Fillers – a key element in compounding

What are fillers?

Fillers are powdery or fibrous additives that are incorporated into rubber or plastic compounds to selectively influence physical properties, processability, or cost structure. In elastomer processing, they affect hardness, abrasion resistance, density, reinforcement, as well as colour and thermal conductivity, among other things. Fillers are a central element in compounding – that is, the formulation development of rubber compounds – and are therefore significantly responsible for the performance of finished Molded Rubber and Molded Silicone such as seals, profiles or technical mouldings. Even with Plastic composite parts The targeted selection of fillers plays a crucial role, as it directly influences the adhesion and the mechanical interaction between the connected materials.

 

What are the properties and types of fillers?

Fillers can basically be divided into two categories:

  • Active fillers: improve mechanical properties (e.g. tear resistance, Abrasion)
  • Inactive fillers: mainly influence processability and costs, without a major reinforcing effect

 

Frequently used fillers in rubber technology:

  • Carbon blacks for mechanical reinforcement, UV protection and black colouring
  • Chalk (CaCO₃) as a cost-effective volumetric filler to reduce costs
  • Talc improves the gliding properties and dimensional stability
  • Kaolin / clayfor improving firmness and increasing volume
  • Silica (silicic acid) for improved abrasion resistance
  • Glass fibres / Aramid fibres for targeted reinforcement and dimensional stability
  • Metal oxides / Barium compounds for shaping weight, density, shielding effect, fire protection e.g. Al(OH)3

 

Filling materials are used in which areas and components?

Fillers are used in practically every technical rubber compound - e.g. for

Fillers have a decisive influence on both the processing properties and the subsequent product properties and are used specifically to adjust Rebound resilience, The materials are used to analyse the properties, formability, thermal conductivity, electrical properties and cost structure.