Why are major PTA producers expanding capacity despite an oversupplied market?

Why are major PTA producers expanding capacity despite an oversupplied market?
China's PTA capacity reached 8,601.5 kt/yr in 2024, over 60% of the global total, with output above 7,300 kt. Although the industry is mature and capacity growth has slowed to a seven-year low, leading producers continue to add capacity. The drivers include scale economics—Sinopec Yizheng's new 3,000 kt/yr unit is the world's largest single-train plant—and new demand from photovoltaic backsheets, which added roughly 500 kt of consumption last year. Meanwhile, about 2.1 million tonnes of outdated capacity, mostly pre-2010 units below 500 kt, were retired. Expansion is therefore a competitive strategy: newer, larger plants enjoy 15-20% lower processing costs, forcing older, higher-cost capacity out of the market and consolidating share among integrated leaders like Hengli and Rongsheng.