Aluminium foil demonstrates some distinct properties when used in theconstruction of honeycomb cored panels and structures. Sandwiched betweenaluminium sheets, the layers of alufoil, joined together and expanded into anopen-celled honeycomb format, provide an extremely strong yet light core. Theresulting panel out-performs competitive materials in strength to weight ratioand lightness, also in terms of rigidity and flatness under load.
The surfaces can be finished according to the needs of the application –aluminium alloys for aircraft components, metal tread plates for floor panels,marble or stone for interior décor, or external cladding, paint or plasticsmaterials for displays or cabinet enclosures.
This material enables architects to lighten building structures andfoundations, engineers to save weight in all types of transport – ships,planes, trucks and cars – due to the properties of the aluminium foil corematerials.
Lightness, durability and flatness means alufoil honeycomb-cored panels arespecified for architectural cladding in many forms. Decorative bonded skinsinvolving marble, granite, untreated or anodised aluminium (in colours oruncoloured) or coil coated lacquers, etc. make these lightweight panelssuitable for all types of building – commercial, industrial or domestic. Theresulting weight economies lead to significant cuts in the load bearingstructure and in foundation work. These can mean big reductions in the amountsof materials needed and the costs of construction. Honeycomb panels also addsound insulation properties to exterior cladding.
Outstanding flatness makes alufoil-cored a primary choice for fascia panelsand road signs. Aluminium honeycomb panels can be shaped and formed to makecurves and bends. Lightness helps in the handling and assembly while itsdurability means these signs and displays have a long useful life. Maintenance,when required, is minimal.
For interior displays and exhibition stands great savings can be achievedby incorporating lightweight, long life and durably finished honeycombenclosure panels.
All aluminium applications in the transport sector using strong and durablehoneycomb panels save deadweight and add to the amounts that can be carried.This, in turn, saves on vehicle usage, fuel consumed and emissions. Future lowemission and alternative fuel systems are likely to require the construction ofvehicles to an absolute minimum of weight. Aluminium foil honeycomb offers manysolutions in this respect.
Aluminium honeycomb material can provide a high level of energy absorptionwhen designed into impact protection components for vehicles. Studies carriedout with car manufacturers have demonstrated that the honeycomb-based elementshave a constant strength and a controlled level of deformation. In alongitudinal force experiment the deformation elements were compressed to 30%of their original length and absorbed large amounts of impact energy, reducingthe effects on other structural components.
A wafer block of aluminium foil core material is stretched into a sheet ofhexagonal structure on purpose built, CNC equipment to give a consistent celldimension. The walls of the cells can be micro-perforated to allow movement ofair between adjacent cells, equalising pressure in environments with rapidtemperature variations.
The expanded core is bonded to the outer facings with a two-part adhesivewhich is applied in a dedicated computer controlled spray booth facility. Thisallows close monitoring of coat weights and accurate application to allsubstrates. The sandwich faces and core are laid up and accurately alignedprior to transferring, by means of roller, table to the press.
The final bonding process is done on a heated, hydraulically operated pressto ensure uniformity of each panel and is closely controlled to ensurereliability of the bond.
The cell size, depth of material, thickness of cell walls and aluminiumalloy are all varied to suit specific requirements and tailored to impart thecorrect, specified properties in the final manufactured units.