Method for manufacture of static filtration media

Abstract

A simple yet effective method and apparatus produce a web suitable for treatment of water as a static filtration media, e.g. to remove chlorine and lead from water in contact with the media. A web is coated with a coating composition that facilitates treatment of water and includes a binder, and the web is compressed in one dimension about 25-75% (e.g. 40-60%) so as to make the void size distribution substantially more uniform. The compression is substantially maintained until the binder substantially cures so that the coated final web produced has a second void size distribution more uniform than the first void size distribution, e.g. the coated final web having void volumes with a mean value of about 6-7×10 liters and/or an RDV/BV ratio of at least 0.4, and a porosity of greater than 90%. Compression may be at least primarily practiced by substantially immediately after coating passing the web through a series of staggered rollers; or by tightly winding the web prior to cure of the binder; or by compressing the web while in a curing tunnel using upper and lower compression belt roller assemblies. Coating may be practiced using a non-woven web having a weight of about 4-7 ounces/sq. ft., and by applying a coating equal to about 100-200% of the uncoated weight of the fabric comprising about 10-20% binder, about 60-90% activated carbon, and about 0-25% zeolite.