Enzymatic Extractives Management
Pitch control or "extractives management" in mechanical pulping mills has long been a challenge. In fact, for many years people thought certain tree species could never be used to produce certain papers and forest products.
This concern increased over the years with the industry’s shift to geographic regions where higher extractives-containing trees make up increasing percentages of the fiber supply or in regions where availability of the “easier” tree species is becoming limited and expensive. Even in more northern regions where extractives contents are not as high, mills that use lower cost tree species (e.g., Red Pine or Jack Pine in North America) often find significant operational and quality challenges.
Though in its early years, EDT’s work focused with mills having “pitch deposit problems,” EDT has increasingly started working with mills with no deposit problems, but having only a desire to improve certain sheet properties or reduce production bottlenecks.
APC® / SEA® Test
EDT takes a mill-specific approach to this market, just as with deinking and other applications. Up-front assessment of a mill’s fiber sources, operations, and goals begins the engagement. EDT’s patented APC® and SEA® Tests measure the apparent pitch content of a pulp stock. These tests require only one hour, use no harmful materials, are highly repeatable, and measure only the problematic extractives on the fiber surfaces and within the filtrate.
The benefits of the APC® and SEA® Tests have led some EDT EnzOx® customers to use their findings in daily meetings to make decisions on how to run the mill that day or procure fiber for the coming weeks. EDT works consultatively with its EnzOx® customers to maximize the mutual value from these tests.
EDT works closely with mills to develop the optimal EnzOx® enzyme blend to best address the extractives profile within each plant. Many engagements target reductions in the expensive virgin kraft pulp that is mixed with the less costly mechanical pulps without the usual decline in sheet properties. Kraft pulp use that is halved or eliminated is common.
EDT’s understanding of mill water loops and extractives flows can be helpful in modifying existing treatments to maximize the value gained from the treatment. In some situations, EDT even develops a season-specific strategy for the mill, as the extractives content of certain tree species in some areas can vary dramatically depending on the time of year.
Reductions in pitch levels made possible with the use of EDT's EnzOx® treatments can materially improve sheet strength and COF properties, as well as address pitch deposition problems on the machine.
The bottom-line economics of EDT’s mechanical pulp treatments can be dramatic. This is especially important in this era of difficult demand scenarios within some mechanical pulp grades. Why not contact EDT to see if one of our treatments might be helpful in meeting your mill’s goals?