High temp.-resistant, inert textile sheet for gas filter - made from temp.-resistant filament, esp. glass fibre, by converting into thread, dip-coating with temp. resistant plastic e.g. PTFE and weaving

摘要

High temp.-resistant inert textile sheets (I) are claimed, based on multifilament textile threads which are resistant to temps. above 300 deg.C., combined into yarn(s) which are then twisted together. The surface of the thread has a plastic coating (A) with temp. resistance above 250 deg.C.. Alternatively, the surface of the yarn, and opt. the thread is coated with (A). Also claimed is a process for producing (I), involving (a) prepn. of multifilament thread from filaments with temp. resistance above 300 deg.C., (b) dip-coating with (A) and (c) converting into (I), pref. by weaving. Pref. filaments consist of glass and/or quartz fibre, and (A) is a fluoroplastic film, esp. PTFE or a TFE copolymer, pref. contg. additives such as active carbon, zeolites, noble metals and/or catalysts. The surface of textile (I) itself is also coated with a further layer of plastic with temp. resistance above 250 deg.C., pref. PTFE etc. as above. (I) is cross-woven fabric. USE/ADVANTAGE - (I) are useful as woven filter sheets for use with hot gas (claimed). Coating the individual threads with PTFE etc. prevents corrosion at the unprotected points of contact between threads (contrast prior-art coated textiles) and gives high-temp. textiles with improved chemical resistance. Applications include filters for removing particles from flue gases and for use in carbon black prodn., etc.