Filler and glass-fiber treatment

Composites consist of two or more components with significantly different physical or chemical properties. One of these materials constitutes the matrix, in which reinforcing fillers are embedded in order to lend specific properties to the composite.

One key problem here is the fact that the materials used within the composite are immiscible with each other and form separate phases. In order to improve interaction between the matrix and filler – thereby enhancing compatibility – the fillers are treated with functional silanes.

Doing so is particularly important when inorganic fillers are used in an organic resin matrix. The filler systems in composite materials can be either isotropic powders or anisotropic fibers.

Advantages:

• Promotes adhesion between the matrix and filler
• Modifies the surface
• Absorbs water

Treatment with a sizing agent is a critical step in manufacturing glass fibers. This involves impregnating the freshly extruded fibers with an aqueous emulsion, which ensures that the fibers will be easier to process, and the properties of the final composite material will be ideal.

Organofunctional silanes from WACKER are an important component of sizing formulations, where they serve as coupling agents between the fiber and the matrix in glass-fiber-reinforced composites.

In order to ensure adhesion between the glass fiber and the matrix, organofunctional silanes are available with different functional groups, allowing them to react with a variety of thermoset resins. Particularly important examples here are silanes having amino, epoxy, methacryloxy and vinyl groups.

Advantages:

• Promotes adhesion between the fiber and matrix
• Modifies the surface
• Absorbs water
• Makes fibers easier to process and improves the performance of the composite