Progress in foam forming technology

TAPPI Journal ◽  
2019 ◽  
Vol 18 (8) ◽  
pp. 499-510 ◽  
Author(s):  
HARRI KIISKINEN ◽  
KRISTIAN SALMINEN ◽  
TIMO LAPPALAINEN ◽  
JAAKKO ASIKAINEN ◽  
JANNE KERANEN ◽  
...  

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.

TAPPI Journal ◽  
2019 ◽  
Vol 18 (8) ◽  
Author(s):  
JANI LEHMONEN ◽  
TIMO RANTANEN ◽  
KARITA KINNUNEN-RAUDASKOSKI

The need for production cost savings and changes in the global paper and board industry during recent years have been constants. Changes in the global paper and board industry during past years have increased the need for more cost-efficient processes and production technologies. It is known that in paper and board production, foam typically leads to problems in the process rather than improvements in production efficiency. Foam forming technology, where foam is used as a carrier phase and a flowing medium, exploits the properties of dispersive foam. In this study, the possibility of applying foam forming technology to paper applications was investigated using a pilot scale paper forming environment modified for foam forming from conventional water forming. According to the results, the shape of jet-to-wire ratios was the same in both forming methods, but in the case of foam forming, the achieved scale of jet-to-wire ratio and MD/CD-ratio were wider and not behaving sensitively to shear changes in the forming section as a water forming process would. This kind of behavior would be beneficial when upscaling foam technology to the production scale. The dryness results after the forming section indicated the improvement in dewatering, especially when foam density was at the lowest level (i.e., air content was at the highest level). In addition, the dryness results after the pressing section indicated a faster increase in the dryness level as a function of foam density, with all density levels compared to the corresponding water formed sheets. According to the study, the bonding level of water- and foam-laid structures were at the same level when the highest wet pressing value was applied. The results of the study show that the strength loss often associated with foam forming can be compensated for successfully through wet pressing.


Holzforschung ◽  
2018 ◽  
Vol 72 (5) ◽  
pp. 397-403 ◽  
Author(s):  
Michael Lecourt ◽  
Tiina Pöhler ◽  
Joanna Hornatowska ◽  
Lennart Salmén ◽  
Petri Jetsu

AbstractX-ray tomography and densitometry (XRT and XRD) were applied to characterise wood fibre based insulation materials, which were produced by the foam forming technology. XRT is a high resolution approach with long measurement times of around 29 h, while XRD measurement needs only a few minutes. The determination of density distribution of boards in the thickness direction was the focus of this study. Both approaches visualised well the impact of raw materials and manufacturing processes on the structure of the panels. The density profiles were dependent on the pulp applied for panel production, and the processing conditions were also influential. Air flow resistance correlated with the maximum density measured inside the board. Both XRT and XRD revealed similar trends, which are useful for the characterisation of insulation materials.


Cellulose ◽  
2021 ◽  
Vol 28 (7) ◽  
pp. 4267-4279
Author(s):  
Jose Cucharero ◽  
Sara Ceccherini ◽  
Thad Maloney ◽  
Tapio Lokki ◽  
Tuomas Hänninen

Abstract In this study, sound absorbing materials were produced through foam forming technique using hardwood and softwood pulps with varying chemical composition, ultrastructural, and morphological properties as raw materials. The sound absorption properties of the produced foams were measured and related to the ultrastructure and the morphology of the pulp fibres. All the fibre foams provided sound absorption properties comparable to those of conventional porous materials used for acoustic purposes. In general, further processing, as well as smaller fibre dimensions contribute to improve the sound absorption properties of the pulp fibre foams. The results provide valuable insight on the optimization of wood-based sound absorbing materials. Graphic abstract


2010 ◽  
Vol 25 (2) ◽  
pp. 185-194
Author(s):  
Anna Svedberg ◽  
Tom Lindström

Abstract A pilot-scale fourdrinier former has been developed for the purpose of investigating the relationship between retention and paper formation (features, retention aids, dosage points, etc.). The main objective of this publication was to present the R-F (Retention and formation)-machine and demonstrate some of its fields of applications. For a fine paper stock (90% hardwood and 10% softwood) with addition of 25% filler (based on total solids content), the relationship between retention and formation was investigated for a microparticulate retention aid (cationic polyacrylamide together with anionic montmorillonite clay). The retention-formation relationship of the retention aid system was investigated after choosing standardized machine operating conditions (e.g. the jet-to-wire speed ratio). As expected, the formation was impaired when the retention was increased. Since good reproducibility was attained, the R-F (Retention and formation)-machine was found to be a useful tool for studying the relationship between retention and paper formation.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2237 ◽  
Author(s):  
P. R. Sarika ◽  
Paul Nancarrow ◽  
Abdulrahman Khansaheb ◽  
Taleb Ibrahim

Phenol–formaldehyde (PF) resin continues to dominate the resin industry more than 100 years after its first synthesis. Its versatile properties such as thermal stability, chemical resistance, fire resistance, and dimensional stability make it a suitable material for a wide range of applications. PF resins have been used in the wood industry as adhesives, in paints and coatings, and in the aerospace, construction, and building industries as composites and foams. Currently, petroleum is the key source of raw materials used in manufacturing PF resin. However, increasing environmental pollution and fossil fuel depletion have driven industries to seek sustainable alternatives to petroleum based raw materials. Over the past decade, researchers have replaced phenol and formaldehyde with sustainable materials such as lignin, tannin, cardanol, hydroxymethylfurfural, and glyoxal to produce bio-based PF resin. Several synthesis modifications are currently under investigation towards improving the properties of bio-based phenolic resin. This review discusses recent developments in the synthesis of PF resins, particularly those created from sustainable raw material substitutes, and modifications applied to the synthetic route in order to improve the mechanical properties.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 996
Author(s):  
Niels Lasse Martin ◽  
Ann Kathrin Schomberg ◽  
Jan Henrik Finke ◽  
Tim Gyung-min Abraham ◽  
Arno Kwade ◽  
...  

In pharmaceutical manufacturing, the utmost aim is reliably producing high quality products. Simulation approaches allow virtual experiments of processes in the planning phase and the implementation of digital twins in operation. The industrial processing of active pharmaceutical ingredients (APIs) into tablets requires the combination of discrete and continuous sub-processes with complex interdependencies regarding the material structures and characteristics. The API and excipients are mixed, granulated if required, and subsequently tableted. Thereby, the structure as well as the properties of the intermediate and final product are influenced by the raw materials, the parametrized processes and environmental conditions, which are subject to certain fluctuations. In this study, for the first time, an agent-based simulation model is presented, which enables the prediction, tracking, and tracing of resulting structures and properties of the intermediates of an industrial tableting process. Therefore, the methodology for the identification and development of product and process agents in an agent-based simulation is shown. Implemented physical models describe the impact of process parameters on material structures. The tablet production with a pilot scale rotary press is experimentally characterized to provide calibration and validation data. Finally, the simulation results, predicting the final structures, are compared to the experimental data.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4466
Author(s):  
Pablo Domínguez de María

Nitriles comprise a broad group of chemicals that are currently being industrially produced and used in fine chemicals and pharmaceuticals, as well as in bulk applications, polymer chemistry, solvents, etc. Aldoxime dehydratases catalyze the cyanide-free synthesis of nitriles starting from aldoximes under mild conditions, holding potential to become sustainable alternatives for industrial processes. Different aldoxime dehydratases accept a broad range of aldoximes with impressive high substrate loadings of up to >1 Kg L−1 and can efficiently catalyze the reaction in aqueous media as well as in non-aqueous systems, such as organic solvents and solvent-free (neat substrates). This paper provides an overview of the recent developments in this field with emphasis on strategies that may be of relevance for industry and sustainability. When possible, potential links to biorefineries and to the use of biogenic raw materials are discussed.


2006 ◽  
Vol 54 (5) ◽  
pp. 33-41 ◽  
Author(s):  
D. Dursun ◽  
M. Turkmen ◽  
M. Abu-Orf ◽  
S.K. Dentel

The effect of enzyme pre-treatment on dewaterability of anaerobically digested sludge was investigated at both laboratory and pilot scale. Our results revealed a significant increase in cake solid content (27% cake solids compared to 18% without enzyme pre-treatment), using an enzyme dose of only 20 mg/L. In order to assess practical application, enzyme pre-treatment was applied at the Wilmington, Delaware (US) wastewater treatment plant, using a pilot-scale centrifuge. However, the efficiency reached in laboratory scale could not be obtained in pilot scale, where the final cake solids content did not exceed 20%. Centrifuge and belt filter press (simulated by Crown Press™) dewatering were compared in terms of the process efficiencies in the absence and presence of enzyme pre-treatment. Possible factors that might cause the differences were tested by experimental and statistical comparisons. Results indicated that the higher shear applied in centrifugation is responsible for the lack of improved cake solids. The network strength of sludge determined by rheological measurements revealed that enzymatic treatment weakens the gel structure of the sludge floc through the hydrolysis of extracellular polymeric substances; this allows improved dewatering by filtration processes, but leads to floc deterioration when subjected to high shear during centrifugation.


2021 ◽  
Vol 8 (1) ◽  
pp. 36-43
Author(s):  
Ngoc Vuong Tran ◽  
Manh Hung Luong ◽  
Dinh Dang Nguyen

Zinc scrap is a source of raw material for zinc oxide production. However, to qualify the requirement of raw material for zinc oxide (99.5%) production, refining this source is needed. Many methods are considered such as rectification, chemical method, etc., but difficult to apply on an industrial scale. This workfocused on the investigation of the influence of temperature and time factors for asessing the possibility of applying liquation method for the purification of impurities from scrap zinc.The experiment results show that the optimum temperature of liquation to remove Pb,Fe from zinc scrap is in the range of 440-450°C, the optimal time of the process is 8h for the pot with 8cm in height and 6cm in diameter (the quantity of raw zinc sample is about 2kg / batch), then we can obtain about 80% of zinc metal with an average Zn content of about 97, 0%, both Pb and Fe content decreased to a range from 0.35 to 0.4%, and 1.0 to 1.1%, respectively, which meet the requirement of raw materials for the production of high quanlity ZnO ( 99,5 %). Based on the parameters obtained on lab-scale, a trial on pilot scale of 250 kg / batch was conducted, The result confirms that the quality of the products meets the requirement of raw materials for production of high quality ZnO (99.5%) and a technology process for refining zinc scrap by the liquation was proposed.


2000 ◽  
Vol 37 (02) ◽  
pp. 100-110
Author(s):  
Michael R. Cocklin ◽  
Michael G. Parsons ◽  
Armin W. Troesch

The United States Coast Guard, in supporting and executing its growing list of missions, employs the 110 ft WPB Coastal Patrol Board as a multipurpose platform. Recently, the internal conflicts in Haiti which resulted in the mass exodus of people required extensive use of 110 ft WPBs. These Coastal Patrol Boats are being deployed for longer periods of time with longer on-scene time than before. But with this growing list of missions and recent developments, the Coast Guard's budget has not increased. The Coast Guard has had to do more with less. In order to do this, one must look at ways of reducing the operating cost of the cutters. Analytical analysis of a 110 ft WPB Coastal Patrol Boat is used to show that retrofitting these vessels with a stern flap will lead to an effective energy enhancement with application to the entire 110 ft WPB Coastal Patrol Boat Fleet. The projected energy savings per cutter per year is over $5165. With a fleet of 49, the projected fleet savings per year is $253 085. The payback period for the installation costs would be just over one year.


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