Sealed closure method for plastic containers partly filled with fluid involves pre-compression of container, welding of cover onto container funnel and releasing external pressure to allow container to recover

摘要

The plastic container is slightly compressed to increase internal pressure and a cover preform(12) is welded(20) onto a closure funnel(10) of the container. Only when welding is complete is the container allowed to return to its non-deformed condition. The method is particularly suited to containers described as cooling accumulators containing salt solution.