| 摘要 |
<p>The present invention is directed to a method and apparatus for providing raw edge protection on the edge (12) of a paper laminate (10) such as a polyethylene-paper-polyethylene-aluminum foil-polyethylene laminate (14, 16, 18,20,22). Such laminates are useful in forming paperboard containers for foodstuffs or other products which are to be protected against the entry of moisture, bacteria, or other contaminants. According to the method and apparatus of this invention, a laser beam is employed to burn away the exposed edge of the paperboard layer of the laminate as it moves relative to the laser beam. After removal of a strip of the paperboard from an edge of the laminate, the remaining areas of the laminate (40,42) are pressed together and sealed as by the application of heat. In a modified method, a polyethylene powder stream, or a polyethylene filament, is continuously melted and flows over the remaining edge (44) of the paperboard, to thus seal it. The invention may be applied to a continuous web or single blank of the paper laminate.</p> |
