| 摘要 |
<p>Combination physical and tamper-proof seal for the mouth of a container accepting a threaded cap is produced by using a crosslinkable cellular adhesive to fix a loose lining within the cap to the rim of the mouth of the container. Expansion of the adhesive during setting ensures an effective interfacial seal and also generates a slight vacuum within the container to help hold the cover in place. The materials are chosen so that when the cover is initially peeled off for access to the contents, the adhesive remains preferentially with the lining, to leave the rim of the container mouth clean and smooth. Having cured after applicn., the adhesive is not reuseable, thus indicating previous access. Esp. applicable to containers for cosmetics, etc. Pref. the expandable adhesive is based on a polyurethane resin. The example refers to use of a glass container with a cap having a double liner - a stiff one of e.g. card and thin film of a 'polyester/polyethylene combination' to be secured by a bead of adhesive applied around the rim of the mouth of the container.</p> |
