Deposit control

Kemira KemFlite concept combines our efficient chemical solutions with process understanding, application expertise, and unique online tools for real-time monitoring and control and helps you control the agglomeration of hydrophobic substances in your machine. It includes

• An investigation of the key points in your process contributing to deposit formation (e.g. mechanical pulp bleaching, wash press operations, broke circulation, recycled fiber processing)
• The choice of correct deposit control products to control hydrophobic substances and their particle size to prevent deposit buildup
• Real-time monitoring of hydrophobic load and the deposition risk of different process waters (e.g. broke filtrate, paper machine white water) with KemConnect™ AutoFlite.

Kemira’s unique KemRevive concept is designed to improve sustainability and productivity in the papermaking process through the efficient reuse of native starch.

Starch that is contained in the furnish is the most abundant carbon source available for bacterial growth in paper machines. Amylase enzymes break down the starch into sugar that promotes bacterial growth, and this in turn results in increased amylase enzyme production, further degrading starch molecules. This cycle of starch degradation can lead to high COD levels in process and wastewaters, bar odors, calcium carbonate scaling, and runnability issues.

Our KemRevive concept breaks the cycle with an efficient combination of amylase enzyme inhibition chemistry, biocides for microbiological control, and a retention program. The comprehensive approach helps the starch to survive throughout the papermaking process and retains it to the sheet while maintaining or improving drainage.

Residual wood resins and colloidal wood pitch can be carried over in the pulp to the paper making process and form deposits on the machine and fabrics, causing product defects, holes, and breaks. Recycled fiber furnish typically contains substantial levels of detrimental material such as acrylates and vinyl acetates that lead to stickies formation. Stickies are even more frequently responsible for deposits-related problems on the paper machine.

Kemira’s FennoDispo™ dispersing agents and FennoSorb™ passivation agents for pitch and stickies control help manage these hydrophobic substances and eliminate deposits on paper, board, and tissue machines.

The benefits of efficient pitch and stickies control

• reduce machine downtime
• reduce sheet breaks
• reduce product defects, holes and dark spots
• extent forming fabric lifetime

Scale formation can cause a number of costly operational problems during the pulping and paper making processes, such as unstable and decreased production, uneven pulp quality, and unplanned stops. Scaling is typically caused by the buildup of moderately soluble to highly insoluble inorganic salts, such as calcium carbonate, calcium sulphate or barium sulphate.

Uncontrolled scale formation can lead to increased maintenance costs and machine downtime for cleaning, issues with decreased quality and increased contaminant defects in end product, and plugging of equipment and corrosion.

Kemira’s portfolio includes FennoDispo™ scale inhibitors for a variety of calcium and barium based scales and FennoScale™ antiscaling agents for inorganic scale control. Our product range covers all process conditions, even high pH and high temperature areas.

The multifunctional FennoFix fixative and passivating agents help minimize the negative effects of colloidal substances and small agglomerated hydrophobic substances in paper, board, and tissue machines.

Our technology combines three control mechanisms for disturbing substances: microfixation, passivation, and stabilization.

FennoFix neutralizes the impact of disturbing substance coming from the furnish and reduces stickies. This improves wet end stability, reduces machine shutdowns for e.g. felt and wires cleaning, prevents converting issues, and improves machine efficiency and productivity.

FennoSpec is a biotechnology product that improves native wet end starch performance and helps increase biocide program efficiency. FennoSpec acts is an amylase enzyme inhibitor and helps avoid starch degradation in broke.

When the starch molecules keep retained, process pH and bacteria count can be improved significantly, among other things. This also helps reduce COD levels in the wastewater. FennoSpec is a Kemira patented technology and a key part of our KemRevive™ concept.

Contaminants, recycled fiber usage, pitch, fines, and specific wet additives, among others, contribute to forming fabric, press fabric, and dryer fabric filling and felt wear at paper, board, and tissue machines.

Maintaining clean, open felts is critical to the press section performance and to the overall machine runnability and efficiency, and help reduce drying energy due to improved dewatering.

Kemira provides a series of products for removing contaminants from the felt (felt cleaning) and preventing the buildup of contaminants to the felt (felt conditioning):

• FennoPur: from alkaline to acidic felt cleaners for both online and offline use
• FennoTrol: continuous felt conditioners
• FennoPas: surface passivators for application at forming fabrics, wet press felts and press rolls
• systems for cleaning both organic and inorganic deposits
• systems for automated batch, batch on-the-fly, and continuous applications