| 摘要 |
The invention relates to a method of, and apparatus for, welding an element comprising paper to a thermoplastic material, without pre-treatment of the plastics material. In one described embodiment a laminate (12) comprising paper, with a vapour permeable, liquid impermeable coating on one major surface, was successfully welded to a polypropylene material (15) some 1.5 mm thick, the uncoated surface of the laminate forming the interface with the polypropylene, by subjecting the interface to conditions between two ranges of parameters, a temperature of 185 DEG C and a pressure of 460 kPa for a period of 10 seconds and a temperature of 220 DEG C and a pressure of 460 kPa for a period of 5 seconds. All the welds effected between said ranges of parameters produced an acceptable weld of the paper to the thermoplastics. |
