Abstract Epoxy powders were investigated as a processing route for fast, low-cost manufacturing of thick-section fibre reinforced polymer parts. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and parallel-plate rheometry were used to characterise the material for realistic processing conditions. The epoxy powders contained heat-activated curing agents and exhibited good thermal stability at and above typical processing temperatures (160–180 °C). The exothermic heat produced during curing was found to be small when compared to some conventional epoxies. Similarly, it was shown that epoxy powders can be melted between 45 and 120 °C to achieve low viscosities for fibre tow impregnation, without inducing significant cure. Semi-empirical cure kinetics and chemorheological models were presented, which can be used to predict the epoxy's behaviour during part consolidation and curing. Modifications were made to an existing cure kinetics model to better represent the behaviour of the epoxy at lower temperatures. The relationship between glass transition temperature and the degree-of-cure was described using the DiBenedetto equation and was implemented in an existing chemorheological model. The chemorheological model was applied to a standard process cycle to assess the accuracy of the model and the effectiveness of the process cycle.

中文翻译：

---

用于加工厚截面复合结构的环氧树脂粉末的表征

摘要 环氧树脂粉末作为一种快速、低成本制造厚截面纤维增强聚合物部件的加工途径被研究。使用热重分析 (TGA)、差示扫描量热法 (DSC) 和平行板流变仪来表征实际加工条件下的材料。环氧树脂粉末含有热活化固化剂，并在典型加工温度（160-180°C）及以上表现出良好的热稳定性。与一些传统环氧树脂相比，固化过程中产生的放热很小。同样，结果表明环氧树脂粉末可以在 45 到 120 °C 之间熔化，以实现纤维束浸渍的低粘度，而不会引起明显的固化。介绍了半经验固化动力学和化学流变模型，可用于预测部件固结和固化过程中环氧树脂的行为。对现有的固化动力学模型进行了修改，以更好地代表环氧树脂在较低温度下的行为。玻璃化转变温度与固化度之间的关系使用 DiBenedetto 方程进行描述，并在现有的化学流变模型中实施。将化学流变模型应用于标准工艺循环，以评估模型的准确性和工艺循环的有效性。玻璃化转变温度与固化度之间的关系使用 DiBenedetto 方程进行描述，并在现有的化学流变模型中实施。将化学流变模型应用于标准工艺循环，以评估模型的准确性和工艺循环的有效性。玻璃化转变温度与固化度之间的关系使用 DiBenedetto 方程进行描述，并在现有的化学流变模型中实施。将化学流变模型应用于标准工艺循环，以评估模型的准确性和工艺循环的有效性。