Pitch Control Agents
The need for pitch control agents (system deposit control & final sheet dirt control)
Pitch deposits (on its own or lumped with other inorganics) can appear anywhere in the paper making process. It could appear in places ranging from the pulp washing plant, screening, bleaching, stock preparation, wet end of pulp dryer or paper machine to the final product i.e. pulp or paper. Pitch deposits and dirt results to lower productivity and are major causes leading to quality downgrade of the final product.
The shortage of fibrous raw materials, mixing of two different raw materials and limitations on debarking increases the need for pitch control.
The use of pitch control agents / dispersants provides the following benefits:
- Effective removal of pitch from fibre in the early stages of production.
- Control of pitch deposition in the entire fibre line.
- Minimisation of pitch dirt in pulp and paper sheets.
- Dispersion of and inhibition of deposition related to pitch and inorganic salts.
Pitch control agents / dispersants are usually dosed at multiple feed points in the brown stock washing process, O2 delignification, thickener before bleach plant and outlet of DO stage (inlet to EO stage) of bleaching system. It may be fed through the top whistle shower for uniform distribution and mixing. The dosage normally varies between 0.10 – 0.40kg/Adt pulp per application point. Continuous feed is necessary for optimum control, of which total dosage level would depend on the raw material furnishes.
Certain types of pitch, such as dammar resin needs to be effectively dealt with within the pulp mill. We would also recommend that pitch should be controlled near where it is released, thus ensuring agglomeration does not occur in the stock system.
Localized treatments, such as wire passivation and felt conditioning can be cost effective alternatives for some pitch problems.
Amazon Papyrus has a range of pitch control agents for different raw material furnishes and specific purposes.
Our pitch control agents are a synergic blend of either non-ionic surfactants or anionic dispersant specially designed to aid the removal of pitch from the fibre and to stabilize the pitch in a colloidal form for easy removal by washing process. Our range of products performs in a wide pH ranging from 3 to 10, some of which are based on encapsulation technology.
Our team of professionals would work with you to select the most appropriate products to meet your specific needs.