REMOVING OF WARPING OF WOOD BOARDS THANKS TO IMBALANCE OF SURFACE HUMIDITY OF THE CHIP MAT
Abstract
Currently, the most hard-to-repair defect of wood boards is their warping, which can be caused by many factors. The main ways to eliminate the warping of wood boards are considered. Previous studies have established that the value of the final warping is determined by the density, format, thickness of the board and the period that has passed since its manufacture. It is established that warpage caused by compensation of internal stresses generated during the piezo-heat treatment proceeds exponentially with an average value of the time constant of 10.5 minutes. One of the active ways to eliminate warping is considered, which consists in one-sided wetting of the surface of the initial briquette, depending on the size and direction of the arrow of the deflection of the made board. Taking into account the corrections for density, format, thickness of the manufactured board and the time of measuring the arrow of its deflection, an expression is obtained that establishes the amount of moisture per 1 m 2 of the surface of the chip package to completely compensate for warp. In the experiment, the deflection of the wood board, purposefully created by the temperature imbalance of the pressing surfaces of the laboratory press, was compensated by the reverse deflection resulting from the controlled imbalance of the surface moisture of the chip mat. Experimental results are presented that confirm the theoretical calculations obtained. The purpose of the study is to obtain a methodology acceptable for practice to eliminate warping of wood boards in the most easily implemented way – by calculated preliminary wetting of one of the surfaces of the formed chip mat. The considered method of eliminating the warping of wood-based boards is easy to automate in the presence or after installation of plate sagging sensors and two aerosol sprays in the line
About the Author
S. M. Plotnikov
Reshetnev Siberian State University of Science and Technology; Krasnoyarsk Institute of Railway Transport
Russian Federation
Russian Federation
31, Krasnoyarskii rabochii prospekt, Krasnoyarsk, 660037
2i, Novaya Zarya str., Krasnoyarsk, 660028
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Review
For citations:
Plotnikov S.M. REMOVING OF WARPING OF WOOD BOARDS THANKS TO IMBALANCE OF SURFACE HUMIDITY OF THE CHIP MAT. Conifers of the boreal area. 2022;40(1):84-90. (In Russ.)
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