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Citrus-based hydrocolloids: A water retention aid and rheology modifier for paper coatings, TAPPI Journal July 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.
Journal articles
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The evolution of reel statistical methods, TAPPI Journal June 2019
ABSTRACT: Multiple statistical methods for calculating the variance partition analysis (VPA) of reel data have existed for decades. In the paper industry, VPA is also commonly known as reel statistics. VPA commonly consists of total variance (TOT) that is then divided into three components: cross direction (CD), machine direction (MD), and residual (RES). A common mathematical procedure is referred to as ANOVA (analysis of variance). TAPPI Standard Test Method T 545 “Cross-machine grammage profile measurement (gravimetric method)” addresses paper testing and includes the ANOVA equations that have also been used to analyze scanning data.In the 1990s, TAPPI published TIP 1101-01 “Calculation and partitioning of variance using paper machine scanning sensor measurements,” which contained simple formulas that were easy to implement and could be used by a nov-ice to generate statistics on a spreadsheet. All involved quality control system (QCS) suppliers agreed to support this common method in their QCS. TIP 1101 was recently revised, and this paper concerns the analysis of data collected from a scanning sensor in a QCS and the creation of a common method for the calculation of reel statistics by TAPPI’s Process Control Division.
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Editor's Note: An Ideal Raw Material for Pulp and Paper, TAP
Editor's Note: An Ideal Raw Material for Pulp and Paper, TAPPI JOURNAL March 2010
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Editorial: The changing face of the coated paper industry, TAPPI JOURNAL January 2018
Editorial: The changing face of the coated paper industry, TAPPI JOURNAL January 2018
Journal articles
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Contrasting underlying mechanisms of different barrier coating types, TAPPI Journal January 2018
Contrasting underlying mechanisms of different barrier coating types, TAPPI Journal January 2018
Journal articles
Magazine articles
Print quality of flexographic printed paperboard related to coating composition and structure, TAPPI Journal January 2018
Print quality of flexographic printed paperboard related to coating composition and structure, TAPPI Journal January 2018
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Pulp in a Frenzy, Paper360º, January/February 2018
Pulp in a Frenzy, Paper360º, January/February 2018
Journal articles
Magazine articles
Dynamic compression characteristics of fiber-reinforced shoe press belts, TAPPI Journal April 2025
ABSTRACT: Shoe press belts contribute significantly to the overall dewatering performance in the press section of a paper machine. Within the shoe press nip, the press belt faces a dynamic and multidimensional load that mainly leads to a compression of the structure. As this will cause a loss in void volume, knowledge of the dynamic compression characteristics of shoe press belts is crucial for optimized dewatering. A novel method was developed to examine the dynamic compression characteristics of grooved polyurethane press belts. Therefore, an experimental setup allowing realistic boundary conditions to test specimens was placed in a servo-hydraulic testing machine. Press belt specimens with different matrix material formulations and groove patterns were tested under varying load rates equivalent to different paper machine operational speeds. The results showed an evident sensitivity of the dynamic compression stiffness to the operational speed of the paper machine. This behavior was seen to be more sensitive to changes in the matrix material formulation than to adaptions of the groove pattern. As a result, the compression of the press belt within a shoe press nip is not only influenced by the peak pressure within the shoe press nip but also depends on the operational speed of the paper machine.
Journal articles
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Numerical investigation of the effect of ultrasound on paper drying, TAPPI Journal March 2022
ABSTRACT: The paper drying process is very energy inefficient. More than two-thirds of the total energy used in a paper machine is for drying paper. Novel drying technologies, such as ultrasound (US) drying, can be assessed numerically for developing next-generation drying technologies for the paper industry. This work numerically illustrates the impact on drying process energy efficiency of US transducers installed on a two-tiered dryer section of a paper machine. Piezoelectric transducers generate ultrasound waves, and liquid water mist can be ejected from the porous media. The drying rate of handsheet paper in the presence of direct-contact US is measured experimentally, and the resultant correlation is included in the theoretical model. The drying section of a paper machine is simulated by a theoretical drying model. In the model, three scenarios are considered. In the first scenario, the US modules are positioned in the dryer pockets, while in the second scenario, they are placed upstream of the drying section right after the press section. The third case is the combination of the first and second scenarios. The average moisture content and temperature during drying, enhancement of total mass flux leaving the paper by the US mechanism, total energy consumption, and thermal effect of heated US transducers are analyzed for all cases. Results show that the application of the US can decrease the total number of dryer drums for drying paper. This numerical study is based on the US correlation obtained with the US transducer direct-contact with the paper sample. Thus, future work should include US correlation based on a non-contact US transducer.
Journal articles
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Predicting strength characteristics of paper in real time using process parameters, TAPPI Journal March 2022
ABSTRACT: Online paper strength testing methods are currently unavailable, and papermakers have to wait for manufacture of a complete reel to assess quality. The current methodology is to test a very small sample of data (less than 0.005%) of the reel to confirm that the paper meets the specifications. This paper attempts to predict paper properties on a running paper machine so that papermakers can see the test values predicted in real time while changing various process parameters. This study was conducted at a recycled containerboard mill in Chicago using the multivariate analysis method. The program provided by Braincube was used to identify all parameters that affect strength characteristics. Nearly 1600 parameters were analyzed using a regression model to identify the major parameters that can help to predict sheet strength characteristics. The coefficients from the regression model were used with real-time data to predict sheet strength characteristics. Comparing the prediction with test results showed good correlation (95% in some cases). The process parameters identified related well to the papermaking process, thereby validating the model. If this method is used, it may be possible to predict various elastic moduli (E11, E12, E22, etc.) in the future as the next step, rather than the traditional single number “strength” tests used in the containerboard industry, such as ring crush test (RCT), corrugating medium test (CMT), and short-span compression strength test.