Search results for "Papermaking"
showing 10 items of 11 documents
The 3D structure of fabric and its relationship to liquid and vapor transport
2004
Polymeric carrier fabrics are commonly used in many industrial processes including manufacture of paper and board. Apart from acting as a carrier for the compressible porous material during the manufacturing process, the synthetic woven fabrics comprising mainly of poly ethylene terypthalate (PET) yarns, impart valuable product attributes, i.e. softness, bulk, absorbency, etc. in consumer products. The three-dimensional structure of the fabrics plays a critical role in deciding the manufacturing and energy efficiency as well as product end-use properties. X-ray micro computed tomography (X-CT) provides a non-intrusive technique to visualize and analyze the three-dimensional structure of por…
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…
Manufacturing Cellulosic Fibres for Making Paper: A Historical Perspective
2018
The manufacture of pulp and paper is an important branch of industry worldwide and is based on complex and multidisciplinary technology. The production and modification of cellulosic fibre, which created the foundation for this industrial sector, has had a rich and colourful history. It has gone through many eras and its development has been closely integrated with the growth of our fundamental knowledge of chemistry and other natural sciences. During the last two decades, modern pulp and paper technologies have undergone some significant developments, especially ones involving the creation of a wide range of new options for different feedstock materials. Nevertheless, the fundamental conce…
Resin and fatty-acid analysis by solid-phase extraction coupled to atmospheric pressure chemical ionization–mass spectrometry
2007
Using gas-chromatographic analysis, the suitability of liquid–liquid extraction and solid-phase extraction (SPE) methods was studied for the rapid separation of resin and fatty-acid fractions from papermaking process waters. In the second phase of this study, a novel procedure (correlation coefficient >0.99 and repeatability RSD <8%) for on-line monitoring of selected individual acid components (limits of detection 11–78 µg L−1) by SPE combined with atmospheric pressure chemical ionization–mass spectrometry was developed. The suitability of this technique for quality control of papermaking process waters was tested by means of industrial samples. The method was also found suitable for the a…
Phase Plane Analysis of Web Drying
2004
The mathematical model which describes the web drying in the papermaking machine has been carried out in the collaboration between our institute and joint-stock company “Paper Mill ‘Ligatne’” engineers. The general principles of this develpopment were underlined in the report [zz00]. Under some simplifying assumptions this model can be reduced to the nonlinear moisture — temperature phase plane equation. This equation promotes to obtain significant physical parameters used in the mathematical model, clarifies the causes which allow to optimize the papermaking machine drying cylinders temperature regime. The phase plane equation also explains the parabolic temperature distribution in a serie…
OVERVIEW OF ANALYTICAL PROCEDURES FOR FATTY AND RESIN ACIDS IN THE PAPERMAKING PROCESS
2012
This review describes the role of wood extractives, especially fatty and resin acids, in papermaking, as well as the importance of their removal from process waters. One of the main aims is also to illustrate versatile analysis methods for this purpose and highlight recent developments in corresponding applications. Most of the current methods require time-consuming and laborious sample pretreatment procedures prior to gas chromatography coupled either with flame ionization or mass selective detection. However, some faster, even online techniques with minimum sample pretreatment, are also available, mainly including high performance liquid chromatography coupled with mass spectrometry. The …
Non-Isothermal Mathematical Model of Wood and Paper Drying
2002
A mathematical model of wood or paper drying based on a detailed consideration of both heat and moisture transport phenomena is proposed. By averaging we express the model as a sequence of initial value problems for systems of two first order nonlinear ordinary differential equations. This mathematical model makes it possible to efficiently investigate the drying process of a thin wood plate or paper sheet for varying temperature and humidity conditions in the surroundings. In particular, we have considered the optimization of the heat regime over a series of steam-heated cylinders in a papermaking machine.
Evaluating pulp stiffness from fibre bundles by ultrasound
2012
A non-destructive ultrasonic tester was developed to measure the stiffness of pulp bundles. The mechanical properties of pulp are important when estimating the behaviour of paper under stress. Currently available pulp tests are tedious and alter the fibres structurally and mechanically. The developed tester employs (933 ± 15) kHz tweezer-like ultrasonic transducers and time-of-flight measurement through (9.0 ± 2.5) mm long and (0.8 ± 0.1) mm thick fibre bundles kept at (19.1 ± 0.4) °C and (62 ± 1)% RH. We determined the stiffness of soft wood pulps produced by three kraft pulping modifications: standard kraft pulp, (5.2 ± 0.4) GPa, prehydrolysis kraft pulp, (4.3 ± 0.4) GPa, and alkali extra…