Internationally most countries are interested in establishing and sustaining high level of fire safety in consumer products. The role of flame retardants as a part of solution is well recognized. Majority of the flame retardants are still halogenated chemicals and they operate in the gas phase by diluting combustible gases. During flame retardant action, there is a loss in the mass of the polymer, which is very high and is responsible for producing toxic gases like carbon monoxide etc .These gases are considered to be harmful and contaminate the fireplace and surroundings due to high toxicity.

Present need is to reduce the toxic gases during fire, this is possible by using non-halogenated flame retardant.

Due to the common efforts made by the producers and end-users, expandable graphite, as a halogen-free intumescent flame retardants, has been found a lot of applications in industries. Today, expandable graphites with special designed properties, so as to satisfy different demands in industries, are already commercially available. Many problems have been solved regarding product properties and quality consistency.
Applications

During the recent ten years, great progress had been achieved regarding the application of expandable graphite in flame retardant materials. Some main applications are listed below.

1 Foam Products

Due to its easy ignition and rapid fire spread rate, reducing fire risk for polymeric foam products had always been considered as a top priority. Now expandable graphite had been used in PU foam. Such flame retarded PU foam had been used as seat material in aircraft and other traffic tools. It was also used as heat and sound insulation sheet for car after special treatment.

In building industry, such flame retarded PU foam has been used as sealing tape in windows and doors. Besides used in PU foam, expandable graphite was also used at EVA foam and now is of interest to be used in EPS foam.

2 Coating

Expandable graphite had been found its application in intumescent flame retarded coatings. Fine particle size expandable graphite had been used in steel structure flame retarded coatings in many countries.

3 Polyolefin

Expandable graphite had already been used in PE, PP and other POs when halogenated flame retardant was forbidden use, although up to know after using expandable graphite the mechanical property would be reduced more or less. Expandable graphite was mainly used in Plastics /Metal (Al) composite board at the moment.

4 Bitumen Roof Sheets

Recently expandable graphite had been used in bitumen roof sheets. For this application the black colour was not a barrier for use. Expandable graphite has very good flame retardancy to bitumen roof material.

5 Other applications

In China, using steel pipes as waste water pipes in buildings are not allowed now. Plastics pipes now are commonly used for rain water pipes and waste water pipes. Anti-fire ring then is forced to be used by regulation when the pipes pass through floors. Expandable graphite had been used in such rings by large amount. Together with resin and other additives, expandable graphite expanded during fire and then sealed the space caused by its melting or burning of the plastics pipes.

In other applications like fire-stop putties, fire-stop pillows, expandable graphite had replaced other intumescent agents and used widely.

In the back adhesives of carpets, we could also find the existing of expandable graphite.

6. New equipment for PU and other applications

In some application areas, for example, for PU foam industry, in order to use expandable graphite into the original system, modification of the equipment was necessary. Nowadays, company like Bayer/Hennecke as well as Cannon had already found solutions to use expandable graphite in PU foam production line by changing some components of the equipment. Because normal expandable graphite has a particle size of about 50mesh (0.3mm), if the expandable graphite sprayed out with the polyol under high pressure, it would damage the mixing header by strongly abrasion in one side. And in other side, the expandable graphite flake will break into very small pieces and lost its capability of expansion. So make some modification to the mixing header is necessary and in fact such work had already been done [5]. Besides, expandable graphite should be dispersed into the polyol homogenously, such a solid / liquid mixing system as well as a suitable tube conveying system were also necessary to be set.

Comparing with other flame retardants, the advantages of expandable graphite are:

• Non-toxic
• No heavy metals
• Halogen free
• Not soluble in water and other solvents
• Smoke reduction and reduction of toxic gas
• Reduced HRR
• Improved thermal conductivity
• Synergism with other halogen-free flame retardants
• SET between 150 and 300 degree C.

However, to use expandable graphite much widely, there are still many works to be done. To change the black color, to reduce SET even lower and to get smaller particle size but still with bigger expansion, etc, many new demands had been put out from industries. On the other side, to work together with equipments suppliers to improve the handling of expandable graphite are still necessary for some applications.

Yes, now we are in North America, Central America, South America, Mexico, Germany, Spain, Italy, Netherlands, Luxemburg, Belgium, Switzerland, United Kingdom and all Asian Countries.  If you are not from these territories please contact us.  We are in search of customers and agents.

Yes, we are having products with different grain sizes.  Please check our product page on this site.  If you are having a different specification than ours, please contact our technical team with your specifications, so that we can make a tailor made product to suit your applications.  And also our product is stable in all properties such as expansion, pH, moisture etc.