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Aging and degradation of oil and grease barrier papers coate

ABSTRACT: The long-term performance and stability of bio-based barrier coatings are critical for sustainable packaging. In this study, the aging and degradation of a biobased starch•wax emulsion coating were examined on two different base papers. Coated samples were stored for 8 months at 23°C and 50% relative humidity (RH) in their original reels to minimize external exposure and isolate internal aging effects. Multiple aging intervals were analyzed using advanced methods to assess both chemical composition and physical structure. The water vapor transmission rate (WVTR) of both coated papers increased during the first 15 days, but after eight months, the WVTR dropped below the initial values. Fourier transform infrared (FTIR) results supported these trends by showing a marked rise in the polarity index (PI), occurring predominantly within the first 15 days. The overall observations, including increases in the PI, carbonyl index (CI), and absolute absorbance in the hydroxyl region, confirm that both hydrolysis and oxidation occurred during aging. The gradual increase in the aliphatic C•H stretching peaks indicated that wax components moved toward the surface over time. The non-uniform surface enrichment of oleophilic wax following migration contributed to the decline in Kit rating upon aging by facilitating oil and grease wetting and penetration. At the same time, increased wax concentration at the surface helped improve the water vapor barrier performance during long-term aging. Scanning electron microscopy (SEM) imaging revealed distinct surface cracks over time on the starch-wax emulsion coated papers. The FTIR analysis supported these observations through an increase in the conformational disorder index (CDI) with aging. Physical changes were further reflected in the barrier performance, as the heptane vapor transmission rate (HVTR) increased significantly for both coated papers over the 8-month period.

A novel dimensionless index for optimizing the thermo-hydrau

ABSTRACT: The comprehensive performance of steam condensation in horizontal rotating channels, which involves a trade-off between heat transfer enhancement and flow resistance, lacks a unified evaluation criterion. This deficiency is particularly critical for applications such as a multi-channel cylinder dryer (MCD) in paper machines, where rotational operation enhances drying efficiency. To address this gap, this study introduces a novel dimensionless index, W/Eu, defined as the ratio of the dimensionless heat transfer coefficient (W) to the dimensionless pressure drop (Eu), thereby taking into account both heat transfer and flow resistance characteristics comprehensively. A functional relationship for this index was established with respect to channel spacing (Wr) and steam mass flux (G), followed by a theoretical optimization analysis. The analysis reveals that W/Eu decreases monotonically as Wr increases and increases monotonically as G increases, ultimately diverging as G ™¨ ™‡. Consequently, for any given operational range, the theoretical maximum performance is achieved at the boundary condition of minimum channel spacing (Wr ™¨ 0) and maximum allowable mass flux (G = Gmax). This work provides a clear theoretical directive for the design and optimization of high-efficiency rotating heat exchanger systems, offering valuable insights for enhancing the drying performance of microchannel dryers in paper machines and similar rotary thermal systems.

Closing the Water Cycle of Pulp Mills by Evaporating Bleaching and Debarking Effluents, 1997 Minimum Effluent Mills Symposium Proceedings

Closing the Water Cycle of Pulp Mills by Evaporating Bleaching and Debarking Effluents, 1997 Minimum Effluent Mills Symposium Proceedings

Troubleshooting Rheology and Runnability Problems in Metered Size Press, 2002 Metered Size Press Forum

Troubleshooting Rheology and Runnability Problems in Metered Size Press, 2002 Metered Size Press Forum

Process Stewardship - Beyond Millwide Systems for Survival in the 90's, 1992 TAPPI Conference Proceedings

Process Stewardship - Beyond Millwide Systems for Survival in the 90's, 1992 TAPPI Conference Proceedings

Summit Seeks to #Accelerate Action

Much of the following article was first published on the International Women's Day website. It is being shared here with AOTC readers interested in empowering women in the pulp, paper, and packaging industries or in attending the upcoming TAPPI WIN Women's Summit on Monday, October 20.

New Members Keep ASPI Growing

ASPI welcomes four new member companies, EcoSynthetix, Hydro-Thermal, Jedson Engineering, and Talo Analytic International, expanding its network of pulp, paper, and packaging industry suppliers. These additions strengthen ASPI's role as the premier forum connecting executive leaders across the supply chain. Senior industry professionals can leverage ASPI's Fall Customer Alignment Meeting at Georgia-Pacific's Atlanta headquarters October 15-17 for unprecedented access to industry insights, sustainability frameworks, and market outlook. This executive networking opportunity provides valuable knowledge sharing and relationship building for experienced leaders seeking to maintain professional relevance and influence industry standards.

In case you missed it in TAPPI’s electronic TISSUE 360° newsletter

Industry leaders showcase strategic investments and sustainability initiatives across global tissue markets. Cascades maintains top sustainability rankings while Georgia-Pacific commits $150M to Oregon facility expansion. Key technology partnerships emerge as Valmet delivers integrated tissue lines to Suzano and Andritz implements innovative hybrid heating systems for Softys Peru. Notable acquisitions include WEPA's expansion into UK markets through Star Tissue acquisition. These developments highlight advanced operational strategies, ROI-focused investments, and leadership opportunities in sustainable manufacturing practices that drive competitive advantage for mid-career professionals managing complex tissue operations.

Continuous Training is the Key to Closing the Skills Gap in Manufacturing

Manufacturing and operations leaders facing critical skills gaps can transform workforce resilience through continuous, personalized training programs. With 85% of packaging companies struggling to find skilled workers and trade roles 11% below 2007 levels, strategic learning and development initiatives offer competitive advantages including faster technology adoption, improved safety compliance, and enhanced productivity. SouthernCarlson's digital training success, delivering 34,000+ courses across 1,500 deskless employees in the first year, demonstrates how mobile-based, role-specific learning modules can reduce turnover while building high-performing teams ready for industry evolution.

Standards Coming Up For Review