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LDPE and PP thermal diffusivity in molten state
Difusividad térmica de mezclas de LDPE y PP en estado fundido
DOI:
https://doi.org/10.15446/ing.investig.v33n2.39501Keywords:
low density polyethylene (LDPE), polypropylene (PP), diffusivity (en)PP, LDPE, difusividad (es)
Experimental results are reported for measuring the thermal diffusivity of two polymer species: low density polyethylene (LDPE) and polypropylene (PP). Measurements were taken in unsteady state heat flow conditions around the materials' melting temperature, using a device specially constructed for this purpose. The experimental results for the sample's temperature profile (temperature gradient product) were adjusted with the theoretical results obtained by solving the heat conduction equation. Diffusivity values were α=6.92×(10)^(-7) m^2⁄s for LDPE and α=5.53×(10)^(-7) m^2⁄s for PP. This was pioneering work in measuring this property at high temperatures in non
Experimental results are reported for measuring the thermal diffusivity of two polymer species: low density polyethylene (LDPE) and polypropylene (PP). Measurements were taken in unsteady state heat flow conditions around the materials’ melting temperature, using a device specially constructed for this purpose. The experimental results for the sample’s temperature profile (temperature gradient product) were adjusted with the theoretical results obtained by solving the heat conduction equation. Diffusivity values were α =6.92 x 10-7 m2/s for LDPE and α =5.53 x 10-7 m2/s for PP. This was pioneering work in measuring this property at high temperatures in non-stationary state heat flow conditions and should be useful in the search for improving the conditions for processing these materials.
-stationary state heat flow conditions and should be useful in the search for improving the conditions for processing these materials.
Se reportan los resultados experimentales de la medición de la difusividad térmica de dos especies poliméricas: polietileno de baja densidad (LDPE) y polipropileno (PP). Las medidas fueron realizadas en condiciones de flujo de calor no estacionario, usando un dispositivo especialmente construido para ello y a temperatura alrededor de la de fusión de los materiales. Los resultados experimentales del perfil de temperatura a través de las muestras, producto de la existencia de un gradiente de temperatura en ellas, fueron ajustados con los resultados teóricos obtenidos de la solución de la ecuación de conducción del calor. Los valores de difusividad hallados fueron α =6.92 x 10-7 m2⁄s y α =5.53 x 10-7 m2⁄s para LDPE y PP respectivamente. Este es un trabajo pionero en la medición de esta propiedad a temperaturas elevadas, en condiciones de flujo de calor no estacionario, y ello es útil en la búsqueda de mejoras de las condiciones de procesado en estos materiales.
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