Polyester Filament Prices Rise Across the Board: Cost Push Versus Weak Demand

A median increase of 100 yuan per ton across most specifications in the Changshu polyester filament market in mid-September may look modest, but it exposes the core tension in the polyester supply chain: raw material costs are pushing prices up while demand refuses to follow.

The Price Map: What Rose and By How Much

Public quotations show that between September 10 and 13, polyester filament prices were adjusted across the board in Changshu and surrounding production areas. In the FDY segment, 68D/24F from Rongsheng Petrochemical rose from 10,250 to 10,400 yuan per ton, up 150 yuan; the same specification from Tongkun Group gained 100 yuan to 10,300 yuan per ton. The 75D/36F from Xiaoshan Shuangtu and Tongxiang Xinfengming both increased by 100 yuan, quoted at 9,950 and 10,000 yuan per ton respectively.

In DTY, 75D/36F from Taicang texturing mills reached 11,300 yuan per ton, up 100 yuan; 100D/36F from Jiangsu Wujiang and Taicang both rose 100 yuan to 11,000 yuan per ton; 200D/96F from Zhejiang Yuandong jumped 200 yuan to 10,450 yuan per ton, the largest gain in the sample. Bright FDY followed suit, with 50D/24F from Rongsheng Chemical Fibre climbing to 10,550 yuan per ton, and 75D/36F from multiple origins concentrated in the 10,100-10,150 yuan per ton range.

Notably, the increases were unevenly distributed. Conventional semi-dull items mostly rose 50-100 yuan, bright and fine-denier specifications reached 100-150 yuan, and coarse-denier DTY saw a 200-yuan jump. This suggests that price adjustments were not uniform but differentiated according to inventory tightness and production scheduling for each specification.

Cost-Driven, Not Demand-Pulled

The direct driver of this rally is firmer polyester raw material prices. PTA and monoethylene glycol, the two main feedstocks for polyester filament, have been trending upward, directly raising costs in the polymerization and spinning stages. When raw material gains outpace filament price increases, mill cash flow is squeezed, making price hikes a passive choice.

The key problem, however, is that sales volume has not expanded. This means the price increase lacks support from end-user orders. If weaving enterprises do not have sufficient urgent orders on hand, they typically choose to wait and see in the face of rising raw materials rather than chase prices and restock. Changshu, as a major warp-knitting and weft-knitting industrial belt, has its polyester filament procurement rhythm directly reflecting downstream operating rates. The current divergence between price and volume indicates that weavers lack confidence in the outlook.

For buyers, the sustainability of this cost-driven rally depends on two variables: whether crude oil and PTA can maintain strength, and whether weaving orders will seasonally recover in late September. If the two do not resonate, the gains could be absorbed or even reversed within one to two weeks.

Supply Chain Transmission: Who Bears the Pressure First

From a supply chain perspective, polyester filament price increases first squeeze the margins of texturing and weaving mills. DTY processors earn from the spread between filament prices and processing fees. When POY and FDY rise simultaneously, the spread in the texturing segment may not widen and could even narrow due to downstream price pressure.

Changshu, Taicang, Xiaoshan, and Tongxiang moved in lockstep in this round of price adjustments, reflecting the strong pricing coordination capability of leading polyester enterprises. Quotation changes from companies such as Rongsheng, Tongkun, Xinfengming, and Hengyi are often viewed by small and medium-sized mills as bellwethers. Under this structure, smaller texturing and weaving mills are essentially price takers with little bargaining power.

The impact on the export side is more indirect. Polyester filament price increases will gradually feed into fabric costs, but fabric export quotations usually have a lock-in period of one to three months. In the short term, exchange rates and tariff factors may have a greater impact on quotes than raw material fluctuations. If filament price gains continue to accumulate, profit margins on fabric exports in the fourth quarter will be compressed.

Practical Recommendations

For Buyers - Avoid chasing prices to restock at current levels; prioritize drawing down existing inventory and wait for clearer order signals in late September. - For bright and fine-denier specifications, consider locking in some forward orders, as these items have seen larger increases and tighter inventory. - In negotiations with suppliers, focus on payment terms and volume discounts rather than haggling over unit price alone, to hedge against raw material volatility.

For Mills - Texturing and weaving enterprises should recalculate processing fee margins. If filament prices continue to rise while downstream refuses to accept higher prices, control operating rates to avoid widening losses. - Monitor PTA and MEG futures trends as leading indicators for short-term filament direction. - Differentiated product lines, such as bright and functional fibers, have stronger pricing power and should be prioritized in production scheduling.