| 摘要 |
<p>1376502 Moulding boxes AIRFIX INDUSTRIES Ltd 2 Jan 1973 [21 Jan 1972] 2992/72 Heading B5A [Also in Division B8] A container having inner and outer walls formed from a composite blank is made by inserting the blank into a mould 10, positioning a core tool 11 therein and joining the adjacent wall edges by injection moulding. The inner wall is then spaced from the outer wall by vacuum forming, blow moulding or a combination of both these methods. The blank is formed in a combined cutting and welding unit 6 in which the outer wall which may be paper, card or synthetic plastics foil and the inner wall which is of synthetic plastics sheet are fed from reels 7, 8 through guides 7a, 8a to the forming tool. When the tools 10, 11 are brought together material injected at 13, 14 seams together adjacent edges of the blank and a cavity 16 gives rise to a base rim on the container and a channel 19 forms a lip on the container mouth. A stripper plate 9 is provided. The inner wall is heated by the inherent heat of the tool or by heater elements therein either before, after and/or during the injection moulding operation. Formation of the inner wall occurs at a suitable moment either by injecting gas between the inner and outer walls through a hole at G formed by the cutting and welding unit 6 so that the inner wall conforms to the shape of the core tool or by applying a vacuum to passages 24 or by a combination of these methods. The material of the outer wall is chosen so that it withstands the heat necessary to form the inner wall.</p> |
