GB936944A - Improvements in and relating to colored glass - Google Patents

Abstract

936,944. Coloured glass. OWENS-ILLINOIS GLASS CO. March 20, 1962 [March 20, 1961], No. 10574/62. Class 56. In the making of a coloured glass, a colourless base glass batch is formed and colouring materials are added in powder form to the batch as it is conveyed to the melting furnace. Colourless batch materials are mixed in a rotary drum 11, discharged to a driven screw 12, thence on to an upwardly inclined belt conveyer 15, through inlet shoot 17 to a vertically operating bucket conveyer 18 to elevate the batch to an overhead conveyer 19, which may be one of a series, the batch discharge being controlled by doors 21 in a shoot 20. Vertically movable idler rolls 26, 27 are used to align a portion of the belt 19 with one of a series of hoppers 25 having a conduit 24 leading to a storage bin 23. Each storage bin 23 discharges through a valve 28 on to a surface 29 aligned with an aperture 30 in the melting furnace 31, a charging ram 32 being used to move the batch into the furnace. As indicated in dotted and full lines, the colouring materials may be added when the batch is on the conveyer 15, the conveyer 19 or the surface 29, from a feeding mechanism 40 comprising a hopper 41 and feeder 42. The amount of colouring material added may be metered mechanically or electronically and preferably a diluent such as sand is added to give more accurate control. The colourless base batch preferably has the following ingredients in percentages by weight: SiO 2 60-75; Al 2 O 3 0.3-10; CaO + MgO 6-15; Na 2 O 12-18; K 2 O 0-5 and BaO 0-5. Colouring materials suggested are as follows: C; Rare earths oxides, particularly Ce with or without Nd or Pd; Chromates; Co oxides; Cu oxides; Fe oxide or chromite; Mn oxide; Ni oxides; Se oxides or Selenides; Ag nitrate; S or as Fe or Cd sulphides. A number of examples are given, for green glasses, containing a mixture of oxides of Fe, Cr, Co and some with in addition Ni.