초록 ▼

A composite filter media includes a fibrous filtration layer of randomly oriented fibers and one or more pleatable stiffening layers which enable the composite filter media to be pleated and hold or retain its pleats. The pleatable stiffening layer(s) may enhance the dirt holding capacity of the com

A composite filter media includes a fibrous filtration layer of randomly oriented fibers and one or more pleatable stiffening layers which enable the composite filter media to be pleated and hold or retain its pleats. The pleatable stiffening layer(s) may enhance the dirt holding capacity of the composite filter media especially when positioned upstream of the fibrous filtration layer. The composite filter media may also include a flexible covering layer which functions to block the loss of fibers from the fibrous filtration layer. Preferably, the mean fiber diameter of the fibers in fibrous filtration layer increases and the density of the fibrous filtration layer decreases throughout the thickness of the fibrous filtration layer from one major surface to the other major surface of the fibrous filtration layer.

대표청구항 ▼

[ What is claimed is:] [1.] A pleatable composite filter media comprising:a fibrous filtration layer of randomly oriented fibers bonded together at their points of intersection; said fibrous filtration layer comprising an air laid blanket of fibers having an average mean diameter between 3.0.times.1

[ What is claimed is:] [1.] A pleatable composite filter media comprising:a fibrous filtration layer of randomly oriented fibers bonded together at their points of intersection; said fibrous filtration layer comprising an air laid blanket of fibers having an average mean diameter between 3.0.times.10.sup.-5 inches and 11.0.times.10.sup.-5 inches,, said fibrous filtration layer having an initial pressure drop no greater than about 0.30 inches of water; said fibrous filtration layer having an average filtration efficiency of at least 20%; and said fibrous filtration layer lacking sufficient formability and stiffness in of itself to be scored and reformed into a pleated configuration and to retain said pleated configuration;a pleatable, permeable stiffening layer means; said stiffening layer means comprising a first pleatable stiffening layer having sufficient formability and stiffness to be scored and reformed into said pleated configuration and to retain said pleated configuration; andsaid fibrous filtration layer and said stiffening layer means being bonded together into a composite filtration media having sufficient formability and stiffness to be scored and reformed into a pleated configuration and to retain said pleated configuration.