Engineering Cellulose Fibers for High-Value Added Products for Pulp & Paper Industry

Ko, Young Chan,Park, Jong-Moon Korea Technical Association of the Pulp and Paper 2015 펄프.종이技術 Vol.47 No.6

Cellulose fibers is one of the most abundant in nature. It has many distinctive features: abundant in nature, biodegradable, non-toxic, eco-friendly, sustainable, easy to fabricate, hydrophilic, and cost-effective. Cellulose fibers, known as pulp, is produced from cellulose-containing materials by the pulping process. As the raw material, wood has been most commonly used while recycled pulp has been also used to some degree. Thus, pulp usually refers to wood pulp. Generally, the pulp and paper industry is regarded as the commodity market where the cost should be much more important than the quality. It also belongs to a mature market where the growth is slow, or even in decline. Accordingly, technological development has been rather stagnant for the industry. Recently, however, the pulp and paper industry has faced very serious challenges. First, due to digital technology, there has been a steady decline in the need for pulp and paper products. The digital industry has continuously replaced printed products such as books, newspapers, and magazines. Second, there has been a trend initiated by developed countries to limit the use of wood as the raw material for the sake of environmental protection. This forces the industry to find a more efficient use of wood pulp as well as finding alternative, non-wood sources. Third, as an individual becomes wealthier and more conscious of health-care, the quality of a product becomes more important than the cost. Thus, a paradigm shift is needed from the cost-conscientious to the quality conscientious. The objective of this article is to review the technologies aimed at engineering cellulose fibers for producing high-value added paper products.

Large Scale Applications of Nanocellulosic Materials - A Comprehensive Review -

Lindstrom, Tom,Naderi, Ali,Wiberg, Anna Korea Technical Association of the Pulp and Paper 2015 펄프.종이技術 Vol.47 No.6

The common production methods of nanocellulosic (cellulosic nanofibrils, CNF) materials from wood are being reviewed, together with large scale applications and particularly papermaking applications. The high energy demand for producing CNF has been one particular problem, which has been addressed over the years and can now be considered solved. Another problem was the clogging of homogenizers/microfluidizers, and the different routes to decrease the energy demand. The clogging tendency, related to the flocculation tendency of fibres is discussed in some detail. The most common methods to decrease the energy demand are TEMPO-oxidation, carboxymethylation and mechanical/enzymatic pre-treatments in the order of increased energy demand for delamination. The rheology characteristics of CNF materials, i.e. the high shear viscosity, shear thinning and the thixotropic properties are being illuminated. CNF materials are strength adjuvants that enhance the relative bonded area in paper sheets and, hence increase the sheet density and give an increased strength of the paper, particularly for chemical pulps. At the same time papers obtain a lower light scattering, higher hygroexpansion and decreased air permeability, similar to the effects of beating pulps. The negative effects on drainage by CNF materials must be alleviated through the appropriate use of microparticulate drainage aids. The use of CNF in films and coatings is interesting because CNF films and coatings can provide paper/board with good oxygen barrier properties, particularly at low relative humidities. Some other high volume applications such as concrete, oil recovery applications, automotive body applications and plastic packaging are also briefly discussed.

The formation of Paper and the Measurement of Formation

Komppa, Olavi Korea Technical Association of the Pulp and Paper 1997 펄프.종이기술 Vol.29 No.2

In paper the evenness of planar distribution of mass in a small scale is called formation (orbetter:mass formation). Traditionally formation has been assessed visually, by looking the sheet of paper against transmitted light. Different kinds of optieal testers are being usd to obtain quantitative rankings htat would be independent of the observer but would well correspond to the visual assessment. However, various raw-material and process factors do influence light trans-mittance in paper and do impair the correspondence between basis weight and the optical formation measurement (or visual assessment). As the optical formation test methods do not incorporate an efficient calib ration routine, the formation of the sophisticated paper grades of today the is rather difficult to measure optically and may lead to erroneous results. It may be concluded that the optical measurement is not suitable for paper grades with high filler content. coating, heavy calendering or that are made of heavily beaten pulp, nordoes it apply for dyed or printed papers. For this reason, visual assessment and optical evaluation shoild be replaced with a measurement that gives reliable results independent on paper grode and manufacturing process. Formation measuremend based on beta radiation is suitable for all paper grades regardless to the material contents or process treatment. It is possible to measure even dyed or printed samples. Thonks to a sim ple and relioble calibration, the results are converted to real basis weight balues that remain reliable even with time. The only beta tester commercially available is the AMBERTEC Beta Formation Tester. Formation of paper does vary locally in the web. Typically there exists a formation profile, too similarly to other properties of paper. Therefore, formation should ? ays be expressed as a mean of a sufficient amount of parallel determinations. All formation measurements should be calibrated against basis weight.

An Overview of Biopulping Research: Discovery and Engineering

Scott, Gary M.,Akhtar, Masood,Lentz, Michael J.,Horn, Eric,Swaney, Ross E.,Kirk, T.Kent Korea Technical Association of the Pulp and Paper 1998 펄프.종이기술 Vol.30 No.4

Biopulping is defined as the treatment of wood chips with lignin-degrading fungi prior to pulping. Fungal pretreatment prior to mechanical pulping reduces electrical energy requirements during refining or increases mill throughput, improves paper strength, reduces the pitch content, and reduces the environmental impact of pulping. Our recent work involved scaling up the biopulping process towards the industrial level, investigating both the engineering and economic feasibility. We envision the process to be done in either a chip-pile or silo-based system for which several factors need to be considered: the degree of decontamination, a hospitable environment for the fungus, and the overall process economics. Currently, treatment of the chips with low-pressure steam is sufficient for decontamination and a simple, forced ventilation system maintains the proper temperature, humidity, and moisture conditions, thus promoting uniform growth of the fungus. The pilot-scale trial resulted in the successful treatment of 4 tons of wood chips (dry weight basis) with results comparable to those on a laboratory. Larger, 40-ton trials were also successful, with energy savings and paper properties comparable with the laboratory scale. The overall economics of the process also look very favorable and can result in significant annual savings to the mill. Although the current research has focused on biopulping for mechanical pulping, it is also beneficial for sulfite chemical pulping and some applications to recycled fiber have been investigated.

Advanced Paper Machine Concepts for the Production of Packaging Papers

Kruska, D.,Mirsberger, P. Korea Technical Association of the Pulp and Paper 1997 펄프.종이기술 Vol.29 No.3

Up to now 5 Voith Sulzer paper machines with multi-layer headbox and Gapfor-mer are sucessfully running on papckaging papers. Linerboard, testliner and corugating medium is produced in the basis weight range from 105 to 275 $g/m^2$ at machine speeds up to 900 m/min. The nest one, starting up in Oct. `96 in Germany, will be the world's fastest paper machine for packaging papers. The 5.6 m wide machine is designed for a maximum operating speed of 1200 m/min. Approx. 220.000 tons of corrugating medium and testliner based on 100% waste paper in the basis weight range from 90 to 160 $g/m^2$ will be produced each year. An expansion stage planned for the future is intended to increase annual output to 280.000 tons. This machine will not only be the fastest one for packaging papers, it also comprises all described innovative key components which are available today in order to fulfill growing demands of the future with regard to quality and productivity. The concept of this advanced machine is shown in Fig. 9.

Development of a New On-line fiber Orientation Sensor Based on Dielectric Anisotropy

Nagata, Shinichi Korea Technical Association of the Pulp and Paper 2002 펄프.종이기술 Vol.34 No.5

A new method is proposed for the on-line measurement of the fiber orientation of sheet materials. The measurement of fiber orientation is very important in manufacturing paper sheets, non-woven fabrics, and glass sheets, because fiber orientation strongly affects product properties represented by, for example, dimensional stability of paper. A method developed in this research utilizes anisotropy of dielectric constants of sheet materials as a key characteristic to determine the fiber orientation. The new on-line sensor, consisting of 5 microwave dielectric resonators set in different directions, was designed to detect the fiber orientation while paper is running with high speed on a paper machine. This sensor can determine the direction and the degree of fiber orientation from the measured direction of the maximal dielectric constant and its variation, respectively. The fundamental performance of this system was examined by the static measurement of printing grade paper, which gave a satisfactory result. Then, the dynamic measurements were done at a speed of 1,000 m/min by using a high-speed test-coating machine.

Bio-Soda Pulping of Rice Straw with Pleurotus cornucopiae under Atmospheric Pressure

Ju, Yong-Chan,Kang, Jin-Ha Korea Technical Association of the Pulp and Paper 2003 펄프.종이기술 Vol.35 No.5

This study was carried out to develop the bio-chemical pulping method to enhance the energy saving and decrease the capital cost through the soda pulping under atmospheric pressure ($100^{\circ}C$). Nonwood substrates, rice straw, were pretreated by white-rot fungi, Pleurotus cornucopiae. Several basic pieces of data that can be applied in soda pulping were acquired. The results of this study were as follows. Under the conditions without any nutrients or with glucose, N and glucose + N, the weight losses of rice straws inoculated by Pleurotus cornucopiae were 12.1∼32.6 %, 12.0∼26.3 %, 13.0∼25.4 % and 15.3∼24.7 % for 5, 10, 15, 20, 25 and 30 days incubation periods respectively. The more the fungal incubation was extended, the more the weight losses were gained. The yield of untreated rice straw was 54.8 % after pulping. When any nutrients was not added or glucose, N and glucose + N were added for the pretreatment, the total yields were ranged to 57.3∼42.9 %, 51.0∼43.3 %, 51.7∼43.9 % and 52.1∼46.1 % for 5 different incubation periods respectively. The yields were gradually decreased based on the extending of the incubation periods. The physical properties of the rice straw soda pulp without fungal treatment, the density, breaking length, burst index, tear index and folding endurance were 0.24g/㎤, 2.32 Km, 0.91 kPaㆍ$m^2$/g, 46.7 mNㆍ$m^2$/g and 21 times, respectively. In the case of pretreatment without any nutrients or with glucose, N and glucose + N as nutrients, the density was 0.24g/㎤, the breaking length was 3.30∼6.46 Km, the burst index was 1.36∼3.01 kPaㆍ$m^2$/g, the tear index was 33.0∼57.0 mNㆍ$m^2$/g and the folding endurance was 14∼381 times at most incubating periods, when pulping was done. The physical properties were increased as the incubation duration was extended. Especially, when N and glucose + N were added, the physical properties showed superior results during each incubation period.

Distortion and Dilatatioin in the Tensie Failure of Paper

Park, Jong-Moon,James L. Thorpe Korea Technical Association of the Pulp and Paper 1999 펄프.종이기술 Vol.31 No.5

Yield and fracture are separated in the tensile failure of paper. Failure in the machine direction of photocopy paper is contrasted with failure in the cross-machine direction . The ratios of distortion (shape change) to dilatation (volume change) for individual elements at yield and fracture are described. The ratios of distortion to dilatation are measured and compared to predicted values of the strain energy density theory. To evaluate the effect of the angle from the principal material direction on the strain energy density theory. To evaluate the effect of the angle from the principal material direction on the strain energy density factor, samples are prepared from machine direction to cross-machine direction in 15 degree intervals. the strain energy density of individual elements are obtained by the integration of stress from finite element analysis with elastic plus plastic strain energy density theory. Poison's ratio and the angle from the principal material direction have a great effect ion the ratio fo distortion to dilatation in paper. During the yield condition, distortion prevails over dilatation . At fracture, dilatation is at a maximum.

Characterization of Tensile Energy Aborption in Paper

Park, Jong-Moon,James L. Thorpe Korea Technical Association of the Pulp and Paper 1999 펄프.종이기술 Vol.31 No.5

Tensile energy absorption in paper has long been measured as the area under the load-elongation curve. Little effort has been made to define where and how that energy is used within the paper itself. Characterization of tensile energy absorption in paper is discussed. Multiple small elements within newsprint and kraft sack have been defined and the energy absorbed in those elements are discussed. The tensile profiles of the weak paper, newsprint, and the tough paper, kraft sack, are presented as separate strain profiles, stress profiles, and strain energy density profiles. This allows a complete analysis of the energy absorption of both papers for comparison or contrast.

Successful Winding of Coated Papers

Viitala, Teuve Korea Technical Association of the Pulp and Paper 1998 펄프.종이기술 Vol.30 No.1

Many new technologies and developments designed to increase paper machine speeds and improve paper printability have emerged in recent years. These improvements have changed the structure of paper and given winder manufacturers new challenges, especially as the requirements of printing presses have also changed. Ever-increasing roll widths and diameters are needed. Along with faster press speeds and shorter acceleration times, the unwinding of roils in the press room has become a true test of paper strength and roll structure, In the following we will review the special winding features of coated papers and discuss a selection of the winder type to meet a mill's specific needs.