What are the composites?
Generally speaking, composites are the constructional materials, which consist of at least two initial materials jointed with each other in a specific manner. There are reinforcing fibres made of different material with higher mechanical strength "flooded" in one of them, called binder or matrix.
It is a material in a certain sense analogous to a reinforced concrete constructions where the binder (concrete) is directionally strengthened with different, more resistant material (concrete steel bars). But the difference is that there are reinforcing fibres with a very small diameter, measured in thousandth parts of a millimeter, used in modern composites. Because there is a general regularity which proves, that the smaller reinforcing fibres' diameter the higher composites' resistance.
We have observed constant expansion and advancement of initial materials for manufacturing of composite products and also advancement of their producing and processing manner during last decades. Finally we can state uncommon development of usage of the composites. Use of composites in rocketry has undoubtedly brought a big influence on this development.
At the present moment composites are a very wide family of modern constructional materials, which find use practically in all scopes of technics and human activity.
Not only type of reinforcing fibres and their proportional part in composite but also this, that their disposition can be adapted to the loading transmitted by the product, it determines strength of the composites. Through manufacturing of the composite products, we can imitate the nature, which was able to create over the millions years of evolution such a perfect “directionally” constructions like for example blade of corn or stalk of bamboo. Composite rods for pole vault made of carbon fibres are the best example of such imitation.
Many various materials can be a binder (matrix) of the composites. Most widely used are the polymers: both thermoplastic and thermosetting. But there are also other materials that can be a binders, like metals and metal alloys or ceramic materials.
Natural fibres (sisal, jute) can be used as the reinforcing fibres. But most widely used are various artificial and synthetic fibres (glass, polyamide, polypropylene, basalt, carbon, boron, metal)
Composites, which have polymers as their binders are called polymer composites. These composites are the main object of BELLA company activity. Most often we use as a binder various thermosetting polymers (polyester resins, vinyl esters, epoxide resins and others).
Our basic reinforced fibre we apply is a glass fibre. But during our production practice we use also carbon fibers or modern, light and resistant polymer fibers so-called second generation fibers (kevlar®, twaron®).