SHIJIAZHUANG, Nov. 18 (Xinhua) -- The chilly weather in winter did not sap workers' ardor at a factory in Xinhe County, north China's Hebei Province.

They are busy manufacturing 600,000 eyeglass cases, a French order. "The client is extremely strict with time so we must ensure on-time delivery," said Li Yingchun, the company manager.

The company produces 27 million eyeglass cases a year, 70 percent of which are exported to Europe, the United States, India and other countries, with an export value of 5.45 million U.S. dollars.

Xinhe County is home to more than 400 manufacturers of eyeglass cases, with more than 10,000 residents of its less than 180,000 population involved in eyeglass case industry.

The county produces over 600 million eyeglass cases a year, grabbing a domestic market share of more than 60 percent. Its products are exported to more than 20 countries and regions, with a global market share of about 40 percent.

What has made the small county a big eyeglass case producer? It all began in the 1970s when a village factory was set up to make eyeglass pouches.

"Their products were later replaced by eyeglass cases and the family workshops here were upgraded into standardized modern factories over the past decades," said Su Jianxin, president of the local eyeglass case industry association.

Now a number of large enterprises have stationed in the county, making it the biggest production base of spectacle cases in northern China.

"To win the favor of international customers, local manufacturers closely follow international and industry trend and constantly improve the design and production level," said Ding Youfen, sales manager of a local eyeglass case producer.

"We have no fixed molds to make the cases," said Ding. "On the contrary, we are completely customized according to the needs of our clients."

"We develop a new mold and purchase materials after receiving a new order, and keep communicating with the clients. We will not enter mass production until they are 100 percent satisfied with our samples," Ding said.

Now with the help of up-to-date technologies, production of glasses cases in Xinhe is embracing a new era.

"Some companies use injection molding to make spectacle cases that can be recycled and withstand pressure and corrosion. This process has raised the output per worker to between 5,000 and 8,000 from just 500 a day," said Su.

Now more and more advanced technologies are being applied in factories in Xinhe. Li said their company had hired six people to form a technological team to focus on mold development and upgrading of production line, and 10 percent of their annual profit goes to research and development.

Clean production is also playing an increasingly important role in the production of eyeglass cases in Xinhe. With all the efforts, the total output value of the spectacle case industry in the county is expected to reach 1.5 billion yuan by 2025.