Graphite EPS vs white EPS: what changes in your process
Lower thermal conductivity, and a few process points to watch.
Graphite EPS, often called grey EPS, contains fine graphite particles. The graphite absorbs and reflects infrared radiation inside the foam, which cuts heat transfer. The result is lower thermal conductivity than white EPS at the same density.
Why insulation makers use it
Lower thermal conductivity means a graphite board reaches a given insulation value at less thickness, or at a lower density. That makes it popular for external wall insulation systems and other building boards where thickness and weight count.
What changes in production
- Pre-expansion: graphite beads respond differently to steam than white beads. Expect to adjust steam pressure and time when you first switch, and check the pre-expanded density closely.
- Ageing: give pre-expanded beads and moulded blocks enough maturing time before moulding and cutting, so dimensions are stable.
- Moulding and cutting: run trials to set block moulding and cooling cycles. Graphite boards are cut on the same hot-wire equipment as white EPS.
Protect boards from the sun
Grey boards absorb much more sunlight than white ones. Left in direct sun on a building site, they can heat up enough to warp or shrink. Store them covered and shade the wall during installation.
Fire performance
The graphite grades we supply are flame retardant and HBCD-free. Check the classification your local building code requires for the finished board.