How super glue is made
Super glue sets because moisture in the air, even on a dry-looking surface, triggers it.
- stations
- 6
- things upstream
- 15
- raw sources
- 7
- steps from the ground
- 5
The short version
Chemical plants make a cyanoacetate ester from ethanol and react it with formaldehyde to form a rubbery polymer. Heating that polymer under vacuum cracks it back into liquid monomer, which is distilled and stabilized. Water on the surfaces being glued later sets it off, and it hardens in seconds.
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Make the ester
Most super glue is ethyl cyanoacrylate. Its ethyl group comes from ethanol, which is joined to cyanoacetic acid to make the starting ester.
Goes in -
React with formaldehyde
The ester reacts with formaldehyde. Water is given off, and a solid polymer forms.
Goes in -
Crack the polymer
The polymer is heated under reduced pressure so it breaks back down into monomer, a liquid that boils off. A dark residue builds up on reactor walls, which makes cleaning a problem for plants.
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Purify the monomer
The monomer is condensed and distilled to remove impurities. Pure monomer is very prone to setting by itself.
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Add stabilizers
Small amounts of stabilizers keep the liquid from polymerizing in the bottle. Fumed silica may be added to make a gel that does not run.
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Fill sealed tubes
Glue goes into small tubes sealed against moisture. Once opened, shelf life is about a month, and a refrigerator can extend it.
Worth repeating
- The glue cures when hydroxide ions in water set off a chain reaction that links molecules into long, strong chains.
- Unopened super glue lasts about a year, but only about a month once opened.
- Fumes from warmed cyanoacrylate react with fingerprint residue on glass and plastic, leaving white ridges that forensic investigators can photograph.
Back to the ground
Follow every input upstream and super glue starts as these 7 raw sources.
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Sources
Cite this page: "How super glue is made." Assembly Line, 2026-11-03. https://assemblyline.org/make/super-glue