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Foam-assisted web forming and chemical application technologies have great potential to improve manufacturing efficiency and product quality in the paper and nonwovens industries. In this study, the benefits of foam forming and foam-assisted application of chemicals were demonstrated in a pilot machine trial. Uniform high-bulk webs of unrefined bleached softwood kraft pulp (BSKP) and viscose fibers were manufactured by foam forming. It was shown that foam formed low-grammage and high-bulk viscose fiber webs can be strengthened by foam-assisted application of latex onto the wet web. Correspondingly, foam-assisted application of carboxymethyl cellulose (CMC) and anionic polyacrylamide (A-PAM) improved the strength of the foam formed low-grammage and high-bulk BSKP web. Overall, the pilot machine results indicated that material cost savings could be achieved and a high-performance product could be manufactured with foam-based technologies.

According to an example aspect of the present invention, there is provided an apparatus and a method comprising a forming section for feeding an aqueous furnish of fibres on a moving surface to form a shape of a product and a pressing and heating section for removing water from the shaped product received from the moving surface. The pressing and heating section comprises a felt and metal belt that are set to run against each other for receiving the furnish from the moving surface and heating elements for heating the web in at least two pulses including at least one first pulse wherein the product is pressed for at least 10-200 ms on a first pressure and at least one second heating and smoothing pulse wherein the product is heated at least for 10-200 ms on a pressure that is higher than the first pressure, and at least one of the surfaces pressing the product being the smooth metal belt.Patent family as of 14.12.2021BR112019006917 A2 20190625 BR20191106917 20171004 CN110036153 A 20190719 CN201780075268 20171004 EP3523476 A1 20190814 EP20170787465 20171004 EP3656915 A1 20200527 EP20190218678 20171004 FI127892 B 20190515 FI20160005747 20161005 FI20165747 A 20180406 FI20160005747 20161005 US10954632 BB 20210323 US20190339476 20171004 US2020040528 AA 20200206 US20190339476 20171004 US2021156089 AA 20210527 US20210167115 20210204 WO18065668 A1 20180412 WO2017FI50696 20171004Link to currentpatent family on right

Kotimaan vihreästä kullasta valmistetuista tuotteista saadaan monia tuotteita kiertotalouden avulla. Olemme kehittäneet uutta, puumateriaaleihin pohjautuvaa liiketoimintaa yhdessä yritysten, tutkimuslaitosten ja koulutusorganisaatioiden kanssa. Olemme hypänneet puusta pidemmälle – määrästä arvoon.Hankkeessa olemme luoneet metsäalalle uusia työkaluja ja toimintamalleja, joiden avulla puutuotteiden laatu korvaa määrän.Kiertotaloudessa puusta valmistetaan mahdollisimman pitkäikäisiä tuotteita, joita voidaan hyödyntää moneen kertaan ja siten luoda samalle puumateriaalille taloudellista arvoa yhä uudelleen ja uudelleen. Nykyään jätteeksi päätyvä puuaines hyödynnetäänkin jatkossa kestävästi uusien tuotteiden valmistamiseen. Puutuotteisiin voidaan lisätä myös aineetonta arvoa digitaalisten teknologioiden ja palveluiden avulla.Hankkeessa testattiin nopean kokeilun ja innovoinnin työpajamallia, jonka avulla metsäalan yritykset, muotoilijat ja markkinoijat kehittivät yhdessä uusia liikeideoita puutuotteille. Hankkeen aikana tutkittiin myös puutuotteiden kiertotalouden edistämismahdollisuuksia, toteutettiin puutuotteiden elinkaarilaskuri, tutkittiin digitalisaation mahdollisuuksia, sekä suunniteltiin ja testattiin kiertotalouden markkinointikonseptia kaikkien yritysten käyttöön.Lisäksi hankkeessa mukana olevat yritykset kehittivät yhdessä teknologiaa uudella tavalla hyödyntäviä puupohjaisia tuotteitaan. Tavoitteena on ollut luoda uutta, kiertotalouden mukaista liiketoimintaa Suomeen ja edistää samalla Suomen kansainvälistä kilpailukykyä.Hankkeen ajankohta: 4.5.2018-15.10.2019

Foam assisted forming technology introduces new exciting opportunities to develop totally new types of sustainable wood fibre products. The technology allows highly porous and thick structures to be produced from fibres and it enables the exploitation of new raw material combinations extending the raw material base. Porous fibre structures can be made of any fibre or fibrous particle blends with or without additives that possess adequate level of bonding or adhesion in wet and dry state. Foam forming technology utilises small air bubbles containing aqueous foam as a process fluid. In the foam forming process fibres, water and foaming agent are mechanically mixed and the aqueous fibre-containing foam is generated with air content between 50-70%. The air bubbles effectively prevent flocculation of fibres. Highly porous, non-paper like materials can be produced by using small vacuums in the drainage phase and by using non-contact drying methods to prevent the collapse of the fibre network. This paper highlights VTT Technical Research Centre of Finland's foam forming research, shows research results and presents end product examples.

Using foam as a carrier phase instead of water is an alternative way to produce fibre-based webs. This old technology has attracted great interest recently as the approach gives many positive influences on sheet properties. Since fibers are locked between foam bubbles during transportation to the wire, they do not flock as easily as in water, which leads to improved formation. Moreover, consistency can be increased, and thus the amount of water in the process and the drying energy can be reduced. In addition, bulk is often increased when applying the foam forming technology. Generally, formation of a fiber sheet deteriorates as fiber length increases. Here we aimed to produce sheets with very long fibers with foam forming. In order to change the fiber length systematically, model 1.7 dtex viscose fibers were used. Fibers were provided as small straight wet bundles that were dispersed in the foam. Sodium dodecyl sulphate (SDS) was used as foaming agent. Floc-free sheet of upto 12 mm fibres could be produced fairly easily by the conventional foam-forming method in laboratory scale. However, longer 24 mm fibers required several developments in the pre-processing phase. Homogeneity of the sheet structure was sensitive to foam properties. The effects of SDS dosage, air content, foam volume and mixing speed were quantitatively characterized for laboratory forming process. In particular, a parameter window for producing homogeneous sheet structure could be found. In the modified process, wet fiber bundles were fed into foam with enlarged bubble size and high foam viscosity. The crowding number characterizing the flocking tendency was reduced by increasing the foam volume. Finally, surfactant concentration affected the air content and the bubble size distribution of the foam and thus its viscosity. The technique could make a way for producing novel fashion and technical textiles, which requires the handling of long fibers in the process. The study was mainly focused on laboratory scale, but necessary development steps in upscaling of the process to the pilot scale were considered as well.

The adhesion between reinforcing fibres and matrix material is crucial for the performance of composite structures. In this study we treated foam formed cellulose fibre sheets with plasma and atomic layer deposition (ALD) treatments to achieve better adhesion between cellulose fibres and epoxy matrix. Plasma treatment was done using 8 kW and 12 kW outputs and ALD cycles with Ti2O and Al2O3. Surface treated foam formed sheets were laminated into composite structure with epoxy resin using vacuum assisted resin infusion. Complete laminated composites were water jet cut and interlaminar shear strength was measured. Effect of plasma treatment to adhesion was minimal and ALD treatment had minimal or no effect at all. Reason for low ILSS values can be explained with high void content of samples caused by processing aids in foam forming process.

The invention relates to composite structures comprising peat moss, to a foam-laid method for their manufacture and to the use thereof.Patent family as of 15.10.2021CA2868935 AA 20140929 CA20132868935 20130327 CA2868935 C 20200324 CA20132868935 20130327 EP2831157 A1 20150204 EP20130769922 20130327 EP2831157 A4 20160413 EP20130769922 20130327 FI126092 B 20160630 FI20120005353 20120328 FI20125353 A 20130929 FI20120005353 20120328 WO13144449 A1 20131003 WO2013FI50342 20130327Link to current patent family on right

Dewatering is an essential step in the processing of fibrous materials. The smaller the material size, the more challenging the dewatering process becomes. The dewatering properties of materials containing microfibrillated cellulose (MFC) are known to be especially challenging, particularly at high MFC contents. This study shows that the foam-laid forming technique enables more effective dewatering compared to water-laid forming and enables structures with both high bulk and sufficient strength. In the study, papers were formed using special water-laid and foam-laid sheet formers and MFC dosage was varied up to 15%. Papers containing high amounts of MFC were found to be unsuitable for water-laid forming due to poor dewatering properties resulting from higher fine material, i.e. MFC, content. Foam forming provided good dewatering characteristics even at high MFC contents. In addition to dewatering properties, the mechanical properties of the papers were also studied. According to the strength results, the strength potential of MFC-containing foam-laid papers was found to be greater with respect to z-directional strength than in-plane strength.

Foam forming technology introduces new and exciting opportunities for manufacturing paper, board, tissue and other fibre based products. It enables production of very high porosity structures, which can be used in light-weighting, and possibilities to develop totally new fibre-based products. Foam forming also offers a way to remarkably reduce production costs and simultaneously improve properties of current products. Compared to traditional water forming technology the forming consistency may be increased substantially with foam. Foam forming also widens remarkably the raw material choice, especially the usage of long fibres. This paper highlights the recent developments especially from the tissue point of view and introduces the research facilities available for studying foam forming at VTT Technical Research Centre of Finland. In general, foam forming enables production of structures with high bulk and excellent formation. The main advantage for tissue comes through improved formation, which at low basis weights leads to significant increase in strength.

The target of this research was to monitor the influence of carbohydrate hydrolysis on dewatering and critical end product characteristics in semi pilot trials using a special unique semi pilot machine at VTT Jyväskylä. The surface chemistry of SC -grade thermo-mechanical pulp (TMP) was modified by commercial endoglucanase rich enzyme. According to results, at least 0.5 - 1.0 % of TMP dry weight had to be hydrolysed in order to increase significantly drainage in former section. Depending on the extent of enzymatic treatment paper properties, such as bulk, porosity, smoothness and strength where influenced by the extent of enzymatic actions. Overall, results indicates that enhanced drainage of TMP could be achieved without deterioration in retention and formation values by controlled enzymatic treatment.

The aim of our work is to broaden the current knowledge of foam-fibre systems. This article focuses on the determination of the bubble size distribution (BSD) of foam containing cellulose fibres. It is well known that BSD has a powerful effect on a wide range of foam properties. The Circular Hough Transform was used in this study as the pattern recognition algorithm, in conjunction with a non-biased rule for sampling partially visible bubbles in an image. This algorithm is suitable for wet foams with almost spherical bubbles. We used a cuvette, with an internal diameter of 1.6 mm, for foam collection. We showed that images of the foam must be acquired within 30 s of collection of the foam sample and that bubbles with a radius larger than 25 µm can be recognised with this technique. The number of images needed to estimate the BSD of wet foam was four i.e. the diameters of 400-800 bubbles per trial point were measured. The Sauter mean radius r[3,2] was used for characterising the BSD of foam. We tested our method using several sets of images. Quantitative determination of the BSD of foam-fibre mixture is possible using the measurement and image analysis method developed in this study. This method can also be used to study foams created using different combinations of surfactants, fibres and additives.

Effects of carbohydrate composition on flocculation, drainage, wet web tension, drying rate, and end-product quality of bleached birch kraft pulps were examined by laboratory handsheets and in pilot former trials. Carbohydrate composition of unrefined and refined never-dried birch pulps were modified with cellulases and hemicellulases. Dewatering, wet web tension, and drying characteristics of the modified pulps were analysed using versatile analytical instruments. Pilot former enabled on-line monitoring of chemical and physical state of the process. Flocculation of fibre suspension was measured on-line with CCD cameras from the headbox of the pilot former. Flocculation results were accompanied by dry sheet formation measurements. Enhanced initial dewatering by modification of carbohydrates was observed in pilot former. Depending on the modified carbohydrate, i.e., xylan or cellulose, and the extent of the enzymatic treatment, the tensile strength of wet sheet samples increased or decreased. Drying rate was noticed to increase due to specific modification of carbohydrates. Enhanced dewatering, tensile strength, and sheet smoothness could be simultaneously achieved by controlled modification of carbohydrates. Modification of carbohydrates of bleached birch pulp had significant influences on all paper-making sections of paper machine.