Search results for "valmistus"

Lignin Inter-Diffusion Underlying Improved Mechanical Performance of Hot-Pressed Paper Webs

2021

Broader use of bio-based fibres in packaging becomes possible when the mechanical properties of fibre materials exceed those of conventional paperboard. Hot-pressing provides an efficient method to improve both the wet and dry strength of lignin-containing paper webs. Here we study varied pressing conditions for webs formed with thermomechanical pulp (TMP). The results are compared against similar data for a wide range of other fibre types. In addition to standard strength and structural measurements, we characterise the induced structural changes with X-ray microtomography and scanning electron microscopy. The wet strength generally increases monotonously up to a very high pressing tempera…

Spectroscopic analysis of hot-water- and dilute-acid-extracted hardwood and softwood chips

2017

Hot-water and dilute sulfuric acid pretreatments were performed prior to chemical pulping for silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips to determine if varying pretreatment conditions on the original wood material were detectable via attenuated total reflectance (ATR) infrared spectroscopy. Pretreatment conditions varied with respect to temperature (130 °C and 150 °C) and treatment time (from 30 min to 120 min). The effects of the pretreatments on the composition of wood chips were determined by ATR infrared spectroscopy. The spectral data were compared to those determined by common wood chemistry analyses to evaluate the suitability of ATR spe…

Patented intelligence: Cloning human decision models for Industry 4.0

2018

Industry 4.0 is a trend related to smart factories, which are cyber-physical spaces populated and controlled by the collective intelligence for the autonomous and highly flexible manufacturing purposes. Artificial Intelligence (AI) embedded into various planning, production, and management processes in Industry 4.0 must take the initiative and responsibility for making necessary real-time decisions in many cases. In this paper, we suggest the Pi-Mind technology as a compromise between completely human-expert-driven decision-making and AI-driven decision-making. Pi-Mind enables capturing, cloning and patenting essential parameters of the decision models from a particular human expert making …

The Quest for Raw Materials in the British Paper Trade : The Development of the Bamboo Pulp and Paper Industry in British India up to 1939

2018

The British paper trade history was defined since the mid-1850s by a quest for a new raw material to replace rags. The requirements of the paper trade were first met by a discovery that esparto grass from Spain, and later from North Africa, could be utilised in British mills. Beginning in the late 1870s, the success of using esparto encouraged mill developments in British India. The increased dependence on imported wood pulp, the likelihood of a pulp famine, and the consequent increase in price for imported wood pulp drew attention to the possibility of making commercial volumes of good quality pulp from indigenous Indian grasses. Bamboo began being treated after the First World War, when t…

Brønsted and Lewis acid catalyzed conversion of pulp industry waste biomass to levulinic acid

2019

Enormous amounts of fiber sludge are generated annually by the pulp industry as a by-product. As a cellulose-rich material, its current usage, mainly as fuel, is inefficient from a material efficiency point of view. This work studied the utilization of fiber sludge from a Finnish and a Swedish pulp mill as a potential feedstock to produce levulinic acid, a valuable platform chemical. The conversion experiments of fiber sludge to levulinic acid were performed in a microwave reactor with a mixture of H2SO4 and Lewis acid as the catalyst. The reaction conditions, which included reaction time and temperature as well as the H2SO4 and Lewis acid concentrations, were studied in detail. The highest…

Technological Transformation in the Global Pulp and Paper Industry : Concluding Remarks

2018

The volume has provided us with illustrative, well-documented case studies of technological transformation in the global pulp and paper industry. The research has focused on the roles played by the availability of technology, knowledge, investments, and raw materials on the one hand and demand characteristics on the other, within local, regional, national and transnational organisational frameworks. It has dealt with the relationships between technology transfer, technology leadership, raw material dependence, and product variety on a global scale. The investigation has followed the tradition of in-depth and rich historical descriptions based on primary sources and secondary literature. The…

Technological Transformation in the Global Pulp and Paper Industry : Introduction

2018

At a high level of abstraction, the evolution of any industry is a function of changes in product market demand, availability and supply of capital, energy resources, raw materials knowledge and technology, the surrounding institutional framework and organisational solutions. New technological innovations emerge because of changes in product market demand or institutional framework that encourage entrepreneurs and firms to take advantage of new business opportunities. This contributed volume provides illustrative, well documented case studies of technological transformation in the global pulp and paper industry from the inception of mechanical papermaking in early nineteenth century Europe …

Ammoniumnitraatin kidefaasitransitiot

1990

Työ jakautuu laajahkoon kirjalliseen osaan ja kokeelliseen osaan. Kirjallinen osa käsittelee yleisia ammoniumnitraatin valmistukseen ja kemiaan liittyvia seikkoja sekä erityisesti sen seitsemää kiderakennetta. Eri rakenteet ja niiden väliset transitiot esitellään painopisteen ollessa rakenteille tunnusomaisessa dynaamisessa epäjarjestäytymisessä. Eri tutkijoiden antamien ristiriitaisten tietojen pohjalta on hahmotettu kosteuden merkitystä transitioihin. Tärkeimmät keskustelua synnyttäneet erimielisyydet liittyvät kosteuden merkitykseen IV III-transition esiintymiselle. Eri tutkijoiden raporteista syntyy käsitys, että kosteuden määrä ei ole määräävä tekijä, mutta kosteudella selvästikin on m…

Aqueous foam as the carrier phase in the deposition of fibre networks

2015

Encryption and Generation of Images for Privacy-Preserving Machine Learning in Smart Manufacturing

2023

Current advances in machine (deep) learning and the exponential growth of data collected by and shared between smart manufacturing processes give a unique opportunity to get extra value from that data. The use of public machine learning services actualizes the issue of data privacy. Ordinary encryption protects the data but could make it useless for the machine learning objectives. Therefore, “privacy of data vs. value from data” is the major dilemma within the privacy preserving machine learning activity. Special encryption techniques or synthetic data generation are being in focus to address the issue. In this paper, we discuss a complex hybrid protection algorithm, which assumes sequenti…