Pitch and Stickies Deposition

Problem Summary

Organic contaminants in the papermaking process originate from either natural or synthetic sources. The natural source is predominantly wood pitch while synthetic sources include adhesives and coating binders from secondary fiber or broke. The latter are often referred to as “stickies.” While the majority of these contaminants are screened out of the process, some pass through as colloidal material. Generally, colloidal pitch and stickies do not cause too many problems. However, under conditions of shear or temperature shock, these contaminants can deposit throughout the stock prep system and headbox, on forming fabrics, press rolls, and uhle boxes, and on other machine surfaces. More often than not, such deposition negatively impacts paper machine productivity and/or the quality of the finished paper by causing holes, breaks, and sheet defects.

Recommended Solution

Three quite different chemical methods are commonly used in the paper industry to control pitch and stickies deposition:

Stabilizing the pitch and stickies with a dispersant or surfactant
Reducing the tackiness of the colloidal pitch and stickies using a detackifier or mineral, such as talc
Removing the colloidal pitch and stickies from the system together with the paper using a highly charged cationic polymer

Traditionally, these methods have rarely been combined because this typically provided few additional benefits and the methods have not been complementary. However, Hercules has developed a new technology that combines an amphoteric, surface-active, structured protein with a highly charged cationic polymer. The structured protein is able both to increase the stability and to reduce the tackiness of colloidal contaminants. The real key to the effectiveness of the program, however, is the effect achieved when the structured protein is used together with a cationic polymer to retain the contaminants with the web. This technology, which is marketed by Hercules as Zenix® Detackifier Technology, has been shown to be considerably more effective at reducing or eliminating pitch and stickies deposition than existing chemical control methods.

Key benefits recorded from practical applications of Zenix® Detackifier Technology include:

Eliminated/reduced deposition
Fewer breaks, holes, and sheet defects
Increased paper production
Increased machine efficiency
Decreased downtime for cleaning
Decreased usage of cleaning chemicals

More Information

If you have a question or would like to know more about Zenix® Detackifier Technology, please complete and submit an Inquiry Form.