Sandwich panel

A sandwich panel is any structure made of three layers: a low-density core (PIR, mineral wool, XPS), and a thin skin-layer bonded to each side.

This results in increasing the overall thickness of the panel, which often improves the structural attributes, like bending stiffness, and maintains or even reduces the weight.

[10] ACP is mainly used for external and internal architectural cladding or partitions, false ceilings, signage, machine coverings, container construction, etc.

ACP has been used as a light-weight but very sturdy material in construction, particularly for transient structures like trade show booths and similar temporary elements.

It has recently also been adopted as a backing material for mounting fine art photography, often with an acrylic finish using processes like Diasec or other face-mounting techniques.

ACP material has been used in famous structures as Spaceship Earth, VanDusen Botanical Garden, and the Leipzig branch of the German National Library.

Its flexibility, low weight, and easy forming and processing allow for innovative design with increased rigidity and durability.

[13] The cladding materials, in this case having the highly combustible Polyethylene (PE) core, were implicated as the principal cause of the rapid spread of flame in the 2017 Grenfell Tower fire in London.

[15] Fire-rated cores (typically designated as "FR" by the manufacturers) are a safer alternative as they have a maximum of 30% Polyethylene Content, and will self-extinguish in the absence of heat/ventilation.

The aluminium sheets can be coated with polyvinylidene fluoride (PVDF), fluoropolymer resins (FEVE), or polyester paint.

However, their good insulation characteristics, their versatility, quality and appealing visual appearance, have resulted in a growing and widespread use of the panels across a huge variety of buildings.