Beneath the eye-catching growth in China’s plastics machinery market, there are signs of big changes, with domestic-made equipment taking significant market share from imported machinery in what has become one of the world’s most vital markets.

New Chinese figures show that the domestic plastics machinery market grew a staggering 60 percent in the last two years, to 31.1 billion yuan (US$4.8 billion), while domestic-made equipment grabbed an additional 20 percent of the market, and now accounts for 70 percent of sales in China.

That’s a big change from 2008, when China’s market was split about equally between imports and domestically made machines.

The switch actually happened in 2009, when the market share of Chinese equipment rose to 70 percent and foreign made machinery fell to 30 percent.

At the time, some analysts attributed that to belt-tightening among plastics processors during the financial crisis, and predicted that foreign firms would gain back much of what they lost when China’s economy came back, which it did in 2010, in a big way.

But that didn’t happen, according to new figures presented at the recent Chinaplas show by Haitian International Holdings Ltd., the country’s largest injection press maker.

Made-in-China equipment held its own in 2010 at about 70 percent (and in fact grew market share by about one percentage point). Those figures originally came from the Beijing-based China Plastic Machine Industry Association, and are for all plastics equipment, not just injection presses.

Judging by conversations at Chinaplas held in Guangzhou in mid-May, the overall market in China has been growing so quickly that there’s been plenty of opportunity to go around.

Chinese statistics say the market for plastics equipment was 19.6 billion yuan ($3 billion) in 2008, 21.4 billion yuan ($3.3 billion) in 2009, and exploded to 31.1 billion yuan ($4.8 billion) in 2010.

There are many ways to interpret the changes in market share.

Chinese-made equipment could be closing the quality gap, the financial crisis could have opened doors for Chinese firms and they’ve taken advantage, and more international machinery firms could be localizing their production in China. All those trends are probably happening together.

Assuming these statistics are broadly true, the test for imported equipment may come when the market slows down, as it seems to be showing some signs of doing now.

Conversations with several injection press makers at Chinaplas suggest growth in China has slowed noticeably since March, as the Chinese government has tightened credit to try to control inflation and keep the economy from overheating.

If there’s no longer a quickly rising tide to lift all [or many] boats, and Chinese-made equipment has made serious inroads, will that leave imported machinery makers scrambling?

I don’t know. There’s a flip side to that argument, which is that China’s rising costs and strengthening currency will make the more sophisticated imported machines more attractive as time goes on.

It’s a point foreign firms have made with me. So I can see arguments going both ways, and every company’s situation is different in a market as diverse as China’s. As for the future, the official projections from the CPMIA say Chinese-made machinery will have about 80 percent of the market by 2015.

A few years ago, when the market was split evenly between domestic and imports, that figure looked optimistic. Now, who can say for sure, but you can’t rule it out as a reasonable possibility.