Composite aluminum facade

For those involved in construction including employers, engineers and contractors, talking about modern facades associates with applying glass in high buildings or its combination with other materials such as stone and wood. As such, following reading references and article such as “the fifth topic of national building regulations”, only materials such as stone, wood and glass are considered as the most useful materials in renowned buildings and the proper pattern of their usage is analyzed in these references. Regardless of the matter of quality which will be discussed, during recent years buildings’ facades industry has been drastically changed whose consequence is changing the visage of big, small and even non-industrial cities.

Despite extensive distribution of applied and various products in buildings’ facades, technical and mechanical characteristics of these materials have not been scientifically considered. It can’t be also claimed that there has been a well-documented reference for those involved in construction in order to obtain information regarding the standard principles in buildings.
However, several texts and articles have been published regarding modern materials in developed countries in which their mechanical characteristics and installation mode have been clarified. Therefore, those experts having access to such references might have more acquaintance with these materials. However, due to the weakness of existing internal resources, engineers and experts of construction have limited acquaintance with such materials. It is therefore obvious that this lack of knowledge will lead to misuse these materials and their advantages will be underestimated.

Aluminum composite sheet presentation

As it is obvious from its name, this product is a hybrid material consisting of two layers of aluminum and a plastic layer in the middle made of poly ethilen stuck together by a polymeric adhesive; two aluminum layers have similar thickness ranging between 30 to 50 Microns depending on the usage. The total thickness is 4 mm.
Dimensions of this product are various. However, the most common one is 12500x3200 mm2. As it has been mentioned, 2 aluminum layers have been used in this product.
One layer is placed on the facade surface and the other one is one the back; the layer placed on surface has various and different colors and patterns depending on design. Depending on the application (interior or exterior facade) different resins are performed on it which has been described in detail. The back layer has also one lining color layer on aluminum.
Aluminum composite sheet is classified as light material. Thus each square meter of these sheets is only about 5 kg.

Aluminum composite sheet applications

As it has been mentioned before, the most common of this product is in facade and decoration. Besides, this product has numerous applications as follow:

01

Commercial buildings and stores interior decoration
02

Commercial buildings and stores interior decoration
03

Billboards
04

Dropped-ceiling projects
05

Tunnels and terminals wall
06

Old buildings façade renovation

Aluminum composite mechanical and technical characteristics

Place of composite aluminum among other materials

As this product is considered as industrial material and factories products, it has enhanced the characteristics of natural materials such as stone and wood.

If this product is exposed against climate conditions, ultraviolet ray as well as acidic and alkaline conditions, pollutions and rusting, it will indicate a significant resistance and preserve its appearance and technical characteristics for several years. Moreover, in terms of mechanical condition, it indicates considerable flexibility and elasticity.

Effective differences in price and quality

Difference in Aluminum ally
Difference in type of polyethylene namely middle layer
Difference in the thickness of aluminum and middle layer
Sheet surface coverage
Patterns or specific colors

Types of composite aluminum in terms of sheet surface coverage

Color of sheet surface is performed using various technologies in terms of the application type and place of installation divided as follow:

1. Poly Esther: Is considered as the simplest color performance on the aluminum layer in which color is performed on the aluminum layer without any protective layer.
This type of sheet is absolutely vulnerable against climate, acidic and alkaline conditions. There is no guarantee to preserve its quality in the building’s exterior façade. Generally using this type of sheet is prohibited for exterior façade; however, it is cost-effective and proper for interior decoration.
2. PVDF protective coverage: This coverage is known as “Polyvinylidene fluoride. It is considered as a special resin whose manufacturer is PPG Company. This resin causes the protection of sheet surface color as well as its resistance and stability against climate conditions, ultraviolet ray and acidic and alkaline condition for minimum 20 years due to polymeric layer and fluoride.
The color performed on the sheet surface using this resin is not directly performed on aluminum. A color lining layer made of polyurethane is performed on aluminum beforehand, after which the color layer is added. Therefore, PVDF sheets contain two color layers.
3. Nano-PDF coverage: It is performed like PVDF resin. The difference is that a third layer will be performed on PVDF having different molecular structure with normal resins.
As such the molecular distance will be less than 9-10 by using Nano technology, leading not to absorb the environmental pollutants such as dust and oil particles in the air.

Division in terms of middle-layer technology

The middle layer of the project consists of different materials based on application and project importance:

01

Recycled polyethylene
02

Anti-fire middle layer B1
03

Anti-fire middle layer A2
It is made of Aluminum hydroxide.

It should be added that the polyethylene used in middle layer of these sheets is not combustible. However, based on the project importance and the combustibles existing in proximity of these sheets, middle layerA1 and B1 are used. It is noteworthy that A1 standard is related to homogenous materials.

Advantages of Aluminum composite

In addition to aesthetic issue of performance variation and distinct quality of aluminum composite, there are other points of difference between this product and other façade materials from two aspects.
The first and most important privilege of this material is its light weight leading to lightening the construction.
It is evident for all the construction experts that reduction the seismic weight of the building leads to reduce the basic cutting force as well as seismic force in construct calculation. As a result, the construct elements of the building become more economic and optimized leading to enlighten the construct’s sections.
Besides, due to the installation of a metal skeleton on the building for the purpose of installing these sheets, the advantageous effect of this skeleton as a middle-frame could not be denied.
The other point of difference of this product is considering the 19th topic of national regulations. Due to the existence of polyethylene layer as well as the sealing characteristic of this product, a acoustic-thermal insulator is formed around the building as well as the bound air between sheet and building whose impact is significant and proper.

Composite aluminum facade