Goal and Strategies
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Develop advanced manufacturing technologies that increase dryness of paper webs entering the paper machine dryer section from the current level of 45-55 percent solids to approach 65 percent solids
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R&D Needs
Understanding Press Section Rewet and Intra-web Transport
High-Priority Projects
Development of an integrated modeling framework for simulating water removal at the press section in paper making
Paper de-watering and re-wet phenomena are not currently well understood primarily due to lack of sufficient data and reliable models
PI: Yue Hao (LLNL), David Trebotich (LBNL)
In January, 2019 the team received its commissioned report by Dr. David MacDonald, Factors That Affect the Press Dewatering of Different Substrates, suggesting alternatives to solving rewet as pathways for achieving 60% solids at the entry to the paper machine drying section. The team is considering potential projects based on the findings of the report.
Understanding Press Section Rewet and Intra-web Transport
- Develop general mathematical model describing water flow rate and direction in the complex 3-D porous media
- Conduct experiments to isolate and quantify the sources of re-wet
- Develop a mathematical model including intra-nip modeling supported by sensor data to measure in-sheet moisture
- Develop “adaptive” felt materials or structures that have high permeability at high nip-loads, and low permeability at low loads
- Identify or develop a membrane that will support unidirectional or preferential flow of water away from the fiber web
- Develop options to shift or decouple the strength/water retention relationship including alternative fiber surface treatments
- Investigate the effect of covalent bonding strength additives to reduce the need for refining
- Investigate alternate chemical strategies to increase hydrogen bond sites without mechanical action and/or block the fiber from absorbing water
- Develop an understanding of the relationship between the fines fraction and water retention
- Investigate methods for increasing filler content; explore the impact of binding bonding material to the surface of bulking agents
High-Priority Projects
Development of an integrated modeling framework for simulating water removal at the press section in paper making
Paper de-watering and re-wet phenomena are not currently well understood primarily due to lack of sufficient data and reliable models
- The objectives of this project were:
- Leverage the HPC capabilities at LLNL and LBNL to develop an integrated, multi-physics modeling framework as a critical first step to understanding and reducing rewet at the press section.
- Provide the pulp and paper manufacturing industry with insights to inform the designs of more energy efficient processes and equipment, resulting in energy reduction.
PI: Yue Hao (LLNL), David Trebotich (LBNL)
In January, 2019 the team received its commissioned report by Dr. David MacDonald, Factors That Affect the Press Dewatering of Different Substrates, suggesting alternatives to solving rewet as pathways for achieving 60% solids at the entry to the paper machine drying section. The team is considering potential projects based on the findings of the report.