GB804511A - Spraying device and method - Google Patents

Abstract

A spraying device comprises a heated supply tank for the spraying liquid connected to a heated elongated container for the liquid adjacent to the object to be sprayed, one or more spray heads adapted to siphon liquid from the container when compressed air is passed through them and spray it on the object, and means for starting and stopping the supply of compressed air. As shown, as applied to coat-ing printed sheets with wax to prevent offset, a tank 10 heated by a heater 12 is connected via a solenoid-controlled valve 54 which is opened when the printing-machine, in conjunction with <PICT:0804511/III/1> which the device operates, is running, and a float-controlled valve 56 to container 18 heated by heaters 64, 66. Spray heads 68 have supply tubes 70 dipping into the liquid in the container, and are supplied by pipe 76 with compressed air which has been pre-heated by passage between heated tank 10 and outer shell 16. The supply of air is controlled by valve 44 which may be electrically operated by each object passing a reference point at which it operates a switch or a photo-electric device as it comes into position for spraying. The apparatus may be used for spraying animal, vegetable, mineral or synthetic waxes or synthetic resins such as polyethylene and nylon on to paper in sheets or rolls, carboard, carton stock, plastic sheeting or pressed hardboard.