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Commercially relevant water vapor barrier properties of high amylose starch acetates: Fact or fiction?, TAPPI Journal September 2021

ABSTRACT: Starches have recently regained attention as ecofriendly barrier materials due to the increased demand for sustainable packaging. They are easily processable by conventional plastics processing equipment and have been utilized for oil and grease barrier applications. While starches have excellent oxygen barrier properties and decent water barrier properties at low relative humidity (RH), they are moisture sensitive, as demonstrated by the deterioration of the barrier properties at higher RH values. Starch esters are chemically modified starches where the hydroxyl group of the starch has been substituted by other moieties such as acetates. This imparts hydrophobicity to starches and has been claimed as a good way of retaining water vapor barrier properties of starches, even at high RH conditions. We studied the water vapor barrier properties of one class of starch esters, i.e., high amylose starch acetates that were assumed to have good water vapor barrier properties. Our investigations found that with a high degree of substitution of hydroxyl groups, the modified starches did indeed show improvements in water vapor response as compared to pure high amylose starch films; however, the barrier properties were orders of magnitude lower than commercially used water vapor barriers like polyethylene. Even though these materials had improved water vapor barrier response, high amylose starch acetates are likely unsuitable as water vapor barriers by themselves, as implied by previous literature studies and patents.

An Overview on Micro- and Macro-Scale Modeling of Aerosol Filters, 2011 Innovative Nonwovens Conference

An Overview on Micro- and Macro-Scale Modeling of Aerosol Filters, 2011 Innovative Nonwovens Conference

An Overview on Modeling Fluid Absorption in Fibrous Media, 2011 Innovative Nonwovens Conference

An Overview on Modeling Fluid Absorption in Fibrous Media, 2011 Innovative Nonwovens Conference

Utilization of Pre-Cleaned Greige Cotton in Nonwovens: A Sensible Approach, 2011 Innovative Nonwovens Conference

Utilization of Pre-Cleaned Greige Cotton in Nonwovens: A Sensible Approach, 2011 Innovative Nonwovens Conference

Real Measurements Lead to Real Understandings and Better Operating Control of the Recovery Liquor Cycle, 2023 PEERS Conference

Energy efficient alternatives to reduce the carbon emissions in the production of linerboard, 2023 PEERS Conference

Modern Approach for Precise Sizing Measurement, 2004 Paper Summit, Spring Technical & International Environmental Conference, (including Papermakers; Process Control, Electrical & Information; Product & Product Quality)

Modern Approach for Precise Sizing Measurement, 2004 Paper Summit, Spring Technical & International Environmental Conference, (including Papermakers; Process Control, Electrical & Information; Product & Product Quality)

Third Generation of Polyoxometalates: The Basis for a Commercially Feasible Closed-Mill Delignified Technology, 2000 Pulping / Process & Product Quality Conference Proceedings

Third Generation of Polyoxometalates: The Basis for a Commercially Feasible Closed-Mill Delignified Technology, 2000 Pulping / Process & Product Quality Conference Proceedings

Exploratory study on how sub-ply fiber orientation affects t

ABSTRACT: The transition to 100% biobased packaging presents considerable challenges, particularly in the development of a petroleum-free barrier. Generally, biobased barriers exhibit lower flexibility compared to traditional barriers, thereby increasing the risk of cracking during the converting process. The present study examines the possibility of optimizing the substrate to reduce cracking in brittle barriers. Five three-ply composites were fabricated using commercial paperboard to enable a composite with different fiber orientation in the individual plies. The different orientations achieved varying mechanical properties, including strain-atbreak and folding resistance, with a ranking that is comparable to a standard multi-ply paperboard. The composites were subjected to creasing at five distinct depths to assess the area percent of barrier cracks across the crease bead. Micro-cracks appeared on the surface before larger coating cracks were registered. As expected, the area percent of barrier cracks increased significantly with greater creasing depths. The orientation of the bulky middle ply showed little difference in the cracking propensity. However, by replacing the stiffer bottom ply with a ply of lower stiffness, the cracking propensity was significantly reduced without a substantial loss in mechanical properties. Hence, these findings indicate that it is possible to reduce the cracks in the barrier by modifying the fiber orientation in the different plies.

Improving barrier performance of coated paper and paperboard

ABSTRACT: Market demand for barrier coated packaging paper and paperboard has been on a steady rise and is forecasted to further increase. As a result, there is a continued interest in improving barrier coating functionalities, which is currently an active area of investigation. In this work, a multi-layer approach was adopted that involved applying a biowax emulsion, latex, or a combination of biowax and latex top coating layer onto the kaolin/latex (20/80, 50/50, 65/35, or 70/30) precoated solid bleached sulfate (SBS) paperboard. Our main objective was to demonstrate the effect of these top coating layers on various barrier properties, especially water vapor transmission rate (WVTR) at high relative humidity (RH) and high temperature (90% RH; 38°C), known as tropical/jungle test conditions. While the top coat with latex and/or biowax showed dramatic improvement in both water resistance (Cobb) and WVTR, the biowax coating increased contact angle significantly compared to the latex top coat. Contact angle increased from about 65° for the latex top coat to as high as 96° for the biowax top coat. Generally, it is much more difficult to improve WVTR at the jungle conditions below 100 g/m2/day, even with the high aspect ratio platy pigment. However, using the coating strategies adopted in this study, we were able to achieve WVTR values notably below 50 g/m2/day at the tropical test conditions, as well as significant improvements in regard to fold crack barrier integrity at high kaolin clay usage.