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Application of ATR-IR measurements to predict the deinking efficiency of UV-cured inks, TAPPI Journal January 2022

ABSTRACT: In recent years, ultraviolet (UV)-curable ink has been developed and widely used in various printing applications. However, using UV-printed products (UV prints) in recovered paper recycling causes end-product dirt specks and quality issues. A new method was developed that can distinguish UV prints from other prints by means of attenuated total reflectance infrared (ATR-IR) spectroscopy. Application of this method could allow more efficient use of UV prints as raw materials for paper recycling.First, a mill trial was performed using UV prints alone as raw materials in a deinked pulp (DIP) process. Second, test prints were made with four types of UV inks: a conventional UV ink and three different highly-sensitive UV inks. Each print sample had four levels of four-color ink coverage patterns (100%, 75%, 50%, and 25%). Next, deinkability of all prints was evaluated by laboratory experiments. Finally, each print was measured using the ATR-IR method, and the relationship between the IR spectra and deinkability was investigated. Mill trial results showed that UV prints caused more than 20 times as many dirt specks as those printed with conventional oil-based ink. There were variations in recycling performance among UV prints taken from bales used for the mill trial. Lab tests clearly revealed that not all UV-printed products lead to dirt specks. In order to clarify the factors that affected deinkability of UV prints, the print samples were investigated by lab experiments. Key findings from lab experiments include: œ The number of dirt specks larger than 250 µm in diameter increased as the ink coverage increased. œ Higher ink coverage area showed stronger intensity of ATR-IR spectral bands associated with inks. These results indicate that deinkability of UV prints could be predicted by analysis of ATR-IR spectra. œ Finally, the method was applied for assessment of recovered paper from commercial printing presses. It was confirmed that this method made it possible to distinguish easily deinkable UV prints from other UV prints. Based on these findings, we concluded that the ATR-IR method is applicable for inspection of incoming recovered paper.

Journal articles
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Open Access
Editorial: TAPPI’s 2022 Nanotechnology Conference convenes in Finland, TAPPI Journal June 2022

ABSTRACT: TAPPI’s International Conference on Nano-technology for Renewable Materials was finally held in person this past June 13-17 in Helsinki, and more than 200 attendees gathered to participate in the 36-session program. A total of 24 countries were represented at the event and more than one-third of attendees were first-time participants.

Journal articles
Magazine articles
Open Access
Editorial: Vipin Varma joins TJ Editorial Board as expert on environmental and sustainability topics, TAPPI Journal October 2022

ABSTRACT: TAPPI and the TAPPI JOURNAL (TJ) editorial staff would like to welcome a new member to the TJ Editorial Board, Vipin Varma, Ph.D., who is vice president, Manufacturing Programs, at the National Council of Air and Stream Improvement (NCASI), headquartered in Cary, NC, USA. NCASI develops technical information that is critical for forest products companies to meet and surpass their environmental and sustainability goals. Vipin will provide expertise on environmental, sustainability, air emissions, and water topics relevant to the pulp and paper industry. In his position on the TJ Editorial Board, he succeeds Paul Wiegand, NCASI’s vice president for Water and Chemical Management Programs, who served from 2007 to 2022.

Journal articles
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Open Access
Effects of orders of addition in nanocellulose•cationic starch• colloidal silica systems for papermaking, TAPPI Journal October 2022

ABSTRACT: Two orders of addition were compared when preparing paper handsheets from recycled copy paper furnish in combination with nanofibrillated cellulose (NFC), cationic starch, colloidal silica, and cationic retention aid (cPAM; cationic polyacrylamide). Faster dewatering and higher fine-particle retention were obtained at equal optimized dosages of additives when the colloidal silica was added last, after addition of the cPAM. The same order of addition also provided a higher gain in the paper’s tensile strength. However, higher paper stiffness was achieved when the colloidal silica was instead added to the NFC, after its pretreatment with cationic starch. Results were consistent with the principle that papermaking additives added shortly before sheetforming tend to have the largest effects on drainage and retention. The results also demonstrated a sensitivity to the relative dosages of positively and negatively charged additives.

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Open Access
Editorial: Ravi Challa brings tissue, nonwovens, and operational expertise to TJ Editorial Board, TAPPI Journal September 2022

ABSTRACT: TAPPI and the TAPPI JOURNAL (TJ) editorial staff would like to welcome a new member to the TJ Editorial Board, Ravi Challa, Ph.D., who is Research & Development (R&D) manager for Suominen Corporation at the company’s Bethune, SC, facility. There, his primary focus is new product development on wetlaid nonwovens paper machines, from maintaining mature technologies and innovation to discovering patterns in paper machine shutdowns and executing nonwovens product development trials.

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Open Access
Extensive function of green synthesized titania nanoparticles: Photodegradation of Congo red, TAPPI Journal September 2023

ABSTRACT: Several extensive research studies have explored the advantages of green templates in the synthesis of structure and morphology-controlled photocatalytic nanomaterials. This paper compares the abilities of zingiber rhizome extract (ZE) and tapioca starch extracts (TS) in modifying the surface and optical properties of titania nanoparticles (TNP) synthesized by solgel technique. The synthesized nanocatalysts were characterized using various physicochemical techniques. While zingiber (ginger) extract effectively promotes the formation of dual anatase and rutile phases, tapioca extract supports formation of the single anatase phase of titania. These two extracts were examined for the degradation of Congo red in the presence of sunlight. The photomineralization and recyclability of catalysts were evaluated through total organic content analysis. The easy recovery and reusability of zingiber and tapioca biomasses, along with good control over the growth of nanoparticles, enable them to be implicit novel green templates in the successful synthesis of photoactive mesoporous nanotitania.

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Open Access
Guest Editorial: Terry Bliss: Editorial board member "extrem

Guest Editorial: Terry Bliss: Editorial board member "extreme", TAPPI JOURNAL May 2012

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Open Access
The winding mechanics of laminate webs, TAPPI Journal February 2020

ABSTRACT: Models that describe the residual stresses due to winding single-layer webs at the end of roll-to-roll manufacturing machines are mature. These models have been used to reduce or avoid defects that are due to winding. Many laminated products exist where two or more webs have been joined to form a thicker composite web. The properties of the web layers provide a unique functionality to the product being manufactured. No laminate winding models exist in the literature. This paper will focus on the development of a laminate winding model and laboratory test verification of the model.

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Open Access
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
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Open Access
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.