| 摘要 |
1,224,959. Coating can seams; coating apparatus. CONTINENTAL CAN CO. Inc. 22 Sept., 1969 [3 Oct., 1968], No. 46584/69. Headings B2E and B2L. A method of coating the side seam of a can while hot with a stripe of predetermined width comprises exposing the seam through a mask, electrically earthing the can, charging fluidised coating powder electrostatically and blowing the charged powder, which may be pigmented, towards the hot can seam. Apparatus for effecting the process comprises a belt 1 supported by pulleys 2 for feeding axially spaced cans past a coating station, the belt having equi-spaced lengthwise slots 4 into which the side seams of the cans fit and bridges 5 between the slots to effect masking of the can ends, a nozzle 6 for projecting powdered coating material generally parallel to the direction of motion of the cans, corona charging pins or plate 8 for electrostatically charging the powder particles, and means E for earthing the can so that the charged coating powder is attracted to the can to coat the seam. After leaving the belt, the coated can seam may be heated to fuse the coating. Excess powder may be removed from the area of the nozzle and charging pins by a port 9 connected to a vacuum source and any powder adhering to the endless belt may be removed by means of brushes 13. The belt may be of nylon or PTFE-impregnated glass fibre. Other charging means such as arcs, sparks or radiation may be used in place of the corona discharge pins. |
