Starch is commonly used in papermaking to achieve desired strength and printability specifications.  Although the use of starch provides many benefits, it frequently binds with system additives and contaminants to form complex deposits in wet press fabrics that negatively impact machine productivity and sheet quality.  A number of commercially available technologies that control deposition in press fabrics exist.  However, none developed thus far specifically addressed starch deposition continuously until the recent introduction of an enzyme-based felt conditioning technology from Hercules Incorporated.

Product Overview

Hercules’ new, enzyme-based technology comprises a family of patented products that are designed to reduce or eliminate press fabric filling caused by starch deposition.  The products, which are marketed as Presstige® Enzyme-based Felt Conditioners, effectively prevent gelled starch from complexing with system additives and contaminants.  In fact, laboratory and commercial evaluations confirm the products are considerably more effective at preventing press fabric filling due to starch deposition than any other commercially available technology.

Presstige® enzyme-based felt conditioning technology is currently available in the United States, Canada, and Latin America.

Mechanisms and Modes of Action

The new enzyme-based technology features three mechanisms.  Table 1 identifies these mechanisms and their corresponding modes of action.

Table 1 – Mechanisms and Modes of Action of the Enzyme-Based Technology.

The combination of these mechanisms allows for effective and efficient removal of contaminants, resulting in improved press fabric performance.  The degradation mechanism makes this product unique and more effective.

Features

The major features of Presstige® enzyme-based felt conditioning technology are as follows:

Easy-to-pump liquid products
Low VOCs per EPA Method 24
No APEs/NPEs or SARA 313 Components
FDA approved products for dry food contact applications per 21 CFR 176.180
FDA approved product for dry, fatty, and aqueous food contact
applications per 21 CFR 176.170
Effective at most papermaking temperatures, pHs, and conductivity levels
Shelf life > 180 days

Benefits

The following benefits were recorded from practical applications of Presstige® enzyme-based felt conditioning technology.  Not all benefits are realized for all applications.

Eliminated/reduced deposition
Fewer breaks, holes, and sheet defects
Increased paper production
Improved machine efficiency
Decreased downtime for cleaning
Improved sheet moisture profiles
Prolongs felt porosity and absorbency through the life of the felt
Increased water removal at the press