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Journal articles
Stress and Strain for Perforated Tensile Specimens, Part 1: Experimental Measurements, TAPPI JOURNAL, March 2007
Stress and Strain for Perforated Tensile Specimens, Part 1: Experimental Measurements, TAPPI JOURNAL, March 2007
Journal articles
Dynamics of Films and Droplets Spreading on Porous Substrates, TAPPI JOURNAL, March 2007
Dynamics of Films and Droplets Spreading on Porous Substrates, TAPPI JOURNAL, March 2007
Journal articles
Improving TMP Rejects Refining through Alkaline Peroxide Pretreatment for Value-Added Mechanical Papers, TAPPI JOURNAL, March 2007
Improving TMP Rejects Refining through Alkaline Peroxide Pretreatment for Value-Added Mechanical Papers, TAPPI JOURNAL, March 2007
Journal articles
Improvement of Plybond Strength of Two-Ply Sheets by Spraying of Starch Blends, TAPPI JOURNAL, May 2007
Improvement of Plybond Strength of Two-Ply Sheets by Spraying of Starch Blends, TAPPI JOURNAL, May 2007
Journal articles
Effects of sheet moisture and calender pressure on PCC and GCC coated papers, TAPPI JOURNAL November 2007
Effects of sheet moisture and calender pressure on PCC and GCC coated papers, TAPPI JOURNAL November 2007
Journal articles
Blade, film, and curtain coating techniques and their influence on paper suface characteristics, TAPPI JOURNAL November 2007
Blade, film, and curtain coating techniques and their influence on paper suface characteristics, TAPPI JOURNAL November 2007
Journal articles
Magazine articles
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
Magazine articles
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
Magazine articles
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.
Journal articles
Imbibition behavior of offset inks part 1: Gravimetric determination of oil imbibition rate into pigmented coating structures, TAPPI JOURNAL, June 2003, Vol. 2(6) (195KB)
Imbibition behavior of offset inks part 1: Gravimetric determination of oil imbibition rate into pigmented coating structures , Solutions! & TAPPI JOURNAL, June 2003, Vol. 2(6) (195KB)