| 摘要 |
A composite pilfer-apparent closure system comprising in combination a moulded plastics container (1) and a screw-threaded moulded plastics cap. An intermediate member (18) preferably an annular metallic ring coated with a thermoplastic film on its upper end lower surfaces is interposed between the said container and cap and is retained in pressure contact with each under the action of the engaging screw threads (2). This composite assembly is rendered pilfer-apparent by the action of an externally applied alternating magnetic field which causes a rapid temperature rise in the metal ring thereby softening the aforementioned plastics film to the point where the bonds or welds are formed with both the closure and the container at the points of pressure contact (W1 and W2). This locks the closure securely to the container through the intermediate member thus rendering the pack unopenable until the pilfer-apparent band (15) is removed in the normal way. Normal unscrewing of the cap brings fingers (20) into contact with shoulder (6) on a tangibly connected top section (4) of the container (1). Continued unscrewing separates the top section from the container thereby exposing the product. The removable top section (4) is retained within the cap by the fingers. A vital aspect of this composite system is the high degree of sterility provided by the bonds (W1) and (W2) which effectively seal the top section of the container preventing ingress of contaminants, bacteria etc. up to the point of use. Bonding in this manner is described in conjunction with a variety of closure types. <IMAGE> |
