Tens of thousands of mask-making companies mushroomed in China when Covid-19 first emerged, but now they struggle to survive.

China boosted production of medical protective gear to deal with a shortage of supplies when Covid-19 broke out in the country at the end of last year and then spread globally.

With huge government support, more than 73,000 Chinese companies registered as export enterprises in the first half of the year, of which more than 36,000 were registered in April alone, when demand soared.

Companies, from making cars to diapers, converting lines to making masks.

Now, with the epidemic in mainland China largely under control, the drastic drop in domestic demand for masks causes prices to be pushed down.

"We don't have to export around the clock like before," Yang added.

Some companies that once rushed in are now withdrawing from the industry.

Many companies have reported significantly reduced orders and some are reorienting businesses.

"Our company has a number of business lines. We have accelerated the export of pangasius when the pandemic hit China, but will shift to other products in the future," said Xu.

Xu said the company now sells masks for 0.4 yuan per piece, a quarter of the price it sold at a time when the epidemic was rampant in China.

After other countries complained about the quality of Chinese export masks, the country's officials tightened the management, requiring companies that export medical supplies to have product quality certificates.

From March to May, China exported more than 50 billion masks, 10 times more than the total volume sold abroad last year.

However, tensions in international relations between China and other countries also affect the industry.

But analysts say China will still be the world's top supplier of masks, as large businesses continue to ramp up production amid the continued global virus attack.

Last month, the US company 3M said it was on track to produce two billion N95 masks by 2020, double its output today.

"There will still be demand from the US, many other countries in Asia and the EU, which cannot be self-sufficient. Meanwhile, many manufacturers of poor quality masks will continue to be rejected.