| 摘要 |
In wound, preferably cylindrical paper containers, reinforcing rings of a synthetic plastic material are applied to the upper and possibly to the lower cut edges and joined by welding with the jacket. In order to insure that the core of the ring remains cold during welding and only the surface becomes liquid, thin-walled projections are provided in locations of the ring where welding is desired and are rendered flowable immediately prior to the placing of the ring on the jacket. Thus, the ring retains its structural integrity while being rendered weldable.
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