模內轉印射出成型薄膜滯熱對產品翹曲影響之研究

Study of the Influence of Film Heat Transfer Retardation on the Warpage of In Mold Roller Injection Molding

陳惠俐(Hui-Li Chen)

指導教授 ： 陳夏宗

中原大學/工學院/機械工程研究所/博士(2010年)

https://doi.org/10.6840/cycu201000934

摘要

中文摘要
模內裝飾射出成型技術(IMD)是近幾年來最具發展性的表面裝飾技術，其中模內轉印(IMR)射出成型技術則是其中最具自動化生產之製程。在IMR的製程中，塑膠薄膜的滯熱效應會造成產品表面品質問題，故透過塑膠薄膜在模穴內所造成公母模溫度場變化了解，探討溫度變化對產品品質影響，進而求得成型製程的改善，以建立該製程成型經驗，提昇該製程技術水準是本研究最大目的。
本研究首先以理論分析來探討不同薄膜厚度及不同製程參數對模具接觸面溫度場變化，評估薄膜滯熱效應對產品成型性品質影響。第二階段則以電腦模擬軟體ANSYS熱傳分析及結構分析，探討薄膜滯熱效應對產品造成翹曲變形影響，進而求得成型製程的改善設計。第三階段則以實驗進行驗證，並探討薄膜滯熱效應對流動波前、結晶度及結晶大小的影響
研究結果顯示，薄膜在成型過程中會提高熔膠與模具面接觸溫度，造成公母模不對稱模溫，使母模面結晶度增加，產品翹曲變形增加。不同薄膜厚度在模具溫度50℃及熔膠溫度230℃，和鋼材(P20)比較下，對熔膠與模具面接觸溫度有83.32℃~38.1℃的變化，翹曲量有0.03mm~0.62mm的變化。在製程條件方面，增加熔膠溫度會增加公母模溫差，使翹曲變形增加，增加模具溫度會減少公母模溫差，使翹曲變形減少，在結晶度及結晶大小方面，滯熱效應會使母模面結晶度增加11%~18%，結晶尺寸增加11%~12%。在IMR產品翹曲改善方面，以不對稱冷卻系統溫度設計可改善翹曲量53%，分析與實驗結果相符，透過本研究之結果，建立完整IMR製程中薄膜效應影響，並提供改善設計，可提供相關業者於製程參數設計上之參考依據。

關鍵字

翹曲變形 ； 滯熱效應 ； 模內裝飾射出成型 ； 模內轉印射出成型

並列摘要

In-Mold Roller (IMR) injection molding is the most commonly used in In-Mold Decoration technology for ink transfer. IMR is easily automated. The issue with the IMR process is product warpage control when the polymer filling and cooling at two different materials mold surfaces. The purpose of this research is to understand the heat retardation influence on a mold surface on IMR Products and optimize mold design and molding process parameters. The aims are to achieve high quality plastic product and to promote technology of IMR injection molding.
The study starts with heat transfer equations to calculate and analyze the mold surface temperatures which are governed by plastic membrane thicknesses and molding parameter levels. Computer aided engineering software, ANSYS, is then used to simulate temperatures and stresses to establish warpage model of the product under different level of heat retardation due to various membrane thickness and molding parameters. Finally a series of IMR injection molding experiments is conducted to verify and benchmark those results obtained from the mathematic calculation and ANSYS simulation. Those experiments are also used to study the effects of heat retardation on the front pattern, the crystallization degree, and the crystal size of the melting flow.
The results show that product warpage results from un-balance mold surface temperature between top mold chase and bottom chase. The Membrane generates heat retardation that results in a higher contact temperature and higher polymer crystallization which increase product warpage level. When the mold temperature is fixed at 50 ℃, melting polymer temperature at 230℃, and the mold material is P20 steel, the contact surface temperature between melting polymer and mold chase surface can vary from 83.32℃ to 38.10℃ and product warpage vary from 0.03 mm to 0.62 mm with various membrane thickness. Increasing melting polymer temperature increases product warpage. Increasing mold temperature reduces product warpage. Membrane heat retardation may increase polymer crystallization by 11%~18% and increase polymer crystal size by 11%~12%.
In controlling product warpage, this research has successfully established an asymmetric mold chase cooling system which is able to improve product warpage by 53%. The improvement is further verified by both analysis and experiment results. This research work has minimized heat retardation effect through membrane thickness design and molding parameters optimization for IMR process technology.

並列關鍵字

IMD ； IMR ； heat retardation ； warpage

參考文獻

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