高精密群組導光條熱澆道成型模具設計

High Precision Optical Group Fiber Hot Runner Molding Design

吳易霖(Yi-Lin Wu)

指導教授 ： 楊哲化

國立臺北科技大學/機電學院/製造科技研究所/碩士(2009年)

摘要

本文研究的動機是因為大多數的模具設計都是以理論的成型條件參數進行模具的設計，本研究係透過實驗方法解析具有縱長比大於80及個別的導光條之實質長度不同的群組導光條(Optical Group Fiber)，在兼顧光學設計與陣列組裝需求的規格要求下，進行模具的設計與射出參數的調整之最佳化技術探討。
群組導光條將以閥針式熱澆道射出模具搭配穩定的模具溫度控制進行的精密成型，射出模具的排氣、流動平衡與縮率補償設計所構成的最佳化成型參數將是主要的核心技術。研究重點包括：流道平衡與遠端成型縮率補償之模具設計，透過滿足群組穿透率(Transmission)與均勻度要求驗證模具，透過量測成型品尺寸之穩定性確認成型之品質；模具設計重點包括群組流長比、澆口位置與熱澆道位置之距離、流道平衡設計等，使群組導光條滿足高尺寸安定性和均勻性之要求，達成穩定成品的色彩傳輸作用。群組導光條成型之後，透過陣列組合的方式組合成光學模組，並以輝度計量測其輝度均勻度用以確認光學特性與射出條件的關聯性。研究顯示在特定成型縮率之補償、流道平衡設計與射出成型參數最佳化設定後，可獲得群組輝度均勻偏差為4%以內，尺寸偏差為0.025mm以內之性能。

關鍵字

群組導光條 ； 群組穿透率 ； 流長比 ； 流動平衡 ； 成型縮率補償

並列摘要

Wildly used on the most of products, backlight module, lens and light-guide become the most popular main optical plastic components. The function of the light-guide and backlight is to guide light source to the desired location; and functions of lens are protector, also as a component for Camera hood or lens. Combining the functions of light-guide and lens, the optical group fiber (OGF ) are assembled to an flexible array tile, and becomes one of the most competitive products in the area of video wall display. Most of the moulds are designed in an idea injection condition. Very limited reference can be found for the critical conditions as in this study, however, limited to individual injection molding or mould. Also, under the business competition environment, technology content regarding to the critical conditions are seldom made public.
This research is focused on the mould design and optimization of injection parameters for the case where individual optical fibers have variable length with aspect ratio larger than 80. Specifically, this study is covers the contents of (1) injection flow balance, (2) shrinkage correction with hot runner system molding design, (3) design for homogeneous optical transmission, (4) verification on the stability of molding dimension, (5) molding the OGF with hot runner system, and (6) a stable temperature control to carry out the parts precision. Here, tooling venting, injection flow balance, and shrinkage corrections are the core technology. Results of this studies have shown an injection flow balance, a design with shrinkage correction, a set of optimized molding parameters. With the optimum design, homogeneous OGF transmission, brightness homogeneity with a deviation of better than 4 % and dimension deviation of 0.025mm are obtained.

並列關鍵字

Optical Group Fiber (OGF) ； transmission homogeneity ； shrinkage correction ； injection flow balance ； aspect

參考文獻

[1] Anthony Cyril Lowe, Barbara Needham, Niall Anthony Gallen, “Display with optical fiber face”, US 2005/0243415 Al，2005。

[4] Jerry M. Fischer,”Handbook of Molded Part Shrinkage and Warpage”, William Andrew, Inc.，2003，Chapter 4。

[10] John Schmidt, “How to evaluate hot runner nozzles”, Moldmaking Technology, No.4, 2008。

[2] http://www.screentechnology.com/index.php,www.screentechnology.com，2008。

[3] Hebert Rees, “Mold Engineering deals with injection molds for thermoplastic molding materials", 2nd Edition，2002。