| 摘要 |
PURPOSE: To obtain a composite filter cloth having excellent filter efficiency by constituting the filter cloth of a first layer interlocked with polyimide fibers having an irregular cross section and having chargeability on the surfaces and a support layer made of cloth having the constituting fiber fineness larger than that of the first layer and having a filter characteristic coupled with the first layer. CONSTITUTION: The first layer of the composite filter cloth consisting of the first layer and the support layer made of the cloth coupled to the first layer is formed of a nonwoven fabric consisting of certain specific polyimide fibers as the component fibers and the cloth support layer consists of the fibers having the surface area smaller than the surface area of the polyimide fibers and having the form of a relatively ordinary crosssection as one of the component fibers. The fineness of the component fibers of the first layer is made smaller than the fineness of the support layer. The first layer is formed of the specific polymide fibers which are interlinked to each other, have the cross-section like that of P84 fibers and are easily chargeable. The interlinkage for the composite filter cloth is formed by a needle punching method and the composite filter cloth has the cloth support like that of, for example, polyester, and having an internal filtration function. Such composite filter cloth is expanded in the fiber surface area and has an effect of efficiently capturing dust or the like. |
