Thermoforming, with applied pressure and dimensional re-shaping, layered, composite-material structural panel

Abstract

A method utilizing elevated temperature and applied pressure to form a layered, composite-material structural panel including (a) establishing a layer-stack assembly in the form of a pre-consolidation expanse having everywhere an independent, location-specific, pre-consolidation local thickness T, and including at least a pair of confronting, different-thermoformable-material layers, (b) heating the assembly to a thermoform temperature, (c) compressing the heated assembly to create a thermal bond between the two layers, and to consolidate the assembly into a post-consolidation expanse having everywhere an independent, location-specific, post-consolidation, local thickness t which is less than the respective, associated, pre-consolidation local thickness T, and (d) cooling the consolidated assembly to a sub-thermoform temperature to stabilize it in its consolidated condition.

Description

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified and structurally fragmentary illustration of the basic methodologic steps of the present invention presented in the physical context of a two-layer, composite structural panel which has been thermoformed in accordance with a preferred and best mode manner of practicing the invention. Each of the two layers in this panel is formed of a thermoformable material which specifically differs from the thermoformable material used in the other layer. Objects shown in this figure, as is true with respect to objects shown all of the other drawing figures, are not drawn to scale.

FIG. 2 is a somewhat more detailed, and partially fragmentary, view, having left and right sides which differently picture the methodology of the present invention in the structural context of two other kinds of basic, composite structural panels that have been made as three-layer sandwich structures in accordance with practice of the invention. Each of the three layers in these two panels is formed of a thermoformable material, with such thermoformable material that is used in the two outer layers being the same, and differing from the thermoformable material employed in the intermediate core layer.

FIGS. 3-6, inclusive, are high-level schematic and simplified views having left and right sides, and which picture, with regard to these four figures, respectively, four different basic and important panel-thermoforming approaches, or methodologic invention facets, that are offered and made possible by practice of the present invention.

FIG. 7 is a fragmentary, schematic, side elevation having left and right sides which, in a somewhat more detailed fashion, illustrate one specific application of the invention practice that is related to the content of FIG. 5.

FIG. 8 is a fragmentary, schematic, side elevation having left and right sides which, in a somewhat more detailed fashion, illustrate another specific application of the invention practice—this application practice being related to the content of FIG. 4.

FIG. 9 illustrates, schematically and fragmentarily, a batch manner of implementing the practice of the present invention.

FIG. 10 illustrates, schematically and fragmentarily, a continuous-flow manner of implementing the practice of the present invention.

Claims

1. A method of forming a layered, composite-material structural panel having predefined, desired, final panel-thickness characteristics comprising establishing a pre-consolidation, layer-stack assembly in the form of a pre-consolidation expanse having everywhere a location-specific, pre-selected, pre-consolidation, independent, local thickness T, and including at least a pair of confronting, next-adjacent, different-thermoformable-material layers,heating the established assembly to a predetermined thermoform temperature,compressing the heated assembly to consolidate it so as (a) to form a post-consolidation expanse having everywhere a location-specific, pre-selected, post-consolidation, independent, local thickness t which is less than the respective, associated, pre-selected, pre-consolidation local thickness T, and which takes the form of the desired, predefined final panel-thickness characteristics, and (b) to create a thermal bond between the two layers,cooling the consolidated assembly to a predetermined sub-thermoform temperature to stabilize it in its consolidated condition, andby said cooling, completing, substantially, the formation of the intended structural panel.

2. The method of claim 1 which is performed in a manner whereby (a) the respective, pre-consolidation, location-specific, local expanse thicknesses T are all substantially the same, and (b) the respective, post-consolidation, location-specific, local expanse thicknesses t are also all substantially the same.

3. The method of claim 1 which is performed in a manner whereby (a) the respective, pre-consolidation, location-specific, local expanse thicknesses T are all substantially the same, and (b) at least certain ones of the respective, post-consolidation, location-specific, local expanse thicknesses t differ from one another.

4. The method of claim 1 which is performed in a manner whereby (a) at least certain ones of the respective, pre-consolidation, location-specific, local expanse thicknesses T differ from one another, and (b) the respective, post-consolidation, location-specific, local expanse thicknesses t are also all substantially the same.

5. The method of claim 1 which is performed in a manner whereby (a) at least certain ones of the respective, pre-consolidation, location-specific, local expanse thicknesses T differ from one another, and (b) ) at least certain ones of the respective, post-consolidation, location-specific, local expanse thicknesses t also differ from one another.

6. The method of claim 1, wherein said establishing is augmented by including in the pre-consolidation layer-stack assembly at least one additional material layer which is non-interposed the first two mentioned layers, and which is made of at least one of (a) a non-thermoformable material, and (b) a thermoformable material.

7. The method of claim 6, wherein said including involves preparing the mentioned augmenting-material layer to have a distributed, differentiated-thickness expanse characteristic.

8. The method of claim 1 which is performed in the context of selecting, for one of the two thermoformable-material layers, a PET material, and for the other layer, a strand-reinforced material which includes a distribution of angularly intersecting reinforcing strands blended with a thermoformable plastic which is thermo-bond-compatible with the PET-material layer.

9. The method of claim 8, which is performed in a context where one of the two thermoformable-material layers is thicker than the other thermoformable-material layer, and wherein the mentioned PET material is selected for use in the one, thicker layer, and the strand-reinforced material is selected for use in the other, thinner layer.

10. The method of claim 9, wherein all assembly thickness reductions from T to t at each specific assembly location during compression consolidation of the assembly occur with a greater thickness reduction taking place in the thicker PET layer than in the thinner strand-reinforced layer.

11. The method of claim 10, wherein said compressing is performed and completed in a manner whereby, at all locations in the assembly, the thicker PET layer is thickness-reduced by at least a predetermined, common thickness amount.

12. The method of claim 11, wherein said compressing is performed in a manner causing the mentioned predetermined thickness amount being about ⅛-inches.

13. The method of claim 8, wherein said selecting of a PET material involves choosing such a material which is non-internally-stranded.

14. A method of forming a layered, composite-material structural panel having predefined, desired, final panel-thickness characteristics comprising establishing a pre-consolidation, layer-stack assembly in the form of a pre-consolidation expanse having everywhere a location-specific, pre-selected, pre-consolidation, independent, local thickness T, and featuring at least a plurality of confronting, next-adjacent, different-thermoformable-material layers, including a PET-material core layer sandwiched between a pair of strand-reinforced, opposite surfacing-material layers each of which surfacing-material layers includes a distribution of angularly intersecting reinforcing strands blended with a thermoformable plastic which is thermo-bond-compatible with the PET-material core layer,heating the established assembly to a predetermined thermoform temperature,compressing the heated assembly to consolidate it so as (a) to form a post-consolidation expanse having everywhere a location-specific, pre-selected, post-consolidation, independent, local thickness t which is less than the respective, associated, pre-selected, pre-consolidation local thickness T, and which takes the form of the desired, predefined final panel-thickness characteristics, and (b) to create thermal bonds between each next-adjacent pair of the three assembly layers,cooling the consolidated assembly to a predetermined sub-thermoform temperature to stabilize it in its consolidated condition, andby said cooling, completing, substantially, the formation of the intended structural panel.

15. The method of claim 14 which is performed in a manner whereby (a) the respective, pre-consolidation, location-specific, local expanse thicknesses T are all substantially the same, and (b) the respective, post-consolidation, location-specific, local expanse thicknesses t are also all substantially the same.

16. The method of claim 14 which is performed in a manner whereby (a) the respective, pre-consolidation, location-specific, local expanse thicknesses T are all substantially the same, and (b) at least certain ones of the respective, post-consolidation, location-specific, local expanse thicknesses t differ from one another.

17. The method of claim 14 which is performed in a manner whereby (a) at least certain ones of the respective, pre-consolidation, location-specific, local expanse thicknesses T differ from one another, and (b) the respective, post-consolidation, location-specific, local expanse thicknesses t are also all substantially the same.

18. The method of claim 14 which is performed in a manner whereby (a) at least certain ones of the respective, pre-consolidation, location-specific, local expanse thicknesses T differ from one another, and (b) ) at least certain ones of the respective, post-consolidation, location-specific, local expanse thicknesses t also differ from one another.