Method and apparatus for modifying bending characteristics of rigid laminated sheets or boards, sheets or boards produced thereby and a method of applying the sheets or boards to a wall surface

摘要

The invention relates to a method of modifying the bending characteristics of a rigid laminated board (20) formed of an expanded plastic foam material (10) bonded between facing materials (12, 13). The board is heated or whilst being hot, is formed with at least one groove or pattern of grooves (24) on one or both faces of the board, the depth and width dimensions of the groove or grooves being sufficient to give the board flexibility in one or more directions to resist the board developing a permanent bend as a result of the board being bent in the respective direction, whilst maintaining the rigidity of the board. Apparatus is provided for forming the required groove or pattern of grooves on one or both faces of the board. The invention also relates to a method of applying the board to a wall surface (28) to dry line the wall.