How melamine resin is made

That hard, glossy plate and the Formica counter come from urea and formaldehyde. So does the Magic Eraser.

stations: 6
things upstream: 13
raw sources: 7
steps from the ground: 4

The short version

Molten urea turns into melamine, a ring-shaped molecule that is 66% nitrogen. Reacted with formaldehyde, it gives a syrupy resin that sets permanently under heat and pressure. Paper soaked in it becomes the top skin of laminate flooring and countertops, and powder pressed in a hot mold becomes tableware, one of the hardest plastics made.

Make the urea

Ammonia and carbon dioxide combine into urea. Melamine plants are often built alongside urea plants because of the feedstock and the gases they hand back.

Goes in
Ammonia Carbon dioxide
Turn urea into rings

Molten urea goes onto a fluidized bed of catalyst, kept moving by hot ammonia gas, or into a high-pressure liquid reactor. Six molecules of urea give one of melamine, and the waste gases return to the urea plant.
Crystallize the white solid

The output is cooled, and off-gas is separated from a melamine-rich slurry. That slurry is concentrated and crystallized into a white solid.
Condense with formaldehyde

Formaldehyde attaches to the melamine rings, up to six at a time ideally. The result is a resin that can still flow. Further heating with acid would link it up permanently, so the reaction is stopped short.

Goes in
Formaldehyde
Saturate paper or dry powder

Decorative paper is soaked in the liquid resin for laminates. Other batches become powder for molding or stay liquid as adhesive for particle board.
Press it hard with heat

Heat and high pressure in a press or closed mold cross-link the molecules into one network. After this it cannot melt again. Cross-link density can be tuned by mixing in related molecules such as benzoguanamine.

End of the lineMelamine resin Next it goes into laminate flooring.

Worth repeating

Molded plates and food containers switched from urea resin to this one beginning in the 1950s, because it resists moisture better and is harder.
The foam sold as the Magic Eraser is a special form of the same resin.
Farmers were once expected to use melamine as fertilizer because of its 66% nitrogen, but it cost too much to produce.