POROUS POLYTETRAFLUOROETHYLENE FILM AND METHOD OF MANUFACTURING THEREOF

• Main Authors: DZUN ASANO, KATSUTOSI JAMAMOTO, OSAMU INOE, TOSIO KUSUMI, OSAMU TANAKA, NOBUKI URAOKA, SINDZI TAMARU, SINITI TAEN
• Format: Patent
• Language: English
• Published: 20.01.1999
• Edition: 6
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

FIELD: polymer materials. SUBSTANCE: invention may be applied in production of liquid filters, air filters for purifying interior atmosphere in sterile semiconductor-production rooms, and to create favorable conditions for precision devices in medicine, biochemistry, etc. Film is manufactured by stretching non-molten polytetrafluoroethylene in longitudinal direction at 250-320 C and in transverse direction at 100-200 C. Average pore size of thus obtained film is 0.2-0.4 mcm, and pressure fall in water passing the film at flow velocity 5.3 mm/s is 20-50 mm water column. EFFECT: enhanced filtration efficiency. 7 cl, 2 dwg, 3 tbl, 9 ex