gas barrier
Recently Published Documents


TOTAL DOCUMENTS

820
(FIVE YEARS 200)

H-INDEX

58
(FIVE YEARS 9)

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Karoliina Helanto ◽  
Riku Talja ◽  
Sai Li ◽  
Orlando J. Rojas

Abstract We study the incorporation of minerals (talc, kaolin and surface-treated calcium carbonate) in paperboard coatings based on PLA to improve their performance, often limited by the low crystallinity and moderate gas barrier of the polymer. Masterbatches of PLA-based blends mixed with the mineral fillers were melt-blended in a twin-screw extruder and applied as a coating on paperboard in a pilot-scale unit operating at velocities up to 140 m/min. Thermal imaging was used during the extrusion coating and the effect of the fillers was investigated as far as processability and their effect on the mechanical performance. A reduction of neck-in and improved adhesion between the coating and the substrate were achieved at intermediate mineral loadings. Excess filler and low coating weight generated pinholes, leading to a reduction of the integrity and mechanical properties of the coatings. Overall, we define the performance window for continuous, pilot-scale coating of paperboard with a biopolyester filled with mineral particles, opening the opportunity to realize operations in industrial settings.


2022 ◽  
pp. 073168442110548
Author(s):  
Ang Li ◽  
Rahul Vallabh ◽  
Philip D Bradford ◽  
David Kim ◽  
Abdel-Fattah M Seyam

The development of hull material with ideal properties to meet all the operation requirements has posed the greatest challenge to flying the airship at high altitude for extended periods. Materials developed in our previous study with a laminated structure achieved high strength-to-weight ratio and excellent gas barrier property at a relatively low total weight. To optimize this novel design and obtain a more comprehensive understanding of the laminate properties, a parametric study involving lamination process parameters (temperature and time), and laminate structural parameter (reinforcement fabric construction), was conducted. The effects of lamination parameters on tensile, peel, tear and helium permeability tests were carried out to assess the laminates. It was found that the tensile strength of the laminate is predominantly determined by the fabric reinforcement material properties. The peel and tear strength results showed that increasing the lamination temperature from 185 °C to 200 °C improved respective strength values. Additionally, the analysis of failure modes and tear propagation suggested that laminate samples with progressive failure have better tear resistant property over those with brutal failure. Extremely low helium permeability was achieved, yet the gas barrier property was not affected by the lamination process parameters and fabric type.


2021 ◽  
Author(s):  
Takao Katsura

New, low-cost transparent vacuum insulation panels (TVIPs) using structured cores for the windows of existing buildings are proposed. The TVIP is produced by inserting the structured core, the low-emissivity film, and the adsorbent into the transparent gas barrier envelopes. In this chapter, the authors introduce the outlines, the design and thermal analysis method, the performance evaluation (test) method. Firstly, five spacers, namely peek, modified peek, mesh, silica aerogel, and frame, are selected as the structured core. The effective thermal conductivity of TVIPs with five different spacers is evaluated at different pressure levels by applying numerical calculation. The result indicated that TVIPs with frame and mesh spacers accomplish better insulation performance, with a center-of-panel apparent thermal conductivity of 7.0 × 10−3 W/m K at a pressure of 1 Pa. The apparent thermal conductivity is the same as the value obtained by the simultaneous evacuation thermal conductivity measurement applying the heat flux meter method. Furthermore, using a frame-type TVIP with a total thickness of 3 mm attached to an existing window as a curtain decreases the space heat loss by approximately 69.5%, whereas the light transparency decreases to 75%.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4431
Author(s):  
Enrique Javier Jiménez-Regalado ◽  
Carolina Caicedo ◽  
Abril Fonseca-García ◽  
Claudia Cecilia Rivera-Vallejo ◽  
Rocio Yaneli Aguirre-Loredo

Starch is a biopolymer with enormous potential for generating new biodegradable packages due to its easy availability and low cost. However, due to its weak functional properties, limitation of its interaction with some hydroxyl groups and evaluation of blends with other polymers are necessary in order to improve its performance. Glycerol-plasticized acetylated corn starch films were developed using the casting method, and the impact of incorporating chitosan (TPS:CH) in various proportions (75:25, 50:50, and 25:75 v/v) was studied in the present research. The effect of chitosan ratios on the physical, mechanical, water-vapor barrier, and thermal properties of the film was studied. Chitosan-protonated amino groups promoted the formation of intermolecular bonds, improving tensile strength, thermal stability, hydrophobicity, water adsorption capacity, and the gas barrier of starch films. The results show that the film composed of TPS25-CH75 proved to be the best barrier to water vapor; thus, these composite films are excellent choices for developing biodegradable packaging for the food industry.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4346
Author(s):  
Yadong Zhao ◽  
Christofer Troedsson ◽  
Jean-Marie Bouquet ◽  
Eric M. Thompson ◽  
Bin Zheng ◽  
...  

Bio-based composite films have been widely studied as potential substitutes for conventional plastics in food packaging. The aim of this study was to develop multifunctional composite films by introducing cellulose nanofibers (CNF) and lignin into starch-based films. Instead of costly and complicated chemical modification or covalent coupling, this study optimized the performance of the composite films by simply tuning the formulation. We found that starch films were mechanically reinforced by CNF, with lignin dispersing as nanoparticles embedded in the matrix. The newly built-up hydrogen bonding between these three components improves the integration of the films, while the introduction of CNF and lignin improved the thermal stability of the starch-based films. Lignin, as a functional additive, improved hydrophobicity and blocked UV transmission. The inherent barrier property of CNF and the dense starch matrix provided the composite films with good gas barrier properties. The prepared flexible films were optically transparent, and exhibited UV blocking ability, good oxygen-barrier properties, high hydrophobicity, appreciable mechanical strength and good thermal stability. These characteristics indicate potential utilization as a green alternative to synthetic plastics especially for food packaging applications.


Author(s):  
Enrique Javier Jiménez-Regalado ◽  
Carolina Caicedo ◽  
Abril Fonseca-García ◽  
Claudia Cecilia Rivera-Vallejo ◽  
Rocio Yaneli Aguirre-Loredo

Starch is a biopolymer with wide potential for the generation of new biodegradable packages due to its high availability and low price. However, due to its weak functional properties, it is necessary to limit the interaction of some hydroxyl, and to evaluate blends with other polymers to improve their performance. Glycerol plasticized acetylated corn starch films were developed by the casting method, and the impact of incorporating chitosan (TPS:CH) at various proportions (75:25, 50:50, and 25:75 v/v) was studied. The effect of the chitosan ratios on the films' physical, mechanical, water vapor barrier, and thermal properties was evaluated. Chitosan protonated amino groups promote the formation of intermolecular bonds, improving the tensile strength, the thermal stability, the water adsorption capacity, and the gas barrier of starch films. Where the film composed of TPS25-CH75 was the one that presented the best barrier to water vapor. These composite films are a good option for development of biodegradable packaging.


Sign in / Sign up

Export Citation Format

Share Document