Composite panels are separate multi-layer panels that are widely used in industry and construction. These panels consist of three main layers: a central layer and two coated layers. Obviously, sub-layers such as adhesive and protector are also added to this quantity of layers. Combining these layers of different materials creates new types of composite panels that have all the features and properties as well and clearly make various uses for theme.
Composite panels are divided into different categories based on indicators such as material type and application, but it is not possible to create a established or defined category of them. Due to the wide range of raw materials and many variable elements in the construction of these panel types, the divisions are based on “various factors” and in most cases have common points. However, in this article, we examine categories based on the type of material, the purpose of construction, the facade, and the protective layer.
Classification based on the type of material used in the central layer of composite panels
The main and central layers of these panels are made of petroleum and polymer products such as polyurethane sponges and polyethylene foam. These sponges can be new or even recycled. In addition, materials such as rock wool, rock fiber, and aluminum (aluminum hydroxide), whose strength point is being non-flammable, are present in the central layer. Also, oval foams, rebound foam, pyramidal cloud, XP foam, flex panel and wood are used in some case.
Three types of wood are used in these sandwich panels as the central layer, if they have a porous texture and a honeycomb structure. But if these woods would not cover with the resin and coated layers, they are vulnerable to moisture and insect bites and unfortunately lose their attributes. Balsa wood and cedar wood are examples of these types of wood that are used in certain applications such as boat building and submarine.
Another way to make the middle layer of these panels is to use polyurethane foam spray. In this method, the polyurethane reacts as soon as it is sprayed with air and becomes a solid foam and forms an insulating layer. Finally, the surface layer is placed on it.
The thickness of the center layer is considered based on the various defined target, and this issue make different types of these composite panels.
Classification based on the type of facings or covering material
The surface material of these panels can be metal or composite.
The word composite means a combination of two or more elements and a composite material that has different properties and attributes than its raw materials before it is combined. As a result, various materials and fibers are used in the construction of the composite procedure. These fibers can be organic, mineral, natural and metallic and include different classifications.
There are different types of metal coating:
- Steel
- Aluminum
- Zinc
- Titanium
Classification based on the specific purpose of production a composite panel
- Fireproof property
- Antibacterial properties
- Thermal, moisture or sound insulation
For each of these purposes, different raw material layers and a central layer are used. For fireproof panels, refractory coatings such as aluminum hydroxide are used to act as a fire barrier and extend the time of burning process. For this purpose, rock wool and rock fiber are also used in the central layer. These materials are tested in the worst conditions and then used in panels so that they do not produce toxic substances when burned in addition to their strength against fire and high temperature.
The antibacterial panels are made of a central layer of polyethylene and an aluminum coating with a layer of antibacterial paint and are used for the hygienic environments of hospitals and laboratories and places prone to contamination.
For sound insulation attribute of panels, different foams with different sound absorption rates has chosen for the central layer, but all of them absorb sound due to their molecular texture. For thermal insulation, it is tried to use refractory and combustible materials in the central and covering layers
Classification based on the appearance of composite panels
Panels can have stone, mirror and wood design facades. Each of these facades has an advantage over natural materials such as stone and wood. For instance, composite panels with wood design are much cheaper than wood itself, unlike wood, they do not suffer from erosion and decay, the sun does not affect them and they are resistant to insects. Also, the panels with the stone design are much lighter than the stone itself. The same advantage of being light in the use of a mirror view over a natural mirror can be enumerated.
And finally, the division of panel types based on the top protective layer
Coating layers can be:
- Polyester paint
- PVDF color
- Nano color
- Shine and glossy color
which acts as a protective layer of panels.
Polyester paint:
The polyester paint itself is considered a protector and is placed alone on the coating layer. This color does not combine with any other protector and is the most basic coating. Naturally, this layer alone is not resistant to natural destructive factors and erosion, and is more suitable for indoor and outdoor decoration than outdoor environments.
PVDF color:
This coating is produced by a specific company and has a kind of resin in it. Due to the preservative’s material used in it, it shows resistance to environmental conditions and climate change. This type of paint uses a primer before painting to make the original color perfectly establish on the aluminum screen. Without this lining, the aluminum coating layer will not stain.
Nano color:
This color type has another layer in addition to the previous color and includes 3 layers of colors. This paint does not absorb dust due to the use of the latest nanotechnology technologies and does not absorb pollution. The very low molecular distance of this color does not allow dust and airborne particles to be placed on the facade.
Shine glossy color:
The color used in these materials is glossy and shiny, and considering the price, it is suitable for some special or unique applications.
Composite panels offer a variety of options to manufacturers due to their wide variety and appearance. Each of them can be selected for a specific purpose, and even for multiple purpose usage, there are composite types that have a combination of specific features.
