Composite panel
A door panel 1 has a peripheral frame 10 of extruded aluminum and a honeycomb core of plastics material tubes 11 . An outer skin 2 of fiber-reinforced polyetherimide material is recessed with a pattern 3 formed in a preliminary operation of vacuum/pressure forming at elevated temperature. An inner skin 4 is plane. Edge channel members 5 of similarly formed, but thicker material are arranged around the edges of the door, enclosing the aluminum frame. A non-woven, polyester based scrim 6 extends across either side of the core and over the flanges 7 of the edge channels. For bonding of the core, skin and edge channels together, the assembly is placed in a jig and compressed at elevated temperature in a heated press. The core is crushed at the recessed pattern 3 and the scrim melts and acts as a hot melt adhesive. On cooling of the press platens, the assembled door is removed from the jig.
1. A composite panel having:
two skin laminae of reinforced polymer material;
a polymer honeycomb core;
at least one local reinforcement; wherein the local reinforcement is: i) bonded inside of at least one of the skin laminae to at least one of the skin laminae and the core; ii) made up of a plurality of stacked pieces of laminar material bonded to each other; and ii) formed at an elevated temperature vacuum/pressure;
one or more metal anchorage members internal to the panel and at least partially surrounded by, and located in, the panel by said local reinforcement, and in which at least one of the one or more metal anchorage members does not contact either of the two skin laminae.
2. A composite panel according to claim 1 , having a non-planar surface,
wherein at least one of the two skin laminae of reinforced polymer material has a non-planar surface with at least one area of it being recessed with respect to adjacent area(s) and wherein the polymer honeycomb core is of non-uniform thickness, the core being adhered to the skin laminae and crushed to a lesser thickness at the recessed area(s) of the non-planar skin lamina(e).
3. A composite panel according to claim 1 , wherein the recessed area is an indented area of the panel in which the panel is thinner than in adjacent area(s).
4. A composite panel according to claim 1 , wherein the recessed area is a tapered area of the panel in which the panel tapers to an edge of the panel.
5. A composite panel according to claim 1 , wherein the non-planar lamina is of PEI material, reinforced with glass fibre material.
6. A composite panel according to claim 1 , wherein at least one non-planar skin lamina is vacuum/pressure formed to shape at elevated temperature, prior to being pressed again at elevated temperature onto the core.
7. A composite pane according to claim 1 , wherein the local reinforcement is comprised of the same material as the skin laminae.
8. A composite panel according to claim 1 , wherein the panel further comprises a thermoset moulding, bonded to at least one of the skin laminae and/or the core.
9. A composite panel according to claim 8 , wherein the thermoset moulding forms an edge of the panel.
10. A composite panel according to claim 1 , wherein each local reinforcement is bonded in position with the interposition between the local reinforcement(s) and the skin laminae of an elevated temperature adhesive material.
11. A composite panel as claimed in claim 10 , wherein the adhesive material is a scrim of non-woven polyester material.
12. A composite panel as in claim 1 , in which the one or more metal anchorage members are permanently located in the panel by said local reinforcement.
13. A composite panel as in claim 1 , wherein the panel is a door panel for an aircraft.
14. A composite panel as in claim 1 , wherein the panel is a floor panel for an aircraft.
15. A composite panel as in claim 1 , wherein the panel is an aircraft seat pallet.
16. An aircraft seat pallet comprising the composite panel of claim 1 .
17. A method of forming a composite panel, comprising the steps of:
providing one or more metal anchorage members and two skin laminae of reinforced polymer material;
locating the one or more metal anchorage members in the panel by at least one local reinforcement; and
bonding the at least one local reinforcement to at least one of the skin laminae and the core, thereby forming a composite panel including (i) the two skin laminae, (ii) a polymer honeycomb core, (iii) the at least one local reinforcement, which is bonded inside of at least one of the skin laminae to at least one of the skin laminae and the core, made up of a plurality of stacked pieces of laminar material bonded to each other, and formed at an elevated temperature vacuum/pressure, and (iv) the one or more metal anchorage members internal to the panel and at least partially surrounded by, and located in, the panel by said local reinforcement, in which at least one of the one or more metal anchorage members does not contact either of the two skin laminae.