Non-woven inorganic fiber mat, process for its manufacture, apparatus for making the same as well as use of such non-woven inorganic fiber mat

摘要

In the present invention, there is disclosed a non-woven mat (18) of inorganic fiber having a substance weight/unit area varying in a cross direction, at least one edge margin of said mat being of lower substance than the remainder of the mat. Disclosed is also a method of making the mat wherein said method includes passing a forming wire (14) past a slurry of inorganic fibers in a liquid while masking a part of the width of the forming wire as it passes through the slurry, the masking varying along the length of the forming wire as it passes through the slurry; and urging the slurry against the forming wire and causing the liquid to pass through the forming wire (14), whereby a non-woven mat (18) of inorganic fiber is formed having an uneven substance (weight/unit area) in the cross direction. This effect is achieved through the mediation of blinding plates (22, 22') arranged in a flowbox (10) at each of both edges obliquely below the slurry level, whereby the blinding plate (22, 22') width varies in the direction of the forming wire (14) movement. So produced non-woven mat (18) is used as reinforcement dipped immediately below one surface of a gypsum building board.