The co‐kneader is a proper tool for processing polyvinyl chloride (PVC) compounds. Gelation of PVC is complex because of a narrow processing window. At low temperature, gelation is incomplete and leads to poor mechanical properties, while at high temperature, degradation may occur. The aim of this study is to gain a fundamental understanding of the gelation process of PVC in co‐kneaders. Careful examination of the gelation state of extruded PVC samples was carried out qualitatively by swelling the extruded samples in acetone and quantitatively by differential scanning calorimetry measurements. Gelation in various conditions of temperature and shear was firstly studied in a capillary device that ensures both pre‐shearing and extrusion through a circular die. This provided a reference basis for comparison with gelation state obtained in the co‐kneader. Samples were collected in the co‐kneader by means of opening the barrel. The gelation state was particularly examined in connection with the measured temperature at a fixed position along the screw at which a temperature sensor was positioned. The obtained results showed that the co‐kneader allows fast gelation with a mixing energy value lower than 200 kJ/kg when the temperature is higher than a critical value of 165°C for the studied formulation. J. VINYL ADDIT. TECHNOL., 2019. © 2019 Society of Plastics Engineers J. VINYL ADDIT. TECHNOL., 26:316–324, 2020. © 2019 Society of Plastics Engineers

中文翻译：

---

共捏合机中增塑的聚氯乙烯化合物的胶凝

共混机是加工聚氯乙烯（PVC）化合物的合适工具。由于加工窗口狭窄，PVC的胶凝非常复杂。在低温下，胶凝不完全，导致较差的机械性能，而在高温下，则可能发生降解。这项研究的目的是对共混机中PVC的胶凝过程有一个基本的了解。通过将挤出的样品在丙酮中溶胀并通过差示扫描量热法定量地定性地仔细检查了挤出的PVC样品的胶凝状态。首先在毛细管装置中研究了在各种温度和剪切条件下的胶凝作用，该装置可确保预剪切和通过圆形模具挤出。这为比较共混机中获得的胶凝状态提供了参考依据。通过打开桶在共捏合机中收集样品。结合在沿着温度传感器所处的螺钉的固定位置处的测得的温度来特别检查胶凝状态。获得的结果表明，当温度高于所研究配方的临界值165°C时，该共混机可实现快速凝胶化，且混合能值低于200 kJ / kg。J.乙烯基添加物。TECHNOL。，2019.©2019塑料工程师协会J.VINYL ADDIT。TECHNOL。，26：316–324，2020.©2019塑料工程师协会 结合在沿着温度传感器所处的螺钉的固定位置处的测得的温度来特别检查胶凝状态。获得的结果表明，当温度高于所研究配方的临界值165°C时，该共混机可实现快速凝胶化，且混合能值低于200 kJ / kg。J.乙烯基添加物。TECHNOL。，2019.©2019塑料工程师协会J.VINYL ADDIT。TECHNOL。，26：316–324，2020.©2019塑料工程师协会 结合在沿着温度传感器所处的螺钉的固定位置处的测得的温度来特别检查胶凝状态。获得的结果表明，当温度高于所研究配方的临界值165°C时，该共混机可实现快速凝胶化，且混合能值低于200 kJ / kg。J.乙烯基添加物。TECHNOL。，2019.©2019塑料工程师协会J.VINYL ADDIT。TECHNOL。，26：316–324，2020.©2019塑料工程师协会 ©2019塑料工程师协会J.VINYL ADDIT。TECHNOL。，26：316–324，2020.©2019塑料工程师协会 ©2019塑料工程师协会J.VINYL ADDIT。TECHNOL。，26：316–324，2020.©2019塑料工程师协会