Patent ID: 6605186
Filing Date: 2003-08-12
Classification: B28B

Abstract:
A water felting process for preparing a board from a suspension of dense crystals and fibrous materials, wherein a foraminous wire mesh is fed the suspension by a headbox comprising a housing, a first rotating horizontal distribution roll positioned in a first chamber of said housing, and a second rotating horizontal distribution roll positioned in a second chamber of said housing, said rolls extending across the width of said headbox, said first chamber including a first curved section shaped to match the outer cylindrical surface of the first roll and being closely spaced to a portion of the surface of the first roll, said second chamber including a second curved section shaped to match the outer cylindrical surface of the second roll and being closely spaced to a portion of the surface of the second roll, said process comprising:rotating the rolls in opposite directions; feeding the suspension of dense crystals and fibrous materials to said first chamber; adjusting the rotational speed of said first roll to impart sufficient energy to the suspension located in the gap between said first closely spaced curved section and the portion of the outer cylindrical surface of the first roll to provide controlled agitation of said suspension without high shear, to maintain said dense crystals in uniform suspension with said fibrous material, and to spread said suspension across the width of paid first roll; passing said suspension from said first chamber to said second chamber; adjusting the rotational speed of said second roll to impart sufficient energy to the suspension located in the gap between said second closely spaced curved section and the portion of the outer cylindrical surface of the second roll to provide controlled agitation of said suspension without high shear, to maintain said dense crystals in uniform suspension with said fibrous material, and to spread said suspension across the width of said second roll; passing said suspension out of said second chamber; and distributing said suspension as a uniform layer across the width of said foraminous wire mesh.