Fillers in a Rubber Compound

August 18, 2023 · Neethu Paramewswaran Namboodiri

FILLERS:

Ingredients added to a large extent to a rubber compound to increase the ultimate properties (stress-strain, fatigue and abrasion resistance) leading to increased service life, at the same time reducing the compound cost.

Fillers are mainly used in rubber compounding to enhance the physical properties of rubber composites

Fillers are classified into Organic and Inorganic Fillers.

FILLERS
ORGANIC		INORGANIC
Natural	Synthetic	Natural	Synthetic
Inactive Semi-Active Active	Inactive Semi-Active Active	Inactive Semi-Active Active	Inactive Semi-Active Active
Cork Saw Dust	Synthetic Resin Cellulose Deriv	Minerals	Carbon Black, Silicas, Metal Oxides, Metal Salts

Filler classification in relation to activity and reproduction

FILLERS
Rein-forcing Type		Extending Type
Carbon- Black	Non-Black	Calcium Carbonate Barium Sulfate Aluminium Trihydrate Talc and Soapstone
Increasing order of particle size: N220(ISAF) N330(HAF) N550(FEF) N762(SRF-LM) N990 (MT)	Silica Zinc Oxide Magnesium Carbonate Aluminium Silicate Sodium Aluminosilicate Magnesium Silicate

Function of a Filler:

To improve wear and tear characteristics of the vulcanisates (Reinforcing Fillers)
Economics of the compound
To take care of the processing characteristics of the compound
To pertain special properties like Flame Resistance, Electrical Properties etc.
To impart colour as required to a compound.

Reference:

https://rubberworld.com/product/rubber-reinforcement-with-particulate-fillers/

https://www.vanderbiltworldwide.com/public/assets/uploads/documents/technical/Non-Black_Fillers_Web.pdf