Case Studies

Pulp & Paper

Case Studies:

Tissue mill gains over $1 million/yr in saving through process chemical saving and productivity gains

Opportunity

A tissue machine producing 100% recycled toweling with a fairly closed whitewater system desired to reduce operating costs by increasing CMC (carboxymethyl cellulose) use and minimize use of a proprietary wet strength resin.

The cost of the CMC was roughly one tenth the cost of the proprietary resin; however, the CMC would cause severe press fabric plugging.

This challenge was so severe that at higher CMC addition rates the fabric could only run for a few hours before a down-time batch wash was required – resulting in production uptime loss.

Secondarily, the machine needed a solution for stickies that were depositing on the TAD fabric.

The machine was using a competitor’s traditional cationic passivation product to treat the press fabric, but it had minimal effectiveness at controlling the CMC deposition.

The DuBois Solution

DuBois implemented new strategies for both press felt and TAD fabric cleaning programs.

For the press fabric, DuBois implemented their patented DuPulse method of felt cleaning.

DuPulse is a unique felt cleaning application method, which utilizes the high pressure, oscillating needle showers on an intermittent or “pulsed” basis.

The cleaning chemistries used were a combination of DuBois’ patented Altrox L peroxygen-based, detergent cleaner and Div-O-Kleen EF alkaline and natural solvent cleaner. This combination has been used effectively to remove recycle contaminants and wet-strength resin, CMC, sizing and various other papermaking materials.

For the TAD fabric cleaning program, an effective batch washing application was developed, using the combination of Altrox L and Div-O-Kleen EF.

Results and Benefits

• CMC use was substantially increased while decreasing the more expensive wet strength resin, resulting in a financial return well in excess of $1,000,000.
• Average press fabric life was increased five to seven weeks on average and permeability levels were higher & more uniform than historical levels.
• The press fabric barrier treatment was eliminated.
• The TAD fabric batch wash program was effective at removing stickies, which led to reduced sheet breaks and significantly lower sheet defects.

• Batch washes were completed while the sheet was still on the Yankee with no detrimental effect to the Yankee coating performance.