| 摘要 |
Compositions from 25% to 65% of a synthetic rubber block copolymer and from 75% to 35% plasticizer by weight are heated and mixed and applied, usually with a curing agent, to the lid or cover of a container such as a drum or pail. The application may take place while the lid or cover is revolved and the heated mixture is flowed on. The synthetic rubbers may be of the groups comprising SBS rubber, SIS rubber, S-EB-S rubber. The plasticizer may be from the group comprising paraffin, oils or waxes, polyethylene, polypropylene or ethyl vinyl alcohol. Apparatus is also shown and described for implementing the application of the compositions to the lid or cover as it is revolved. If a groove is formed in the cover before reception of the composition, the apparatus extrudes or flows it into the groove and then the flowed-in material is permitted to set.
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