| 摘要 |
1381041 Sintered fibre fabric GAF CORP 3 Jan 1972 [27 Jan 1971] 165/72 Heading D1R [Also in Division H1] Battery electrodes may be separated by a porous nonwoven fabric comprising sintered thermoplastic fibres. The fabric having uniform porosity with pores of 5 to 35 microns and an open area of 25 to 60%. Exemplified batteries are vented and sealed nickel-cadmium and silver-cadmium batteries having sodium hydroxide or 35% potassium hydroxide electrolytes and a vented lead/acid battery. 1¢ to 3 inch, 1.5 to 8 denier polyvinyl chloride (including copolymers thereof), polyvinyl acetate, polyvinyl alcohol, polyethylene, polypropylene, nylon, polytetrafluoroethylene, polyester or polyacrylics and copolymers thereof are used. They may be helically, zig-zag or sinusoidally crimped and coated with a hydrophilic agent. They are carded or air laid to produce an at least partly orientated mat in which 67% to 97% of the fibres are aligned to within 30‹ of the preferred direction. Sintering at specified temperatures 10‹F to 50‹F below the fibre melting point is carried out by a heated calender or a heated mandel. The web first is cut into sections and rotated through 90‹ in order that it may feed through the press with the preferred fibre direction perpendicular to the direction of feed. A calender pressure of 0.2 to 0.4 tons/linear inch reduces the web thickness by 90 to 98%, whilst a mangle pressure of 150 to 600 p.s.i. reduces the web thickness by 88 to 96%, yielding a more porous web suitable for sealed cells. The webs have a voids volume of 50% to 90%, an air permeability of 0.5 to 250 cfm/ft<SP>2</SP>/¢ inch water column, a fibre count of 350 to 10,000 per inch, a weight of 0.5 to 8.0 oz per square yard and a thickness of 0.002 to 0.05 inch. |
