臺灣博碩士論文加值系統

多數常見塑膠有蓋容器，其蓋子與容器的連接處有一薄且短的一體式設計，該種設計相較傳統的兩件式分體設計，可大量減少組裝時間，且單次開模可一次成型整個有蓋容器，而這個連接處的設計被稱為塑膠活動鉸鏈(Plastic living hinge，PLH)，設計方式通常採用經驗法則，但其過程缺乏基本的材料力學概念。本研究以彎曲樑的應變為基礎，提出具備學理基礎的塑膠活動鉸鏈的分析與設計方法，當設計的材料已選定，再根據此材料之機械性質進行幾何尺寸設計，以設計彈性、純塑性、塑性加拉伸及純拉伸四種主要的鉸鏈，藉由有限元素分析觀察應變分佈，利用射出成型進行樣品打樣，將樣品透過折彎實驗探討各類型鉸鏈折彎前後應力應變之變化，觀察其使用壽命。透過對設計參數的研究，相同的材料時，鉸鏈的跨距越短、厚度越厚以及凹槽越深皆會減少鉸鏈的壽命，其中凹槽深淺對鉸鏈的壽命影響最大，若材料不同時，軟韌的材料比硬脆的材料更適合製作鉸鏈；透過有限元素分析驗證鉸鏈彎曲時，應變分佈與理論幾乎相符合，藉由實驗可看出樣品折彎後，平均最大應力皆比未折彎之樣品高。本研究提出設計鉸鏈的方法，其發展的分析方程式足以快速評估PLH的設計優劣。

Plastic living hinge (PLH) is welcome since it performs a convenient approach to bridge two components for a relative motion. The design of PLH is usually implemented using empirical methods, which merely considers the dimensional design and the strain of the hinge is seldom concerned. This process lacks of basic mechanics of materials concepts and the performance of the hinge is difficult to be estimated. In this wok, a novel method for the design of the plastic living hinges based on stress and strain of hinge is established. When the material has been selected, three design parameters, hinge length, hinge thickness and recess mutually influence each other. Too short hinge length makes a plastic deformation happen. However, reduce the hinge thickness can improve the strain from plastic deformation to elastic deformation. The research results are validated through the finite element analysis and experimental assessment. In conclusion, the proposed method provides a generalized method to predict the strain state of the designing PLH and provide a quick, systematic evaluations of PLH performance.

摘要...........................................................................i
Abstract......................................................................ii
誌謝.........................................................................iii
目錄..........................................................................iv
表目錄........................................................................vi
圖目錄.......................................................................vii
第一章 緒論....................................................................1
1.1前言........................................................................1
1.2文獻回顧....................................................................2
1.3研究動機與目的...............................................................3
第二章 理論基礎.................................................................5
2.1鉸鏈功能....................................................................5
2.2鉸鏈設計分析.................................................................6
2.2.1彎曲和拉伸原理.............................................................6
2.2.2鉸鏈應變分析...............................................................8
2.3設計流程...................................................................17
第三章 實驗方法與流程..........................................................19
3.1實驗流程...................................................................19
3.2材料取樣...................................................................19
3.3有限元素分析................................................................20
3.4模具設計...................................................................21
3.5射出實驗...................................................................22
3.6疲勞測試...................................................................23
第四章 實驗結果與討論..........................................................26
4.1設計參數對鉸鏈之影響........................................................26
4.1.1變化設計參數觀察鉸鏈趨勢...................................................26
4.1.2不同材料對設計參數的影響...................................................28
4.1.3改變設計參數與應變計算.....................................................29
4.2鉸鏈之應變分佈..............................................................31
4.3樣品折彎實驗................................................................33
4.3.1射出成品.................................................................33
4.3.2尺寸量測.................................................................34
4.3.3鉸鏈折彎前後應力變化......................................................35
4.4如何設計鉸鏈................................................................37
第五章 結論與未來展望..........................................................38
5.1結論.......................................................................38
5.2未來展望...................................................................38
參考文獻......................................................................39
附錄A.........................................................................40
Extended Abstract.............................................................44

[1] P.A Tres, Designing Plastic Parts for Assembly, 7th ed. Cincinnati: Hanser, 2014.
[2] A living hinge on the lid of a Tic Tac box, Check from：
https://en.wikipedia.org/wiki/Living_hinge
[3] R.A. Tatara, R.M. Sievers, Valentin Hierzer, “Modeling the injection molding processing of a polypropylene closure having an integral hinge”, Journal of Materials Processing Technology, Volume176, Issue1-3, pp. 200-204, 06 June 2006.
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[5] G. Beall, “Polypropylene part design, Part 2 – Living hinges”, Injection Molding Journal, 25 July 2002.
[6] César Omar Balderrama Armendáriz, et al. “Folding behavior of thermoplastic hinges fabricated with polymer extrusion additive manufacturing”, The International Journal of Advanced Manufacturing Technology,105, pp.233-245, 06 August 2019.
[7] Cassandra Gribbins, Heidi M. Steinhauer, Ph. D, “Experimental Analysis on an Additively Manufactured ABS Living Hinge”, International Solid Freeform Fabrication Symposium, pp.1412-1424, August 2014.
[8] A living hinge on the water bottle, Check from：
https://s.yimg.com/zp/MerchandiseImages/71FBC26DDE-SP-7060103.jpg
[9] A water bottle - Jack-Light Incorporation, Check from：
https://jack-light.com.tw/p1000ml/
[10]Weekly 7 Day Mini Tablet Pill Box, Check from：
https://ae01.alicdn.com/kf/Hea981b22859f4591a8ab809d982a862cQ/White-rectangular-hard-plastic-drug-box-pill-box-box-7-days.jpg
[11]Dispensing Flip Top Caps - Radian Design Limited, Check from：
https://radiandesign.co.uk/project/flip-top-caps/