Patent ID: 7582132

Claim:
A method for making a fibrous, wet laid, nonwoven pleatable filter media comprising; a) dispersing fibers comprising different types of fibers in a fluid dispersion, b) subjecting the dispersion to a moving forming screen to form a wet laid fibrous web, c) optionally applying an aqueous resin binder to the web in sufficient amount to produce a binder level in the filter media of about 18 to about 25 wt. percent, and d) drying the wet web and at least partially curing the resin in the binder to form a resin bound fibrous, wet laid, nonwoven pleatable dry mat, wherein; i) the fiber dispersion comprises about 28 to about 40 weight percent polymer fibers, having a denier in the range of microdeniers to 6, about 40 to about 28 weight percent H glass fibers about 0.5 to about 1 inch long and about 15+/−10 wt. percent of either a chemically cross linked bleached Kraft pulp or a fully bleached softwood Kraft pulp, based on the weight of said pleatable dry mat, and ii) the aqueous binder comprises a mixture of water and an acrylic resin having a glass transition temperature in the range of about 5 to about 30 degrees C. whereby the resultant filter media, when pleated and formed into a pleated gaseous filter using conventional pleating and assembly techniques produces a filter meeting at least MERV 6 specifications and requires no additional means of support in the pleated gaseous filter.