SHENYANG - A branch company of China's largest oil and gas producer PetroChina has put into operation a new production line of melt-blown nonwoven fabric in Northeast China's Liaoning province on Thursday.

It is expected to manufacture 500 tonnes of melt-blown nonwoven fabric a year. Another production line with the same annual capacity is being built to further boost the raw material supply to mask producers, according to PetroChina Liaoyang Petrochemical Company.

As the essential material to make medical masks, melt-blown nonwoven fabric is the filtering layer in the middle part of the mask.

It took workers around 38 days to build the production line, which usually needed at least six months, the company said.

China's centrally-administered State-owned enterprises have joined the efforts to stem COVID-19 by producing raw materials for mask makers. On Wednesday, China's largest oil refiner Sinopec has built and begun operating another two production lines of melt-blown nonwoven fabric in Beijing.