GB1082910A - Improvements relating to the removal of dirt particles from the surface of a paper web - Google Patents

Abstract

1,082,910. Electrostatic separation. LOWE PAPER CO. Dec. 14, 1965, No. 53078/65. Heading B2J. Dirt particles are removed from the surface of a paper web by engaging a portion of the web with a film of plastic and producing relative motion between the web and the film so as to rub them against each other whereby an electrostatic charge is generated on the film and causes the dirt particles to leave the web and adhere to the film. The film may be of polyethylene, nylon, cellulose acetate or polyvinilidine chloride. In one embodiment, Fig. 1, a plastic film 16 is hung from a stationary rod 14 above a travelling paper web 10 so that it engages the web. In another embodiment, Fig. 2, supply and take-up rolls 27, 28 for the film are mounted on rotatable shafts 24, 25, the latter being driven via a pulley 21. Rotatable shafts 24', 25', which may be biased toward the web 20, stretch the film so that its intermediate portion 26 is in contact with the web. The film and web may move in the same direction or in opposite directions. The film may be held stationary when desired. In a further embodiment, Fig. 3 (not shown), a continuous film band 36 is stretched over rollers 37, 38 arid move in the same direction as the web 30 but at a faster or slower speed. In a still further embodiment, Fig. 4 (not shown), a continuous film band 43 is stretched over a single roller 41 and is made to move faster or slower than the web and in the same direction or opposite directions. A brush 44 serves to remove the static charge from the band and the particles are sucked off the band by a vacuum device 45.