| 摘要 |
<p>PURPOSE:To sufficiently improve the bonding strength of a sheet to a film in a laminate by a method in which when a thermoplastic film is laminated on the sheet having higher melting point than that of the film, the film and the sheet are mutually welded under heating at the temperature between the softening point and the melting point of the film, and then said film and sheet are heated at the temperature higher than the melting point of the film and equal to or lower than the melting point of the sheet under stationary condition. CONSTITUTION:A film and a sheet are heated preliminarily at the temperature between the softening point and the melting point of the film and are welded under heating, whereby a temporarily bonded laminate is obtained. Next, this laminate is heated at the temperature higher than the melting point of the film and equal to or lower than the melting point of the sheet under stationary condition, and then the film and sheet are mutually welded perfectly. As the upper limit of heating temperature, the temperature at which the molten film does not flow out at liquid state, is preferable. Since the heating is carried out under stationary condition, the breakage in molten state or the adhesion on a roll of the thermoplastic film due to the heat of the roll, does not occur.</p> |
