共射成型製程已經廣泛地應用於我們日常生活與各類科技產品之製作，它的特點是可以利用皮層與芯層之組合，創造許多新穎或是環保之產品。比如：利用純料皮層/含纖芯層組成外觀良好內在強韌之產品；或是透過適當地皮/芯層控制產生獨特之皮層自然穿透，構成特殊美觀之產品，提昇美感價值。然而，想完成前述在產品機械特性及美感具有競爭力之共射成品，無法一蹴即成，須考慮到影響共射成型的許多影響因子，從實務面來說，要掌握對芯層材料滲透型態的控制是一大挑戰。為此，本研究利用CAE模擬分析(Moldex3D)以及實務實驗研究，深入探討共射成型之機理。具體而言，我們採用標準拉伸試片(ASTM D638 TYPE V)的幾何模型作為研究之系統平台，並且選定純PP材料(簡稱材料 PP)及含纖PP複合材料(簡稱材料 30SFPP)進行研究。結果顯示，以PP材料進行單一射出基本流場行為觀察，CAE模擬結果與實驗相當吻合。接著以PP/PP系統為例，改變不同皮/芯層比例發現皮/芯層比例為60/40時，皮層材料還未被吹穿，且皮/芯層界面滲透距離最遠，分佈最均勻，定義它為最佳皮/芯層比例，以及在不同流率變化中得到流率增加會使芯層距離變短且往厚度方向增加。進一步，我們將模擬之芯層滲透距離進行量化。再者，對於共射流場內部的型態準確性利用電腦斷層掃描及影像重建進行驗證，發現在30SFPP/PP系統相較於PP/PP系統，芯層滲透呈現寬扁且短的介面。而在PP/30SFPP系統中，芯層滲透有抖動的行為。更進一步探討芯層滲透型態對機械性質的影響，當使用PP/30SFPP組合，內部使用含纖維複合材料能有效提升產品的機械強度，並且隨著芯層滲透距離的增加機械性質也會隨之增加，此部分利用CAE模擬並與實驗進行觀察，發現內部芯層深透型態為影響其機械性質一大主因。再者，芯層滲透的機理包括：皮/芯層比例為50/50、 70/30、 30/70也被深入討論；特別是當皮/芯層比例為30/70產生非常有趣之 “core-skin-core”結構，此部分是之前文獻沒有提過的，該等結構形成物理機制也深入探索。

The co-injection molding process has been widely used in our daily life and various products. Its special characteristic is to combine the skin and the core layers to create many novel or environmentally friendly products. For example: the structure of the virgin skin layer and the fiber-contained core layer can form a product with good appearance and inner toughness; the properly controlled skin/core ratio with breakthrough structure can produce a unique and beautiful product to enhance the aesthetic value. However, to produce the co-injection products with competitive mechanical properties and aesthetics in the product is not so easy. Many factors will affect the product design and development in co-injection molding processes. One of the most crucial factors to influence the quality of co-injection molding product development is to the prediction and management of the penetration pattern of the core material. To catch the penetration behavior of the core material, both of numerical simulation using Moldex3D and experimental study methods have been adopted in this study. Specifically, the geometric model of the standard tensile test piece (ASTM D638 TYPE V) has been used as the system. The pure polypropylene material (abbreviated as material PP) and polypropylene with 30 wt% short fiber reinforced material (abbreviated as material 30SFPP) are selected. The results show that through the basic flow field behavior testing of a single injection, both simulation prediction and experimental observation is quite matched. Moreover, through the skin/core ratio effect testing, the break-through is happened at skin/core ratio is 50/50 for PP/PP system.  Hence, the optimized skin/core ratio is 60/40 (where the core ratio is maximum with skin break-through). This skin/core ratio break-through happened all at the skin/core ratio of 50/50 for other systems including 30SFPP/30SFPP, PP/30SFPP, and 30SFPP/PP systems. Moreover, the relation between the mechanical property and the core material penetration distance of the co-injected products has been discovered.  Basically, the tensile stress of the co-injected products is proportional to the core material ratio. Furthermore, the physical mechanisms of the core material penetration behavior for the skin/core of 50/50, 70/30, and 30/70 have also been investigated.  Specifically, when the skin/core of 30/70 system will generate a very interesting “core-skin-core” structure.  The internal mechanism to cause this special structure was also discovered.

致謝	I
中文摘要	II
英文摘要	IV
目錄	VI
圖目錄	VIII
表目錄	XII
第一章	緒論	1
1.1	前言	1
1.2	文獻回顧	2
1.2.1	共射成型製程在產業之應用	2
1.2.2	共射成型製程影響因子的探討	5
1.2.3	數值模擬分析應用於共射成型製程	9
1.2.4	文獻總結	10
1.3	研究動機與目的	11
1.4	論文架構	12
第二章	共射成型製程與其原理說明	14
2.1	共射成型製程介紹(Co-injection molding)	14
2.2	共射成型製程影響因子探討	20
2.3	共射成型製程皮層/芯層界面之探討	22
2.4	高分子材料及其特性對共射成型製程之影響	22
2.4.1 聚丙烯(Polypropylene)	25
2.4.2 纖維複合聚丙烯 (Fiber reinforced polypropylene)	26
第三章	研究方法與流程	28
3.1	研究流程	28
3.2	研究方法	29
3.2.1	CAE數值模擬分析與相關系統資訊	30
3.2.2	實務實驗研究與相關資訊	47
第四章	結果與討論	58
4.1	共射成型CAE數值模擬分析	58
4.1.1	單一材料射出模擬分析	58
4.1.2	共射成型之成型條件對芯層滲透形態影響之探討	59
4.1.3	共射成型之異質材料組合效應	62
4.2	共射成型實務實驗研究與驗證	67
4.2.1 單一材料射出模擬與實驗驗證	67
4.2.2 共射成型之成型條件對芯層滲透形態影響之研究與驗證	68
4.2.3	共射成型之異質材料組合效應對芯層滲透形態影響之研究與驗證	72
4.2.4	共射成型之芯層滲透形態與機械性質關聯性探討	76
第五章	結論	93
第六章	未來研究方向	95
第七章	參考文獻	96
第八章 附錄	102
作者簡歷	102
符號說明	103

圖目錄
圖1-1 共射成型之PET罐頭[8]	3
圖1-2 共射成型之LEGO玩具[9]	4
圖1-3共射產品之汽車零件示意圖[6]	4
圖1-4不相溶之高分子皮/芯層之間環狀(halo)界面[14]	6
圖1-5 利用SEBS改善不相容高分子之手指形狀缺陷[15]	7
圖1-6 共射成型中芯層材料流動行為示意圖[13]	9
圖2-1 共射成型射出階段示意圖[23]	15
圖2-2 共射成型之產品阻隔層應用示意圖	16
圖2-3 ENGEL利用共射成型技術製造瓶蓋[23]	16
圖2-4 Mold Masters利用共射成型技術製造杯子[25]	17
圖2-5 Mold Masters 利用共射成型技術製造塑膠罐頭取代傳統金屬罐頭[5]	18
圖2-6 ENGEL針對皮層與芯層材料控制方式示意圖[8]	19
圖2-7 共射成型設備示意圖[24]	20
圖2-8 高分子材料分類	23
圖2-9 熱塑性高分子	24
圖2-10 熱固性高分子	24
圖2-11 聚丙烯塑膠材料	26
圖3-1 研究流程圖	28
圖3-2 成品幾何模型(單位: mm)	33
圖3-3 模座水路配置	34
圖3-4 網格種類示意圖[35]	35
圖3-5 ASTM D638 Type V模型網格品質圖	36
圖3-6 不同層數網格之進澆口壓力曲線	38
圖3-7本研究之實體網格內部結構圖, 特別在厚度方向切割成不同層數，改變網格密度: (a) 5層，(b) 10層，(c) 15層，(d) 20層，(e) 25層	41
圖3-8 PP與30SFPP材料黏度對剪切率之關係圖	42
圖3-9 PP與30SFPP材料之pvT關係圖	43
圖3-10 PP與30SFPP 熱容量關係圖	43
圖3-11 PP與30SFPP熱傳導係數圖	44
圖3-12 射出實驗流程圖	47
圖3-13 TA-4.0ST-2ST-80T共射成型機台	48
圖3-14 共射成型系統之模具規格以及模穴尺寸圖	49
圖3-15 循環油溫控制機	50
圖3-16 塑膠乾燥機	51
圖3-17 Bruker SkyScan 2211 微電腦斷層掃描機台[40]	53
圖3-18 模擬結果量測芯層滲透長度之示意圖	54
圖3-19 LS1萬能測試機	55
圖3-20 拉伸試片尺寸示意圖	56
圖4-1 PP材料單一射出系統之波前流動行為數值模擬分析(流率=10 cm3/s)	57
圖4-2 PP/PP系統中不同皮/芯層比例效應(流率為10 cm3/s)	59
圖4-3 PP/PP系統下最佳皮/芯層比例的動態行為(流率=10 cm3/s)	59
圖4-4 PP/PP系統在最佳皮層/芯層比例(60/40)之流率效應	60
圖4-5 利用CAE模擬分析進行可視化分析流率對芯層材料滲透的影響(PP/PP系統)	61
圖4-6 PP/30SFPP系統中不同皮/芯層比例效應(流率為10 cm3/s)	62
圖4-7 30SFPP/PP系統中不同皮/芯層比例效應(流率為10 cm3/s)	62
圖4-8 PP/30SFPP系統在最佳皮層/芯層比例下之流率效應	63
圖4-9 30SFPP/PP系統在最佳皮層/芯層比例下之流率效應	64
圖4-10 利用CAE模擬分析進行可視化分析流率效應對芯層材料滲透的影響(PP/30SFPP系統)	64
圖4-11 利用CAE模擬分析進行可視化分析流率效應對芯層材料滲透的影響(30SFPP/PP系統)	65
圖4-12 異質材料組合系統芯層材料滲透型態比較	65
圖4-13 PP材料射出波前流動行為模擬分析與實驗驗證(流率為10 cm3/s)	66
圖4-14 PP/PP系統皮層/芯層比例效應之實務實驗驗證(流率為10 cm3/s)	67
圖4-15 皮層/芯層比例為50/50吹穿現象位置	68
圖4-16 PP/PP系統芯層材料動態行為驗證(皮層/芯層比例為60/40，流率為10 cm3/s)	69
圖4-17 PP/PP系統不同流率對芯層滲透型態之影響(皮層/芯層比例為60/40)	70
圖4-18 PP/PP系統中心切面芯層滲透型態比較結果(皮層/芯層比例為60/40，流率為10 cm3/s)	70
圖4-19 PP/30SFPP系統皮層/芯層比例效應之實務實驗驗證 (流率為10 cm3/s)	72
圖4-20 30SFPP/PP系統皮層/芯層比例效應之實務實驗驗證(流率為10 cm3/s)	72
圖4-21 PP/30SFPP系統流率效應之影響(皮層/芯層比例為60/40)	73
圖4-22 PP/30SFPP系統中心切面芯層滲透型態比較結果(皮層/芯層比例為60/40，流率為10 cm3/s)	74
圖4-23 30SFPP/PP系統流率效應之影響(皮層/芯層比例為60/40)	74
圖4-24 30SFPP/PP系統中心切面芯層滲透型態比較結果(皮層/芯層比例為60/40，流率為10 cm3/s)	75
圖4-25 PP/30SFPP系統拉伸強度比較圖	78
圖4-26 PP/30SFPP系統頸縮區域厚度方向皮層/芯層型態解析	79
圖4-27 不同材料組合系統皮/芯層材料分布	79
圖4-28 PP/30SFPP系統皮層/芯層型態解析	80
圖4-29 利用CT-scan及CAE數值模擬分析觀察core-skin-core現象(XY平面)	81
圖4-30 利用CT-scan及CAE數值模擬分析觀察core-skin-core現象(XZ平面)	81
圖4-31 利用CT-scan及CAE數值模擬分析觀察core-skin-core現象(YZ平面)	82
圖4-32 動態流動行為比對(skin/core ratio = 50/50)	84
圖4-33 共射成型中吹穿機理示意圖[13]	84
圖4-34 動態流動行為量化圖(skin/core ratio = 50/50)	85
圖4-35 熔膠溫度以及速度分布情形(皮/芯層比例為50/50，吹穿現象發生時)	86
圖4-36 動態流動行為比對(skin/core ratio = 30/70)	88
圖4-37 動態流動行為量化圖(skin/core ratio = 30/70)	89
圖4-38 動態流動行為比對(skin/core ratio = 70/30)	90
圖4-39 動態流動行為量化圖(skin/core ratio = 70/30)	91

表目錄
表3-1 網格收斂性測試之網格相關資訊	37
表3-2 本研究之網格資訊	38
表3-3 材料資訊	42
表3-4 成型條件之相關表	46
表3-5 射出機台相關資訊	49
表3-6 循環油溫控制機規格表	50
表3-7 塑料乾燥機規格表	52
表3-8 拉伸機台相關資訊	55
表3-9 拉伸試片相關尺寸	57

[1]	Garner, P. J., & Oxley, D. F. (1971). British Patent 1.
[2]	Goodship, V., & Love, J. C. (2002). Multi-material Injection Moulding: iSmithers Rapra Publishing.
[3]	https://www.milacron.com/cs/produkty-2/technologie-spoluvstrikovani-2/co-injection-applications/. (2018). Co-injection Applications | Milacron. 
[4]	Kim, Y. S., & Zhao, X. (2014). Multi-Layered Co-Injection Molded Article: Google Patents.
[5]	https://www.moldmasters.com/products/co-injection/klear-can. (2020). Klear Can | Mold Masters. 
[6]	Birka, M. P., Korte, K. G., Dobbs, D. R., Dew, J. K., & Parker, C. T. (2019). Co-injection of molded parts for weight reduction: Google Patents.
[7]	Swenson, P. M. (2020). Co-injection molded multi-layer article with injection-formed aperture between gate area and peripheral edge: Google Patents.
[8]	What is coinjection. (2020). Plastics Technology. 
[9]	Davies, S. (2017). LEGO-like blocks build new possibilities for microfluidics.https://ioppublishing.org/news/lego-like-blocks-open-up-new-possibilities-for-microfluidics/. 
[10]	White, J. L., & Dee, H. B. (1974). Flow visualization for injection molding of polyethylene and polystyrene melts. Polymer Engineering & Science, 14(3), 212-222. 
[11]	White, J. L., & Lee, B. L. (1975). An experimental study of sandwich injection molding of two polymer melts using  simultaneous injection. 
[12]	Young, S. S., White, J. L., Clark, E. S., & Oyanagi, Y. (1980). A basic experimental study of sandwich injection molding with sequential injection. Polymer Engineering & Science, 20(12), 798-804. 
[13]	Watanabe, D., Ishiaku, U., Nagaoka, T., Tomari, K., & Hamada, H. (2003). The flow behavior of Core material and breakthrough phenomenon in sandwich injection molding. International polymer processing, 18(4), 405-411. 
[14]	Goodship, V., & Kirwan, K. (2001). Interfacial instabilities in multimaterial co-injection mouldings Part 1–Background and initial experiments. Plastics, Rubber and Composites, 30(1), 11-15. 
[15]	Gomes, M., Martino, D., Pontes, A., & Viana, J. (2011). Co‐injection molding of immiscible polymers: Skin‐core structure and adhesion studies. Polymer Engineering & Science, 51(12), 2398-2407. 
[16]	Selden, R. (2000). Co‐injection molding: Effect of processing on material distribution and mechanical properties of a sandwich molded plate. Polymer Engineering & Science, 40(5), 1165-1176. 
[17]	Nagaoka, T., Ishiaku, U. S., Tomari, T., Hamada, H., & Takashima, S. (2005). Effect of molding parameters on the properties of PP/PP sandwich injection moldings. Polymer Testing, 24(8), 1062-1070. doi: 10.1016/j.polymertesting.2005.04.003
[18]	Vangosa, F. B. (2011). Effects of process parameters on the skin/core distribution in co-injection: experiments and simulations using a simple geometry. Polymer-Plastics Technology and Engineering, 50(13), 1314-1322. 
[19]	Zhang, K., Nagarajan, V., Zarrinbakhsh, N., Mohanty, A. K., & Misra, M. (2014). Co‐Injection Molded New Green Composites from Biodegradable Polyesters and Miscanthus Fibers. Macromolecular Materials and Engineering, 299(4), 436-446. 
[20]	Zaverl, M., Valerio, O., Misra, M., & Mohanty, A. (2015). Study of the effect of processing conditions on the co‐injection of PBS/PBAT and PTT/PBT blends for parts with increased bio‐content. Journal of applied polymer science, 132(2). 
[21]	Suhartono, E., Chen, S.-C., Lee, K.-H., & Wang, K.-J. (2017). Improvements on the tensile properties of microcellular injection molded parts using microcellular co-injection molding with the material combinations of PP and PP-GF. International Journal of Plastics Technology, 21(2), 351-369. 
[22]	Huang, C.-T. (2017). Numerical visualization and optimization on the core penetration in multi-cavity co-injection molding with a bifurcation runner structure. The International Journal of Advanced Manufacturing Technology, 92(5), 2545-2557. 
[23]	Huang, C.-T., Chen, X.-W., & Fu, W.-W. (2020). Investigation on the Fiber Orientation Distributions and Their Influence on the Mechanical Property of the Co-Injection Molding Products. Polymers, 12(1), 24. 
[24]	Gall, M., Steinbichler, G., & Lang, R. W. (2021). Learnings about design from recycling by using post-consumer polypropylene as a core layer in a co-injection molded sandwich structure product. Materials & Design, 202, 109576. 
[25]	Turng, L., Wang, V., & Wang, K. (1993). Numerical simulation of the coinjection molding process. 
[26]	Schlatter, G., Agassant, J.-F., Vincent, M., & Davidoff, A. (1999). An unsteady multifluid flow model: Application to sandwich injection molding process. Polymer Engineering & Science, 39(1), 78-88. 
[27]	Ilinca, F., & Hétu, J.-F. (2002). Three-dimensional numerical modeling of co-injection molding. International polymer processing, 17(3), 265-270. 
[28]	Li, C., & Isayev, A. (2003). Interface development and encapsulation in simultaneous coinjection molding. I. Two‐dimensional modeling and formulation. Journal of applied polymer science, 88(9), 2300-2309. 
[29]	Li, C., Lee, D., & Isayev, A. (2003). Interface development and encapsulation in simultaneous coinjection molding of disk. II. Two‐dimensional simulation and experiment. Journal of applied polymer science, 88(9), 2310-2318. 
[30]	ENGEL. (2019). combimelt Smart combination of plastics Combine materials for innovative products and economic production combimelt process  Multi-component injection moulding In the simplest case. 
[31]	Kienzl, W. (2021). Types of Sandwich Injection Moulding - Functionalities & Applications. 
[32]	https://www.moldmasters.com/products/co-injection/connect-package. (2020). Co-Injection CONNECT Package - Mold-Masters. 
[33]	Halimatudahliana, H. I., & Nasir, M. (2002). The effect of various compatibilizers on mechanical properties of polystyrene/polypropylene blend. Polymer Testing, 21(2), 163-170. 
[34]	A. Derdouri, A. G.-R., K. T. Nguyen, Y. Simard, K. A. Koppi and B. A.  Salamon. (1999). Effect of the skin / core ratio on the flow behavior during co-injection  moulding. Annual Technical Conference - Society of Plastics Engineers, 57th, 481. 
[35]	科盛科技股份有限公司. (2007). Moldex3D 模流分析技術與應用. 全華圖書公司. 
[36]	Chang, R. Y., & Yang, W. H. (2001). Numerical simulation of mold filling in injection molding using a three‐dimensional finite volume approach. International Journal for Numerical Methods in Fluids, 37(2), 125-148. 
[37]	Kim, N. H. (2009). Injection-compression and co-injection moldings of amorphous polymers polymers : viscoelastic simulation and experiment. 
[38]	International, A. (2015). ASTM D638-14, Standard Test Method for Tensile Properties of Plastics: ASTM International.
[39]	Rigort, A., Günther, D., Hegerl, R., Baum, D., Weber, B., Prohaska, S., Hege, H.-C. (2012). Automated segmentation of electron tomograms for a quantitative description of actin filament networks. Journal of structural biology, 177(1), 135-144. 
[40]	Bruker. (2017). Bruker SkyScan 2211 Brochure.