Fillers

Depending on the application, fillers perform various functions:

• Cost reduction: using low-cost fillers allows more expensive base materials to be replaced.

• Property modification: improvement of mechanical properties such as strength, hardness or elasticity.

• Optimised processability: reduction of viscosity or improvement of formability.

• Increased resistance: higher resistance to heat, chemicals or UV.

Fillers can be divided into organic and inorganic categories, depending on their origin and chemical composition.

Type	Material	Properties	Typical applications
Inorganic fillers	Chalk, carbon black, talc, silicates	Heat-resistant, chemical-resistant, stable	Rubber, plastics, paints
Special fillers	Glass fibres, ceramics	High strength, insulating	Automotive industry, aerospace

Fillers are indispensable in numerous industries. Their versatility allows them to be used in a wide variety of materials and products.

Plastics industry

• Improving the stiffness and strength of plastic parts.

• Reducing costs by replacing base materials.

• Production of composites (e.g. glass fibre reinforced plastic).

Rubber industry

• Use of carbon black and silicates to increase tensile strength and elasticity.

• Improving resistance to abrasion and weathering.

Using fillers offers numerous advantages:

• Cost savings: reducing production costs by using lower-cost materials.

• Improved properties: adapting mechanical, thermal and chemical properties to specific requirements.

• Sustainability: use of recycled materials or biodegradable fillers.

• Material compatibility: not all fillers are compatible with every base material.

• Even distribution: uneven distribution can lead to weak points in the end product.

• Cost-benefit trade-off: high-quality fillers can increase production costs.

Fillers and reinforcing materials perform similar tasks but differ in their primary function:

Feature	Fillers	Reinforcing materials
Primary function	Cost reduction, increase in volume	Mechanical reinforcement
Typical materials	Chalk, carbon black, talc	Glass fibres, carbon fibres
Applications	Plastics, rubber, paints	Composites, structural materials
Costs	Low	High

• Are fillers always cheaper than base materials? Yes, as a rule fillers are used to replace more expensive materials, although high-quality fillers can also be expensive.

• Can fillers affect the recyclability of a material? Yes, inorganic fillers in particular can make plastics more difficult to recycle.

• Which fillers are biodegradable? Organic fillers such as wood fibres or cellulose are biodegradable and are often used in sustainable applications.

• How do fillers influence material properties? Fillers can specifically change the hardness, elasticity, thermal conductivity and other properties of a material.

Fillers are indispensable additives in numerous industries. They not only improve the mechanical and chemical properties of materials but also contribute to cost reduction and sustainability. Whether in plastics, rubber or paints, choosing the right filler can have a decisive influence on the performance and efficiency of a product.