Filter sheet media and method for manufacturing a filter sheet media

A filter sheet media (1) for air and gas filtering applications, the filter sheet media (1) comprises:

• a first group of glass fibers (20) having a fiber diameter in a range of greater than or equal to 6 μm up to 20 μm;
• a second group of glass fibers (30) having a fiber diameter in a range of 0.2 μm to less than 6 μm, wherein the second group includes at least one subset of glass fibers with the fiber diameter being greater 1 μm;
• a binder (40) for adhering the first group of glass fibers (20) to each other and further adhering the second group of glass fibers (30) to the first group of glass fibers (20), wherein the binder (40) is from 10 to 20 wt % of the total weight of the filter sheet media (1);
• wherein the filter sheet media (1) has a first surface (11) and a second surface (12) and a thickness (13) in a direction perpendicular to the first surface (11) and the second surface (12),
• wherein the filter sheet media (1) fulfils at least criteria of standard EN779:
• 2012 class M6 filter media;
• wherein the first group of glass fibers (20) comprises from 60 wt % to 90 wt % of the fiber content of the filter sheet media (1);
• wherein the second group of glass fibers (30) comprises from 10 wt % to 40 wt % of the fiber content of the filter sheet media (1), and have a fiber distribution gradient range of 1:1.5 to 1:10 over the thickness (13) of the filter sheet media (1) such that the second group of glass fibers (30) are distributed through the thickness (13) of the filter sheet media (1), and the filter sheet media (1) has 1.5 to 10 times more second group of glass fibers (30) near the first surface (11) than the second surface (12).