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  • 學位論文

反壓對液輔射出成型品質的探討

The Study of Forming Quality of the Counter Pressure Mechanism on Liquid-assisted Injection Molding

指導教授 : 鍾文仁

摘要


液體輔助射出成型原理為在短射熔膠填充後,當核心層熔膠還在熔融狀態下注入液體使成品呈現中空,透過中空成型和液體特性可達到節省材料與提升成品品質之目的。液體輔助射出成型中,輔助液體的穿透力為影響製程的主要因素,液體的穿透力比氣體高加上不可壓縮性,容易產生成品核心層混亂;而影響液體穿透力的參數為液體壓力與溫度,壓力的控制需在流動管路加裝壓力感測器,並透過液輔機的可調參數來做變化,再觀察各壓力變化對成品的影響,溫度控制需在近模具側加裝溫度感測器,並在流動管路外層包覆隔熱泡棉以減少熱量散發。 本研究以可視化模具迴紋針型模仁,藉由可視化窗口與材料粒子的添加來紀錄反壓機制下成品的熔膠流動狀態、液體穿透行為與皮層厚度變化,並與氣體反壓氣體輔助射出成型成品做流體穿透行為的皮層厚度比較;再經由改變注入液體之黏度,探討黏度對液體穿透能力之影響,並進行氣體反壓應用於液輔成型之模流分析,再與實際流動情形驗證,來完成液體輔助射出成型結合氣體反壓的資料庫。實驗分析結果顯示,加入氣體反壓可增加液體穿透的穩定性,雖然會減少成品的中空截面積,但可提升成品穿透長度使整體穿透平均,在氣體反壓液體輔助射出成型與氣體反壓氣體輔助射出成型比較部分,氣體反壓液體輔助射出成型因液體的不可壓縮性與導熱快速,故所需的成型保壓時間較短,在穿透的均勻性與穩定性也優於氣體反壓氣體輔助射出成型,而提高注入液體之黏度則會改變液體的熱傳導效應與黏滯力,進而改變成品的穿透長度與中空截面積。

並列摘要


Liquid-Assisted Injection Molding(LAIM) is short shot filling plastic melt. When center layer plastic melt under melting state add liquid let finished presented hollow. The purpose is Use hollow forming and liquid feature can reached save materials and upgrade finished quality. In LAIM, The assisted liquid penetration capability is impact process main factor. Liquid penetration capability than gas higher and Incompressibility capability easy produce finished center layer orderless. Impact liquid penetration capability parameters is liquid pressure and temperature. Control Pressure need mobile directions install pressure sensors, and use liquid assisted machine variable adjustment changes, and observation pressure changes for finished impact. Control temperature need near mold side install temperature sensors, and mobile directions outside pack insulation foam reduce heat diffuse. In this study, use visualization mold and paperclip shape mold insert. Record Gas Counter Pressure(GCP) under finished plastic melt flow state and liquid penetration capability and epidermal layer thickness changes by the visualization window and the plastic join particle. GCP LAIM and GCP GAIM make than penetration capability and thickness changes. Use changes liquid viscosity , the study of viscosity for liquid penetration capability impact. Get on GCP applications in LAIM mold flow analysis and real mobile state prove. Complete LAIM combined GCP database. The results of Experiments analysis, join GCP can subjoin liquid penetration stability, although reduce finished hollow area, but can upgrade finished penetration length cause overall penetration average. In GCP LAIM and GCP GAIM compare section. LAIM because liquid incompressibility and thermal fast, so it need forming pressure hold time short in penetration average and stable also than GAIM. Improve injection liquid viscosity can change heat conduction and viscous force, further change finished penetration length and hollow area.

並列關鍵字

LAIM Visualization CAE GCP

參考文獻


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