| 摘要 |
A process and apparatus for sealing plies of thermoplastic material included in laminated sheets having thickened sections in a manner such that strong side seals result with substantially no delamination of one or more plies of a laminated sheet comprises performing a first blocking operation on the laminated sheets by application of heat and pressure through a first pair of seal bars having an effectively matched cross-section such that the laminated sheets remain substantially planar during the first blocking operation. A second blocking operation is performed over the previously blocked areas by the application of heat and a soft pressure through a second pair of seal bars having an effectively matched cross section such that the laminated sheets remain substantially planar during the second blocking operation. Finally, a cooling blocking operation is performed over the previously blocked areas by the pressure application of a pair of cooling bars having an effectively matched cross section such that the laminated sheets are maintained substantially planar during the cooling blocking operation. The first blocking operation is preferably performed at a temperature ranging from 140 to 175.degree.C. |
