Improvements in or relating to the manufacture of pots, cartons, and like receptacles of paper, cardboard, and the like

摘要

To render paper &c. cartons and the like o the kind consisting of a rolled blank provided with channelled metal end closures engaging over the beaded or plain ends of the tapered or cylindrical body portion, suitable for containing oils or fatty substances, the body portions 1, Figs. 3, 4, are treated interiorly or exteriorly or both with a proofing 10 of casein hardened with formalin and containing glycerine, the exterior being sometimes further proofed with thin sheet aluminium &c. and the joints within the channels of one or both of the end closures 3, 4 are sealed by means of tar pitch or asphalt 22, the p longitudinal seam of the body being also if desired treated with this substance. The pitch or asphalt is applied to the end or ends of the carton body by means of the apparatus shown in Fig. 5. The pitch &c. contained in a supply tank 23 and maintained molten by means of an electric immersion heater, is delivered as required on to an absorbent felt &c. pad 26 disposed within a ring 27 containing an electrical heating element, the ring being connected by a forked lever 29 with cam or other means for raising and lowering the pad in applying the coating to the ends of the bodies. The carton bodies are held in ring members or dies 30 of which five may be provided, rotatable about their own axes and also about a central axis. In the manufacturing operation the members 30 assume in turn positions in which (1) the bodies are inserted in the machine; (2) the sealing material 22 is applied to the ends; (3) the bases 4 are fitted; (4) the bases are clinched to the bodies, the beads 2 being formed simultaneously at the upper ends; and (5) the cartons are ejected from the machine. The casein &c. proofing may be applied to the material of the carton body before manufacture, but is preferably applied to the formed body, the apparatus shown in Fig. 6 being used for proofing the interior. In this the placing of the carton 1 in position causes levers 12, 13 to operate a valve 14 enabling the proofing liquid to flow from the supply tank 16 to the spraying nozzle 11; removal of the treated carton again operates the valve to direct the liquid through a pipe 21 into a sump from which it is returned to the supply tank by the action of a pump 18.