本研究的目標是利用三軸共押出機之加工製程，開發出具有適當剛性、聲學效果的複合薄膜，並探討不同之單層、三層薄膜結構對聲學效果之影響。
實驗上先分別測定各塑膠粒之性質，通過熱重損失(TGA)、示差掃描量熱(DSC)、熔流指數(MFI)及迴轉式流變儀(MCR)等分析，測定各材料之特性，而後參考各材料之玻璃轉移點(Tg)、熔點(Tm)、MI值及黏度，進而歸納出最合適之加工參數，最後透過三軸共押出機來製作單層薄膜、三層複合薄膜。
一般圓形微型揚聲器的聲膜組成是由中間的剛性薄膜和周圍的軟性材料組合的，實驗中以共押出方式製造外層為剛性材料-聚對苯二甲酸乙二酯-1,4-環己烷二甲醇酯(PETG)，內層為彈性材料-乙烯醋酸乙烯酯(EVA)或熱塑性聚氨酯(TPU)之三層複合薄膜，通常微型揚聲器振膜總厚度為90~100μm，製作的薄膜以此厚度為參考，實驗中我們將設計各層厚度不同比例之三層複合膜，測試原本各材料之單層膜和不同厚度結構的三層複合膜之材料剛性，以這些薄膜製成中間振膜和外圍懸邊，再組成各式的揚聲器，探討薄膜各層比例、材料剛性和聲學效果之相互關係。

The study objective is by using the thraxial co-extrusion process develop the composite film, that own the appropriate rigidity for acoustics effect. Then, we investigate the difference on the acoustics effect between one single-layer and three-layer film structure.
First , every kind of plastic pellet was analyzed by thermogravimetric analysis(TGA) , differential scanning calorimetry(DSC) , melt flow index tester(MFI) , and modular compact rheometer (MCR) to measure the heat characteristic of these materials. Then reference the glass transition temperature(Tg), melting temperature (Tm) , MI value and viscosity of these materials to sum up the most appropriate processing parameters .Finally , through the co-extrusion machine to produce single-layer film and three layer composite film.
Generally, the acoustic diaphragm of one circle micro-speaker is composed of intermediate rigid film and surrounding soft material. In this experiment, we use co-extrusion measure to produce the three-layer film, which combine with the outer layer : rigid material - polyethylene terephthalate, cyclohexane-1,4-dimethylene terephthalate (PETG), and inner layer : an elastic material - ethylene vinyl acetate (EVA) or thermoplastic polyurethane ( TPU). Usually, the micro-speaker total thickness is 90 ~ 100 μm, as the reference thickness. In the experiment, we will design different film with different thickness ratio in each layer. Then, test the material rigid of these single-layer films and three-layer composite film, composited with different thickness and materials. In addition, these films are made of the intermediate diaphragm and the peripheral surround, then composite of various types of speakers to discuss the relationship between the ratio of the film layers, the rigidity of materials and the acoustic effects.

[1]N. González-Vidal, A. Martínez De Ilarduya, S. Muñoz-Guerra，Poly(ethylene-co-1,4-cyclohexylenedimethylene terephthalate) copolyesters obtained by ring opening polymerization，J. Polym. Sci. Poly Chem., 47 (22) (2009),5954-5966
[2]Y. Tsai, C.H. Fan, C.Y. Hung, F.J. Tsai，Amorphous copolyesters based on 1,3/1,4-cyclohexanedimethanol: synthesis, characterization and properties，J. Appl. Polym. Sci., 109 (4) (2008), 2598-2604
[3]Y. Rao, J. Greener, C.A. Avila-Orta, B.S. Hsiao, T.N. Blanton，The relationship between microstructure and toughness of biaxially oriented semicrystalline polyester films，Polymer, 49 (10) (2008), 2507-2514
[4]H. Shadpour, H. Musyimi, J. Chen, S.A. Soper，Physiochemical properties of various polymer substrates and their effects on microchip electrophoresis
performance，J. Chromatogr. A, 1111 (2) (2006), 238-251
[5]O. Bayer, H. Rinke, W. Siefken. L. Ortner, and H. Schild, German Patent
728981, 1937
[6]A. E. Christ and W. E. Hanford, U.S. Patent 2,333,639, 1940
[7]British Patent 580 524; British Patent 574 134, 1942
[8]Achim Frick, Arif Rochman，Characterization of TPU-elastomers by thermal analysis (DSC)，Polymer Testing 23 (2004), 413–417
[9]C. S. Schollenberger and K. Dinbergs, J. Elastoplastics, 1973 5, 222; 1975 7,65
[10]溫耀賢，功能性塑料薄膜，北京機械工業出版社, 2005
[11]J.E. Martín-Alfonso, J.M. Franco，Ethylene-vinyl acetate copolymer (EVA)/
sunflower vegetable oil polymer gels: Influence of vinyl acetate content， Polymer Testing 37 (2014), 78–85

[12]Ou, Yang-Chiu. Method of making EVA shoe midsole. U.S. Patent No. 5,177,824. 12 Jan. 1993.
[13]Marshall Long，Architectural Acoustics(Second Edition),3-Human Perception and Reaction to Sound，2014, 39-79
[14]Marshall Long，Architectural Acoustics(Second Edition),2-Fundamentals of Acoustics，2014, 81-127
[15]Fleming, John Ambrose，Magnets and Electric Currents，2nd Edition. London E.& F. N. Spon. (1902) ,173–174.
[16]Griffiths, David J，Introduction to Electrodynamics (3rd ed.).，Prentice Hall. 204, 326, 541,1998
[17]LIN ChiiRuey,LIU ShinHwa, LIOU WangJeng,CHANG ChienKuo，Improving the high frequency response of a loudspeaker using hydrogen-free diamond-like carbon film coating at low temperature，Science China Physics, Mechanics and Astronomy 55(3) 2012,385-391
[18]Woldemar Voigt,，Lehrbuch der Kristallphysik ，Berlin,Germany,Teubner, 1910
[19]賴耿陽，揚聲器之設計與製作，台南啟學出版社(1979),430-436
[20]T.J.M.Boyd , J.J.Sanderson，The Physics of Plasma，January 2003
[21]周紹儒，揚聲器的認識與製造，台北市徐氏基金會(1983),41-43
[22]MA Lu-jian , XI Ai_jun，Design of Diaphragm and Mini Speaker
Performance，(2008)05-0017-06
[23]U Jikel , SHANG Xinchun , JIN Mingyu，Analysis of Micro-loudspeaker Harmonic Distortion，China,Beijing 100176
[24]ZHU Deming , KUANG Yonghui , AI Xiaoxiao，Electrodynamic Loudspeaker Impedance Curve Analysis and Measurement，Jiangmen Guangdong 529000，China
[25]FEI Yan-feng，Discussion on Impedance Curve of Micro Loudspeaker， (2009)10-0027-05
[26]Toshitaka Kanai , Gregory Campbell，Film Processing (Second Edition)，2014 Elsevier Inc.
[27]Kirk Cantor，Blown Film Extrusion，Carl Hanser Verlag, Munich 2011
[28]FANG Xiao xia , WEN Bian ying，Research Progress on Preparation of Polymer-based Functional Materials by Solution Casting，China,Beijing 100048
[29]Schrenk W.J.，Multilayer Film From a Single Die，Plastics Engineering, 1974(30), P65-68
[30]Schrenk W.J. , Pinsky J.，Coextruded Iridescent Film，AGARD Conference Proceedings,1976,141-145