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A fast and non-destructive alternative to the burnout method for paperboard quality inspections using phase-contrast X-ray imaging, TAPPI Journal February 2023

ABSTRACT: An X-ray based quality inspection method for paperboard was implemented and tested as a fast and non-destructive alternative to the burnout method. An argument against X-ray imaging for inspection of paper and paperboard has been that X-ray absorption is low in paper. To overcome this limitation, we used phase-contrast X-ray imaging (PCXI), which gives higher contrast than conventional attenuation-based imaging for low-absorbing materials such as paper. The suggested PCXI method was applied to previously prepared and quality rated samples using the burnout method. A strong similarity between the burnout images and the PCXI images was observed. In conclusion, further development of the phase-contrast X-ray method would provide an interesting option for replacing or complementing the standard burnout method.

Water chemistry challenges in pulping and papermaking – fundamentals and practical insights: Part 1: Water chemistry fundamentals and pH, TAPPI Journal June 2022

ABSTRACT: Water is an essential component of the papermaking process. Nevertheless, papermakers often overlook its importance compared to fibers and chemical additives. A better understanding of water properties and chemical interactions associated with water at the wet end leads to a sound foundation for high-quality paper production and smooth operation. Not all fresh water and process water is the same. Fresh water varies from mill to mill, primarily due to the location and availability of water sources. Some industrial trends, such as enhancing water conservation and production yield, gradually shift process water quality over time. The current work serves as a primer on water and water chemistry fundamentals to help the papermaker prepare for the future challenges of increased contamination of process water associated with reduced fresh water usage. This paper focuses on basic water chemistry definitions and discusses the impact of pH on wet-end operation. It is clear that pH is a fundamental factor that directly affects the process and impacts other factors relevant to the papermaking process. It is crucial to understand what pH represents, how it is measured, how to select the proper pH and carefully control it, and how to closely maintain the process at target setpoints. Understanding the sensitivity of operation to pH change will lead to an appropriate focus on these issues. In addition to basic theory, we also review onsite experience and practical mill cases. It is imperative to stress that, although critical, pH is not the only chemical parameter impacting papermaking operations. Other factors, such as ionic concentration measured by conductivity, surface, soluble charge, and hardness, are critical and will be discussed in Part II of this series. As pH is a primary and independent factor that impacts various forms of charge and conductivity, the authors decided to start the current series of papers by discussing pH.

Development of paper quality parameter measurement in China, TAPPI Journal May 2022

ABSTRACT: Paper quality parameters are important indicators of paper production, such as paper moisture, basis weight, ash content, strength, and so on. This study focuses on the online measurement methods and development of paper basis weight, moisture, and ash measuring. First, the measurable paper parameters and quality control system products in China are analyzed. Then, the basis weight measurement methods, accuracy, and development are given in the range of 10~1000 g/m2. Third, the distinction between infrared and microwave methods for moisture measurement is discussed. Finally, the ash measurement is introduced. Production and consumption of tissue paper in China have continually increased during the past decade. Near-infrared light technology is mature for the measurement of paper parameters in the range of 10~200 g/m2 basis weight. However, the near-infrared online measurement of tissue paper is not widely used, and few tissue paper lines are equipped with this type of quality control system in China. Therefore, technology for near-infrared measurement of basis weight has a great potential market in the field of tissue paper production. This article analyzes the future development trend of near-infrared light in tissue paper basis weight measurement and summarizes the difficulties in near-infrared light measurement of tissue paper basis weight.

Improving refining efficiency with deflocculation, TAPPI Journal May 2022

ABSTRACT: The ability to load a refiner requires the formation of a fiber mat between opposing refiner bars. One of the consequences of this is the formation of flocs that persist through the refiner grooves and exit the refiner. These flocs interfere with sheet strength, requiring additional energy to make up the strength deficit. In addition, flocs can initiate string formation, resulting in machine efficiency issues such as cross-machine profile deterioration and the downtime required to correct it. Novel refiner plate modifications have been shown to improve refining efficiency in otherwise identical refiner plates. Energy savings are typically around 15% of gross refining energy on the basis of the treated stock, although much higher reductions have also been seen. Addressing this previously underappreciated flaw in conventional refining enables greenhouse gas reduction and other benefits related to sheet strength and machine efficiency.

Editorial: Reflections on the Page equation, laboratory work, and new concepts, TAPPI Journal May 2022

ABSTRACT: I began teaching paper physics to undergraduates in the late 1980s when the recognized giants in the field were still actively debating their subjects in the literature and scientific conferences.

The Effect of Component Removal Upon the Porous Structure of the Cell Wall of Wood. II. Swelling in Water and the Fiber Saturation Point, TAPPI Journal May 2022

ABSTRACT: The word "swelling" applied to an assemblage of fibers such as wood or wood pul p is very vague.

Proposed Legislation To “Go Digital” Still Pending

Flexco Elevate® Belt Rip Prevention

The Flexco Elevate® Belt Rip Prevention System is an innovative AI-powered solution that detects belt damage in real time and automatically initiates corrective actions. The system’s approach: rather than reacting, it proactively prevents damage before it occurs.

FSC and Partners Launch EU-Funded Project Worth 6.7 Million Euros to Strengthen Circularity in Forest-Based Value Chains

The Forest Stewardship Council (FSC) has secured substantial EU LIFE funding for a €6.7 million project, including €4 million from the EU LIFE program, together with a broad range of project partners. 

TAPPI’s Engineering Division Releases Major TIP Updates for Critical Equipment

Updated TIPS provide latest guidance on how to best inspect critical mill equipment.