China Labor Watch, the advocacy group investigating the factories, said it found that employees had worked longer weeks than Chinese labor law allows, even excluding breaks. Such violations are common in Chinese factories.
A Huajian spokesman, Wei Xuegang, said the company knew nothing about the activists. Asked about the accusation from China Labor Watch, he said Huajian scheduled extra hours during busy times but paid workers according to the law. In a December interview, Zhang Huarong, the company’s founder and chairman, said Huajian followed overtime laws.
The Ivanka Trump brand declined to comment on the labor conditions or the activists. In terms of bringing jobs back to the United States, the company said, it was “looking forward to being a part of the conversation.”
Such tensions are fueling the drive of Huajian’s founder, Mr. Zhang, to move work to Ethiopia. A former drill sergeant in the Chinese military who sometimes leads his workers on parade-ground drills, Mr. Zhang says work like making shoes will never return to the United States and is increasingly difficult in China as well.
“Do Americans really like to work, to do these simple and repetitive tasks?” said Mr. Zhang, in the December interview. “Young Chinese also don’t want to do this after they graduate from college.”
In many respects, China’s economy is maturing.
The number of people who turn 18 each year and do not enroll in college — the group that might consider factory work — had plummeted to 10.5 million by 2015 from 18.5 million in 2000, government data shows. Because of the effects from China’s former “one child” policy, the figure is on track to fall below seven million by 2020.
Costs are rising too, as the government raises minimum wages and benefits in an effort to shift China’s economy away from cheap manufacturing. Wages in Dongguan have increased ninefold since the late 1990s, Mr. Zhang said.
Workers said they resented the hours, especially the unpaid breaks.
One employee’s printed schedule in December showed that the factory required 60 hours and 10 minutes of paid work per week. Chinese laws require that workweeks average no more than 44 hours and limit overtime to 36 hours per month.
On Monday, in the middle of China’s three-day Dragon Boat Festival holiday, throngs of workers filed into the factory. Asked whether he would be eating zongzi, the traditional rice dumpling served during the holiday, one worker replied that they don’t get to celebrate. Another said Huajian gave each worker two small dumplings and an egg for the holiday.
One worker, a middle-aged woman with the surname Du, said her children had gone home to central China. Ms. Du wished for time off to celebrate, so she could make rice dumplings for them.
Mr. Zhang said that his company kept working hours within legal limits, despite workers who want more overtime pay.
“We cannot let them work extra hours just because they have low pay,” Mr. Zhang said in a lengthy interview in December. “We have thought about it, but we want to do business well.”