GB715448A - Improvements in method of making embossed electric battery separators - Google Patents

Abstract

715,448. Batteries. UNITED STATES RUBBER. CO. Oct. 14, 1952, [Jan. 4, 1952.] No.25686/52. Class 53. [Also in Group VIII] Separators are made from a fibrous cellulose sheet which is impregnated with a phenol formaldehyde, phenol furfural, melamine formaldehyde or other resin and partially dried and then embossed by pressure and finally heated to cure the resin. Figs. i and 2 show apparatus for carrying out the process in which 10 is a roll of paper which is unwound and passed through a tank I5 containing a solution or suspension of the resin. Rolls I7 squeeze out excess liquid and the impregnated sheet is passed through a drying chamber I9 and wound into a roll 24. The roll is transferred to the apparatus shown in Fig. i and is shown at 24<SP>1</SP> from which the sheet I is drawn and passed between heated plates 28, 29 and then between embossing rollers 31, 32. Cracking of the sheet as it passes between the rollers is prevented by covering it on both sides with protecting aprons 35, 36 which may be made of metal foil, plastic film or a stretchable fabric. The aprons are in the form of endless belts which on the sides that come into contact with the sheet may be coated with rubber and talc the latter being applied by rotating brushes 43, 46. The aprons are kept taut by weights 39, 42 and slidable rolls 37, 4I round which the aprons pass. The embossing rollers 3I, 32 produce ribs on the sheet which are slightly higher than required and which are reduced to the required size by accurately spaced rollers 50. The sheet then passes through a curing chamber heated by two electric heaters 51, 52, Fig. 4, situated in housings 53, 54 hinged together at 55. The housing 53 can be raised by a handle 56. The embossed and cured sheet is sprayed at 58, 59 with a wetting agent and the sides trimined by cutter discs 6o which are driven by a motor 64 which also drives rollers 62 which draw the sheet through the apparatus from the roll 24<SP>1</SP>. The sheet is cut into short lengths by a cutter 67.