The project is expected to be completed by early April. Within three years, the company plans to add some 100 workers to operate the expanded plant.

The Grand Rapids facility is operating at full capacity, says Mark de Naray, the president and chief executive officer of Minnesota Diversified. Continuing demand for US Postal Service mail trays--also called totes--as well as Minnesota Diversified's growing commercial business are driving the expansion. Corrugated plastics is a big opportunity for the company, as is a trend to use plastic contains as a replacement for fiberboard cartons. The US Postal Service is the company's largest customer.

The nonprofit company, which hires disabled and disadvantaged people, has received grants and commitments of more than $3.5 million. Iron Range Resources, Minnesota Power and the Northland Foundation have committed more than $1 million, while the Blandin Foundation has awarded Minnesota Diversified a $2.5-million grant, according to company officials.