Epoxy resin - Interesting facts about epoxy resin

The term epoxy resin, epoxy resin or even epoxy comes from the oxygen three-ring molecule called epoxide.

Fiber composite materials manufactured with the help of epoxy resin belong to the group of duroplastics. Fiber composite materials consist of a fiber component and a synthetic resin component. Thermosets are plastics that cannot be plastically deformed again after curing. They are insoluble, non-weldable and non-fusible. Here, on the other hand, thermoplastics can be plastically deformed again after curing, mostly through the application of heat. Epoxy resin is the so-called matrix in a fiber composite material. As a rule, epoxy resin is laminated with glass filament fabric, glass fiber fabric or carbon fabric. When using epoxy resin, no glass fiber mat should be processed. These contain a binder that is dissolved by the styrene in the polyester resin. Epoxy resin does not contain styrene. When using epoxy resin, it is recommended to use glass filament fabric, glass fiber fabric, carbon fabric.

The matrix is ​​the embedding material for the reinforcement fabric and is responsible for the shape of the component. The form is determined by the lamination form with the hardening of the laminate. In addition, it ensures that the forces that occur are introduced into the reinforcing fibers. The protective function of the matrix that encloses the reinforcing fibers should also not be neglected.

In contrast to polyester resin, the ratio of epoxy resin and epoxy hardener must be precisely observed when mixing epoxy resin, otherwise parts of the resin or hardener remain without reactants. If the proportion of epoxy resin is too high, the surface of the workpiece will appear sticky, while if the proportion of hardener is too high, the workpiece will become brittle. In both cases, the breaking strength of the workpiece is reduced. Another feature of epoxy resin is its use restriction with respect to the reinforcing fabric.

Epoxy resins can be used both as laminating resins and as casting resins.

Epoxy resins cure by polyaddition. Put simply, a polyadditive reaction is a chemical reaction in which two components “combine” into one. A prerequisite for thorough curing is that each epoxy group is opposite an amine group as a hardener. When processing epoxy resin, it is very important to set the correct epoxy resin-hardener ratio, as otherwise excess molecules of a component will not find a reaction partner and, as short, unlinked molecules, can impair the mechanical and thermal properties of the fiber composite material.