Unsaturated polyester resins: Cycles
How a trade war hit China's quartz stone exports
How a trade war hit China's quartz stone exports What this tab covers How its prices and margins move: past booms and busts with price levels, the spread or margin that the industry watches, the drivers of the cycle and the metrics to track.UPR is a conversion business with few published prices. Its price moves with styrene, maleic anhydride and glycols; producer margins depend on how quickly they pass on raw-material changes. Volumes cycle with construction, quartz stone exports, boats and cars. In China, output fell in 2018-2019 when US tariffs hit quartz stone, fell again in 2021-2022 with COVID and the property downturn, and recovered by 7% in 2023 (Chyxx). Listed Chinese producers earn low single-digit net margins, such as Shangwei's ¥65 million profit on ¥1.097 billion revenue in 2024.
The spread to watch UPR price minus (0.35 x styrene + 0.18 x maleic anhydride + 0.26 x phthalic anhydride + 0.27 x propylene glycol)Not published as an index; resin makers track it internally. Level not found in sources reached.
Booms and busts
- 2018-2019
The US-China trade war blocked quartz stone exports, a key Chinese UPR outlet, and Chinese UPR output fell (Chyxx).
not published in sources reached
- 2021-2022
COVID disruption and China's property downturn cut output again (Chyxx). Styrene and glycol costs rose with oil in 2022, squeezing resin makers (indicative).
not published in sources reached; MEG above $1,000/t in early 2018 and near $350/t in April 2020 show input volatility (MEG tile)
- 2023-2024
China output rose 7.27% to 3.23 Mt in 2023 and to about 3.45 Mt in 2024 on downstream demand and wind power; Yongyue's UPR revenue grew 13.4% to ¥158 million in H1 2024 (Chyxx).
not published in sources reached; styrene $990.50/t FOB ARA on 21 Nov 2023 (styrene tile)
- 2026
Aromatics spiked in March-April 2026 with Gulf disruption, raising styrene cost (benzene and styrene tiles).
Asian styrene $1,030/t on 2 March 2026, a one-year high (styrene tile)
What drives the cycle
- Styrene and glycol prices. About a third of the resin is styrene; aromatics and PO shocks pass through within weeks.
- Construction and water infrastructure. Pipes, tanks, panels and sanitaryware are the largest uses.
- Quartz stone trade. Tariffs on Chinese engineered stone cut UPR output in 2018-2019 (Chyxx).
- Wind and automotive composites. Wind blade composite demand rose 22% in 2025; SMC parts for electric vehicles grow (Mordor).
Metrics to track
| Metric | Why it matters | Where to track it |
|---|---|---|
| Styrene and maleic anhydride prices | Main cost signals | S&P Global, ICIS, Chinese data services |
| China UPR output (monthly) | Half of world volume | Oilchem (Longzhong), Chyxx |
| Listed producer results (Shangwei, Yongyue) | Margin signal | company filings |