Pitch Control

Contaminants such as wood pitch, "stickies" from recycled fiber, and coated broke can cause major runnability problems within the papermaking system. Trends in the industry such as increased closure of mill water systems and increased use of recycled fiber sources can be expected to increase the problems from such contaminants. Control of pitch is necessary to eliminate troublesome system deposits that interfere with optimal machine runnability and best possible finished product quality. The DuBois Total Pitch Control philosophy includes optimization of the mechanical systems for pitch removal prior to chemical consideration as well as specialized, targeted chemistries for control of residual pitch in the system.

DuBois Pitch Control Expertise

Analytical Expertise

The key to a successful pitch deposit control program is an effective analytical approach to the product application. DuBois utilizes both laboratory and field analytical techniques, for monitoring & analyzing pitch extractives in stock samples, in order to both predict and adjust chemical influence upon pitch particle morphology and its propensity to agglomerate and become sticky. Pitch particle size is controlled with DuBois' pitch management program, and particle size distribution is evaluated to effectively prevent pitch deposits in pulp and papermaking processes.

Application Expertise

DuBois has extensive experience solving contaminant problems in numerous types of systems and furnish conditions. For stock applications in the pulp mill or papermaking system, there are three different strategies for eliminating stickies problems. The first strategy is to disperse contaminants into smaller colloidal particles that will not be problematic. The second strategy is to agglomerate the particles into larger macroparticles that can be more easily screened or washed from the stock. The third strategy is to neutralize the charge of the contaminants and remove them from the system by fixation to the fibers. DuBois will evaluate system parameters and recommend the strategy and corresponding product that best meets the objectives of the mill.

Beyond the stock flow

DuBois also offers products used to prevent contaminant buildup on machine fabrics and rolls. These products are applied directly to the surface of the fabric or roll to form a microscopic layer, which prevents contaminant deposition and aids in sheet release.