How Do You Make Nylon? Part 1

Making Nylon Salt

▪ Add 1 molal part of hexamethylene diamine [NH2(CH2)6NH2].
▪ Add 1 molal part of adipic acid [HOOC(CH2)4COOH].
▪ Stir in deionized water at 70 oC.
▪ Precipitate the nylon salt from solution.

Making Nylon Polymer

▪ Evaporate nylon salt solution to ~80% salt. Drop (feed) solution into autoclave.
▪ Add acetic acid (stabilizer) and TiO2 (delusterant) if needed.
▪ Set autoclave controls to 295 oC and 250 psi.
▪ At 250 oC instantaneous polymerization occurs resulting in a polymer of 15,000 to 18,000 desired molecular weight.
▪ Automatically the H2O is bled off to 0 psi over a 30 minute period.
▪ Hold autoclave at 0 psi for 30 minutes to "settle" molten polymer.
▪ Extrude (cast) nylon [as ribbon] over a roll sprayed with water.
▪ Cut nylon ribbon into chips.
▪ Blend batch with five other batches to obtain average uniformity (molecular weight).