Material Insights · Understanding the Material World

Caprolactam and Nylon (PA6, PA66)

Caprolactam is the monomer of nylon 6, so the two form one chain in which nylon 6 is priced as caprolactam plus a margin. Nylon 66 is made from other monomers, so caprolactam ties to only part of the nylon family, and older caprolactam routes also turn out large volumes of ammonium sulphate fertiliser.

Caprolactam (chemical) and Nylon (PA6, PA66) (chemical): 5 relationships.

How they are linked

1. Monomer of nylon 6

Physical flow · Strong · Caprolactam into nylon 6

Nylon 6 is made by opening and polymerising the caprolactam ring, so caprolactam is its only monomer; nylon 66 instead comes from adipic acid and a diamine made via adiponitrile.

  • 9.9 Mt world caprolactam capacity a year, 2024

Caprolactam is the key raw material for nylon 6, which goes into tyre cord, filament yarn and engineering plastics. Nylon 66 links instead to butadiene through the adiponitrile route, so a caprolactam shock moves nylon 6 prices but only indirectly those of nylon 66.

Sources: Chemical Week; Indian Chemical News; American Chemistry Council

2. Ammonium sulphate co-product

Joint production · Medium · Caprolactam plants also make fertiliser

Classic caprolactam routes neutralise acid with ammonia during the process, leaving ammonium sulphate that is sold as nitrogen and sulphur fertiliser.

  • about 4.5 t ammonium sulphate per tonne of caprolactam at FACT's plant (225 kt with 50 kt)

The fertiliser credit lowers the net cost of caprolactam when fertiliser prices are firm and raises it when they are weak, which feeds through to nylon 6 costs. It also means nylon demand affects ammonium sulphate supply in farm markets.

Sources: Fertilisers and Chemicals Travancore (FACT)

3. China dominates both

Geography and ownership · Strong · Same country sets both markets

China built most new caprolactam capacity together with nylon 6 polymer and yarn plants, so Chinese decisions set prices for both.

  • about 63% China's share of world caprolactam capacity of 9.9 Mt a year, 2024
  • 1.2 Mt a year capacity of the largest producer, Highsun, China

After prices fell to multi-year lows, Chinese caprolactam producers agreed after an industry meeting on 5 November 2025 to cut output by 20% across the board. Over 6 to 20 November, east China molten caprolactam rose by 450 to 500 yuan to 8,600 to 8,650 yuan a tonne, while nylon 6 resin was assessed at US$1,170 a tonne FOB China on 19 November.

Sources: Chemical Week

4. Price link: main product

Cost and price · Strong · Both ways

With caprolactam the only monomer of nylon 6, monomer prices pass quickly into polymer and yarn prices, and weak nylon demand pushes back on caprolactam.

  • 0.38 monthly change correlation
  • 0.73 12-month change correlation
  • 1.14 fitted elasticity

The site's series are broad proxies, a cyclic intermediates index and a resin index, so they understate the very tight link between caprolactam and nylon 6 chip prices. They also blend in nylon 66, which follows a different chain.

Sources: Material Insights (World Bank, FRED, IMF data)

5. Trade remedies on the monomer

Policy · High in India · Caprolactam duties reach nylon users

A duty on caprolactam protects the domestic monomer maker but raises costs for nylon 6 polymer, yarn and tyre cord makers that buy imported monomer.

In October 2026 India opened an anti-dumping investigation into caprolactam from China, Russia, Thailand and the US on a petition from GSFC, which said imports had surged while local demand fell. The outcome will set the cost base for Indian nylon 6 tyre cord and textile yarn.

Sources: Indian Chemical News; ChemAnalyst

For investors

Key learnings

  1. Nylon 6 is priced off caprolactam, its only monomer, so the monomer cycle drives margins along the whole chain.
  2. China held about 63% of caprolactam capacity in 2024, so coordinated Chinese output cuts, like the 20% cut of November 2025, move both monomer and polymer prices.
  3. Ammonium sulphate credits make caprolactam costs partly a fertiliser story, which matters most for older plants.

What to track

  • Caprolactam price against benzene: Shows monomer margin and pressure on nylon 6 (Weekly · industry price reports)
  • Nylon 6 chip price against caprolactam: Shows polymer margin and downstream demand (Weekly · industry price reports)
  • Chinese caprolactam operating rates and agreed cuts: Signal supply discipline or a glut (Monthly · industry reports)

For policymakers

Key learnings

  1. India has only two caprolactam makers, GSFC and FACT, and imports the rest, so trade remedies on the monomer shift costs to nylon yarn and tyre cord makers.
  2. Caprolactam plants are also fertiliser producers: FACT's 50 kt plant makes about 4.5 t of ammonium sulphate per tonne of caprolactam.
  3. Chinese capacity sets world prices, so a duty on caprolactam raises Indian nylon 6 costs against Chinese yarn and fabric competitors.

What to track

  • DGTR caprolactam investigation and findings: Duties raise nylon 6 input costs in India (As notified · DGTR)
  • India caprolactam and nylon 6 imports: Show reliance on imported monomer and polymer (Monthly · DGCI&S)

India

GSFC and FACT are India's only caprolactam makers; India's demand was about 144 kt in 2018. FACT's 50 kt Udyogamandal plant, commissioned in 1990 with 225 kt of ammonium sulphate by-product, was shut in 2013 and restarted in 2021. In October 2026 GSFC petitioned for anti-dumping duties on imports from China, Russia, Thailand and the US, which nylon 6 users would bear.

Sources

  1. Price correlation, Material Insights, Material Insights (World Bank, FRED, IMF data)
  2. China's caprolactam producers agree to production cut, Chemical Week (2025)
  3. India launches anti-dumping investigation into caprolactam imports from China, Russia, Thailand and US, Indian Chemical News (2026)
  4. Overview of 1,3-butadiene: physical and chemical properties, American Chemistry Council
  5. Caprolactam plant, Udyogamandal, Fertilisers and Chemicals Travancore (FACT)
  6. Caprolactam plant in Kerala resumes operation, ChemAnalyst (2021)