About TAPPI Journal
An internationally recognized technical publication for over 60 years, TAPPI Journal (TJ) publishes the latest and most relevant research on the forest products and related industries. A stringent peer-review process and distinguished editorial board of academic and industry experts set TAPPI Journal apart as a reliable source for impactful basic and applied research and technical reviews. Read more.
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July 01, 2019
ABSTRACT: In this issue of TAPPI Journal (TJ), researchers Olejnik and Pelczynski of Lodz University of Technology in Poland and researcher Bloch of the University of Gre-noble Alpes in France use an experimental device to measure the liquid absorption properties of tissue (p. 417). The device, called the eXtended liquid penetration analyzer (XLPA), was initially built at the Institute of Papermaking and Printing at the University of Lodz. Results from the study published here showed that the XLPA measurements were in good agreement with the ISO 12625:-8:2010 standard measurements. The researchers believe this method could ultimately help mills characterize the liquid absorption of their tissue in a better and faster manner.
July 01, 2019
ABSTRACT: Peroxide bleaching of softwood and hardwood (eucalypt) kraft pulps was performed in solutions of sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3), and sodium hydroxide (NaOH). The conventional P stage (hydrogen peroxide + sodium hydroxide; H2O2 + NaOH) was the most effective brightening system without an additional activator. However, peroxide activation by bicarbonate anion (HCO3•) was obvious in all cases where NaHCO3 or Na2CO3 was used. When N,N,N’,N’-tetraacetylethylenediamine (TAED) was added to the bleaching sys-tem, Na2CO3 as the alkali source afforded equal or slightly higher bleached brightness compared to NaOH usage for both the softwood and hardwood pulps. This outcome is attributed to simultaneous peroxide activation by HCO3• and TAED. When applied to the eucalypt pulp, the H2O2/Na2CO3/TAED bleaching system also decreased the bright-ness loss due to thermal reversion.
July 01, 2019
ABSTRACT: Liquid absorption ability belongs to the most important features of tissue papers. Due to non-homo-geneous internal and superficial structures, precise and fast evaluation of this property is challenging. The main aim of the presented research was to design an experimental device dedicated to the measurement of the kinetics of wetting phenomenon for tissue papers. The second aim was to evaluate whether it was possible to use image analysis for more precise characterization of liquid absorption properties of tissue paper. The obtained results showed that the method used, based on image analysis supported by gravimetric methods, proved to efficiently and quantitatively characterize the dynamics of liquid absorption for tissue papers. Supplementary parameters such as absorption anisotropy and in-plane velocity were obtained. Different experi-mental results were obtained for various tissue paper grades. Furthermore, water absorption capacity calculated from image analysis data correlated with results obtained according to the standard method EN ISO 12625-8:2010 “Tissue paper and tissue products—Part 8: Water-absorption time and water-absorption capacity, basket-immersion test method.” Hence, the presented device quantitatively characterizes and discriminates water absorption phenom-enon for tissue papers.
Enhancement of processability, surface, and mechanical properties of paper based on rice straw pulp using biopolymers for packaging applications, TAPPI Journal July 2019
July 01, 2019
ABSTRACT: wo biopolymers, chitosan and oxidized starch, were used as wet-end additives to improve the strength properties of the paper because of their biodegradable and non-hazardous qualities. The present study reports the improvement in surface and strength properties of packaging-grade paper made with rice straw pulp using biopolymers, chitosan, oxidized starch, and surface sizing added at the wet end of the paper machine.Use of chitosan at all doses from 0.5 to 10 kg/ton enhanced important surface and strength properties of paper. The breaking length, tear index, burst index, ring crush strength, stretch, tensile energy absorption index, and Taber stiff-ness of the paper with 10 kg/ton of chitosan as a wet-end additive showed 22%, 14%, 20%, 59%, 16%, 44%, and 48% improvement, respectively, in comparison to control, (i.e, without its addition). The Cobb60 was also reduced by 45%, showing better resistance to water in comparison to rice straw paper alone. The effects of chitosan added at the wet end on the paper surface were investigated using Fourier transform infrared spectroscopy (FTIR). The use of 10 kg/ton of chitosan at the wet end reduced the color and total suspended solids in the back water of the papermak-ing system by 55% and 51%, respectively. Further enhancement in the surface and strength properties of paper was observed following surface sizing with oxidized starch.
Citrus-based hydrocolloids: A water retention aid and rheology modifier for paper coatings, TAPPI Journal July 2019
July 01, 2019
ABSTRACT: The rheological and dewatering behavior of an aqueous pigmented coating system not only affects the machine runnability but also affects the product quality. The current study describes the use of natural hydrocol-loids derived from citrus peel fibers as a rheology modifier in paper coating applications. The results were compared with carboxymethyl cellulose (CMC) in a typical paper coating system. Water retention of the coating formulation was increased by 56% with citrus peel fibers compared to a default coating, and it also was higher than a CMC-containing coating. The Brookfield viscosity of paper coatings was found to increase with citrus peel fibers. Compared to CMC, different citrus peel fibers containing coating recipes were able to achieve similar or higher water retention values, with no change or a slight increase in viscosity. Coatings were applied on linerboard using the Mayer rod-coating method, and all basic properties of paper were measured to assess the impact of citrus peel fiber on the functional value of the coatings. Paper properties were improved with coated paper containing citrus peel fibers, including brightness, porosity, smoothness, surface bonding strength, and ink absorption.