LEWISTON, Idaho (From news reports) -- Clearwater Paper has filed a civil case in Nez Perce County District Court against Valmet, a company that sold it some equipment used in a $160 million upgrade at the company's Lewiston operations.

The litigation alleges polysulfide equipment "could not function as designed" and didn't "achieve start-up" until November 2019 even though it had been scheduled to reach that stage by September 2017.

Clearwater Paper officials have previously described polysulfide as a chemical compound that protects wood chips from degradation.

As of Tuesday afternoon, Valmet hadn't filed its response in the case. Attempts to get comment from Valmet on Monday and Tuesday were not successful.

Clearwater Paper contends in a complaint it filed in the case that Valmet did not promptly fix issues with the polysulfide equipment and had agreed to help get the machinery running.

A contract with Valmet had a detailed description of the benefits of using the polysulfide process and a primary one was an increase in cooking yield, according to Clearwater Paper's complaint.

"Several performance guarantees (important contract-defined technical parameters to measure performance) for the cooking equipment, including cooking yield, depended upon the polysulfide equipment being operational, and could not even be measured until the polysulfide equipment achieved start-up," according to Clearwater Paper's complaint.

Clearwater Paper and Valmet understood when they entered the contract that the benefits of the polysulfide equipment were a "crucial part" of the bargain and motivated Clearwater Paper's decision to purchase equipment from Valmet, according to the complaint.

The company wants an unspecified amount for lost profits, plus prejudgment interest and costs, as well as attorney fees, according to the complaint filed earlier this spring.

Clearwater Paper is seeking damages that include "out-of-pocket expenses incurred due to a defective design ... costs incurred in replacement and repair of equipment supplied by Valmet, and costs incurred by Clearwater (Paper) for goods or services that were within Valmet's responsibility," according to Clearwater Paper's complaint.

The polysulfide equipment was installed during one of the largest overhauls in recent decades of Clearwater Paper's biggest manufacturing facility where it produces tissue and paperboard. The tissue is made into toilet paper, paper towels, paper napkins and facial tissue. The paperboard is used for paper dishes as well as packaging for products like cosmetics.

The work in Lewiston involved replacing 12 batch pulp digesters installed at various times with a single continuous pulp digester. It was promoted by Clearwater Paper executives as a way to make the facility, one of Lewiston's largest employers, more competitive.