Rotational molding growing quickly in China

Linda Xu, a consultant and former polymer expert at Little Tikes Co., opened the door to the mysterious world of rotational molding in China at a recent industry meeting. A Chinese trade association sets the official number of Chinese rotomolders at 500. “They say 500, but a lot of them are small, making rotomolding in their backyards,” Xu said. “So realistically, there’s about 180 rotomolders in China.”

But the industry is growing fast. Xu said there were only 30 Chinese rotomolders in 1994. About 30 percent of them mold tanks, 25 percent make containers and 25 percent mold toys, she said. About 20 or 30 companies in China rotomold toys.

Across Asia, Xu estimates, there are 700 rotomolding firms, more than the 550 in the United States and Canada. Just looking at the number of molders is misleading. Like the United States, China has many small rotomolders, but Xu said the average company in China is much smaller than its average U.S. counterpart.

For example, Xu said a “large-size” molder in China uses about 17 million pounds of resin a year. A midsize molder uses about 2.5 million pounds. Xu, who used to work at Little Tikes Co. in Hudson, Ohio, has a doctorate in rotomolding from Queen’s University of Belfast in Northern Ireland. A native of China, she started LiDa Corp., a consulting firm in Stow, Ohio, to link up rotomolding companies in the United States and China.

Her husband, John Zang, is based in China. He holds a master’s degree in rotomolding from Queen’s University. Xu presented a slide show of products molded in China during her Oct. 4 presentation at the Association of Rotational Molders International’s fall meeting in Cleveland.

Even though China is exploding, its rotomolding industry still uses old equipment and has to import resin, said Xu, who attended the Chinaplas show this summer in Shanghai. That could mean an opportunity for U.S. suppliers to sell there.

Chinese molders use machines made in China, Italy and Taiwan, as well as some U.S.-made Ferry machines. “But most of the machines they use in China, they make themselves,” Xu said. Most pulverizers — equipment used to grind the plastic into powder for rotomolding — are low-quality models made in China, she said.

Molds are very basic. “Most of them are made by fabricated sheet metals. It’s very difficult to get good-quality, cast-aluminum molds in China” because of the spotty quality of alloys there.

China imports polyethylene for rotomolding from Korea, Japan, Malaysia and Saudi Arabia. Only a few Chinese companies can produce rotomolding-grade resin, and the material often “has all kinds of problems,” she said.