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Supercritical fluid extrusion is usually a recent technical development for production of extended starch-based foams where formation of a microcellular structure is in fact achieved by injection of supercritical CO2 into the melt. The high effective diffusivity of CO2 in the porous matrix favors escape of the gas to the surroundings, reducing the amount designed for diffusion in to the bubbles, posing an important challenge thus. This research utilized two methods to address this problem: increasing the nucleation charge and thus the ultimate bubble density in the foam, and minimizing the melt temp. The former was achieved by decreasing the nozzle diameter to be able to achieve a higher pressure drop rate because the starch-CO2 melt flows through the nozzle. The next procedure was evaluated by introducing a cooling zone before the entry of the melt into the nozzle.  If you cherished this article and you would like to receive more info with regards to plastic extruder nicely visit the web-site. Bubble density raised more than fourfold when the nozzle radius was decreased from 3.00 to 1 1.50 mm. A higher bubble density resulted in a larger barrier or level of resistance to diffusion of CO2 to the surroundings, and increased expansion ratio by as substantially as 160%. Cooling of the melt resulted in a reduction in diffusion coefficient of CO2 in the starch melt, and therefore reduced CO2 reduction to the environment. The growth ratio increased by 34% as the melt heat range reduced from 60 to 40°C. The above-mentioned tactics can be useful in enhancing and controlling expansion, which determines the textural attributes of the expanded food product ultimately.
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Supercritical fluid extrusion is a recent technological development for production of expanded starch-based foams where formation of a microcellular structure is achieved by injection of supercritical CO<sub>2</sub> into the melt. The increased effective diffusivity of CO2 in the porous matrix favors get away of the gas to the environment, reducing the amount designed for diffusion into the bubbles, thus posing a significant challenge. This research utilized two approaches to address this issue: increasing the nucleation price and thus the final bubble density in the foam, and lowering the melt temperature. The former was attained by decreasing the nozzle diameter in order to achieve an increased pressure drop rate as the starch-CO2 melt flows through the nozzle. The next methodology was evaluated by presenting a cooling zone prior to the access of the melt into the nozzle. Bubble density improved more than fourfold once the nozzle radius was decreased from 3.00 to at least one 1.50 mm. If you have any questions relating to where and the best ways to utilize plastic compounding machines, you can contact us at our internet site. An increased bubble density resulted in a greater resistance or barrier to diffusion of CO2 to the environment, and increased expansion ratio by as much as 160%. Cooling of the melt led to a reduction in diffusion coefficient of CO2 in the starch melt, and therefore reduced CO2 damage to the environment. The growth ratio increased by 34% because the melt temperature decreased from 60 to 40°C. The above-mentioned strategies can be useful in enhancing and managing expansion, which ultimately determines the textural features of the expanded meals product.
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La extrusión de fluidos supercríticos es un desarrollo tecnológico reciente para la producción de espumas expandidas a base de almidón en las que la formación de una estructura microcelular se consigue mediante la inyección de CO<sub>2</sub> supercrítico en la masa fundida. La mayor difusividad efectiva del CO2 en la matriz porosa favorece la salida del gas al medio ambiente, reduciendo la cantidad destinada a la difusión en las burbujas, lo que plantea un reto importante. Esta investigación utilizó dos enfoques para abordar este problema: aumentar el precio de nucleación y, por tanto, la densidad final de burbujas en la espuma, y reducir la temperatura de fusión. El primero se consiguió disminuyendo el diámetro de la boquilla para lograr una mayor tasa de caída de presión a medida que la masa fundida de almidón y CO2 fluye por la boquilla. La siguiente metodología se evaluó presentando una zona de enfriamiento antes del acceso de la masa fundida
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El coeficiente de crecimiento aumentó un 34% porque la temperatura de la masa fundida disminuyó de 60 a 40°C. Las estrategias mencionadas pueden ser útiles para mejorar y gestionar la expansión, que en última instancia determina las características texturales del producto de harinas expandidas.
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Última revisión de 12:29 17 jun 2024

Supercritical fluid extrusion is a recent technological development for production of expanded starch-based foams where formation of a microcellular structure is achieved by injection of supercritical CO2 into the melt. The increased effective diffusivity of CO2 in the porous matrix favors get away of the gas to the environment, reducing the amount designed for diffusion into the bubbles, thus posing a significant challenge. This research utilized two approaches to address this issue: increasing the nucleation price and thus the final bubble density in the foam, and lowering the melt temperature. The former was attained by decreasing the nozzle diameter in order to achieve an increased pressure drop rate as the starch-CO2 melt flows through the nozzle. The next methodology was evaluated by presenting a cooling zone prior to the access of the melt into the nozzle. Bubble density improved more than fourfold once the nozzle radius was decreased from 3.00 to at least one 1.50 mm. If you have any questions relating to where and the best ways to utilize plastic compounding machines, you can contact us at our internet site. An increased bubble density resulted in a greater resistance or barrier to diffusion of CO2 to the environment, and increased expansion ratio by as much as 160%. Cooling of the melt led to a reduction in diffusion coefficient of CO2 in the starch melt, and therefore reduced CO2 damage to the environment. The growth ratio increased by 34% because the melt temperature decreased from 60 to 40°C. The above-mentioned strategies can be useful in enhancing and managing expansion, which ultimately determines the textural features of the expanded meals product.

La extrusión de fluidos supercríticos es un desarrollo tecnológico reciente para la producción de espumas expandidas a base de almidón en las que la formación de una estructura microcelular se consigue mediante la inyección de CO2 supercrítico en la masa fundida. La mayor difusividad efectiva del CO2 en la matriz porosa favorece la salida del gas al medio ambiente, reduciendo la cantidad destinada a la difusión en las burbujas, lo que plantea un reto importante. Esta investigación utilizó dos enfoques para abordar este problema: aumentar el precio de nucleación y, por tanto, la densidad final de burbujas en la espuma, y reducir la temperatura de fusión. El primero se consiguió disminuyendo el diámetro de la boquilla para lograr una mayor tasa de caída de presión a medida que la masa fundida de almidón y CO2 fluye por la boquilla. La siguiente metodología se evaluó presentando una zona de enfriamiento antes del acceso de la masa fundida El coeficiente de crecimiento aumentó un 34% porque la temperatura de la masa fundida disminuyó de 60 a 40°C. Las estrategias mencionadas pueden ser útiles para mejorar y gestionar la expansión, que en última instancia determina las características texturales del producto de harinas expandidas.

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