NON-WOVEN INORGANIC FIBRE MAT

摘要

A non-woven mat (18) of inorganic fibre is disclosed having a substance which is lower at the edges (26') of the mat than in the remainder (28) of the mat. Apparatus for making such a mat comprises: a source of a slurry of inorganic fibre in a liquid; a forming wire disposed to move past the source, through which the liquid passes to deposit the inorganic fibre on the forming wire; a mask across a part of the width of the forming wire to hinder passage of the liquid through the forming wire over the said part, the effectiveness of the mask varying in the direction of movement of the forming wire past the slurry source. A method of making the mat comprises passing a forming wire past a slurry of inorganic fibres 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, whereby a non-woven mat of inorganic fibre is formed having an uneven substance (weight/unit area) in the cross direction.