玻纖強化PA66複合材料於縫合線之研究

A study of glass fiber reinforced PA 66 composites existing weld line

徐振欣(Chen-Hsin Hsu)

指導教授 ： 韓麗龍

國立臺北科技大學/機電學院/製造科技研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00638

摘要

本研究係利用射出成形工法，對不同玻纖含量(20%GF, 30%GF, 50%GF)之Nylon 66 (PA66)，在不同斷面厚度(1, 2, 3 mm)，及單點進料(無縫合線)與雙點進料(有縫合線)的實驗設計下，分析試片的拉伸性質及衝擊性質，並以電子顯微鏡(SEM)觀察，對拉伸破斷面與衝擊破斷面及玻纖配向性作進一步驗證。
研究結果顯示，有縫合線試片之抗拉強度及衝擊值均低於無縫合線之試片。因為雙點進料之兩股熔膠波前(melt front)交會時形成縫合線，SEM觀察破斷面呈現剝離型態。無縫合線狀態，其玻纖配向性較佳，SEM觀察破斷面呈現拉斷型態。結果亦顯示試片厚度愈大，抗拉強度亦隨之增加，因流動阻力愈小而得到較佳的充填效果。楊氏係數則是隨玻纖含量增高而增加，但有縫合線之試片，當玻纖含量超過30%時楊氏係數即開始下降。進一步探討縫合線與玻纖含量對抗拉強度的影響時，發現無縫合線時玻纖含量愈多，抗拉強度也愈高。但有縫合線存在且當玻纖含量超過30% GF時，抗拉強度呈現下降趨勢，亦即縫合線因子(weld line factor)下降。而在衝擊試驗方面，無論是有縫合線或無縫合線，其衝擊值均隨著玻纖含量的增加而呈現上升的趨勢。

關鍵字

Nylon 66 ； 玻纖配向性 ； 熔膠波前 ； 楊氏係數 ； 縫合線因子

並列摘要

This study is to analyze the tensile and impact properties of Nylon 66 (PA66). Specimens including 1, 2, and 3 mm of three types thickness and 20%, 30% and 50% of three types glass fiber (GF) content prepared by injection molding technique with a single gate (non-existing weld line) and a dual gates (existing weld line). Moreover, the breaking cross sections of tensile and impact specimen observed by using scanning electron microscope (SEM) to verify the flow orientation of glass fiber.
Results show both the tensile strength and impact value of the specimens existing weld lines are lower than those of non-existing weld lines. Because the weld line formed at the intersection of the two melt front, the cross section of the specimen observation by SEM indicates a breakaway type in existing weld line specimen, and a tensile-break type in non-existing weld line one. Results also show the larger the specimen thickness, the higher the tensile strength will be.
This is due to the smaller flow resistance in larger thickness specimen that caused a better filling effect. Young’s Modulus increases with the containing glass fiber increasing in non-existing weld line specimen. However, in existing weld line specimen, Young’s Modulus decreases when the fiber glass content is above 30%. Furthermore, if the sample is a non-existing weld line type, the more of the glass fiber content is, the higher the tensile strength. However, the tensile strength also decreases in existing weld line sample when the sample contains fiber glass above 30% GF, i.e. the weld line factor decrease. For the impact test, the impact values increase with the glass fiber increasing whether the specimen contains weld line or not.

並列關鍵字

Nylon 66 ； glass fiber orientation ； melt front ； Young’s Modulus ； weld line factor

參考文獻

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