探討射出成型製程參數與PC+ABS材料性質於縫合線強度影響之研究

Study on the Influence of Weld-line Strength in Molding Process and PC+ABS Material Property

朱淳衛(Chun-Wei Chu)

指導教授 ： 陳夏宗

中原大學/工學院/機械工程學系/碩士(2009年)

https://doi.org/10.6840/cycu200900080

摘要

中文摘要
縫合線無論在塑膠製品或在射出成型品上，皆往往會造成嚴重的
強度缺陷與外觀不良。在可攜式電子產品4C 的時代裡，講求短、小、
輕、薄、品質、安全、產品外觀及舒適性的要求，已達到極緻的重視。
由此可見塑膠薄件的強度、品質的要求及其相關的影響因子將會越來
越被重視，因此縫合線的強度又再度成為射出成型的主要課題。
本研究將針對4C 電子產品最常用的PC+ABS 工程塑膠之薄殼件
當對象，取兩種PC-345 & PC-510 流動指數不同的塑料來進行射出成
型之探討。採用不同厚度、不同製程條件，把有縫合線和無縫合線的
結果去作符合標準之ASTM D 638 的拉伸試驗，以研究和比較有關它
們在機械性質、品質與強度方面的影響。
其間過程係採用迴歸分析法，參考Kim 和Suh 所建立的高分子
縫合線鍵結強度理論模型，並考慮厚度、料溫、模溫和射出速度等參
數，去針對真正的成型狀況，推導出一新的半經驗公式，以達到和實
際實驗的結果相吻合。由研究中的實驗結果得知，製程參數將會對成
品的強度及鍵結度產生影響性，也就是當料溫、模溫、射出速度增加
時，成品的鍵結度及拉伸強度會有增加的趨勢；這也是首次將縫合線
理論用在PC+ABS 薄殼件所做的預測及分析。不僅如此，也提供了
對PC+ABS 薄殼件強度研究上的一項新進展與貢獻。
進一步與其他不同的塑膠材料或較厚的成品研究作個比較，會發
現理論上有大體相同的趨勢，不過在實際中跟它們仍存有不同的差異
性。主要本研究所使用的成型品較薄和塑料為PC+ABS；故藉著本文
對本領域相關發展的業者和正對此塑料開發成型技術方面的精密薄
殼射出業者們，盼在產品上能有助於他們獲得品質改善的一個參考。

關鍵字

拉伸強度 ； 縫合線 ； 鍵結度

並列摘要

ABSTRACT
No matter in plastic products or injection molding products,
weld-line will sometimes cause seriously defect on strength and
appearance. In the age of 4C portable electronic products, it's highly
emphasized on the requirements of small, thin, light, with fine appearance,
good quality, and also need to reach the standard of both safety & cozy.
In other aspect, we can say that the strength & quality of thin-plastic
components as well as the relative factors affecting them will get much
attention these days. Therefore, the strength of weld-line becomes a main
issue on injection molding.
This research will focus on PC+ABS engineer plastics thin-wall
component which have been most frequently applied on 4C electronic
products. We will further explore injection molding using 2 kinds of
plastics with different melt flow index. Using different thickness,
different condition of manufacturing process, comparing the result of
with and without weld-line for reaching the standard of ASTM D 638
tensile test, in order to research and compare them for how it will
influence on mechanical characteristics, quality, and strength.
We used regression analysis, and referring to the model for weld-line
polymers proposed which Kim & Suh constructed, and also considering
the parameters of thickness, melt temperature, mold temperature, injection
velocity, packing pressure, processing under the actual molding situation,
trying to find an empirical correlation to match the experiment result. We
can know from the research result that the parameter of the manufacturing
process have crucial influence on the strength and the polymer strength of
finished goods. Which is to say that when the increase of melt & mold
temperature, also the injection velocity, or the decrease of packing pressure,
we can see the increase trend of the polymer & tensile strength of the finished goods. This is also the first time we use weld-line theory on the
prediction & analysis of PC+ABS thin-wall component. Besides that, we
also provided a new progress & contribution on the strength research of
PC+ABS thin-wall component as well.
Further compared to other plastic components or thicker products,
we can find the same trend theoretically. However in reality, they still
existed some differences. Basically, the molding product this research
used is thinner, and with PC+ABS materials. We hope to provide a
reference to improve the quality for those enterprises that are in the
related areas or are developing this kind of plastic thin-wall molding
technique, that it can be helpful for their products.

並列關鍵字

Tensile strength ； PC+ABS ； Weld-line

參考文獻

1. S. C. Malguarnera, “Weld Line in Ploymer Processing”, Polym. Plast.

Structure in Amorphous Polymers”, Polym. Eng. and Sci., Vol. 26, No.

3. E. M. Hagerman, “Weld-Line Facture in Moulded Parts”, Plastics Eng.

8. 鍾明修，“ABS 薄殼射出成型件縫合線之探討”，中原大學碩士論

10. 林文卿，“射出成型之探討及實務對策”，中原大學碩士論文，(2005)