Process for forming expanded laminates and products

• US 3,919,445 A
• Filed: 12/26/1973
• Issued: 11/11/1975
• Est. Priority Date: 12/29/1971
• Status: Expired due to Term

• Current Assignee: Walter H. Smarook
• Original Assignee: Walter H. Smarook
• Inventors: Smarook, Walter H.
• Primary Examiner(s): Anderson, Philip
• Application Number:
  US05/427,502
• Time in Patent Office: 685 Days
• Field of Search: 264/41,47,164,291,21R,261,275,346 425/812,110 65/DIG.5,59 161/68,69 168/161
• US Class Current: 428/116
• CPC Class Codes: B29C 67/00 Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
• CPC Class Codes: B29C 67/0011 for shaping plates or sheets
• CPC Class Codes: B29D 24/005 the structure having joined ribs, e.g. honeycomb
• CPC Class Codes: B29D 99/0089 Producing honeycomb structures consisting of porous ceramic ware C04B38/0006
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 2038/0088 Expanding, swelling
• CPC Class Codes: B32B 2307/738 Thermoformability
• CPC Class Codes: B32B 3/12 characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure
• CPC Class Codes: Y10S 425/812 Venting
• CPC Class Codes: Y10T 428/24149 Honeycomb-like
• CPC Class Codes: Y10T 428/24174 including sheet or component perpendicular to plane of web or sheet
• CPC Class Codes: Y10T 428/24298 Noncircular aperture [e.g., slit, diamond, rectangular, etc.]
• CPC Class Codes: Y10T 428/24322 Composite web or sheet

Abstract

A low pressure process for preparing laminates by expanding the cross-section of a blank of thermoformable material between mold plates serving as skin laminae with the attendant formation of one or more voids having a partial vacuum or reduced pressure within the cross-section of such blank, which comprises venting the voids during the expansion of the cross-section so as to equilibrate the level of pressure within the voids with the level of pressure without the blank of thermoformable material so as to thereby regulate the uniformity and integrity of the resulting cross-sectional geometry of the expanded blank which serves as the core lamina of the resulting laminate. Laminate products having an expanded cross-section are formed by such process.

Claims

1. A PROCESS FOR PREPARING A LAMINATE FROM A THERMOFORMABLE MATERIAL HAVING A TA AND A PAIR OF MOLD PLATES HAVING A TA HIGHER THAN THAT OF SAID THERMOFORMABLE MATERIAL WHICH COMPRISES POSITIONING SAID THERMOFORMABLE MATERIAL BETWEEN SAID MOLD PLATES WHILE SAID THERMOFORMABLE MATERIAL IS HEATED TO A TEMPERATURE WHICH IS $ THE TA OF SAID THERMOFORMABLE MATERIAL AND AT WHICH TEMPERATURE SAID THERMOFORMABLE MATERIAL IS IN A THERMOFORMABLE STATE ADHESIVELY BONDING SAID THERMOFORMABLE MATERIAL BY HOT TACK ADHESION TO SAID MOLD PLATES PULLING SAID MOLD PLATES APART, WHILE SAID THERMOFORMABLE MATERIAL IS THUS ADHESIVELY BONDED THERETO AND IS IN SAID THERMOFORMABLE STATE, SO AS TO THEREBY EXPAND THE CROSS SECTION OF SAID THERMOFORMABLE MATERIAL AND EFFECT WITHIN SAID EXPANDING THERMOFORMABLE MATERIAL ONE OR MORE VOIDS HAVING A PARTIAL VACUUM THEREIN, VENTING SAID VOIDS DURING SAID PULLING APART SO AS TO EQUILIBRATE THE LOWER LEVEL OF PRESSURE WITHIN SAID VOIDS WITH THE HIGHER LEVEL OF AMBIENT PRESSURE WITHOUT SAID THERMOFORMABLE MATERIAL AND THEREBY REGULATE THE UNIFORMITY AND INTEGRITY OF THE GEOMETRY OF THE RESULTING EXPANDED CROSS SECTION OF SAID THERMOFORMABLE MATERIAL, AND COOLING THE EXPANDED THERMOFORMABLE MATERIAL TO A TEMPERATURE BELOW THE HEAT DISTORTION POINT OF SAID THERMOFORMABLE MATERIAL, SO AS TO THEREBY FORM A LAMINATE OF THE EXPANDED THERMOFORMABLE MATERIAL WITH AT LEAST ONE OF SAID MOLD PLATES.

2. A process as in claim 1 in which said thermoformable material comprises thermoplastic material.

3. A process as in claim 2 in which said thermoplastic material comprises synthetic resin.

4. A process as in claim 3 in which said synthetic resin comprises vinyl resin.

5. A process as in claim 4 in which said vinyl resin comprises ethylene polymer resin.

6. A process as in claim 5 in which said ethylene polymer resin is a homopolymer.

7. A process as in claim 5 in which said ethylene polymer resin is a copolymer.

8. A process as in claim 7 in which said copolymer is a copolymer of ethylene and ethyl acrylate.

9. A process as in claim 7 in which said copolymer is a copolymer of ethylene and vinyl acetate.

10. A process as in claim 3 in which said synthetic resin comprises urethane resin.

11. A process as in claim 3 in which said synthetic resin comprises polysulfone resin.

12. A process as in claim 3 in which said synthetic resin comprises silicone resin.

13. A process as in claim 3 in which at least one of said mold plates comprises metal.

14. A process as in claim 13 in both of said mold plates comprise metal.

15. A process as in claim 13 in which said metal comprises iron.

16. A process as in claim 13 in which said metal comprises aluminum.

17. A process as in claim 4 in which at least one of said mold plates comprises cellulosic material.

18. A process as in claim 17 in which said cellulosic material comprises cardboard.

19. A process as in claim 1 in which said venting is accomplished through at least one of said mold plates.

20. A process as in claim 19 in which said venting is accomplished through both of said mold plates.

21. A process as in claim 1 in which said venting is accomplished through said thermoformable material.

22. A laminate product of the process of claim 1.

23. A process as in claim 1 in which a laminate is formed from said expanded thermoformable material and one of said mold plates.

24. A process as in claim 1 in which a laminate is formed from said expanded thermoformable material and both of said mold plates.