Chinese manufacturers say almost 90 percent of the vuvuzelas used in South Africa are made in China.
The Ninghai Jiying plastics factory based in the gritty eastern Chinese coastal city of Ningbo is one such manufacturer raking in the profits from the vuvuzelas.
Its general manager Wu Yijun said he has been trying to market the vuvuzela for a long time, and South Africa's successful bid for the World Cup was the turning point for them.
"We had developed this vuvuzela trumpet in 2001, but we did not manage to sell it back then. During the 2006 World Cup in Germany, we did not manage to market it for the event, even when we sold other kinds of trumpets," Wu told Reuters.
"After South Africa was successful in its bid for the World Cup, we made our hardest push for the vuvuzela to be used for the tournament," he added.
His factory also manufactures other plastic products such as toys and water bottles, but he said demand for the vuvuzela has pushed his production line into overdrive.
"With regards to the production volume, from January to April this year, we were producing 250,000 vuvuzelas every day to fill containers that are exported from Ningbo port," Wu said.
"The production had stopped in April but there has been a gradual increase in our production in recent days.
"We were making 10,000 vuvuzelas a day for the past few days and I estimate we will make 25,000 per day in the next few days.
"The demand from the Chinese market alone is surpassing our production capability," he said.
