- 學位論文
棉絮+聚丙烯/陶瓷+聚丙烯複合材料射出成形特性之研究
Study Injection Molding Performance of Composite Material (Cotton Fiber Polypropylene / Ceramic Polypropylene )
摘要
聚丙烯(PP)材料是一種典型結晶體聚合物運用非常廣泛，因為具良好的物性、高耐溫效果、優秀的加工特性、廣泛性的複合材料用途。本研究利用棉絮纖維(CTN)與陶瓷粉末(CE)兩種材料加入至聚丙烯中，產出棉絮/聚丙烯及陶瓷/聚丙烯兩種複合材料進行機械性質比較，在複合材料製作方面利用Brabender Mixer進行塑性混煉，混煉出複合材料，再進行Brabender Extruder擠出、冷卻、造粒。 為了提升聚丙烯產品的穩定度，利用模穴壓力感測器來偵測材料在模穴中的流動壓力及時間在射出成形中，塑膠黏度受到溫度、壓力與剪切率影響，透過模穴壓力感測器求其黏度、剪切率及剪切應力，並以此三種數據作為產品的穩定性的依據，在射出成形方面，以改變射出速度，探討射出速度之剪切率、黏度與剪切應力對複合材料性質的影響，最後以衝擊與拉伸試驗做進一步的驗證。 實驗結果發現PP、CTN/PP、CE/PP三種材料在射出速度50-60%時，衝擊強度較佳，然而在CE/PP與PP相比較下衝擊強度成長了9.2%，然而CTN/PP與PP相較下強度表現就沒有這麼優越反而在70%時，CTN/PP較PP佳約9.4%，但此值相對於PP材料最佳衝擊強度時還要低，而拉伸試驗方面在未加入結合劑之前提下，CTN/PP與CE/PP拉伸強度都較PP差。
並列摘要
Polypropylene (PP) material, one of crystalline polymers, is used widely because of good properties in high temperature resistance, good mechanical strength, and easy processing characteristics. In this study, the fillers including cotton fiber (CTN) and ceramic powders (CE) were added to polypropylene and compounded by Brabender as composite materials to analyses the effect of the fillers on mechanical property. In order to understand the stability of polypropylene products in injection molding process, the cavity pressure sensor was installed into the cavity to detect the cavity pressure and the corresponding time for stability investigation. The melt viscosity is influenced by temperature, pressure and shear rate, those data can be measured and calculated by measurement in molding process. A series of different injection speeds were set to investigate the effect of molding parameter on the molded part quality stability, such as tensile strength. Experimental results show that the impact strength of three materials, PP, CTN/PP, and CE/PP achieved their best performances when the injection speed is set as 50-60%. However, that impact strength of the composite material CE/PP and CTN/PP is still less than the PP material. In addition, the tensile strength of CE/PP and CTN/PP were less than that of PP material.