|국가/구분||United States(US) Patent 등록|
|미국특허분류(USC)||554/86 ; 505/487 ; 505/522 ; 505/524 ; 905/057 ; 905/078 ; 905/287 ; 105/347 ; 105/352|
|발명자 / 주소|
|출원인 / 주소|
|대리인 / 주소||
|인용정보||피인용 횟수 : 38 인용 특허 : 11|
A dual- or multi-layer filter medium for air filtration, having at least one meltblown layer (2, 2a and 5) at least one meltblown layer (2 and 2a) is placed on the inlet side of the filter medium. The meltblown layer has a pore size larger than that of the next following layer or layers.
[ What is claimed is:] [1.]1. A dual- or multi-layer filter medium for air filtration, which comprises at least one meltblown layer located on an inlet side of the filter medium and having a pore size larger than that of the following layer or layers, wherein the meltblown layer has a pore size of more than 100 .mu.m, an area mass in a range between 10 and 100 g/m.sup.2, a permeability to air (at 200 Pa) of over 2000 l/m.sup.2 s and fibers having a diameter of over 10 .mu.m.