| 摘要 |
<p>Plastics, glass or similar vessels are closed and sealed by first applying a cold sealing material onto the rim, and then placing onto this a covering foil precoated on its side towards the rim with a cold sealing mass; the foil is then briefly pressed onto the rim. The preferred sealing mass is an aq. dispersion, subsequently dried. The foil may be of aluminium 30-60 (40) microns thick, or an aluminium band 9-20 micron thick coated on its rear face with paper 30-60 (50) microns thick. Alternatively, the foil may be PVC or polyethylene, esp. a polyethylene foil with a polyvinylidene chloride facing on one side. The method is partic. suitable for glass and plastic beakers and enables the closure to be carried out at a high prodn. rate.</p> |
