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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 stru

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.

Valuable hardwoods, such as oak, although renewable, present limitations in product realisation in terms of their cost and availability, often attributed to production waste and sub-optimal product design factors. The slicing technique facilitates the production of thin wood lamellae, minimising waste and ensuring optimal material conversion. This study explores the application of sliced lamellae in engineered wood flooring, focusing on quality aspects and control. The performance of sliced lamella-based engineered flooring was compared with traditional parquet flooring elements through standard performance tests, which scrutinised the characteristics of appearance, delamination, and dimensional stability under varying climate conditions. The climate tests highlighted the significant flaws of sliced lamella-based flooring elements: surface-checking. Despite diminished delamination resistance, the dimensional stability excelled for the sliced lamella–based flooring. Primary observations indicated that the study’s constraints are related to a lack of surface-checking quantitative measurements and an absence of sliced lamellae quality control. The subsequent research characterised sliced lamellae quality using the properties of slicing checks and mechanical performance perpendicular to the grain. Slicing thickness is considered a critical variable in both lamella-processing and product performance factors. A detection method using image processing and analysis was developed to characterise slicing check occurrence. The method considered slicing check characteristics, check depth ratio and check frequency. The results of the slicing check inspection indicated a decrease in the check depth ratio and check frequency with increased slicing thickness. Mechanical testing revealed that oak sliced lamellae exhibited considerably lower strength and stiffness compared to sawn solid wood. The slicing check depth ratio was found to be negatively correlated with the sliced lamel

The effect of oblique cutting on the chipper-canter wood chipping mechanism was studied. A bent knife was modified to obtain inclination angles (IA) of 30° and 50° between the chipping edge and the log feeding direction. The standard knife had an IA of 40°. These three knives were tested on 15 logs each, under frozen (-10°C) and unfrozen conditions. Chip dimensions were assessed by thickness (Domtar distribution) and width/length (Williams distribution). Characteristics and physical properties of the log knots were also measured. Experiments revealed that IA had a significant effect on chip formation mechanism. The IA affected the chipping edge entering the log and the form of the wood slice that was transforming into chips. These changes provoked variations in chip size. An IA of 30° produced wider chips, mostly in the first half of the cut, shaped as an elongated parallelepiped that resulted from a tangential, oblique and radial splitting in a single chip. The shape of chips obtained with IAs of 40° and 50° was more like an upright parallelepiped that was detached mostly by radial and oblique splitting. At the beginning and at the end of the cut, chips were produced by tangential splitting. As a result, for a same chip length of 23 mm, weighted mean chip thickness (WCT) decreased almost 1 mm when IA decreased from 50° to 30°. The knot ratio (total knot area / cant total area) affected both chip size distributions and WCT. Chipping frozen wood at -10°C reduced the chip thickness by 0.55 mm with respect to unfrozen wood. The amount of fines and pin chips also increased nearly two times compared to unfrozen wood. The amount of the Williams accepts chip class increased by 6% when IA decreased from 50° to 30° and by 8% when chipping unfrozen wood compared to frozen wood.