PTA surged 54.21% year-on-year while cotton yarn 21S fell back to 23,366 yuan/tonne — within a single week, the textile raw materials market staged the sharpest version of the "upstream feast, downstream famine" script. In Week 38 of 2026 (21-25 September), China's textile commodity sector showed a rare two-way split: polyester raw materials edged up against the trend, while cotton yarn accelerated its decline, leaving the sector's average weekly change at -0.11%, essentially flat. This structural divergence beneath a calm surface is more alarming than a one-way fall.
The Solo Rally in the Polyester Chain
All five gainers this week were concentrated in the polyester and viscose chain. PTA led with a 1.39% weekly gain, closing at 7,147.50 yuan/tonne, up 54.21% year-on-year. Polyester POY followed with a 0.40% rise to 9,380 yuan/tonne, a 34.96% year-on-year increase. Viscose staple fibre and spun rayon yarn posted modest gains of 0.41% and 0.27% respectively.
This rally is not demand-driven. PTA's strength stems more from crude oil cost support and its own processing fee recovery, yet downstream polyester chip and staple fibre prices have failed to follow. Polyester staple fibre actually fell 0.56%. Upstream unilateral gains without midstream pass-through suggest polyester plants are losing appetite for raw material restocking. For buyers, current PTA levels have already priced in part of the peak-season expectation, and chasing highs carries accumulating risk.
Weakness Signals in the Yarn Segment
Two of the top three decliners were cotton yarns. Cotton yarn 21S dropped 1.27% to 23,366.67 yuan/tonne, while 32S fell 1.20% to 24,800 yuan/tonne. More notably, their year-on-year gains were only 5.89% and 5.31% respectively, creating a massive gap with PTA and polyester POY's 30%-plus annual increases.
What does this gap mean? Cotton costs rose 15.18% year-on-year (cotton lint closed at 17,399.17 yuan/tonne), yet yarn prices lag far behind raw material gains, severely squeezing spinning mills' spot margins. This week cotton lint dipped 0.02% while yarn prices accelerated downward, indicating insufficient loom utilisation and high yarn inventories. Spinners are trading price for volume. Polyester FDY fell 1.57% to 9,633.33 yuan/tonne, also pointing to order contraction in filament weaving.
Industrial Belt Transmission and Expectations
From a regional perspective, polyester filament clusters in Jiangsu and Zhejiang face narrowing FDY-POY spreads this week, compressing texturing plant margins. Cotton spinning clusters in Shandong and Henan confront dual pressure from falling yarn prices and high cotton costs, with some small and medium mills showing signs of production cuts.
Raw silk, spandex, and nylon prices were flat this week, with year-on-year changes of -6.17%, +19.59%, and +29.83% respectively. Nylon's notable annual gain but weekly stagnation reflects a standoff between caprolactam cost support and weakening downstream demand. Acrylonitrile rose 36.10% year-on-year but was flat weekly, also indicating firm costs and cautious demand.
Overall assessment: the textile raw materials market is shifting from "cost-push inflation" to "demand-verification divergence." Whether the polyester chain's high year-on-year gains can hold depends on whether weaving orders materialise from late September to October; the cotton yarn decline may persist until around the concentrated new cotton arrival.