Polyester filament prices rose 2% in a single week while acrylonitrile plunged 4.46% - the textile raw material market in the last week of August 2026 displayed an extreme divergence rarely seen in recent years. This divergence is not accidental; it reveals the deep logic of profit redistribution along the upstream-downstream chain and signals that procurement strategies need structural adjustment in the coming period.
Event Background
According to price monitoring data from Shengyi She, during the 34th week of 2026 (August 24-28), textile sector bulk commodity prices showed mixed movements, but the direction of changes was highly concentrated. Among 17 monitored varieties, 10 rose, only 3 fell, with an average change of 0.03%. On the surface, it seemed calm, but underneath, currents were strong.
The top three gainers were all from the polyester family: polyester POY rose 2.00% to 8,767.50 yuan/ton, polyester DTY gained 1.76% to 9,930.71 yuan/ton, and polyester FDY increased 1.70% to 8,970.00 yuan/ton. All three recorded year-on-year gains above 21%, indicating the polyester chain is in an upward prosperity cycle. Meanwhile, nylon filament rose 0.86%-0.97%, viscose yarn and staple fiber gained 0.69% and 0.42%, respectively, showing a broad upward trend in raw materials.
Falling varieties were concentrated in upstream chemical raw materials. Acrylonitrile dropped 4.46% to 11,433.33 yuan/ton, PTA fell 3.67% to 6,213.25 yuan/ton, and polyester staple fiber declined 0.96% to 7,744.82 yuan/ton. Notably, despite the largest weekly drop, acrylonitrile still rose 44.12% year-on-year, indicating prices remain at historically high levels; this decline may be a correction to earlier excessive gains.
Industrial Impact
The divergence between polyester filament and PTA is the most intriguing signal this week. Theoretically, PTA is the main raw material for polyester filament, and their prices should be highly correlated. However, PTA fell 3.67% while polyester filament rose 2%, implying that processing margins for polyester filament producers are expanding significantly. According to industry estimates, the spread between polyester POY and PTA widened from 2,146 yuan/ton at the start of the week to 2,554 yuan/ton at the end, a nearly 20% increase in weekly processing profit.
This margin expansion is a clear positive for polyester plants. On one hand, lower raw material costs ease cost pressure; on the other hand, downstream weaving enterprises are showing stronger restocking intentions, keeping polyester filament sales rates at high levels. Year-on-year, polyester filament prices are up over 21%, recovering losses from 2024-2025, and industry profitability has markedly improved.
The consecutive decline in acrylonitrile sounds a warning for the acrylic fiber chain. As the main raw material for acrylic fiber, acrylonitrile fell 4.46% in a week, but year-on-year it is still up 44.12%, indicating prices remain at nearly two-year highs. For acrylic fiber producers, falling raw material costs are beneficial, but if downstream demand does not recover in tandem, product prices may face greater downward pressure.
Notably, cotton prices edged up 0.06% this week while cotton yarn prices were flat, widening the gap between cotton and polyester. Currently, polyester POY is about 14,600 yuan/ton cheaper than cotton yarn 21S, a historically wide gap that will continue to push downstream weaving enterprises toward polyester, substituting for cotton demand. For cotton textile enterprises, maintaining orders amid a widening polyester-cotton spread has become an unavoidable challenge.