Method for joining thermoplastic polymer material

• US 9,296,185 B2
• Filed: 04/19/2011
• Issued: 03/29/2016
• Est. Priority Date: 04/19/2010
• Status: Active Grant

• Current Assignee: Dart Container Corporation (Robert Charles Dart), University of Washington
• Original Assignee: Dart Container Corporation (Robert Charles Dart), University of Washington
• Inventors: Nadella, Krishna, Wang, Xiaoxi, Kumar, Vipin
• Primary Examiner(s): DODDS, SCOTT
• Application Number:
  US13/640,665
• Publication Number:
  US 20130032289A1
• Time in Patent Office: 1,806 Days
• Field of Search: 156/77, 156/78, 156/309.6
• US Class Current: 1/1
• CPC Class Codes: B29C 44/06 Making multilayered articles B29C44/0407 - B29C44/0492 take precedence
• CPC Class Codes: B29C 65/10 using hot gases (e.g. combustion gases) or flames coming in contact with at least one of the parts to be joined
• CPC Class Codes: B29C 65/1412 Infrared [IR] radiation
• CPC Class Codes: B29C 65/203 being several single mirrors, e.g. not mounted on the same tool
• CPC Class Codes: B29C 65/30 Electrical means B29C65/38 takes precedence
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/8253 by the use of waves or particle radiation, e.g. visual examination, scanning electron microscopy, or X-rays B29C65/8292 takes precedence
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• 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 66/727 being porous, e.g. foam
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/8264 using the thermal expansion of the parts to be joined
• CPC Class Codes: B29C 66/83413 cooperating rollers, cylinders or drums
• CPC Class Codes: B29C 66/9292 in explicit relation to another variable, e.g. pressure diagrams
• CPC Class Codes: B29K 2067/003 PET, i.e. poylethylene terephthalate
• CPC Class Codes: B29K 2105/041 Microporous
• CPC Class Codes: B29K 2105/043 Skinned foam
• CPC Class Codes: B29K 2105/046 with closed cells
• CPC Class Codes: B29L 2031/776 Walls, e.g. building panels
• CPC Class Codes: B32B 2038/0084 : Foaming
• CPC Class Codes: B32B 2250/22 : All layers being foamed
• CPC Class Codes: B32B 2266/08 : Closed cell foam
• CPC Class Codes: B32B 2305/022 : Foam
• CPC Class Codes: B32B 2307/54 : Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/542 : Shear strength
• CPC Class Codes: B32B 2307/546 : Flexural strength; Flexion stiffness
• CPC Class Codes: B32B 2307/732 : Dimensional properties
• CPC Class Codes: B32B 2307/734 : Dimensional stability
• CPC Class Codes: B32B 2309/04 : Time
• CPC Class Codes: B32B 2309/105 : Thickness
• CPC Class Codes: B32B 2309/12 : Pressure
• CPC Class Codes: B32B 2367/00 : Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2419/04 : Tiles for floors or walls tiles for roofs B32B2419/06
• CPC Class Codes: B32B 2451/00 : Decorative or ornamental articles wall paper B32B2607/02
• CPC Class Codes: B32B 2607/00 : Walls, panels
• CPC Class Codes: B32B 27/065 : of foam
• CPC Class Codes: B32B 27/302 : comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 27/304 : comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: B32B 27/32 : comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/36 : comprising polyesters
• CPC Class Codes: B32B 27/365 : comprising polycarbonates
• CPC Class Codes: B32B 37/04 : characterised by the partial melting of at least one layer
• CPC Class Codes: B32B 37/12 : characterised by using adhesives
• CPC Class Codes: B32B 37/203 : One or more of the layers being plastic
• CPC Class Codes: B32B 5/18 : characterised by features of a layer of foamed material
• CPC Class Codes: B32B 7/04 : Interconnection of layers
• CPC Class Codes: B32B 7/12 : using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10T 156/10 : Methods of surface bonding and/or assembly therefor

Abstract

A method for joining two components includes positioning a thermoplastic polymer portion of a first component adjacent a thermoplastic polymer portion of a second component such that the first and second portions form an interface. At least one of the portions includes a microstructure having a plurality of closed cells, each cell containing a void and each cell having a maximum dimension extending across the void. The method also includes exerting pressure on the thermoplastic polymer portions to form a bond at the interface that holds the portions together. The plurality of closed cells, and especially those adjacent the surface of the thermoplastic polymer portion that form the interface, help isolate thermally and/or chemically the surface from the remainder of the portion.

Claims

1. A method for joining two components, the method comprising:

positioning a thermoplastic polymer portion of a first component adjacent a thermoplastic polymer portion of a second component such that the first and second portions form an interface, wherein at least one of the portions includes a microstructure having a plurality of closed cells, each cell containing a void and each cell having a maximum dimension extending across the void within the cell that ranges between 1 micrometer and 200 micrometers long and wherein a plurality of the cells has a temperature equal to ambient temperature and includes gas in their respective voids in an amount sufficient to exert pressure on the microstructure; and

after positioning the polymer portion, exerting pressure on the exterior of the thermoplastic polymer portions to form a bond at the interface that holds the portions together, wherein the positioning and exerting the pressure occurs before the gas in the voids equalizes with the surrounding environment such that the pressure from the gas in the voids helps the microstructure resist the pressure exerted on the thermoplastic polymer portions.

2. The method of claim 1 wherein the plurality of closed cells each has a maximum dimension that ranges between 1 micrometer and 50 micrometers.

3. The method of claim 1 wherein at least one of the thermoplastic polymer portions includes a skin having a surface that defines an exterior surface of the portion and that forms the interface with the other thermoplastic polymer portion.

4. The method of claim 1 wherein the at least one thermoplastic polymer portion that includes the microstructure that has a plurality of closed cells, also includes a skin having a surface that defines an exterior surface of the portion and that forms the interface with the other thermoplastic polymer portion.

5. The method of claim 1 wherein the thermoplastic polymer portion of the first component and the thermoplastic polymer portion of the second component each includes:

a microstructure having a plurality of closed cells, each cell containing a void and each cell having a maximum dimension extending across the void within the cell that ranges between 1 micrometer and 200 micrometers long, and

a skin having a surface that defines an exterior surface of the thermoplastic polymer portion and that forms the interface with the surface of the other thermoplastic polymer portion'"'"'s skin.

6. The method of claim 1 wherein while pressure is exerted on the thermoplastic polymer portions to form a bond at the interface, the pressure inside each cell is equal to or greater than the pressure exerted on the thermoplastic polymer portions.

7. The method of claim 1 further comprising continually moving the first component'"'"'s thermoplastic polymer portion and the second component'"'"'s thermoplastic polymer portion in substantially the same direction while the thermoplastic polymer portions are positioned and pressure is exerted to form the bond.

8. The method of claim 1 wherein the pressure exerted on the thermoplastic polymer portions cause the portions to fuse at the interface.

9. The method of claim 1 further comprising heating a surface of at least one of the thermoplastic polymer portions, which forms the interface, to a temperature close to the surface'"'"'s melting temperature, without causing a remainder of the portion to melt, before exerting pressure on the thermoplastic polymer portion.

10. The method of claim 1:

wherein the thermoplastic polymer portion of the first component and the thermoplastic polymer portion of the second component each includes;

a microstructure having a plurality of closed cells, each cell containing a void and each cell having a maximum dimension extending across the void within the cell that ranges between 1 micrometer and 200 micrometers long, and

a skin having a surface that defines an exterior surface of the thermoplastic portion and that forms the interface with the surface of the other thermoplastic portion'"'"'s skin; and

further comprising heating each surface to a temperature close to the surface'"'"'s melting temperature, without causing a remainder of each thermoplastic portion to melt, to help each skin coalesce with the other to form the bond at the interface.

11. The method of claim 10 further comprising cooling the interface to solidify the bond.

12. A method for making a panel, the method comprising:

positioning a first thermoplastic polymer sheet adjacent a second thermoplastic polymer sheet such that the first and second sheets form an interface, wherein at least one of the sheets includes a microstructure having a plurality of closed cells, each cell containing a void and each cell having a maximum dimension extending across the void within the cell that ranges between 1 micrometer and 200 micrometers long, and

wherein a plurality of cells has a temperature equal to ambient temperature and includes gas in their respective voids in an amount sufficient to exert pressure on the microstructure; and

after positioning the thermoplastic polymer sheets, exerting the pressure on the thermoplastic polymer sheets to form a bond at the interface that holds the sheets together, wherein the positioning and exerting the pressure occurs before the gas in the voids equalizes with the surrounding environment such that the pressure from the gas in the voids resists the pressure exerted on the thermoplastic polymer sheets.

13. The method of claim 12 wherein the first thermoplastic polymer sheet and the second thermoplastic polymer sheet each includes:

a microstructure having a plurality of closed cells, each cell containing a void and each cell having a maximum dimension extending across the void within the cell that ranges between 1 micrometer and 200 micrometers long, and

a skin having a surface that defines an exterior surface of the thermoplastic polymer sheet and that forms the interface with the surface of the other thermoplastic polymer sheet'"'"'s skin.

14. The method of claim 12 wherein while pressure is exerted on the thermoplastic polymer sheets to form a bond at the interface, the pressure inside each cell is equal to or greater than the pressure exerted on the thermoplastic polymer sheets.

15. The method of claim 12:

wherein the first thermoplastic polymer sheet and the second thermoplastic polymer sheet each includes;

a microstructure having a plurality of closed cells, each cell containing a void and each cell having a maximum dimension extending across the void within the cell that ranges between 1 micrometer and 10 micrometers long, and

a skin having a surface that defines an exterior surface of the thermoplastic polymer sheet and that forms the interface with the surface of the other thermoplastic polymer sheet'"'"'s skin; and

further comprising heating each surface to a temperature close to the thermoplastic polymer'"'"'s melting temperature, without causing a remainder of first thermoplastic polymer sheet and a remainder of the second thermoplastic polymer sheet to melt, to help each skin coalesce with the other to form the bond at the interface.

16. The method of claim 15 further comprising cooling the interface to solidify the bond.

17. The method of claim 12 wherein the pressure exerted on the thermoplastic polymer sheets cause the sheets to fuse at the interface.

18. The method of claim 12 further comprising:

positioning a third thermoplastic polymer sheet adjacent the second thermoplastic polymer sheet such that the third and second sheets form a second interface, and wherein the second sheet lies between the first and third thermoplastic polymer sheets; and

exerting pressure on the third and first thermoplastic polymer sheets to form a bond at the second interface that holds the sheets together.

19. The method of claim 18 wherein the third sheet includes a microstructure having a plurality of closed cells, each cell containing a void and each cell having a maximum dimension extending across the void within the cell that ranges between 1 micrometer and 200 micrometers long.