| 摘要 |
Apparatus and method for forming sealed joints, including a pouring lip sanitarily protected therein, by welding layers of thermoplastic coated paperboard together. Paperboard layers are pressed together by jaws, with relieved areas where excessive pressure would render pouring lip less satisfactory, while or after heat is applied to said paperboard layers. The apparatus and method is particularly useful for forming sealed joints for paperboard cartons, such as milk cartons.
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