METHOD FOR LAMINATING PLASTIC TO GLASS EMPLOYING GLASS MOLD

• US 3,808,077 A
• Filed: 09/16/1971
• Issued: 04/30/1974
• Est. Priority Date: 09/16/1971
• Status: Expired due to Term

• Current Assignee: Joseph Chabal, Raymond G. Rieser
• Original Assignee: Joseph Chabal, Raymond G. Rieser
• Inventors: Rieser, Raymond G., Chabal, Joseph
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Kendell, Lorraine T.
• Application Number:
  US05/181,137
• Time in Patent Office: 957 Days
• Field of Search: 156/99,101,102,104,242,245,247,228,289,344,106 117/5.1,124F 161/190,199,192 264/331,338
• US Class Current: 156/102
• CPC Class Codes: B32B 17/10018 comprising only one glass sheet
• CPC Class Codes: B32B 17/10688 Adjustment of the adherence to the glass layers
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/1077 containing polyurethane
• CPC Class Codes: B32B 17/10853 the membrane being bag-shaped
• CPC Class Codes: B32B 17/10889 shaping the sheets, e.g. by using a mould B32B17/10816 takes precedence
• CPC Class Codes: B32B 17/10899 by introducing interlayers of synthetic resin
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/3163 Next to acetal of polymerized unsaturated alcohol [e.g., formal butyral, etc.]

Abstract

Fabricating a transparent, laminated window having an exposed sheet of plastic material softer than glass adhered to glass, such as a bilayer windshield consisting essentially of an outer glass sheet and an inner preformed sheet of polyurethane plastic produced by lamination under heat and pressure with the polyurethane sheet supported in pressurized engagement against a smooth surface of a mold, which is preferably a second glass sheet having a shape conforming to that of the glass sheet of the resulting laminated window. The windshield is fabricated by assembling a preformed plastic sheet between a glass sheet to be laminated thereto and the mold with a suitable parting material between the mold and the plastic sheet to facilitate separating the mold and the bilayer windshield readily after lamination is completed. The assembly is exposed to elevated heat and pressure to effect the lamination. Preferably, the mold has certain physical properties the same as the glass sheet to be laminated so as to minimize optical distortion of the preformed plastic during lamination.

Claims

2. A method As in claim 1, wherein said glass sheet to be laminated to said preformed sheet is in turn laminated to an additional transparent sheet disposed on the side opposite that assembled facing said preformed sheet.

3. A method as in claim 1, wherein said preformed sheet is a polyurethane.

4. A method as in claim 3, wherein an adhesive is applied to at least one interfacial surface between said preformed sheet and said glass sheet.

5. A method as in claim 1, wherein said mold and said glass sheet of said assembly have curved surfaces of matching configuration.

6. A method as in claim 5, wherein said glass sheet to be laminated is preshaped to a shape desired for said laminated curved window and has a convex surface and a concave surface and said preformed plastic sheet is assembled against said concave surface.

7. A method as in claim 1, wherein an adhesive is applied to at least one interfacial surface between said preformed sheet and said glass sheet to be laminated thereto.

8. A method as in claim 7, further including the step of removing air that may be entrapped in the interfaces of said assembly before said pressure subjection step.

9. A method as in claim 1, wherein said preformed sheet is polyvinyl butyral and said parting material becomes adherent to said preformed sheet under the elevated temperature and pressure conditions existing during said subjecting step, whereupon said parting material separates from said mold with said preformed sheet and said glass sheet.

10. A method as in claim 1, further including the step of removing air that may be entrapped in the interfaces of said assembly before said pressure subjection step.

11. A method of making a transparent, laminated window comprising a smoothly surfaced layer of polyurethane laminated to a sheet of glass comprising:

a. assembling a preformed sheet of polyurethane having approximately uniform thickness between 1 mil and 100 mils throughout its entire extent in aligned relation to a glass sheet having approximately uniform thickness between 50 mils and 250 mils to be laminated to said preformed polyurethane sheet to form a sub-assembly, b. assembling a glass mold more rigid than said preformed sheet throughout the temperature cycle associated with laminating and having a smooth, rigid surface that conforms to the shape of said glass sheet to be laminated and having physical properties compatible with those of said glass sheet throughout said temperature cycle in aligned relation to said polyurethane sheet with parting material that is separable from at least one of said mold and said preformed sheet interposed between said mold and said polyurethane sheet to form an assembly in which said smooth, rigid surface is positioned to apply pressure against said polyurethane sheet, c. maintaining said assembly in said assembled relationship while subjecting said assembly to elevated pressure of more than 50 pounds per square inch and an elevated temperature of approximately 200* to 400* F. for sufficient time to laminate said polyurethane sheet to said glass sheet and to develop a surface in said polyurethane sheet that reproduces said smooth, rigid surface, d. reducing said pressure and temperature applied to said assembly, and e. separating said polyurethane sheet with said glass sheet laminated thereto from said mold to form a transparent laminate having said surface in said polyurethane sheet a reproduction of said smooth, rigid surface.

12. A method as in claim 11, wherein said glass sheet is curved and has a convex surface and a concave surface and said preformed polyurethane sheet is assembled in aligned relation to said concave surface of said glass sheet to form said sub-assembly, whereby said glass sheet and said preformed polyurethane sheet are laminated to form a transparent, laminated window having a convex surface of glass and a concave surface of polyurethane.

13. A method as in claim 11, wherein aN adhesive is applied to at least one interfacial surface between said glass sheet and said preformed polyurethane sheet prior to assembling said sub-assembly.

14. A method as in claim 11, further including the step of removing air that may be entrapped in the interfaces of said assembly before said pressure subjection step.