Aluminum manufacturer Constellium said today it has invested $40 million to expand its plant in Van Buren Township to meet the increasing demand for aluminum by automotive manufacturers.

The company is holding a celebration today to commemorate the completion of a 210,000-square-foot expansion of its plant.

Constellium has hired nearly 200 additional workers at the Van Buren site and will employ a total of 370 there after it hires about 20 additional workers.

The average wage of Constellium's workers is about $17 per hour, not counting benefits, while robot technicians make about $25 per hour.

The company also is in the process of closing two smaller plants in Novi and is transferring all of the employees who work in those plants to the expanded plant.

"It's a big investment, and it means a lot to our customers," said Eric Krepps, managing director of automotive structures for Constellium North America. "This is a long-term investment in Michigan."

Constellium is a global aluminum parts manufacturer with $3.9 billion in annual revenue.

At its Van Buren Township site, the company designs and engineers crash management systems, body structures and instrument panels.

The company also takes large aluminum blocks, or billets, heats them, and forms them into aluminum automotive parts for BMW, Daimler, FCA US (previously Chrysler), Ford and General Motors.

Constellium decided to expanded its plant because of increasing demand for aluminum automotive parts.

Last year, Ford introduced a new Ford F-150 pickup with an aluminum body and FCA US is considering an aluminum body for its next-generation Jeep Wrangler.

Krepps said automakers are using more aluminum in new cars and trucks because it weighs less than steel and automakers are trying to improve the fuel efficiency of their vehicles.

"The automakers, our customers, are switching from steel to aluminum in order to lightweight the vehicle to meet the 2025 fuel efficiency requirements," Krepps said. "And in that form of light-weighting, aluminum is the material of choice, and that is what's behind our growth."