Expandable Graphite

The story of today’s flame retardant additives began 50 years ago. Fire suppression as such was the initial focus. New requirements were quickly added, such as reducing smoke development and preventing the formation of toxic gases. Environmental and health protection are also essential today. Expandable graphite is gaining great popularity as a halogen-free, mineral-based flame retardant that meets all of these requirements.

What makes expandable graphite so special and unique?

The secret of expandable graphite lies in its expanding and therefore flame-retardant effect. Natural graphite has a special layer structure that allows the intercalation of molecules between the graphite layers. In case of fire, the graphite layers are pushed apart like an accordion. This effect is used to form a protective intumescent layer or to partition off cavities and feedthroughs, depending on the application. The extension of the fire is slowed as a result and underlying materials are protected.

  1. Halogen-free and registered according to REACH
    as a flame retardant on a mineral basis, expandable graphite is not just free of halogens but also REACH-compliant

     

  2. Easy to apply and highly efficient
    expandable graphite can be integrated as flakes or a master batch, and has a flame retardant effect even at a low degree of filling due to even distribution

  3. Works on its own and as a synergist
    expandable graphite can be used as the sole flame retardant additive or works as a synergist in combination with other additives, such as APP or ATH

     

Selecting the appropriate grade of expandable graphite to meet individual requirements is an art.

Expandable graphite is typically integrated into composites, compounds, master batches and coatings. Fire protection systems, foam products and plastic components are just a few of the many possible applications in which expandable graphite is used as a flame retardant today. However, the requirements for the flame retardant additive are different for each base material and every application.

The start temperature, expansion rate and particle size are among the key selection criteria. With foam products, the pH value plays a particularly important role so as not to impair the reaction of the two components.

Concise explanation of the product characteristics

Start temperature

has to be matched to the processing temperature and ambient temperature

Composition

determines the properties of the expandable graphite grade

Expansion rate

determines the density and thickness of the protective intumescent layer

Purity

should be high in case ash components interfere with the application

Particle size

determined by the application or manufacturing process

pH value

in the neutral range, prevents chemical reactions and corrosion

Your contact person

Alexander Schleider

The right additive or special raw material specification exists for every application. Let’s find the appropriate solution together. Our team and I are happy to help you.

+49 (0)6123 798-24

Fields of application

Expandable graphite is used primarily as a halogen-free flame retardant additive, but further processing into conductivity additives or films and moulded parts made of natural graphite foam is possible as well.