What's in the Sandwich?

Often referred to as "sandwich" panels, steel faced composite cladding panels can have a variety of different "fillings". Hence the title. Like their namesake, some sandwich fillings are healthier than others.

Eurobond's steel faced composite "sandwich" panels have all the ingredients for a healthy environment and a successful build.

The core of our composite cladding panels (the sandwich filler if you like) is made from mineral wool, which is 100% recyclable, has zero Ozone Depleting Potential and zero Global Warming Potential. The "bread" to our composite panels is a pre-finished steel face supplied by Corus Colorcoat®. For Prisma® and HPS200® Ultra finishes, there is the additional option of Confidex Sustain® – the first CarbonNeutral building envelope in the world.

Each sandwich panel is manufacturered with a high recycled content due to the fact that we purchase our composite panel components from the same companies as we recycle them with – a unique ‘cradle to cradle’ approach. This ‘cradle to cradle’ approach separates the steel and stone wool core of our composite panels at end of life where they are then sent back to Corus and Rockwool respectively. Each component is then recycled to make new, virgin products. It is with credentials like this that make up the ingredients for success when using our composite cladding panels and why brand names such as Tesco, Asda and Marks and Spencer choose us for many of their buildings. In fact, that sandwich that you bought for lunch and are about to devour in 2 minutes flat might well have been made, stored or sold within a building built with our composite cladding panels.

When it comes to steel faced composite panels, many different core materials can be used and ultimately it’s this core, like the filling of a sandwich, that most differentiates one composite cladding panel from the next, especially in relation to environmental performance. Plastic PIR foam cored composite panels are usually manufactured where a blowing agent like HFC-134a is mixed with the component materials creating a light cell structure that hardens. HFCs (Hydrofluorocarbons) were virtually unused before 1990 but since then they have been used to replace ozone-depleting substances, such as chlorofluorocarbons (CFCs) and (HCFCs). However, the EU continues to push hard to reduce the use of fluorinated gases such as HFCs and although the use of HFCs in composite panels has not yet been outlawed, the general consensus is that they will be under increased scrutiny during the next Regulation (EC) No 842/2006 review in 2011. A bit like a sandwich that’s past its sell by date.

Comparatively, stone wool cored composite panels rely only upon trapped air for their thermal properties. Rockwool mainly comprises diabase rock, a natural, plentiful resource and according to Eurisol, the UK Mineral Wool association, producing stone wool requires only half the energy needed to manufacture other types of insulation.

The preferred route to disposal requires composite panels to be cut down for processing at one of the existing fridge recycling plants, again do you see the sandwich theme here. I told you that my lunch today was related to this blog. The processes involved separates the various materials and the steel can then be made available for recycling. The polyurethane dust is liberated from the foam for landfill and the gases captured and sent to specialist waste companies for high temperature incineration. The Corus Colorcoat® Technical Paper estimates the cost for this process to be £8/m2. Fridge recycling facilities also currently offer a practical means of truly recycling stone wool composite panels. The facility allows for the successful separation of the mineral wool and the steel face, which can then be recycled back into the manufacturing process. Corus estimates the cost for this process is only around £2/m2, which covers the transport cost.The environmental impact of our everyday decisions is continuing to move up the news agenda, especially when it comes to specification and end of life disposal.

Architects and designers need to look at every aspect of a product’s environmental impact, in order to make a responsible and healthy decision – just like you would with your sandwich choice for lunch. On a Friday you probably opt to have the big fat, greasy burger from Macdonald’s because you think you have eaten reasonably healthy all week but can you truly say that you have made reasonably healthy choices for the environment in your choice of composite panel for your design.

Colorcoat and Confidex Sustain is a registered trademark of Corus