Drying wood, a hygroscopic, porous, and anisotropic material, involves complex coupled heat and mass transfer processes that make it the most time-consuming and energy-intensive operation in the wood industry. Increasing the drying temperature above 100 °C under atmospheric conditions, referred to as high-temperature drying (HTD), can accelerate the drying process but risks defects if not controlled. This study quantifies moisture transport under three drying schedules in a lab-scale convective kiln using in-situ X-ray computed tomography (CT) and evaluates whether HTD can shorten the process without visible cracking. Three drying schedules were tested: conventional, moderate-, and high-temperature. Moisture contours derived from CT image processing were validated against gravimetric measurements with less than 3.1% error. HTD reduced the drying time from 19 h to 13.5 h relative to conventional drying. CT-derived moisture contours revealed rapid free-water evaporation followed by bound water removal in HTD, driven by convective and conductive heat transfer, respectively. Higher temperatures shortened the capillary phase and advanced diffusion onset. HTD showed the steepest and highest drying rates, indicating enhanced moisture diffusivity, even at low moisture contents. The maximum surface-to-core temperature difference was 3 °C in moderate-temperature drying and 11 °C in HTD. Moisture gradients rose with higher temperature and lower moisture content, tripling between conventional and HTD schedules. Post-drying CT confirmed a visually defect-free specimen, demonstrating that the applied HTD schedule can significantly shorten drying time without causing surface cracking.

The demand for safe and durable modified-wood products is increasing in the construction sector. In this work, the in situ wet-chemistry synthesis of a glassy MgO/Na2O–SiO2 solid in Scots pine (Pinus sylvestris L.) sapwood via a two-stage impregnation process using an industrial timber-impregnation autoclave is reported. Magnesium sulphate heptahydrate (MgSO4·7H2O), a historic fire retardant, and silica-rich sodium silicate (Na2O·3.3SiO2) solutions were used as the precursors. The degree of wood matrix saturation was controlled by adjusting the Na2O·3.3SiO2 concentration (0.06 M, 0.3 M and 0.6 M). Wood saturation and density at various stages of the treatment were assessed by X-ray computed tomography (CT), which showed that the internal regions of the wood blocks remained saturated with the solution up to 24 hours post-impregnation. Phase analysis of the coprecipitated powders revealed the formation of amorphous silicates in the MgO/Na2O–SiO2 system. Thermal analysis showed that the wood treated using a low Na2O·3.3SiO2 concentration exhibited a behaviour similar to that of the untreated wood and indicated that the thermal stability of Scots pine sapwood can be improved through the incorporation of silicates. This work demonstrates the potential for fabricating hybrid bio-based building materials using water-insoluble solid additives, thereby advancing sustainable construction practices.

Cross-laminated timber (CLT) is increasingly used in sustainable construction but is sensitive to moisture, which can compromise durability and promote microbial growth. Damage to temporary weather protection during construction can lead to unintended moisture exposure. In such cases, it is important to understand how the material may have been affected. While X-ray computed tomography (CT) is not suitable for field application, it offers a detailed means of studying internal moisture behaviour and contributes to a better understanding of moisture-related risks in CLT following barrier failure.This study uses CT to investigate how moisture distributes and changes within CLT after protective covering damage. Eight CLT specimens from Scots pine were subjected to controlled wetting and drying cycles. Time-resolved CT scanning, combined with image processing techniques, was used to capture internal moisture variation with high spatial resolution. The method enabled detailed observation of both absorption and drying, revealing transport patterns between layers and interfaces.The study demonstrates that CT effectively reveals both moisture spread and slow drying in CLT following barrier failure.

We present the Mokume dataset for solid wood texturing consisting of 190 cube-shaped samples of various hard and softwood species documented by high-resolution exterior photographs, annual ring annotations, and volumetric computed tomography (CT) scans. A subset of samples further includes photographs along slanted cuts through the cube for validation purposes.Using this dataset, we propose a three-stage inverse modeling pipeline to infer solid wood textures using only exterior photographs. Our method begins by evaluating a neural model to localize year rings on the cube face photographs. We then extend these exterior 2D observations into a globally consistent 3D representation by optimizing a procedural growth field using a novel iso-contour loss. Finally, we synthesize a detailed volumetric color texture from the growth field. For this last step, we propose two methods with different efficiency and quality characteristics: a fast inverse procedural texture method, and a neural cellular automaton (NCA). We demonstrate the synergy between the Mokume dataset and the proposed algorithms through comprehensive comparisons with unseen captured data. We also present experiments demonstrating the efficiency of our pipeline's components against ablations and baselines. Our code, the dataset, and reconstructions are available via https://mokumeproject.github.io/.

The size and distribution of the eyes play a crucial role for the sensory attributes, aesthetic value and quality of the cheese. This article focuses on investigating the feasibility of using computed tomography (CT) scanning as a non-destructive tool to observe early-stage eye formation in Grevé cheese within an industrial trial. It is crucial to achieve a perfect combination of small and big sized eyes, evenly distributed within the cheese wheel, without having cracks/splits for optimal quality. Such variations could be visualized using CT-scanning of cheeses at a young and mature stage by providing high-resolution, three-dimensional CT-scanning images of the cheese's internal structure, without the need for physical dissection. Further, the distribution of eyes, their shape and number, could be visualized and compared for the same cheese scanned at young and mature stages. Thus, the importance of monitoring eye formation through non-destructive techniques is emphasized to ensure consistent product quality.

This research delves into the unexplored territory of using CT image processing techniques to assess capillary flow in freshly felled Scotch pine logs during the drying process. Leveraging a high-resolution CT scanner, the study captures intricate details of the wood’s internal structure, which were then quantified using image processing algorithms. The findings confirm the efficacy of CT image processing in accurately determining capillary flow in wood. This opens up new opportunities for non-destructive testing methods and contributes to a deeper understanding of wood properties. The implications of these findings are farreaching, offering substantial advancements in quality control and processing optimization in the wood industry.

Sawn-timber drying is the wood industry’s most time- and energy-consuming process. This process can be more efficient than the conventional method by elevating the dry-bulb temperature to above 100 °C in a high-temperature drying (HTD) process, which for some species shortens the drying process by up to 50% without deteriorating the quality. Comprehending the complex correlation between the wood drying physics at high temperatures and the anatomical features of the specific species, along with its mechanical and physical properties, is crucial, as it limited its application from being broadly implemented in industry and the necessity of generalizing this method for wood species. The present study has been conducted to comprehensively review and tackle the challenges of applying this method on various species and the consequences, such as high moisture content gradients resulting in stress residual, unevenness, and color changes. Energy, environment, and economic (3E) assessments of HTD were evaluated. The accelerated drying process in HTD reduces heat losses and air leaks, resulting in higher energy efficiency than the conventional methods. Furthermore, it was proved to be 20% economically in the long term. Confliction in reported studies, such as HTD's effect on permeability and volatile organic compound (VOC) emissions, was raised, highlighting the importance of further studies for generalizing this method to adapt appropriate drying schedules, focusing on Scandinavian species by referring to previous industrial trials.

Determining moisture content (MC) distribution during the drying of porous materials such as wood is crucial for developing drying schedules and assessing their suitability to achieve optimised processes. This study aimed to determine the causes of the unique drying behaviour and the well-known unusual longer drying time of western hemlock compared to other similar softwoods. In situ X-ray computed tomography (CT) was used to study the evolution of MC in timber during the drying process. The drying behaviour of western hemlock (Tsuga heterophylla (Raf.) Sarg.) was compared with Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) from green to oven-dried condition with industry-proposed drying schedules used for steering a custom-made experimental kiln combined with a CT scanner. CT scanning was performed at 30 min intervals during the complete drying period of 30 h, and the CT images were processed to calculate the MC evolution within the specimen. Western hemlock showed a considerably slower capillary-phase drying and did not go into the transition and diffusion phases when a schedule adapted to pine and spruce drying was applied for its drying. CT images and MC gradient calculations showed a lower drying rate and severe non-uniformity in MC distribution, which could be due to the effect of higher green MC and the presence of wet pockets. Furthermore, the evaporation front at the first 5 h of drying receded faster into the hemlock specimen, and as drying proceeded, it slowed down compared to other specimens.

The charring behaviour of timber elements under fire is well understood, however, the effects of fire and heat on connections are not equally well known. Timber connections often use steel fasteners, like screws or angle brackets, which conduct heat much better than wood. Moreover, these fasteners lose their mechanical resistance and capacity under elevated temperatures. X-ray computed tomography (CT) can be used to reconstruct the internal structure of wood non-destructively. It should therefore be possible to use this technology to also study the progressive degradation due to fire of a timber connection. The goal of the present study is to investigate how CT can be used to analyse the degradation of a timber connection due to fire. Samples of Norway spruce with self-tapping screws were scanned before and after a fire exposure, and mechanical tests were performed. The results indicate that the degradation due to fire in a timber connection can be observed in CT scans, but that certain measures need to be taken to minimise the effects of image artefacts due to X-ray scattering and photon starvation.