PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL Volume 7, Number 3, 2021
lignocellulosic materials are of interest. This includes traditional pulp fibers, regenerated cellulose fibers, lignin binders and nanomaterials derived from wood. The development of water stable, strong interfiber bonding concepts is one of the main problems to be solved for advancing bio-based nonwoven products. PACKAGING TECHNOLOGY “One -step Coassembled Nanocoatings on Paper for Potential Packaging Applications”, Sonia E. Chavez, Hao Ding, Brandon L. Williams, Sunghyun Nam, Zaili Hou, Dongqiao Zhang & Luyi Sun, ES Materials & Manufacturing , Vol.15, (2022). Plastics films have been widely used in food packaging. But due to the environmental concerns of plastics films, there is a trend of replacing plastics films with paper for food packaging. To meet the requirements of packaging, the paper must be modified to improve its barrier properties. In this report, a sonication and dip coating method was developed to deposit a PVA/MMT nanocoating on two representative paper substrates: regular paper and cotton paper. The coated paper substrates were characterized by X-ray diffraction, scanning electron microscopy (SEM), water vapor transmission rate (WVTR), and microscale combustion calorimetry (MCC). The XRD results support the formation of well- aligned MMT nanosheets on paper substrates and the SEM images show that most pores on the substrates were covered by the nanocoatings, which leads to a drastic decrease in WVTR of the coated substrates. The nanocoatings also led to a minor improvement in flame retardancy. The results suggest that applying nanocoating is a promising approach to improve the barrier properties of paper for potential packaging applications. “ Preparation of eco-friendly wax-coated paper and its rheological and water- resistant characteristics ”, Eun Ju Lee & Kwang-Hee Lim, Korean Journal of Chemical Engineering , published online (2021). The blend (wax M) of crude by-product polyolefin wax (wax K) and a fractionated commercial paraffin wax (wax J) was suggested to replace the wax J as a coating agent for wax-coated papers. The rheological properties of waxes J, K, and M were examined and compared. The correlation between viscosity and shear rate applied on these waxes maintained at 90 °C and 130 °C was identified. In particular, this paper, for the first time, presented non-Newtonian shear thinning behavior of not only wax K but also its blend of wax M in terms of their viscosity affected by shear rate at an operating temperature below their melting temperature of higher-melting- temperature DSC endothermic peaks (HMTEPs). They showed non-Newtonian behavior, so-called shear thinning behavior, at 90 °C in the light of characteristics of both suspension systems and polymer systems. In addition, the profiles of viscosity at 130 °C of all the waxes versus the shear rate exhibited Newtonian fluid behavior. Wax J also showed the behavior of a dilatant fluid. Then, the physical properties including water vapor transmission rates (WVTR), surface roughness, and coated weights, of thin papers coated with waxes J (WJP), K (WKP), and M (WMP) were evaluated, characterized, and compared. As a result, WMP had an equivalent value to that of WJP or the lowest value among wax-coated papers in terms of WVTR. The surface roughness and the barrier property of WVTR were minimized and enhanced, respectively, by blending waxes J and K. The additional physical properties, including dynamic contact angles, surface tension, wet and dry tensile strength, optical examination of the wax-coated fiber structure, and antimicrobial properties of the wax-coated papers, were evaluated. The excellent antimicrobial properties of clinoptilolite added to wax J or wax M appeared. “The Effect of Different Virgin Fibers to the Properties of Paper Products, Tibor Czene & László Koltai, Proceedings of the 2 nd International Conference on Circular Packaging , 2021. The products from paper are widely used materials with several
Technical Abstracts
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