Polyester filament yarns rose collectively within a week, while acrylonitrile plunged 4.46% in the same period—such a sharp divergence within one sector is uncommon in recent textile raw material markets. According to data from Shengyi She, in week 34 of 2026 (August 24-28), 10 textile commodities rose, only 3 fell, yet the average weekly change was a mere 0.03%. On the surface, it seems calm, but beneath lies strong undercurrents.
Background
Among the gainers, the polyester filament trio—POY, DTY, and FDY—recorded weekly increases of 2.00%, 1.76%, and 1.70%, respectively, with year-on-year gains exceeding 21%, indicating that this uptrend is not a short-term blip but a sustained recovery with fundamental support. Meanwhile, nylon series (DTY, POY, FDY) rose between 0.29% and 0.97%, lower than polyester but still positive, suggesting the entire synthetic fiber sector is in a moderate recovery channel.
The feedstock side told a different story. Acrylonitrile dropped 4.46% weekly, yet its year-on-year gain remained high at 44.12%, meaning prices are retreating but still far above last year. PTA fell 3.67% (up 26.54% YoY), and polyester staple fiber declined 0.96% (up 17.93% YoY). This pattern of "finished goods rising, raw materials falling" points to a key insight: the current polyester filament price hike is not purely cost-driven but largely a result of downstream demand recovery and inventory destocking.
Notably, cotton rose only 0.06% weekly, cotton yarn 21S and 32S were flat, while viscose staple fiber and spun rayon rose between 0.42% and 0.69%. The natural and regenerated fiber segment was generally mild, contrasting with the active synthetic fiber sector. This may imply that downstream order improvements are currently concentrated in chemical fiber products, while the cotton textile chain awaits clearer recovery signals.
Industry Impact
The divergence between polyester filament and PTA directly affects profit distribution along the chain. According to conventional cost pass-through logic, falling raw material prices should compress the room for polyester filament price hikes, but the opposite occurred, indicating that polyester filament producers have gained some pricing power, backed by improved supply-demand dynamics. For buyers, this means polyester filament prices are likely to remain firm in the short term; to lock in costs, monitor next week's inventory data and downstream loom operating rates.
The sharp drop in acrylonitrile sends different signals to acrylic fiber and ABS-related chains. Still over 40% higher YoY, the current correction looks more like a pullback from earlier overvaluation than a trend reversal. For plants relying on acrylonitrile, this decline may offer a brief restocking window, but be cautious of supply tightening from Q4 plant turnarounds.
PTA's decline is a double-edged sword for the polyester chain. On one hand, it reduces production costs for polyester filament, helping sustain margins. On the other, if PTA continues to weaken, it may raise doubts about downstream demand strength, potentially capping further polyester filament price increases. Foreign trade firms should especially watch this price linkage, as it directly impacts export quote competitiveness and profit margins.
From a regional industrial belt perspective, rising polyester filament prices benefit chemical fiber clusters like Shengze and Changxing, where improved profitability may spur equipment upgrades or capacity expansion. Conversely, the acrylonitrile drop favors coastal petrochemical downstream processors in Ningbo and Shanghai, but inland acrylic fiber production areas may face greater price competition pressure.