Search
Use the search bar or filters below to find any TAPPI product or publication.
Filters
Publications
Level of Knowledge
Collections
Journal articles
Magazine articles
Improving the inkjet codability of folding boxboard, TAPPI Journal February 2019
Improving the inkjet codability of folding boxboard, TAPPI Journal February 2019
Journal articles
Magazine articles
Case study: Paper mill power plant optimization—balancing steam venting with mill demand, TAPPI Journal June 2020
ABSTRACT: Most Power departments are tasked with generating steam to support mill wide operations, generate electricity, and reduce operating costs. To accomplish these tasks, power boilers generate high pressure steam that is reduced to intermediate and low pressures for process utilization in the mill by means of steam turbine generator extraction or pressure reducing valves. The most economical method to reduce steam pressure is the use of steam turbine generators, as electricity is generated from the steam when it is reduced in pressure. Electricity that is produced by these generators provides a substantial financial benefit and helps offset overall operational costs. To achieve tangible financial gains, the mill must evaluate the overall cost of steam production and the price of electricity.The current work provides a case study of power plant optimization that evaluated electricity production and steam production costs balanced with mill steam demand. Process and cost optimization led to a significant reduc-tion in low pressure steam venting, resulting in reduced fuel consumption and reduced operating cost.
Journal articles
Magazine articles
Effects of different ammonium lignosulfonate contents on the crystallization, rheological behaviors, and thermal and mechanical properties of ethylene propylene diene monomer/polypropylene/ammonium lignosulfonate composites, TAPPI Journal January 2020
ABSTRACT: Thermoplastic elastomer (TPE), made from ethylene propylene diene monomer (EPDM) and polypropylene (PP) based on reactive blending, has an excellent processing performance and characteristics and a wide range of applications. However, there are currently no reports in the literature regarding the usage of TPE in making composite boards. In this paper, EPDM, PP, and ammonium lignosulfonate (AL) were used as the raw materials, polyethylene wax was used as the plasticizer, and a dicumyl peroxide vulcanization system with dynamic vulcanization was used to make a new kind of composite material. This research studied the influences of the AL contents on the crystallization behaviors, rheological properties, thermal properties, and mechanical properties of the composites. The results showed that the AL content had a noticeable impact on the performance of the composite board. Accordingly, this kind of composite material can be used as an elastomer material for the core layer of laminated flooring.
Journal articles
Magazine articles
A new approach for the preparation of cellulose nanocrystals from bamboo pulp through extremely low acid hydrolysis, TAPPI Journal January 2020
ABSTRACT: As a renewable and biodegradable nanomaterial, cellulose nanocrystal (CNC) has a wide range of potential applications, but production of CNC faces significant challenges in capital investment and manufacturing cost. In this work, the one-step preparation of CNC from bleached kraft bamboo pulp by extremely low acid (concen-tration of acid = 0.1 wt%) hydrolysis was demonstrated. The experimental data indicated that the yield of CNC was strongly affected by the operating pressure and concentration of hydrochloric acid (HCl), as well as temperature. Rod-like CNC with a mean particle size of 524 nm was obtained through an extremely low acid (ELA) hydrolysis pro-cess. The yield of CNC can reach to 37.1% by an ELA hydrolysis process at 180°C for 60 min with 0.08 wt% HCl and 20 MPa operating pressure. The Fourier transform-infrared spectroscopy (FTIR) measurements show that the as-pre-pared CNC maintained cellulose structure. Compared with a conventional CNC prepared by strong sulfuric acid (H2SO4) hydrolysis, the CNC prepared by ELA hydrolysis process exhibited much higher thermal stability.
Journal articles
Magazine articles
Root cause analysis of cationic polymer additive efficiency decline in virgin and recycle containerboard mills, TAPPI Journal January 2020
ABSTRACT: It is well known that retention, drainage and strength polymers struggle to perform (if at all) in virgin containerboard mills. In-depth studies have been undertaken in this area for more than seven years, investigating the issue from all directions. A key finding of this work is that soluble lignin is detrimental to chemical efficiency. A strong correlation exists between decreased chemical efficiency and high soluble lignin. Both recycled systems and virgin systems have been studied, and this correlation holds true regardless of furnish. The primary area of concern is virgin container-board, because these mills tend to have the highest lignin levels. Some highly closed recycled mills can also build elevated lignin levels that can negatively affect chemical efficiency.
Journal articles
Magazine articles
The solubility of calcium carbonate in green liquor handling systems, TAPPI Journal October 2019
ABSTRACT: The formation of hard calcite (CaCO3) scale in green liquor handling systems is a persistent problem in many kraft pulp mills. CaCO3 precipitates when its concentration in the green liquor exceeds its solubility. While the solubility of CaCO3 in water is well known, it is not so in the highly alkaline green liquor environment. A systematic study was conducted to determine the solubility of CaCO3 in green liquor as a function of temperature, total titratable alkali (TTA), causticity, and sulfidity. The results show that the solubility increases with increased temperature, increased TTA, decreased causticity, and decreased sulfidity. The new solubility data was incorporated into OLI (a thermodynamic simulation program for aqueous salt systems) to generate a series of CaCO3 solubility curves for various green liquor conditions. The results help explain how calcite scale forms in green liquor handling systems.
Journal articles
Magazine articles
Comparing a linear transfer function-noise model and a neural network to model boiler bank fouling in a kraft recovery boiler, TAPPI Journal, July 2024
ABSTRACT: Boiler bank fouling reduces heat transfer efficiency in kraft recovery boilers. Here, we model the relationships between boiler parameters and boiler bank pressure drop, an indicator of fouling, based on recovery boiler operating data. We compared two models: an autoregressive integrated exogenous (ARIX) model and a feedforward neural network. The ARIX model better simulates boiler bank pressure drop compared to the neural network (R2 of 0.64 vs. 0.58). Based on the ARIX model, we identified six boiler parameters that significantly influence boiler bank fouling and their relative contributions. Finally, we demonstrate how the models can simulate boiler bank pressure drop given artificial perturbations in boiler parameters.
Journal articles
Magazine articles
Improvements in oil and grease resistance (OGR) test methodology for waterborne barrier coatings, TAPPI Journal November 2022
ABSTRACT: Paper-based food packaging is becoming more popular due to consumer demands for sustainable packaging options. Waterborne paper coatings that provide performance properties (i.e., resistance to oil and grease) not inherent to paper and board substrates offer improved sustainability profiles over earlier paper treatment options, including fluorocarbon treatment and coating with extruded plastics. The continued development of new paper coating technologies requires re-evaluation of current test methods and development of new methods to ensure lab evaluations can serve as accurate predictors of real-world performance. This paper provides an overview of commonly used oil and grease resistance (OGR) test methods within the paper coatings industry, and then describes improvements and developments made to two key methods: the 3M Kit test and an internally developed oil breakthrough test. The combined use of these adapted methods provides a more efficient testing workflow and a more complete understanding of the OGR performance of barrier coatings.
Journal articles
Magazine articles
New opportunities in the paper and nonwovens industries with foam-assisted web forming and chemical application, TAPPI Journal January 2023
ABSTRACT: Foam-assisted web forming and chemical application technologies have great potential to improve manufacturing efficiency and product quality in the paper and nonwovens industries. In this study, the benefits of foam forming and foam-assisted application of chemicals were demonstrated in a pilot machine trial. Uniform high-bulk webs of unrefined bleached softwood kraft pulp (BSKP) and viscose fibers were manufactured by foam forming. It was shown that foam formed low-grammage and high-bulk viscose fiber webs can be strengthened by foam-assisted application of latex onto the wet web. Correspondingly, foam-assisted application of carboxymethyl cellulose (CMC) and anionic polyacrylamide (A-PAM) improved the strength of the foam formed low-grammage and high-bulk BSKP web. Overall, the pilot machine results indicated that material cost savings could be achieved and a high-performance product could be manufactured with foam-based technologies.
Journal articles
Magazine articles
Continuous digester process safety improvements • Stress corrosion cracking and overpressure protection lessons learned and opportunities, TAPPI Journal October 2024
ABSTRACT: Georgia-Pacific has recent experience with continuous digester stress corrosion cracking (SCC) repairs where the extent of SCC was more than previous spot inspections had predicted (one digester had anodic protection, one did not). This paper offers case studies of reviewed and improved digester inspections by use of “boat” samples to quantify the depth of cracking mechanism. Boat sample test data is used to support repair recommendations based on hardness testing. Georgia-Pacific also reviewed overpressure protection systems and corrected gaps found in these systems. These included updating to the latest original equipment manufacturer (OEM) designs and formalizing functional testing procedures and practices. This review of digester inspection, testing, and repairs since 2020 provides: (1) a basis for including a 3rd party corrosion expert to be a part of inspections; (2) removes the use of power-wire brushes; (3) enhances digester inspection with 100% phased-array ultrasonic testing to detect SCC; and (4) ensures overpressure protection design and testing is aligned with corporate needs and the site-specific challenges.