A clear price redistribution is taking shape inside the polyester chain. On September 24, PTA rose 2.85% in a single day to 7,147.50 yuan per tonne, while polyester staple fiber gained 1.53% to 8,596.75 yuan per tonne. In contrast, the three main filament varieties all weakened: FDY fell 1.37%, POY dropped 1.19%, and DTY slipped 0.27%. Within the same chain on the same day, the raw material end and the processing end moved in opposite directions, a sign that the market is repricing profit distribution.
Profit Redistribution Behind the Divergence
The year-on-year picture makes this divergence even clearer. PTA is up 56.30% year on year, polyester staple fiber up 33.80%, while FDY, POY and DTY are up 35.80%, 34.84% and 31.36% respectively. Raw material gains have consistently outpaced the processing end, meaning the conversion spread for polymerization and spinning has been continuously squeezed. For downstream mills, the higher the raw material price and the thinner the processing fee, the closer the volume-driven cost dilution model comes to its limit.
Another set of figures deserves attention. Acrylonitrile is up 35.82% year on year, nylon POY up 38.88%, nylon FDY up 26.55%, and nylon DTY up 29.83%. The nylon chain's year-on-year gains are broadly higher than those of polyester filament, indicating a tighter supply-demand balance for nylon raw materials. Spandex is up 19.59%, viscose staple fiber up 11.13%, rayon yarn up 6.97%, and cotton yarn 21S and 32S up 5.89% and 5.31%. The gains in regenerated cellulose and cotton spinning are notably milder, and the uneven temperature across sub-sectors is widening.
What Filament Concessions Mean
The simultaneous decline in the three filament varieties is the most industrially meaningful signal in this dataset. FDY, POY and DTY are typically seen as the finished end of the polyester chain, and their weakness usually points to two possibilities: weakening procurement willingness among weaving and texturing mills, or filament producers actively conceding margin to keep inventory turning. Combined with rising staple fiber and falling filament, the latter is more likely. Staple fiber has support from cotton-spinning substitution demand, while filament faces limited order visibility at the weaving end.
For buyers, falling filament prices do not mean cost pressure has eased. With PTA up more than 50% year on year, the raw material cost center for filament producers has already been lifted. The current price cut is more likely a phase of destocking than a trend reversal. Once polyester raw materials strengthen further, filament prices could rebound quickly. Treating the spot decline as a long-term positive is the easiest mistake to make in procurement right now.
Cotton edged down 0.23% to 17,399.17 yuan per tonne but remains up 15.30% year on year. Raw silk held flat at 435,600 yuan per tonne, down 6.17% year on year. The directional gap between cotton and raw silk shows that natural fibers are also diverging internally: cotton is constrained by global supply-demand and the new crop arrival pace, while raw silk is more affected by exports and cocoon costs. For blended and interwoven products, this divergence directly changes the cost ranking of fiber mix options.
Transmission Paths Upstream and Downstream
Stronger upstream raw materials combined with filament concessions affect weaving and fabric segments in two directions. On one hand, higher raw material costs compress the quotation space for weavers, especially in woven and knitted categories using polyester filament as the main input. On the other hand, the phase of falling filament prices gives weavers a short restocking window. The key is judging how long that window lasts.
Exporters should pay extra attention to year-on-year figures. PTA, nylon and acrylonitrile are broadly up more than 35% year on year, meaning the cost base for export products dominated by these materials is clearly higher than a year ago. If overseas customers still negotiate on last year's prices, supplier margins will be squeezed further. Writing raw material year-on-year increases into price adjustment clauses is more urgent than simply hedging currency.
From an industrial cluster perspective, texturing and weaving enterprises in polyester filament hubs are most sensitive to filament price swings, while cotton spinning and regenerated cellulose clusters face a milder but more persistent cost rise. The two types of clusters should not adopt the same strategy: the former should focus on procurement timing, the latter on optimizing fiber mix.