How can surface sizing be optimized while also being cost-effective?

In this case study, we present and discuss HABER’s approach to optimizing the sizing process to maintain the Cobb value within the target range.

Introduction:

A leading Kraft paper manufacturer was facing the issue of high Cobb values post the internal sizing process. Internal sizing refers to the surface sizing method in which additives are introduced to the pulp stock to reduce the liquid-soaking capabilities of the paper produced. It is a crucial process carried out at the screw press and influences the end product quality by varying the sheet strength, which is improved by controlling the resistance of paper to stress or penetration by liquids such as water oil, ink grease, etc.

The sizing agents used by the manufacturer were Rosin and PAC (Polyaluminium Chloride). More than 0.5% PAC was also added in the process of Size Press, which is the process of applying solutions that improve the surface strength of paper, to the dry paper’s surface.

The customer approached HABER and had a detailed technical discussion to understand the issues experienced. This was followed by a thorough system study and lab screening of suitable products, to determine how to improve upon the process.

The following issues were identified:

-         Rosin and PAC in the wet end needed to be withdrawn;

-         Overall costing was at the higher end;

-         High inorganic load was observed in the system.

Our Approach:

HABER’s eLIXA® platform provided real-time artificial intelligence and machine learning-based closed-loop control catered towards optimizing the surface sizing of the paper.

Key process variables like pH, temperature, the quantity of Rosin & PAC, and others were measured and uploaded to the cloud in real-time, on which bigdata analysis was carried out. The solution was based on maintaining the addition of chemicals and ensuring that the pH of the starch solutions was under specified norms, by adjusting the PAC dosage through eLIXA®.

HABER also introduced specialized surface sizing chemicals along with cationic donors in the Size Press process and ensured that the Cobb values was maintained within the target range at all times.

Results:

HABER’s solution resulted in the better functioning of the system, with:

-         A reduction in PAC addition to 0.2% from 0.5%

-         A 150% reduction in the overall cost

-         The stabilization of Cobb values to within the stipulated target range

The implementation of AI/ML optimized the process as it resulted in a marked improvement in the quality of paper, through the real-time adjustment of chemicals and PAC dosage by eLIXA®.