| 摘要 |
<p>A multiple layer sheet structure (10) suitable for making tubular squeeze containers, such as for dentifrice, incorporates a uniaxially oriented polymeric e.g. polypropylene layer (16) within 0.2 to 4 mils (0.005 to 0.10 mm) of a surface of the structure destined to be the exterior of the container, the said polymer layer (16) conveniently being coextruded with low density polyethylene (12), and an intervening adhesive polymer (14) to form a three layer coextruded film substructure. The substructure is then uniaxially oriented at a stretch ratio of 2/1 to 6/1 or 3/1 to 8/1 depending on the said polymer, and then laminated to the other layers (18 to 30) of the multiple layer structure, the low density polyethylene layer (12) forming one of the exterior surfaces of the sheet structure. Lap-seamed tubes are formed from the sheet structure with the uniaxially oriented layers (12 to 16) at the outer surface of the tube, and with the direction of orientation running either along the length of the tube or peripherally around the tube.</p> |
