Method and apparatus for selective lamination of thermoplastic layers

• US 4,356,052 A
• Filed: 04/10/1981
• Issued: 10/26/1982
• Est. Priority Date: 01/12/1979
• Status: Expired due to Term

• Current Assignee: Hoechst Aktiengesellschaft (Sanofi )
• Original Assignee: Hoechst Aktiengesellschaft (Sanofi )
• Inventors: Moraw, Roland, Schadlich, Renate
• Primary Examiner(s): Wityshyn, Michael G.
• Application Number:
  US06/253,019
• Time in Patent Office: 564 Days
• Field of Search: 156/108, 156/282, 156/308.4, 156/498, 156/581, 156/583.4, 156/583.1, 156/583.2, 156/583.7, 156/583.9, 156/219, 156/514, 283/7, 40/2.2, 219/243, 100/93 P
• US Class Current: 156/498
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/30 Electrical means B29C65/38 takes precedence
• CPC Class Codes: B29C 66/3472 in the plane of the joint, e.g. along the joint line in the plane of the joint or perpendicular to the joint line in the plane of the joint
• CPC Class Codes: B29C 66/45 Joining of substantially the whole surface of the articles methods or apparatus for laminating B32B37/00
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/80 General aspects of machine operations or constructions and parts thereof
• CPC Class Codes: B29C 66/81261 Thermal properties, e.g. thermal conductivity, thermal expansion coefficient
• CPC Class Codes: B29C 66/8181 characterised by the cooling constructional aspects
• CPC Class Codes: B29C 66/81811 of the welding jaws
• CPC Class Codes: B29C 66/81821 of the welding jaws
• CPC Class Codes: B29C 66/8322 Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/91212 involving measurement means being part of the welding jaws, e.g. integrated in the welding jaws
• CPC Class Codes: B29C 66/91231 of the joining tool
• CPC Class Codes: B29C 66/91421 of the joining tools
• CPC Class Codes: B29C 66/91651 by controlling or regulating the heat generated by Joule heating or induction heating
• CPC Class Codes: B29K 2027/06 PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29L 2017/00 Carriers for sound or information
• CPC Class Codes: B32B 2425/00 Cards, e.g. identity cards, credit cards
• CPC Class Codes: B32B 37/06 : characterised by the heating method
• CPC Class Codes: B32B 37/065 : resulting in the laminate being partially bonded B32B37/0076 takes precedence
• CPC Class Codes: B32B 37/1045 : Intermittent pressing, e.g. by oscillating or reciprocating motion of the pressing means B32B37/0076 takes precedence
• CPC Class Codes: B32B 37/185 : Laminating sheets, panels or inserts between two discrete plastic layers
• CPC Class Codes: B32B 38/06 : Embossing
• CPC Class Codes: B42D 2033/04 : Transparent material
• CPC Class Codes: B42D 2033/22 : Perforated or incised material
• CPC Class Codes: B42D 2033/28 : Paper or card board
• CPC Class Codes: B42D 2035/02 : Nature of the markings
• CPC Class Codes: B42D 2035/08 : Alphanumerical data
• CPC Class Codes: B42D 2035/44 : Miniaturised markings
• CPC Class Codes: B42D 25/309 : Photographs
• CPC Class Codes: B42D 25/328 : Diffraction gratings; Holograms
• CPC Class Codes: B42D 25/455 : using heat
• CPC Class Codes: B42D 25/46 : using pressure
• CPC Class Codes: Y10T 156/1039 : Surface deformation only of sandwich or lamina [e.g., embossed panels]
• CPC Class Codes: Y10T 156/1309 : and securing separate part over hole or aperture
• CPC Class Codes: Y10T 428/24802 : Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24868 : Translucent outer layer

Abstract

Disclosed is a method and apparatus to facilitate the method of discontinuously laminating at least two thermoplastic layers together. The layers are heated and pressed together over all but a selected window portion of the layers to facilitate lamination between the layers at all points except the selected window portions. Relief grid images can be embossed in the selected window portion or holograms or other difficult to forge inserts can be provided in these window areas prior to lamination. During lamination, the reduced or absence of heating in these window portions permits lamination of the card without destruction of the selected window portion insert.

Claims

1. An apparatus for the selective lamination of thermoplastic layers by heating and pressurizing the internal surfaces of at least two thermoplastic layers, at least one of said layers including one window portion in which at least one insert is located, said lamination not occurring in said window portion, said apparatus comprising:

first and second lamination plates, each of said plates defining an opening corresponding to the window portion of said at least one layer;

a plug inserted in said opening of each plate;

means for thermally insulating said plugs from said plates;

means for discontinuously heating said first and second laminating plates, including resistance elements placed in said plates, said resistance elements having a greater packing density in the vicinity of the opening in each plate than in other areas of each plate; and

means for pressing said plates together with said at least two thermoplastic layers therebetween, whereby said discontinuous heating means heats external surfaces of said layers less at said window portion than at the remainder of said layers.

2. The laminating apparatus according to claim 1, wherein said insulating means comprises polyfluoroethylene having a thickness of from 0.5 to 2 mm.

3. The laminating apparatus according to claim 2, wherein said plug is comprised of a material having relatively good thermoconductivity and includes means for reducing the temperature of said plug, said temperature reducing means comprising a system of channels through which a cooling agent flows.

4. The laminating apparatus according to claim 3 wherein said cooling agent is carbon dioxide gas.

5. The laminating apparatus according to claim 1, wherein said plug comprises a removable pressure resistant material of low thermoconductivity.

6. The laminating apparatus according to claim 1, wherein said plug is recessed within said opening in said plate by an amount of from 20 μ

m to 150 μ

m.

7. The laminating apparatus according to claim 1 wherein said discontinuously heating means comprises a laminar resistance layer in each of said laminating plates, each of said layers extending over the laminating plate, said laminar heating layer including means defining an opening in said layer, said opening in said layer coincident with said opening in each of said plates.

8. The laminating apparatus according to claim 7, further including an insulating layer interposed between each of said laminar heating layers and said laminating plates.

9. The laminating apparatus according to claim 1 wherein at least one of said laminating plates includes means for providing at least a portion of one of said external surfaces with a textured surface.

10. The laminating apparatus according to claim 9, wherein said textured surface means further includes means for providing a given geometric arrangement in said textured surface.