Efecto del tratamiento alcalino de la fracciónde rechazos en las propiedades del papel Duo en CPP San Pedro de la Paz.
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Date
2025
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Universidad de Concepción
Abstract
El presente estudio se centra en analizar, mediante ensayos de laboratorio, los efectos de la modificación del tratamiento alcalino aplicado a la fracción de rechazos de la pulpa mecánica sobre las propiedades del papel Duo, producido en la planta Papelera del Pacífico (CPP), ubicada en San Pedro de la Paz.
Se realizaron ensayos de laboratorio en los que se variaron la dosificación de soda cáustica, la temperatura del tratamiento y el tiempo de residencia sobre pulpa proveniente de la fracción de rechazos de pulpa mecánica. Para el estudio experimental se evaluaron tres niveles por factor: carga de soda de 4%, 5% y 6%; temperaturas de tratamiento de 70, 90 y 120 °C; y tiempos de residencia de 10, 20 y 30 min. Posteriormente, se fabricaron hojas de laboratorio y se midieron propiedades críticas para la evaluación de la calidad del papel Duo, tales como índice de tracción, índice de rasgado, resistencia a la explosión, SCT, porosidad y rigidez.
A partir del análisis gráfico y estadístico de los resultados se determinó que la carga de soda cáustica y la temperatura del tratamiento son los factores con mayor influencia sobre las propiedades evaluadas, generando cambios significativos principalmente en aquellas asociadas a la resistencia del papel, como el índice de tracción, el índice de rasgado, la explosión y el SCT. El análisis estadístico evidenció que la carga de soda es estadísticamente significativa para el índice de tracción y el SCT, el tiempo de residencia influye de manera significativa en la porosidad y la temperatura en la rigidez, mientras que propiedades como el índice de rasgado y la explosión no presentaron dependencia estadísticamente significativa respecto de los factores estudiados. Así mismo, el proceso de optimización permitió identificar que el ensayo N°12 logra optimizar el conjunto de propiedades evaluadas, con énfasis especialmente en el índice de tracción, el índice de rasgado y la rigidez, bajo condiciones de 5% de carga de soda, 70 °C de temperatura y 30 min de tiempo de residencia.
Finalmente, el análisis comparativo entre hojas elaboradas con pasta tratada bajo condiciones del óptimo señalado y hojas fabricadas con pasta proveniente del estanque TQ-5 demuestra que la modificación de las condiciones de proceso permite mejorar la calidad del papel. En función de estos resultados, se recomienda realizar una prueba a nivel industrial aplicando los ajustes en la dosificación de soda y en el tiempo de residencia, con el fin de validar que la modificación de los factores estudiados constituye una solución efectiva al problema planteado.
This study focuses on analyzing, through laboratory tests, the effects of modifying the alkaline treatment applied to the mechanical pulp rejects fraction on the properties of Duo paper, produced at the Papelera del Pacífico (CPP) plant, located in San Pedro de la Paz. Laboratory tests were conducted varying the caustic soda dosage, treatment temperature, and residence time were varied on pulp from the mechanical pulp reject fraction. For the experimental study, three levels were evaluated for each factor: caustic soda loading of 4%, 5%, and 6%; treatment temperatures of 70, 90, and 120 °C; and residence times of 10, 20, and 30 minutes. Subsequently, laboratory sheets were manufactured, and critical properties for evaluating the quality of Duo paper were measured, such as tensile strength, tear strength, burst strength, SCT, porosity, and stiffness. Based on the graphical and statistical analysis of the results, it was determined that the caustic soda loading and the treatment temperature are the factors with the greatest influence on the evaluated properties, generating significant changes primarily in those associated with paper strength, such as tensile strength, tear strength, burst strength, and SCT. The statistical analysis shows that the soda loading is statistically significant for the tensile strength and SCT, residence time significantly influences porosity, and temperature influences stiffness, while properties such as tear strength and burst strength did not show a statistically significant dependence on the studied factors. Likewise, the optimization process identified that test No. 12 optimizes the set of evaluated properties, with particular emphasis on tensile strength, tear strength, and stiffness, under conditions of 5% soda loading, 70 °C, and a 30-minute residence time. Finally, the comparative analysis between sheets manufactured with pulp treated under the specified optimal conditions and sheets manufactured with pulp from tank TQ-5 demonstrates that modifying the process conditions improves paper quality. Based on these results, it is recommended that an industrial-scale trial applying the adjustments to the caustic soda dosage and residence time to validate that modifying the studied factors constitutes an effective solution to the problem.
This study focuses on analyzing, through laboratory tests, the effects of modifying the alkaline treatment applied to the mechanical pulp rejects fraction on the properties of Duo paper, produced at the Papelera del Pacífico (CPP) plant, located in San Pedro de la Paz. Laboratory tests were conducted varying the caustic soda dosage, treatment temperature, and residence time were varied on pulp from the mechanical pulp reject fraction. For the experimental study, three levels were evaluated for each factor: caustic soda loading of 4%, 5%, and 6%; treatment temperatures of 70, 90, and 120 °C; and residence times of 10, 20, and 30 minutes. Subsequently, laboratory sheets were manufactured, and critical properties for evaluating the quality of Duo paper were measured, such as tensile strength, tear strength, burst strength, SCT, porosity, and stiffness. Based on the graphical and statistical analysis of the results, it was determined that the caustic soda loading and the treatment temperature are the factors with the greatest influence on the evaluated properties, generating significant changes primarily in those associated with paper strength, such as tensile strength, tear strength, burst strength, and SCT. The statistical analysis shows that the soda loading is statistically significant for the tensile strength and SCT, residence time significantly influences porosity, and temperature influences stiffness, while properties such as tear strength and burst strength did not show a statistically significant dependence on the studied factors. Likewise, the optimization process identified that test No. 12 optimizes the set of evaluated properties, with particular emphasis on tensile strength, tear strength, and stiffness, under conditions of 5% soda loading, 70 °C, and a 30-minute residence time. Finally, the comparative analysis between sheets manufactured with pulp treated under the specified optimal conditions and sheets manufactured with pulp from tank TQ-5 demonstrates that modifying the process conditions improves paper quality. Based on these results, it is recommended that an industrial-scale trial applying the adjustments to the caustic soda dosage and residence time to validate that modifying the studied factors constitutes an effective solution to the problem.
Description
Tesis presentada para optar al título de Ingeniero/a Civil Químico/a.
Keywords
Industria de alcalinos, Hidróxido de sodio, Industria papelera