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Polyvinyl alcohol as foaming agent in foam formed paper, TAPPI JOURNAL August 2019
ABSTRACT: The use of polyvinyl alcohol (PVOH or PVA) as a foaming agent in foam formed paper was investigated. Polyvinyl alcohol is a linear, nonionic water-soluble polymer. It has hydrophobic and hydrophilic parts that give it a surface-active character. PVOH is mainly characterized by degree of hydrolysis and molar mass. Degree of hydrolysis is given as mol-% hydroxyl groups on the polymer. Molar mass is measured indirectly by measuring the viscosity of a 4% PVOH solution. The results show that the degree of hydrolysis of PVOH had a strong effect on the foamability of PVOH. Foamability decreased strongly when the degree of hydrolysis increased from 88 to 98 mol-%. The effect of molar mass on foamability was weaker. We saw an increase in foam stability and bubble size with increasing molar mass, but we did not see any effect on maximum air content. PVOH dosage needed to reach >70% air content (F) varied from 2 g/l up to 10.5 g/l, and the lowest addition levels of PVOH needed were achieved with a low molar mass PVOH with a low degree of hydrolysis. The best strength properties were achieved when using fully hydrolyzed PVOH as the foaming agent. Strength properties (both in- and out-of-plane) of samples made using PVOH were better than those made using an anionic foaming agent (sodium dodecyl sulfate, SDS). By adding PVOH binder fibers to the pulp, we were able to further enhance the strength properties of paper and board.
Journal articles
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Real-time monitoring of bubble size distribution in a foam forming process, TAPPI JOURNAL August 2019
ABSTRACT: Foam forming is an intricate option to lessen fiber flocculation and to get better energy and water efficiency when making fiber-based products. Developed during the 1970s, this approach has recently received renewed attention, mainly because it also offers possibilities to widen the fiber-based product portfolios with novel and more valuable products. In addition to air content, bubble size is the most important property of foam. Foam quality control is essential for building real-world foam forming processes. In this work, we show how bubble size can be monitored with direct optical imaging in real time in real process conditions, and how such analysis helps adjust foam quality and discover process faults in foam forming.
Journal articles
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Progress in foam forming technology, TAPPI JOURNAL August 2019
ABSTRACT: This paper summarizes recent developments in foam forming that were mainly carried out in pilot scale. In addition to improving the efficiency of existing processes and allowing better uniformity in material, a wide variety of raw materials can be utilized in foam forming. The focus of this paper is thin webs—papers, boards and foam-laid nonwovens, along with the pilot scale results obtained at VTT in Finland. For paper and board grades, the most direct advantage of foam forming is the potential to produce very uniform webs from longer and coarser fibers and obtain material savings through that. Another main point is increased solids content after a wet press, which may lead to significant energy savings in thermal drying. Finally, the potential to introduce “difficult” raw materials like long synthetic or manmade fibers into a papermaking process enables the manufacturing of novel products in an existing production line. This paper also briefly discusses other interesting foam-based applications, including insulation and absorbing materials, foam-laid nonwovens, and materials for replacing plastics.
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Creating adaptive predictions for packaging-critical quality parameters using advanced analytics and machine learning, TAPPI Journal November 2019
ABSTRACT: Packaging manufacturers are challenged to achieve consistent strength targets and maximize pro-duction while reducing costs through smarter fiber utilization, chemical optimization, energy reduction, and more. With innovative instrumentation readily accessible, mills are collecting vast amounts of data that provide them with ever increasing visibility into their processes. Turning this visibility into actionable insight is key to successfully exceeding customer expectations and reducing costs. Predictive analytics supported by machine learning can provide real-time quality measures that remain robust and accurate in the face of changing machine conditions. These adaptive quality “soft sensors” allow for more informed, on-the-fly process changes; fast change detection; and process control optimization without requiring periodic model tuning.The use of predictive modeling in the paper industry has increased in recent years; however, little attention has been given to packaging finished quality. The use of machine learning to maintain prediction relevancy under ever-changing machine conditions is novel. In this paper, we demonstrate the process of establishing real-time, adaptive quality predictions in an industry focused on reel-to-reel quality control, and we discuss the value created through the availability and use of real-time critical quality.
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Slot die coating of nanocellulose on paperboard, TAPPI Journal January 2018
Slot die coating of nanocellulose on paperboard, TAPPI Journal January 2018
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Discrete element method to predict coating failure mechanisms, TAPPI JOURNAL January 2018
Discrete element method to predict coating failure mechanisms, TAPPI JOURNAL January 2018
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Factors affecting the free shrinkage of handsheets: apparent density, fines content, water retention value, and grammage, TAPPI JOURNAL June 2018
Factors affecting the free shrinkage of handsheets: apparent density, fines content, water retention value, and grammage, TAPPI JOURNAL June 2018
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Dielectric spectroscopic studies of biological material evolution and application to paper, TAPPI JOURNAL September 2018
Dielectric spectroscopic studies of biological material evolution and application to paper, TAPPI JOURNAL September 2018
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Effect of conductivity on paper and board machine performanc
Effect of conductivity on paper and board machine performance— a review and new experiences, TAPPI JOURNAL October 2017
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A true green cover for industrial waste landfills, TAPPI Journal April 2024
ABSTRACT: Greenhouse gas (GHG) emissions in the United States totaled 5,981 million metric tons of carbon dioxide equivalent (MMT CO2eq) in 2020. Of that, GHG emissions by the pulp and paper sector amounted to 35 MMT CO2eq direct emissions and those by industrial waste landfills summed to 7.4 MMT CO2eq direct emissions. Loss of GHG sinks due to change in land use further contributes to the net GHG emissions. Industrial waste landfills are typically required to comply with certain federal and state regulations, including meeting requirements for final cover systems. Conventional final cover systems have included use of soil covers and/or soil-geosynthetic composite covers. An engineered turf cover provides for an excellent “green” alternative final cover system for industrial waste landfills.This paper discusses various sustainability aspects pertaining to use of an engineered turf final cover, including: (i)significantly low carbon footprint associated with the construction of an engineered turf alternative final coverwhen compared to closure using a traditional or prescriptive cover system; (ii) saving valuable soil and land resourc-es; (iii) saving water resources by reduction in its use during and after construction; (iv) reducing impacts associated with borrow areas; and (v) reducing overall carbon footprint. Further, when using an engineered turf cover, opportunities exist for beneficial reuse of land, including development of solar energy. A brief discussion on the potential fordevelopment of solar energy is included.