GLASSWARE COATING PROCESS

摘要

1424460 Composite coated containers: coating apparatus DART INDUSTRIES INC 20 July 1973 [24 July 1972] 34837/73 Headings B2E and B2L A process for manufacturing composite glass and plastics containers comprises heating a moulded glass container portion to 350 to 450‹C, coating an area of it with chemically adherent, resilient, thermoplastic polymer particles and fusing the particles to form a flexible resilient coating on the glass container portions. In a preferred process, glass bottles are preheated in an oven arranged in ranks on a conveyor (Fig. 1, not shown), then rearranged into single file onto a further conveyor 22. A screw feeder 24 feeds bottles to a transfer tractor belt device 26 which conveys the bottles through an electrostatic spray booth 12 having apertures 54 providing access spray guns and which is cleaned by a plurality of vacuum stations 38, 40, 42, 44. A fluidised bed 48 feeds the spray guns and also receives excess particles through an aperture in the floor of the booth 12. The bottles are then heated in an oven and cooled by forced draught. Several pairs of spray guns may be provided in the spray booth, the guns at each pair being directed to one another from opposite sides of the booth, and the sprays from the guns being segregated by an air curtain to facilitate multiple coating of the bottles. It is stated that a precoat of an emulsion or solution of thermoplastics polymer may be applied. Once the bottles have cooled after sintering the coating may be provided with a lubrication layer of a wax composition, or alternatively the coating is subjected to flame treatment to facilitate application of labels. Preferred coatings are ethylene homopolymers and copolymers with acylic acid, methacrylic acid, ethacrylic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, vinyl sulphonic acid, maleic anhydride, mono-methyl maleate, mono-ethyl maleate, mono-ethyl fumarate, and mono-ethyl fumarate.