Hardwood sawmills traditionally saw logs in a manner that either orients sawlines parallel to the log central axis (straight sawing) or the log surface (allowing for taper). Sweep is characterized as uniform curvature along the entire length of a log. For logs with sweep, lumber yield losses from straight and taper sawing increase with increasing levels of sweep. Curve sawing logs with sweep wi...

Accurate sawing requires attention to proper alignment and maintenance. Alignment is critical to modern sawmills using thin kerf saws. In fact, the improvements in machine design were critical to the development of thin kerf sawing systems. About two-thirds of sawing problems are caused by misalignment, not saw preparation. Good alignment reduces down-time and machinery wear and should be part ...

Curve sawing is a primary log breakdown process that incorporates gang-saw technology to allow two-sided cants from logs with sweep to be cut parallel to the log surface or log axis. Since curve-sawn logs with sweep are cut along the grain, the potential for producing high quality straight-grain lumber and cants increases, and strength, stiffness, and dimensional stability are maximized. Presen...

In the classical approach, cutting forces and cutting power in sawing processes of orthotropic materials such as wood are generally calculated on the basis of the specific cutting resistance kc (cutting force per unit area of cut). For every type of sawing kinematics (frame saws, band saws and circular sawing machines) different empirical values of specific cutting resistance kc have to be appl...

The consistency and repeatability of movement patterns has been of long-standing interest in locomotor biomechanics, but less well explored in other domains. Tool use is one of such a domain; while the complex dynamics of the human-tool-environment system have been approached from various angles, to date it remains unknown how the rhythmicity of repetitive tool-using action emerges. To examine ...

Softwood logs are processed into green boards through a series of horizontal or vertical sawing operations that reduce lumber thickness. This paper uses physical understanding to model how systematic and random errors in board thickness accumulate during sequential resawing. The error model is validated on board thickness measurements gathered at a northern California sawmill. The analysis • ex...

Optimization of the wire sawing process of silicon ingots requires a profound understanding of the dynamic interaction of wire, slurry and silicon material. In this paper, the influence of wire velocity and applied wire stress on the process is investigated using dissipative particle dynamics and discrete element simulations for modelling the fluid and the grains in the abrasive suspension. In ...

The objective of this work was to study maritime pine (Pinus pinaster Ait.) wood characteristics and their impact on the sawing yield using virtual stem models and sawing simulation procedures. In the first part of the work, a characterisation of maritime pine as raw material for the wood industry was performed. The stem shape, distribution of knots, and heartwood/sapwood contents were studied....

A 3D log sawing optimization system was developed to perform log generation, opening face determination, sawing simulation, and lumber grading using 3Dmodeling techniques. Heuristic and dynamic programming algorithms were used to determine opening face and grade sawing optimization. Positions and shapes of internal log defects were predicted using a model developed by the USDA Forest Service. L...