| abstract |
This invention relates to the lamination of large glass sheets using plasticized interlayer material without the use of autoclaves. Excess liquid plasticizer is applied to the major surfaces of a sheet of plasticized interlayer material to soak the major surfaces at room temperature for sufficient soaking time to soften the surfaces so that the interlayer becomes more amenable to adhesion to glass sheets, but insufficient time to normalize the plasticizer content throughout the thickness of the plasticized sheet. The interlayer sheet is assembled between a pair of glass sheets and the excess plasticizer is removed by compressing the assembly before the soaking time is excessive and the plasticizer concentration can normalize throughout the thickness of the plasticized interlayer sheet. With the excess liquid plasticizer at the interfacial surfaces only, the assembly is subjected to a temperature range above room temperature and below the temperature at which the plasticizer develops a volatile product and a superatmospheric pressure not more than two atmospheres. This removes excess plasticizer from the interfacial surfaces so as to limit the increase in normalized plasticizer content and also permits the sheets to be laminated to one another. |