PRODUCTION OF EXTRUDED FOAM

• US 20120248645A1
• Filed: 10/13/2010
• Published: 10/04/2012
• Est. Priority Date: 10/13/2009
• Status: Active Grant

• Current Assignee: Gurit Limited (Gurit Holding AG)
• Original Assignee: Gurit Limited (Gurit Holding AG)
• Inventors: Lavoie, Bernard
• Granted Patent: US 9,457,500 B2
• Time in Patent Office: Days
• US Class Current: 264/45.9
• CPC Class Codes: B29C 44/24 Making multilayered articles
• CPC Class Codes: B29C 44/352 Means for giving the foam different characteristics in different directions
• CPC Class Codes: B29C 44/5654 Subdividing foamed articles to obtain particular surface properties, e.g. on multiple modules
• CPC Class Codes: B29K 2025/00 Use of polymers of vinyl-aromatic compounds or derivatives thereof as moulding material
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/04 cellular or porous
• CPC Class Codes: B29L 2009/00 Layered products
• CPC Class Codes: B32B 2038/0028 Stretching, elongating
• CPC Class Codes: B32B 2250/22 All layers being foamed
• CPC Class Codes: B32B 2266/0207 Materials belonging to B32B25/00
• CPC Class Codes: B32B 2266/0228 Aromatic vinyl resin, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 2266/0264 Polyester
• CPC Class Codes: B32B 2305/022 Foam
• CPC Class Codes: B32B 2305/08 Reinforcements
• CPC Class Codes: B32B 2307/718 Weight, e.g. weight per square meter
• CPC Class Codes: B32B 2309/08 Dimensions, e.g. volume
• CPC Class Codes: B32B 2310/0825 using IR radiation
• CPC Class Codes: B32B 2603/00 Vanes, blades, propellers, rotors with blades
• CPC Class Codes: B32B 37/02 characterised by a sequence of laminating steps, e.g. by adding new layers at consecutive laminating stations
• CPC Class Codes: B32B 37/04 characterised by the partial melting of at least one layer
• CPC Class Codes: B32B 37/153 : at least one layer is extruded and immediately laminated while in semi-molten state
• CPC Class Codes: B32B 38/0004 : Cutting, tearing or severing, e.g. bursting; Cutter details cutting in general B26D; laminating combined with punching or perforating B32B38/04; removing all or part of the layers B32B38/10; cutting in combination with laying up and registration B32B38/185 takes precedence
• CPC Class Codes: B32B 39/00 : Layout of apparatus or plants, e.g. modular laminating systems
• CPC Class Codes: B32B 43/003 : Cutting
• CPC Class Codes: B32B 5/32 : at least two layers being foamed and next to each other
• CPC Class Codes: B65H 45/101 : in combination with laying, i.e. forming a zig-zag pile

Abstract

A method of producing a laminated body of structural thermoplastic foam, the method comprising the step of successively extruding a plurality of foam layers from an extrusion die, each next layer being extruded onto a previously extruded layer to form a stack of mutually bonded layers.

Claims

1. A method of producing a laminated body of structural thermoplastic foam, the method comprising the step of successively extruding a plurality of foam layers from an extrusion die, each next layer being extruded onto a previously extruded layer, to form a stack of mutually bonded layers, the same extrusion die forming a plurality of individually extruded layers of the stack.

2. A method according to claim 1 wherein the extrusion die and the stack are relatively moved translationally during extrusion of each foam layer.

3. A method according to claim 1 wherein a single extrusion die extrudes all of the layers of the stack.

4. A method according to claim 1 wherein the extrusion die is continuously operated.

5. A method according to claim 1 wherein the extrusion die is fixed in position and the stack is translationally moved under the extrusion die during extrusion of each foam layer.

6. A method according to claim 5 wherein the stack is translationally moved at a velocity greater than the velocity of the extruded foam layer exiting the extrusion die thereby anisotropically to stretch cells of the foam layer in the moving direction.

7. A method according to claim 5 wherein the stack is translationally moved by a conveyor system in a single direction under the extrusion die during extrusion of each foam layer.

8. A method according to claim 7 wherein the conveyor system translationally moves the stack around a loop, the extrusion die being located at one position above the loop.

9. A method according to claim 8 wherein the loop is substantially horizontal.

10. A method according to claim 7 wherein after each layer has been extruded, the layer is cut into at least two layer portions to form at least two independent blocks, each block comprising a respective stack of a plurality of mutually bonded layers.

11. A method according to claim 10 wherein the conveyor system translationally moves the stack around a loop, the extrusion die being located at one position above the loop, and wherein the layer is cut into at least two layer portions to form at least two independent blocks, and the blocks are conveyed around the loop so that when one block is under the extrusion die, the other block or blocks is or are being cut downstream of the extrusion die and/or being conveyed around the loop to a position upstream of the extrusion die.

12. A method according to claim 10 wherein the layer is cut while the layer is moving on the conveyor system downstream of the extrusion die and the cutting is carried out by a cutter mechanism moving downstream of the extrusion die at the same velocity as the layer.

13. A method according to claim 5 wherein the stack is translationally moved by a conveyor system in reciprocal directions under the extrusion die during extrusion of the foam layers so that one foam layer is extruded with the stack moving in a first direction and a successive foam layer is extruded with the stack moving in a second opposite direction.

14. A method according to claim 1 wherein a radiation heater is mounted adjacent to the extrusion die for heating a foam surface onto which a foam layer is to be extruded.

15. A method according to claim 1 wherein a calibration tool is mounted adjacent to the radiation heater to shape the upper surface of the extruded foam layer.

16. A method according to claim 1 wherein the laminated body on formed on a table having an adjustable height.

17. A method according to claim 16 wherein after the extrusion of at least one of the layers onto the previously extruded layer or layer, the height of the table is lowered in an indexable manner by a distance substantially corresponding to an increase in the thickness of the stack of foam layers.

18. A method according to claim 17 wherein the height of the table is lowered in an indexable manner by a distance substantially corresponding to a thickness of the foam layer after the extrusion of each foam layer onto the previously extruded layer.

19. A method according to claim 1 wherein the extrusion die has a plurality of extrusion orifices and each extruded foam layer comprises a plurality of co-extruded foam segments bonded together.

20. A method according to claim 19 wherein the foam layer has a plurality of foam segments in both the width and thickness directions of the extruded foam layer.

21. A method according to claim 19 wherein the extrusion die co-extrudes foam segments and unfoamed walls between foam segments.

22. A method according to claim 21 wherein the walls extend in the thickness direction of the extruded foam layer.

23. A method according to claim 22 wherein the walls additionally extend in the width direction of the extruded foam layer, to form a network of intersecting orthogonal walls in the foam layer.

24. A method according to claim 21 wherein the walls of adjacent foam layers intersect.

25. A method according to claim 21 wherein the walls are composed of a thermoplastic material.

26. An apparatus for producing a laminated body of structural thermoplastic foam, the apparatus comprising an extrusion die for extruding a foam layer, a support mounted beneath the extrusion die, the support being adapted to support at least one block comprising a stack of mutually bonded foam layers so that a foam layer can be extruded from the extrusion die onto a previously extruded layer at the top of the block, and a conveyor system on the support, the conveyor system being adapted translationally to move at least one block under the extrusion die during extrusion of each foam layer.

27. An apparatus according to claim 26 comprising a single extrusion die.

28. An apparatus according to claim 26 wherein the extrusion die is fixed in position.

29. An apparatus according to claim 26 wherein the conveyor system is adapted to move the stack in a single direction under the extrusion die.

30. An apparatus according to claim 26 wherein the conveyor system comprises a loop.

31. An apparatus according to claim 30 wherein the loop is horizontal.

32. An apparatus according to claim 30 further comprising a cutter mechanism adapted to cut an extruded layer into at least two layer portions to form at least two independent blocks, each comprising a plurality of layers.

33. An apparatus according to claim 32 wherein the conveyor system is adapted to convey the blocks around the loop.

34. An apparatus according to claim 32 wherein the cutter mechanism is mounted on a movable carriage which is adapted to move downstream of the extrusion die at the same velocity as the conveyor system.

35. An apparatus according to claim 26 wherein the conveyor system is adapted to move the stack in reciprocal directions under the extrusion die.

36. An apparatus according to claim 26 further comprising a radiation heater mounted adjacent to the extrusion die for heating a foam surface onto which a foam layer is to be extruded.

37. An apparatus according to claim 26 further comprising a calibration tool mounted adjacent to the radiation heater for shaping the upper surface of the extruded foam layer.

38. An apparatus according to claim 26 wherein the support comprises a table having an adjustable height.

39. An apparatus according to claim 38 further comprising an indexable height adjusting mechanism for the table which is adapted to lower the height of the table is lowered in an indexable manner by a selected distance.

40. An apparatus according to claim 26 wherein the extrusion die has a plurality of extrusion orifices and is adapted to co-extrude a plurality of foam segments.

41. An apparatus according to claim 40 wherein the extrusion die has an array of a plurality of extrusion orifices, the array extending in both a width direction and a height direction of the extrusion die.

42. An apparatus according to claim 40 wherein the extrusion die is adapted to extrude foam segments from first orifices and unfoamed walls between foam segments from second orifices.

43. An apparatus according to claim 42 wherein at least one elongate second orifice for extruding a wall extends in the height direction of the extrusion die.

44. An apparatus according to claim 43 wherein at least one elongate second orifice for extruding a wall additionally extends in the width direction of the extrusion die, to form a network of intersecting mutually orthogonal elongate second orifices in the extrusion die.