Abstract:

Objective: A three-dimensional grid format sequential dissection method is proposed to improve common defects of existing wood-based reconstituted materials such as wood-based panels. This method offers a new theoretical approach for wood processing and unit preparation in engineered wood and provides a foundational raw material for the development of novel wood-based reconstituted materials. Method: Based on the main characteristics of wood microscopic structure, a technical approach is established involving the setup of a three-dimensional grid of logs, followed by longitudinal scoring and slicing. This process, combined with the design of composite tool structures and the functional roles of various tool components, explains the forming process of wood rod lumber units. Taking small-diameter wood as the research object, a three-dimensional rectangular coordinate system in a stereoscopic grid is established for the wood. The main cutting motion of the tool and the feeding motion of the wood segments are designed accordingly; combined with the division of the small-diameter wood processing area and the layout of the combined cutting tools on the transfer chain and the corresponding allocation of the small-diameter wood processing area, a new method for preparing wood-based panel units is proposed, namely the three-dimensional grid format sequential dissection method. The relationship between the cutting tool and the wood in the three aspects of speed, time and distance in the three-dimensional grid format sequential dissection method is analyzed, and the speed relationship formula for the main cutting motion and the feed motion is derived. Based on the three-dimensional grid format sequential dissection method, an experimental machine for processing wood rod lumber units is developed and processing experiments are conducted for verification. Result: The relationship between the speed of the main motion and the feed motion is v=[(N×H)/S]×V (where N is the number of combined cutting tools in each processing area and S is the circumference of the transmission chain); The main motion speed is V=2.49 m·s^?1, and the feed motion speed is v=0.0053 m·s^?1 or 0.0057 m·s^?1, successfully achieving continuous automatic processing and forming of wood rod units. The produced wood rod units are non adhesive, undamaged, and have the same shape, with dimensions of length (L) ×width (B)×height (H) = 90.0 mm×1.5 mm×(1.1?1.5) mm. Conclusion: 1) A novel method for preparing engineered wood units, namely the three-dimensional grid format sequential dissection method, is originally proposed, demonstrating technical feasibility. 2) The speed relationship formula for the main cutting motion and feed motion is given by v=[(N×H)/S]×V. This formula provides a theoretical basis for calculating the relevant motion parameters in unit processing experiments and for selecting equipment for unit preparation. 3) The validity of the speed relationship formula for the main cutting motion and feed motion is confirmed. The height (or thickness) (H) of the wood rod lumber units depends on the transmission system of the main and feed motions and their speed ratios. The length (L) of wood rod lumber units is equal to the length of the log segment, and the width (B) is determined by the combined cutting tools.

Key words: wood rod lumber unit, process forming, three-dimensional grid format sequential dissection method