [ed] Gary S. Schajer, 2023, article id 2Conference paper, Published paper (Refereed)
Abstract [en]

Handsaws are well-established tools for wood processing. Handsaw tooth geometries have customarily been adapted for hand-held electric saws, which utilise higher cutting velocities. Fundamental studies in wood cutting mechanics suggest that a cutting velocity of up to 50 m s−1 has negligible effect on the cutting forces acting on an orthogonal cutting tool. There is a lack of research on the mechanisms involved in the use of native handsaw teeth for wood cutting. This study investigates how cutting velocity affects the forces acting on four bevel-ground cross-cutting teeth extracted from a handsaw blade. Conditioned specimens of Norway spruce [Picea abies (L.) Karst.] were used in the tests. The mean densities of wood specimens were assessed using X-ray computed tomography. Cutting tests were performed on a pre-existing, custom-made cutting-force test machine. Cutting data were collected using piezoelectric dynamometers linked to a data acquisition system. Cutting velocity was controlled by the rotational speed of the arm holding the wood specimen. A customised software application logged and processed the forces acting on the teeth. The results show that the mean resultant force does not vary significantly within a 2.5–15 m s−1 velocity range. The current study suggests that velocity is nearly independent of the system mean cutting force acting on bevelled handsaw teeth cutting across the grain. The findings are particularly relevant for developing cutting tools for wood applications since knowledge from handsaw tooth geometry can be adapted for the design of cutting blades for power tools.

Keywords
Cutting Force, Cutting Speed, Material Processing, Sawing, Wood Machining
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-127791 (URN)
Conference
25th International Wood Machining Seminar (IWMS-25), Nagoya, Japan, October 4-7, 2023
Available from: 2024-02-15 Created: 2024-02-15 Last updated: 2024-02-15
Johansson, J., Nilsson, D., Lennartsson, T., Ramsö, J. & Gustavsson, G. (2023). Kaskadanvändning och cirkulära perspektiv på skogsbränslen och biprodukter. Institutionen för skog och träteknik, Linnéuniversitetet
Open this publication in new window or tab >>Kaskadanvändning och cirkulära perspektiv på skogsbränslen och biprodukter
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2023 (Swedish)Report (Other academic)
Place, publisher, year, edition, pages
Institutionen för skog och träteknik, Linnéuniversitetet, 2023. p. 46
Series
Rapportserie: Forskningsrapporter inom skog och träteknik ; 1/2023
National Category
Wood Science Energy Systems Environmental Sciences
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-125811 (URN)10.15626/sot.2023.01 (DOI)9789180821087 (ISBN)
Available from: 2023-11-29 Created: 2023-11-29 Last updated: 2023-11-29Bibliographically approved
Grubîi, V., Johansson, J. & Dagbro, O. (2023). Measurement of surface-checking in sliced lamellae-based engineered wood flooring using digital image correlation. European Journal of Wood and Wood Products, 81, 1427-1436
Open this publication in new window or tab >>Measurement of surface-checking in sliced lamellae-based engineered wood flooring using digital image correlation
2023 (English)In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 81, p. 1427-1436Article in journal (Refereed) Published
Abstract [en]

The lack of quantitative methods for surface-checking measurements may hinder improving the product characteristics of engineered wood flooring products built with sliced top-layer lamellae. This study evaluated the digital image correlation method for its applicability to surface checking measurements in engineered wood flooring elements with the top-layer comprising the plain sliced lamellae of oak (Quercus spp.) species with nominal thicknesses of 1.5–4.5 mm. The method involves observing full-field surface displacements of the sliced lamellae-based wood flooring specimens subjected to an accelerated sorption/desorption cycle. Detection of surface checks relates to discontinuities in surface displacements which can be interpreted from the output strain data as strain peak regions. Additionally, a surface-checking index was defined to describe the extension of surface-checking. Exposure tests were performed on a combination of coating presence and a different number of testing cycles. The main findings provide insight into the method procedure parameters, such as exposure duration, climate conditions, analysis parameters and recommendations regarding the digital image correlation setup settings and specimen manufacturing.

Place, publisher, year, edition, pages
Springer, 2023
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-123688 (URN)10.1007/s00107-023-01975-y (DOI)001049071800001 ()2-s2.0-85167815053 (Scopus ID)
Available from: 2023-08-14 Created: 2023-08-14 Last updated: 2023-11-27Bibliographically approved
Grubîi, V. & Johansson, J. (2023). The Impact of Top-Layer Sliced Lamella Thickness and Core Type on Surface-Checking in Engineered Wood Flooring. Forests, 14(11), Article ID 2250.
Open this publication in new window or tab >>The Impact of Top-Layer Sliced Lamella Thickness and Core Type on Surface-Checking in Engineered Wood Flooring
2023 (English)In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 14, no 11, article id 2250Article in journal (Refereed) Published
Abstract [en]

Surface-checking is a significant quality issue of veneer and sliced lamellae-based wood products. This study explores how surface-checking in sliced lamellae-based engineered wood Flooring (EWF) is influenced by two key structure parameters: core type and top-layer thickness. The core types assessed were a standard solid wood lamellae with a veneer back-end layer (S), a standard solid wood lamellae core with veneer back-end layers on the two sides (DS), and a single-layer oriented strand board (OS) core. The EWF element's top-layer lamellae were plain sliced at nominal dimensions of 1.5, 2.5, 3.5, and 4.5 mm from freshly sawn slabs of European oak (Quercus spp.). The surface-checking of EWF specimens was quantified based on a digital image correlation (DIC) method, which outputs a surface-checking index. The surface-checking results were evaluated using a Tweedie compound Poisson data distribution to fit a general linear model. The model evaluated the impact of individual factors, sliced lamellae thickness and core type, and their interaction. The checking index confidence intervals were estimated using a bootstrapping technique. Findings reveal a significant interaction between studied factors and provide insight into optimizing top-layer thickness and core construction to diminish surface-checking. A low sliced lamella thickness on standard solid wood lamellae core resulted in low surface-checking, deemed relevant for further research.

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
core type, digital image correlation (DIC), engineered wood products, slicing checks, sliced lamellae, slicing thickness, surface cracks
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-126279 (URN)10.3390/f14112250 (DOI)001120608900001 ()2-s2.0-85177675708 (Scopus ID)
Available from: 2024-01-09 Created: 2024-01-09 Last updated: 2024-02-05Bibliographically approved
Grubîi, V. & Johansson, J. (2023). The Influence of Slicing Thickness on the Perpendicular to Grain Tensile Properties of Oak (Quercus robur L. and Quercus petraea L.) Lamellae. Applied Sciences, 13(22), Article ID 12254.
Open this publication in new window or tab >>The Influence of Slicing Thickness on the Perpendicular to Grain Tensile Properties of Oak (Quercus robur L. and Quercus petraea L.) Lamellae
2023 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 13, no 22, article id 12254Article in journal (Refereed) Published
Abstract [en]

The mechanical properties of sliced lamellae are critical for structural and decorative engineered wood products. This study evaluates the impact of slicing thickness on the tensile mechanical properties of plain oak (Quercus robur L. and Quercus petraea L.) sliced lamellae, perpendicular to the grain direction. The mechanical performance parameters in terms of the modulus of rupture (MOR), strain at break, and modulus of elasticity (MOE), were analysed using a one-way analysis of variance (ANOVA) and contrast analysis. Our findings indicate that slicing thickness substantially affects the mechanical properties of the modulus of rupture and strain at break, whilst the modulus of elasticity was somewhat independent of the slicing thickness. The mean MOR value increased from 0.8 to 1.43 N mm(-2) for an increase in the sliced lamellae thickness from 1.5 to 4.5 mm. The strain at break increased, on average, from 1.37 to 2.64% for an increase in the sliced lamellae thickness from 1.5 to 4.5 mm. The MOE was approximately 100-120 N mm(-2), indicating a substantially reduced stiffness compared to other sliced lamellae species and solid oak reported values. The slicing check depth ratio diminished from approximately 69% to 50% for an increase in the sliced lamellae thickness from 1.5 mm to 4.5 mm. These findings indicate a negative correlation between the slicing check depth ratio and the tensile performance perpendicular to the grain, suggesting the importance of obtaining an optimal slicing quality. This study employs digital image correlation (DIC) analysis to gain insights into the fracture mechanisms of the tested sliced lamellae and provides an alternative method for strain and stress measuring. The DIC analysis highlighted the role of slicing checks in the stress concentration and ultimate failure areas. This research provides insights into the fracture behaviour of sliced lamellae that are perpendicular to the grain, which is critical for the performance of both structural and decorative products.

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
veneer mechanical properties, tensile strength, slicing checks, digital image correlation (DIC), slicing thickness
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-126280 (URN)10.3390/app132212254 (DOI)001120506200001 ()
Available from: 2024-01-09 Created: 2024-01-09 Last updated: 2024-02-05Bibliographically approved
Gustafsson, Å. & Johansson, J. (2022). Identifying present drivers of product development and describing roles of identified actors primarily affecting the development of harvesters: a multiple-case study. Silva Fennica, 56(3), Article ID 10660.
Open this publication in new window or tab >>Identifying present drivers of product development and describing roles of identified actors primarily affecting the development of harvesters: a multiple-case study
2022 (English)In: Silva Fennica, ISSN 0037-5330, E-ISSN 2242-4075, Vol. 56, no 3, article id 10660Article in journal (Refereed) Published
Abstract [en]

Forest operations involve several different actors. Each actor imposes their own requirements on the harvester in relation to their differing roles in the industry, whether they are concerned with the harvester itself, information, environmental concerns, etc. The manufacturers of harvesters need to meet the requirements imposed by multiple actors, among them logging contractors, whose survival depends on their harvesters. This paper aims to identify the present drivers of product development and describe the roles of the actors who have been identified as those currently affecting the development of harvesters. A multiple-case study of harvester manufacturers was conducted. In total, 4 cases were studied. Each case was comprised of five interviewees: two from each harvesting manufacturer, two logging contractors, and one dealer. Following 20 interviews and 3 validation interviews (with experts from both the industry and academia), the paper concludes that the present drivers of product development of harvesters are legislators, logging contractors, and expert and research organizations. Harvester manufacturers appear to develop harvesters aligned with requirements coming from both logging contractors and legislators. Logging contractors are the primary customers, and they prioritize requirements that reduce cost and improve work environments. Legislators, and expert and research organizations are supporting development in relation to current regulations.

Place, publisher, year, edition, pages
Finnish Society of Forest Science, 2022
Keywords
forest operations, logging contractor, industry driver, interview, softwood lumber supply chain
National Category
Forest Science
Research subject
Economy; Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-117709 (URN)10.14214/sf.10660 (DOI)000907002800008 ()2-s2.0-85142371597 (Scopus ID)
Available from: 2022-11-28 Created: 2022-11-28 Last updated: 2023-02-07Bibliographically approved
Mellqvist, D. & Johansson, J. (2022). Setting Pattern Influence in Woodworking Handsaws. In: Brischke, C. & Buschalsky, A. (Ed.), Proceedings of the 18th Annual Meeting of the Northern European Network for Wood Science and Engineering (WSE): . Paper presented at 18th Annual Meeting of the Northern European Network for Wood Science and Engineering (WSE 2022), September 21-22, 2022, Goettingen, Germany (pp. 185-187). Goettingen: Universität Göttingen
Open this publication in new window or tab >>Setting Pattern Influence in Woodworking Handsaws
2022 (English)In: Proceedings of the 18th Annual Meeting of the Northern European Network for Wood Science and Engineering (WSE) / [ed] Brischke, C. & Buschalsky, A., Goettingen: Universität Göttingen , 2022, p. 185-187Conference paper, Published paper (Refereed)
Abstract [en]

One of the earliest and still-essential studies on cutting mechanics in wood waspublished in Finland about 70 years ago (Kivimaa 1950). Efforts since then have,to a large extent, consisted of understanding applications in an industrial context,such as the use of bandsaws and circular saws in primary wood processing. Thehandsaw is one of the most common hand tools. Most people have used one andare familiar with this tool either in the form of a manual saw or a reciprocatinghandheld power tool, where an equal geometric build-up of the tooth is common.Modest efforts have been made to describe the mechanics of a cross-cuttinghandsaw sawing through a piece of wood. A small number of studies, e.g. Hirataand Ohta 2006, Naylor et al. 2011 and Naylor 2014, have been identified in whichan unambiguous connection to handsaws is found. In these, the focus hasprimarily been on investigating the impact of a single tooth. A significant part indesigning handsaw parameters, such as tooth geometry and setting pattern,seems to have occurred through a process of learning by doing. Suchapproaches, however, have failed to address the basic understanding of forcedistribution and surface conditions for sawing with bevelled handsaw teeth. Theexperiment conducted for this paper aimed to determine whether the settingpattern significantly affects the performance of cross-cutting handsaws. 

Place, publisher, year, edition, pages
Goettingen: Universität Göttingen, 2022
Keywords
handsaw, cutting force, set pattern
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-119582 (URN)
Conference
18th Annual Meeting of the Northern European Network for Wood Science and Engineering (WSE 2022), September 21-22, 2022, Goettingen, Germany
Available from: 2023-02-28 Created: 2023-02-28 Last updated: 2023-03-27Bibliographically approved
Grubîi, V. & Johansson, J. (2021). An image processing algorithm for detection and analysis of slicing checks. European Journal of Wood and Wood Products, 79(4), 999-1006
Open this publication in new window or tab >>An image processing algorithm for detection and analysis of slicing checks
2021 (English)In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 79, no 4, p. 999-1006Article in journal (Refereed) Published
Abstract [en]

In this paper, a new method of measuring slicing checks for flat-sliced veneers was evaluated. The method is based on image analysis of veneer cross-sections, having highlighted the slicing checks using surface staining. The segmentation of the checks consists of global thresholding followed by some morphological operations. The outputs of the algorithm are check depth ratio and check frequency. The method was tested on flat-sliced oak (Quercus robur L. and Quercus petraea (Matt). Liebl.) veneers of different thicknesses (1.5, 2.5, 3.5 and 4.5 mm). Two distinct wood qualities and two different cutting directions (lengthwise-sliced and plain-sliced veneers) were evaluated. The algorithm performance resulted in an overall accuracy of 85% enabling an accessible method for relatively fast and accurate measurements of slicing check characteristics in lamella cross-sections. Regression analysis indicated a lack of fixed bias but the presence of proportional bias with the presented method. Check measurements indicate that by varying cutting parameters, it is possible to achieve desired check characteristics independent of slicing thickness. The semi-automated slicing check detection method could benefit further research and optimisation of the slicing process parameters and pave the way towards industrial quality control of slicing checks. The intended area of application is veneer-laminated products for interior use with the focus on veneered wood flooring.

Place, publisher, year, edition, pages
Springer, 2021
Keywords
Slicing veneer oak checking crack detection wood image analysis quality control
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-101656 (URN)10.1007/s00107-021-01672-8 (DOI)000627249200002 ()2-s2.0-85102426849 (Scopus ID)2021 (Local ID)2021 (Archive number)2021 (OAI)
Funder
Knowledge Foundation, Prowood+
Available from: 2021-03-18 Created: 2021-03-18 Last updated: 2023-11-27Bibliographically approved
Nilsson, D., Johansson, J. & Gustavsson, G. (2021). Skogliga biobränslen i Kalmar och Kronoberg: Förutsättningar för effektivt uttag. Fakulteten för teknik, Linnéuniversitetet
Open this publication in new window or tab >>Skogliga biobränslen i Kalmar och Kronoberg: Förutsättningar för effektivt uttag
2021 (Swedish)Report (Other academic)
Abstract [sv]

Följande rapport är en del av projektet i Förstudie - Hållbart och effektivtskogsbränsleuttag, vilket är ett samverkansprojekt utfört av Linnéuniversitetetoch Energikontor sydost. Projektet har finansierats av Tillväxtverket, RegionKronoberg, Region Kalmar och Bioenergigruppen i Växjö.

Place, publisher, year, edition, pages
Fakulteten för teknik, Linnéuniversitetet, 2021. p. 30
Series
Rapporter: Fakulteten för teknik, Linnéuniversitetet ; 53
National Category
Forest Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-107127 (URN)9789189460249 (ISBN)
Available from: 2021-09-24 Created: 2021-09-24 Last updated: 2021-09-27Bibliographically approved
Jalilzadehazhari, E., Vadiee, A. & Johansson, J. (2021). Subsidies Required For Installing Renewable Energy Supply Systems Considering Variations In Future Climate Conditions. Journal of Building Engineering, 35, 1-9, Article ID 101999.
Open this publication in new window or tab >>Subsidies Required For Installing Renewable Energy Supply Systems Considering Variations In Future Climate Conditions
2021 (English)In: Journal of Building Engineering, ISSN 2352-7102, Vol. 35, p. 1-9, article id 101999Article in journal (Refereed) Published
Abstract [en]

Improving the energy performance of detached houses is expected to play an important role in achieving energy and climate targets in Sweden. The majority of detached houses require energy renovations due to technical deteriorations in heating, ventilation, and air conditioning systems approaching the ends of their lives. Renewable energy supply system implementation leads to total energy use reduction. No previous studies provided information regarding how possible climate futures could affect subsidies required to implement these systems. This study compared the performance of an air-to-water heat pump (ASHP), a ground-source heat pump (GSHP), and an integrated system of a ground-source heat pump and photovoltaic solar panels (GSHP-PV) in reducing the total energy use of a detached house, which was initially supplied by an electric boiler. The performances of the supply systems were analysed in regard to three different climate scenarios, following the Special Report of Emissions Scenarios, A2 storyline. The effects of three different interest rates and two different lifetimes on subsidies were also investigated for all three energy supply systems. The GSHP-PV system was the most efficient system, as it secured 97%–100% of the total energy consumption, followed by GSHP and AWHP. The analyses of the results showed that variations in future climate conditions changed the subsidies required to install the supply systems. Furthermore, the results showed that changes in lifetime had greater impact on subsidies than interest rate growth.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
Energy supply systems, Subsidy, Possible climate futures, Detached houses
National Category
Other Civil Engineering
Research subject
Technology (byts ev till Engineering), Sustainable Built Environment
Identifiers
urn:nbn:se:lnu:diva-99024 (URN)10.1016/j.jobe.2020.101999 (DOI)000618177600003 ()2-s2.0-85097052750 (Scopus ID)2020 (Local ID)2020 (Archive number)2020 (OAI)
Projects
LC-Districts
Available from: 2020-11-21 Created: 2020-11-21 Last updated: 2021-05-17Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0130-3356

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