Heated platten press

A method of manufacturing particle boards by pressing a mat of particulate material including a heat curable binder in a heated platten press, the method comprising the steps of providing a heated platten press with a first rigid platten and a second elastically deformable compensation platten supported on an array of piston-in-cylinder arrangements to form a plurality of uniformly distributed contiguous support fields for one side of said mat;

• initially pressing a mat to form a particle board by producing relative closing movement of the press plattens to an end separation substantially equal to the thickness of the desired particle board;
• measuring the thickness of the board;
• either directly outside the press or indirectly inside the press, at positions corresponding to the positions of the piston-in-cylinder arrangements within the array;
• deriving the deviation of the board thickness at each of the said positions from the desired board thickness;
• pressing a second mat and, after a period sufficient to allow the mat to soften through initial heating, controlling the individual piston-in-cylinder arrangements to deflect the compensation platten to correct the said deviations in board thickness desired from the first mat, and repeating the measurement and correction steps for further mats as manufacture proceeds.