GB1175993A - Packaging Articles. - Google Patents

Abstract

1,175,993. Coating apparatus. EASTMAN KODAK CO. 2 March, 1967 [2 March, 1966], No. 9980/67. Heading B2L. [Also in Division B8] A curtain coating method of packaging articles 1 on a substrate 2 comprises forming a coatable assembly of at least one article superposed on an air-permeable substrate 2 positioned on a receiving member 3 on a horizontally rotatable support means 29 adapted to provide a vacuum to the underneath surface of the substrate 2, reducing the air pressure beneath the substrate sufficiently to produce enough suction at the upper surface of the substrate to assist in immobilising the article, indexing the coatable assembly to a curtain coating station, moving a falling curtain 8 of a viscous molten thermoplastic coating composition over the coatable assembly to cover the exposed upwardly and outwardly facing surfaces of the substrate and the articles thereon with a shape conforming film, indexing the coated assembly out of the coating station and maintaining at least a portion of the reduced air pressure underneath the substrate until the film solidifies. The reduced air pressure is provided from vacuum tank 26 through passageways 28, 37, 38 and interior conduits in the arms 24. In the arrangement shown there are four identical arms 24 each with a receiving member 3 at one end and secured at the other end to the support bearing 29. The support 29 is rotatable so that the members 3 pass through, in succession, a station at which the substrate 2 is placed on the member 3, a station at which the articles are placed on the substrate, a coating station and an unloading station. Any other suitable number of stations with a corresponding member of arms may however be provided. At the coating station, a curtain 8 of molten thermoplastic material is extruded from a die orifice 7 in an overhead reciprocating die 5. The material is supplied to the die 5 by an extruder 14 which converts solid material fed in at hopper 5 into a molten mass of proper consistency in reservoir 13. Coating material not used is collected in collector 16 and returned to reservoir 13 via pump 18. The die 5 is moved at such a speed as to cause the curtain 8 to trail behind and to form a contact angle 22 with the substrate of not greater than 45‹ and preferably not greater than about 30‹.