STUDIES ON THICKNESS DEFORMATION OF WOOD COMPOSITE Ⅱ. THE FOUNDATION AND COMMENTING OF DEFORMATION IN THE THICKNESS OF PARTICLEBOARD THE PHENOMENON OF THE THICKNESS SWELLING PARALLELITY IN PARTICLEBOARD STUDIES OF THICKNESS SWELLING ON WOOD COMPOSITE Ⅲ. ESTABLISHMENT OF EQUATIONS FOR DEFORMATION IN THE THICKNESS OF PARTICLEBOARD THE EFFECTS OF ALL MAIN MANUFACTURING FACTORS ON THE THICKNESS SWELLING IN PARTICLEBOARD