Characterization of PLA-talc films using NIR chemical imaging and Multivariate Image Analysis techniques

Abstract

Maîtrise en génie chimiqueToutefois, puisque la structure de ces films est plus complexe, le contrôle de qualité de ces derniers est plus difficile. Dans l'industrie, des méthodes hors-ligne sont très souvent utilisées pour effectuer le contrôle de qualité des films produits. Le contrôle est nécessaire puisque la variabilité de la matière première ainsi que le changement des conditions opératoires amènent des modifications qui changent considérablement les propriétés du film. Par conséquent, une inspection en temps réel ainsi qu'un contrôle des films de polymère est nécessaire sur la ligne de production afin d'obtenir un contrôle de qualité s'approchant de l'analyse en temps réel.Un système d'imagerie proche infrarouge (NIR) rapide et non-destructif est proposé pour caractériser les films biodégradables d'acide polylactique contenant du talc produits par extrusion-soufflage et utilisés pour l'emballage. Le but ultime est d'utiliser le système pour faire un contrôle de qualité sur la ligne d'extrusion ainsi qu'après le post-traitement thermique, soit le recuit. Un ensemble d'échantillon de film de PLA contenant différentes concentrations en talc ont été fabriqués. Ces derniers ont ensuite été soumis à différentes conditions de recuit. Des images NIR ont été collectées avant la caractérisation des propriétés physiques et mécaniques ainsi que l'étanchéité aux gaz. Des techniques d'imagerie multivariées ont été appliquées aux images hyperspectrales. Celles-ci ont montré que la quantité de talc peut être déterminée et que l'information du spectre NIR permet de prédire les propriétés du film. Dans tous les cas, la méthode proposée permet de déterminer les variations dans les propriétés du film avec une bonne précision. iv AbstractFood packaging plays a great role in the food industry to maintain food products quality as long as possible. Polymer films are widely used in food packaging and also attract attention because of their outstanding advantages. Since petroleum-based polymers are known to cause environmental concerns, biodegradable polymers like PLA were studied more intensively in recent years due to their environmentally friendly properties. The application of reinforced films exceeds simple ones in achieving specific functions and enhancing their properties such as barrier properties. Since the films structures are more complex, quality control is more challenging. In industry, off-line methods are vastly used for quality control of the produced films while variability in raw materials and processing conditions substantially change the film specifications. Consequently, real-time inspection and monitoring of polymer films is needed on the production line to achieve a real-time quality control of the films.A fast and non-invasive near-infrared (NIR) imaging system is proposed to characterize biodegradable polylactic acid (PLA) films containing talc, and produced by extrusion film-blowing for packaging applications. The ultimate goal is to use the system for quality control on the extrusion line, and after a po...

Talc reinforcement of polylactide and biodegradable polyester blends via injection‐molding and pilot‐scale film extrusion

“…Nevertheless, the low heat resistance, brittleness, low crystallinity, and modest barrier properties of PLA have limited its use. 3,[6][7][8][9] In order to improve PLA film properties, flexible polymers, plasticizers, fillers and nucleating agents have been considered. [7][8][9] PLA has been blended, for example, with poly(butylene adipate-co-terephthalate) (PBAT), 8,10 poly(e-caprolactone) (PCL), 8,11 poly(ethylene glycol) (PEG), 9,11 poly(propylene glycol), poly(trimethylene carbonate) (PTMC) 11 and triphenyl phosphate, 9 altering the physicochemical properties, crystallinity, viscoelasticity, processability and overall end-product performance.…”

“…As an evolution of extrusion coating of PLA, [24][25][26][27] talc has been incorporated in PLA to produce composite PLA/talc films. So far, this has been achieved by using compression molding, 21,23 solvent casting, 11,17 extrusion film-blowing 6,12,15 and extrusion casting. 28 Differentiating from this earlier work, we produced PLA/talc films by using a pilot-scale extrusion coating unit which endowed films with significantly smaller thicknesses (18-26 μm).…”

“…PLA, as a renewable and biodegradable polymer, has become an alternative for petroleum‐based polymers. Nevertheless, the low heat resistance, brittleness, low crystallinity, and modest barrier properties of PLA have limited its use 3,6–9 . In order to improve PLA film properties, flexible polymers, plasticizers, fillers and nucleating agents have been considered 7–9 .…”

Gas transport properties of cellular hollow fiber membranes based on LLDPE/LDPE blends

“…As a result, the overall permeability should decrease with increasing crystallinity, especially for larger molecules. 50,51 This can be described by the limitation of polymer chains mobility in the crystalline regions. However, the same effect is expected when chemical/physical crosslinks are present.…”

Effect of filler additions on pilot-scale extrusion coating of paperboard with PLA-based blends

“…This is despite some PLA's drawbacks, which include low thermal resistance, brittleness, low crystallinity, and poor solvent resistance and gas barrier performance. (Sonjui and Jiratumnukul 2014, Zou et al 2015, Khuenkeao et al 2016, Phetwarotai and Aht-Ong 2016, Amirabadi et al 2018, Helanto et al 2019 To meet these challenges, flexible polymers, plasticizers, fillers, and nucleating agents have been introduced in PLA matrices (Zou et al 2015, Khuenkeao et al 2016, Phetwarotai and Aht-Ong 2016. Filler addition has been reported to benefit PLA's mechanical, thermal and barrier performance, and can potentially reduce the end-product cost.…”