LISBON FALLS - A temporary shutdown that shuttered the Knight-Celotex fiberboard plant on Aug. 1 is over, but when the facility reopens Sept. 2, less than half its 84 workers will be invited to return.

To improve efficiencies and reduce rising energy costs, the company has decided to make only one product line at the Route 196 facility.

"The result of this is that only 40 of the 84 employees affected (by the shutdown) will be recalled," said Charles Micoleau, general counsel for the Chicago-based company. "While focusing on one product puts us on a solid economic footing, we will be operating with fewer employees with this new specialized production."

The plant will make Conflex, a concrete expansion board used in road construction. Micoleau said the facility will be able to run its equipment much more efficiently with only one product, saving time and energy. Conflex was chosen because it has been the most profitable product made at the Lisbon Falls plant, Micoleau said.

He said management also explored ways to reduce energy use during the shutdown by consulting with local, state and federal agencies. Last winter, Knight-Celotex was paying $9 per million British thermal units for natural gas, which had risen to $13 per MBTU in July just before the company decided to shut down the Maine operation.

Although the price for natural gas in Maine has moderated, Micoleau said Knight-Celotex expects to pay this winter at least what it paid last year in energy costs. It is exploring collaborations and programs through state, federal and local energy agencies to reduce costs in the long term.

But for now, some of the work that had been done in Lisbon Falls will be picked up by other Knight-Celotex facilities with lower energy costs. The company has plants in Sunbury, Pa., Marrero, La., and Danville, Va.

"Electricity and natural gas costs are one of the principal challenges the company faces," Micoleau said. "We are working collaboratively (with various agencies) to deal with these underlying problems."

Workers will be notified of their job status via mail, probably over the weekend, said Micoleau. He said the company intends to select the returning workers based on skill sets and seniority. It has contacted the machinists union, which was voted in at the plant in April, to discuss recall arrangements. A message left with the District 4 office of the International Association of Machinists wasn't returned by deadline.

"These decisions are always difficult," Micoleau said. "The company has been in touch with the Department of Labor, which will be working with the employees not recalled."

Stephen Eldridge, town manager, said the town would do what it could to help the displaced workers and the company. He said he'd had some preliminary discussions with another company that might be willing to partner with Knight-Celotex, but nothing was firm.

Knight-Celotex was the town's third largest employer.

"It's unfortunate not everyone is going back to work," he said. "But hopefully, they can build on it. There are a lot of good employees there."