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畢業(yè)設(shè)計（論文）中期報告 題目：控制器殼體蓋塑料模具設(shè)計 系 別 機電信息系 專 業(yè) 機械設(shè)計制造及自動化 班 級 姓 名 學 號 導 師 2013年 3月 19 日 1. 設(shè)計（論文）進展狀況 本階段的主要任務是完成外文文獻的翻譯，對塑件進行更深層次的分析和理解，包括塑件的幾何特性與物理特性，以及塑件材料的性能等。 通過以上分析，基本上完成了塑件的二維的裝配草圖及三維零件圖，同時深刻體會到Pro/e軟件功能的強大；大概了解了注塑機在選用過程中所依據(jù)的原則，及所選注塑機的型號與參數(shù)；大概了解了注塑模具工藝過程與流程圖。 1.1注射機的選擇：由于采用一出二腔，需要至少注射量為56.3x2=112.6g，流道水口 廢料3.5g，總注塑量達到116.1g，再根據(jù)工藝參數(shù)（主要是注射壓力），綜合考 慮各種因素，選定注射機為海天120W1×B。 選型為：海天120W1×B型。相關(guān)參數(shù)如下： 理論注射量： 214cm3 注射重量： 195g 最大模具厚度：430mm 鎖模力： 1200KN 最小模具厚度：150mm 頂出行程： 120mm 移模行程: 350mm 拉桿內(nèi)距： 410×410mm 1.2進一步完善了零件三維圖，如下圖1、2所示： 圖1.零件圖 圖2.三維圖 1.3型腔布局如下：因為本設(shè)計中采用側(cè)入式澆口，且塑件的尺寸不大，為提高塑件 成功概率，并從經(jīng)濟型的角度出發(fā)，節(jié)省生產(chǎn)成本和提高生產(chǎn)效率，采用一模兩 腔，如下圖3所示： 圖3.型腔分布圖 1.4初步完成了零件的裝配圖，如下圖4所示： 圖4.裝配圖 2. 存在問題及解決措施 2.1未考慮到模具冷卻問題。 解決措施：在模具內(nèi)添加了冷卻系統(tǒng)。 2.2通過繪制三維裝配圖，發(fā)現(xiàn)冷卻水道與定距拉桿限位孔有局部干涉。 解決措施：通過三維圖的顯示位置，相應移動定距拉桿限位孔的位置使其避開冷 卻水道。 3. 后期工作安排 （1）9～14周：運用Pro/E完成模具整體結(jié)構(gòu)3D圖，完成模具零件的選材、工藝規(guī)程的編制、裝配圖及零件圖的 繪制等工作。 （2）15周：對所有圖紙進行校核，編寫設(shè)計說明書，所有資料提請指導教師檢查，準備畢業(yè)答辯。 指導教師簽字： 年 月 日 畢業(yè)設(shè)計(論文)開題報告 題目：控制器殼體蓋塑料模具設(shè)計 系 別： 機電信息系 專 業(yè)： 機械設(shè)計制造及其自動化 班 級： 學 生： 學 號： 指導教師： 20012年12月22日 1、畢業(yè)設(shè)計（論文）題目背景、研究意義及國內(nèi)外相關(guān)研究情況。 1.1、課題名稱 控制器殼體蓋塑料模具設(shè)計 1.2、課題研究背景和意義 模具工業(yè)是現(xiàn)代制造業(yè)和先進制造技術(shù)的重要組成部分。模具生產(chǎn)的特點是高精度、高復雜度、高一致性、高生產(chǎn)率和低消耗，是衡量一個國家產(chǎn)品制造水平高低的重要標志，而決定著企業(yè)產(chǎn)品質(zhì)量、效益及新產(chǎn)品開發(fā)能力。模具作為一種運用先進開發(fā)技術(shù)和精密加工手段制造而成的工藝裝備，被稱為“工業(yè)之母”。作為一種高附加值的技術(shù)密集產(chǎn)品，模具的技術(shù)水平應直接成為衡量一個國家制造業(yè)水平高低的重要指標，模具在很大程度上決定著產(chǎn)品質(zhì)量。模具結(jié)構(gòu)設(shè)計合理，操作方便，壽命長短，所產(chǎn)生的塑料件能達到使用要求。而模具鋼則是影響模具質(zhì)量的重要因素。模具鋼是模具產(chǎn)業(yè)最重要的技術(shù)和物質(zhì)基礎(chǔ)，其品種規(guī)格、性能、質(zhì)量對模具的性能、壽命、模具制造周期以及工業(yè)產(chǎn)品向高級化、個性化、多樣化和附加值化方向發(fā)展具有決定的意義，因而模具鋼的研究開發(fā)一直受到各國的重視。 各種模具的分類和占有量 模具主要類型有：沖模，鍛摸，塑料模，壓鑄模，粉末冶金模， 玻璃模，橡膠模，陶瓷模等。除部分沖模以外的的上述各種模具都屬 于腔型模，因為他們一般都是依靠三維的模具形腔使材料成型。<1> 沖模：沖模是對金屬板材進行沖壓加工獲得合格產(chǎn)品的工具。沖 模占模具總數(shù)的 50％以上。按工藝性質(zhì)的不同，沖?？煞譃槁淞夏?， 沖孔模，切口模，切邊模，彎曲模，卷邊模，拉深模，校平模，翻孔 模，翻邊模，縮口模，壓印模，脹形模。按組合工序不同，沖模分為 單工序模，復合模，連續(xù)模。 <2> 鍛模： 鍛模是金屬在熱態(tài)或冷態(tài)下進行體積成型時所用模具的總 稱。按鍛壓設(shè)備不同，鍛模分為錘用鍛模，螺旋壓力機鍛模，熱模鍛 壓力鍛模，平鍛機用鍛模，水壓機用鍛模，高速錘用鍛模，擺動碾壓 機用鍛模，輥鍛機用鍛模，楔橫軋機用鍛模等。按工藝用途不同，鍛 模可分為預鍛模具， 擠壓模具， 精鍛模具， 等溫模具， 超塑性模具等。 <3> 塑料模：塑料模是塑料成型的工藝裝備。塑料模約占模具總數(shù)的 35％，而且有繼續(xù)上升的趨勢。塑料模主要包括壓塑模，擠塑模，注 射模，此外還有擠出成型模，泡沫塑料的發(fā)泡成型模，低發(fā)泡注射成型模，吹塑模等。 <4> 壓鑄模：壓鑄模是壓力鑄造工藝裝備，壓力鑄造是使液態(tài)金屬在 高溫和高速下充填鑄型，在高壓下成型和結(jié)晶的一種特殊制造方法。 壓鑄模約占模具總數(shù)的 6％。<5> 粉末冶金模：粉末冶金模用于粉末成型，按成型工藝分類粉末冶 金模有：壓模，精整模，復壓模，熱壓模，粉漿澆注模，松裝燒結(jié)模 等。 模具所涉及的工藝繁多，包括機械設(shè)計制造，塑料，橡膠加工，金屬 材料，鑄造（凝固理論） ，塑性加工，玻璃等諸多學科和行業(yè)，是一 個多學科的綜合，其復雜程度顯而易見。 我國模具技術(shù)的現(xiàn)狀及發(fā)展趨勢 20 世紀 80 年代開始，發(fā)達工業(yè)國家的模具工業(yè)已從機床工業(yè)中 分離出來，并發(fā)展成為獨立的工業(yè)部門，其產(chǎn)值已超過機床工業(yè)的產(chǎn) 值。改革開放以來，我國的模具工業(yè)發(fā)展也十分迅速。近年來，每年 都以 15％的增長速度快速發(fā)展。許多模具企業(yè)十分重視技術(shù)發(fā)展。 加大了用于技術(shù)進步的投入力度， 將技術(shù)進步作為企業(yè)發(fā)展的重要動 力。 此外， 許多科研機構(gòu)和大專院校也開展了模具技術(shù)的研究與開發(fā)。 模具行業(yè)的快速發(fā)展是使我國成為世界超級制造大國的重要原因。 2、本課題研究的主要內(nèi)容和擬采用的研究方案、研究方法或措施。 2.1 、主要內(nèi)容： 塑件測繪圖、模具裝配圖、模具零件圖、說明書。 本設(shè)計的基本要求如下： 2.1.1、不少于3000字的文獻綜述； 2.1.2、充分了解塑件結(jié)構(gòu)，繪制3D圖，完成基本參數(shù)的計算及注塑機的選用； 2.1.3、確定模具類型及結(jié)構(gòu)，完成模具的結(jié)構(gòu)草圖的繪制； 2.1.4、運用Pro/E或solidwork等工具軟件輔助設(shè)計完成模具整體結(jié)構(gòu)； 2.1.5、對模具工作部分尺寸及公差進行設(shè)計計算； 2.1.6、對模具典型零件需進行選材及熱處理工藝路線分析； 2.1.7、編制模具中典型零件的制造工藝規(guī)程卡片； 2.1.8、對設(shè)計方案和設(shè)計結(jié)果進行經(jīng)濟和環(huán)保分析； 2.1.9、繪制模具零件圖及裝配圖； 2.1.10、對模具結(jié)構(gòu)進行三維剖析，輸出模具開合結(jié)構(gòu)圖； 2.1.11、編寫設(shè)計說明書（所有3D圖插入說明書中恰當位置）。 2.2 、擬定方案： 2.2.1、課題名稱：控制器殼體蓋塑料模具設(shè)計 2.2.2、材料選擇：ABS 2.2.3、生產(chǎn)批量：大批量 2.2.4、精度要求：中 2.2.5、塑料等級：4級 方案一：選連接座的側(cè)端面為分型面，采用整體式的直澆道，側(cè)澆口，澆口設(shè)在零件的側(cè)面上，手動推出機構(gòu)脫模，用手動側(cè)向分型方式抽芯。 此方案的優(yōu)點是制造方便，但操作麻煩，生產(chǎn)率低，勞動強度大。 方案二：選連接座的上端面為分型面，采用整體式的直澆道，點澆口，澆口設(shè)在分型面的上端面，選用臥式注射機，選用機動推出機構(gòu)脫模，機動側(cè)向分型方式抽芯。 此方案生產(chǎn)效率高，操作簡便，動作可靠，方便脫出流道凝料。 經(jīng)過兩種方案的對比，方案二的可靠性高，經(jīng)濟性價比高，適合大批量生產(chǎn)，故選此次模具設(shè)計選用方案二。 設(shè)計的連接座零件圖見圖1： 圖1 零件圖 2.3 、研究方法、手段： 本設(shè)計題目涉及目標均為工程實際零件，通過對塑件的實體測繪，完成基本參數(shù)的采集，然后運用《注塑模具設(shè)計》、《塑料模具設(shè)計》、《塑料成型工藝》等知識，指導學生利用AutoCAD和Pro/E軟件完成模具結(jié)構(gòu)的設(shè)計，并進行相關(guān)的校核計算，完成包括選材熱處理、制造工藝規(guī)程、可行性分析等工作。本設(shè)計旨在鍛煉學生在專業(yè)技術(shù)應用能力上達到培養(yǎng)目標的基本要求，在塑料成型工藝與塑料模具設(shè)計技術(shù)方面得到全面提高，并受到模具設(shè)計工程師的基本訓練。 3、本課題研究的重點及難點，前期已開展工作。 3.1、重點及難點: 本課題研究的重點是模具總體結(jié)構(gòu)的設(shè)計優(yōu)化選擇,應用相關(guān)軟件進行零件圖和裝配圖繪制,以及對模具結(jié)構(gòu)進行三維剖析輸出開合模具結(jié)構(gòu)圖.難點在于抽芯機構(gòu)的設(shè)計和總體方案的優(yōu)化選擇,以及模具三維結(jié)構(gòu)剖析和開合模具圖輸出. 3.2 、前期工作： 3.2.1、查閱了相關(guān)專業(yè)資料為設(shè)計做好準備； 3.2.2、完成模具二維圖、3D圖的繪制、文獻綜述； 3.2.3、完成了零件圖的測繪及其工藝性分析； 3.2.4、進行了模具結(jié)構(gòu)的分析，擬訂了兩套備選結(jié)構(gòu)方案。 4、完成本課題的工作方案及進度計劃（按周次填寫）。 1～2周：熟悉課題，根據(jù)老師給的資料運用AutoCAD、Pro/E軟件繪制塑件3D圖，翻譯外文資料。 3～4周：確定模具類型及結(jié)構(gòu)，繪制模具結(jié)構(gòu)草圖，準備開題答辯。 5～8周：對模具工作部分尺寸及公差進行設(shè)計計算，并運用Pro/E輔助設(shè)計完成部分模具零件，準備中期答辯。 9～14周：運用Pro/E完成模具整體結(jié)構(gòu)3D圖，完成模具零件的選材、工藝規(guī)程的編制、裝配圖及零件圖的 繪制等工作。 15周：對所有圖紙進行校核，編寫設(shè)計說明書，所有資料提請指導教師檢查，準備畢業(yè)答辯。 五、指導教師意見（對課題的深度、廣度及工作量的意見） 指導教師： 年 月 日 六、所在系審查意見： 系主管領(lǐng)導： 年 月 日 參考文獻 [1] 夏玉海， 模具產(chǎn)業(yè)的現(xiàn)狀及發(fā)展趨勢[J], 現(xiàn)代制造技術(shù)與裝備，2007 [2] 蔣媛，聚焦中國模具[J]. 模具?？üI(yè)設(shè)計），2008 [3] 賀平，王巍. 線圈注射模設(shè)計[J]， 機械設(shè)計與制造，2007 [4] 馬黨參，陳再枝，劉建華. 我國模具鋼的發(fā)展機遇與挑戰(zhàn)[J]， 金屬加工（冷加工）， 2008 [5] 葛正浩，楊芙蓮，Pro/E塑料制品設(shè)計入門與實踐，化學工業(yè)出版社 [6] 徐政坤，塑料成型工藝與模具設(shè)計[M]，北京：國防工業(yè)出版社，2008 [7] 李秦蕊，塑料模具設(shè)計[M]，西北工業(yè)大學出版社，2006 [8] 王樹勛，蘇樹珊模具實用技術(shù)設(shè)計綜合手冊，華南理工大學出版社，2003 [9] 李秦蕊，塑料模具設(shè)計[M]，西北工業(yè)大學出版社，1988年修訂本 [10] 申開智，塑料成型模具[M]，中國輕工業(yè)出版社，2002 [11] 陳劍鶴，模具設(shè)計基礎(chǔ)[M]，機械工業(yè)出版社，2003 [12] 陳萬林，實用模具技術(shù)[M]，機械工業(yè)出版社，2000 [13] 陳志剛，塑料模具設(shè)計[M]，機械工業(yè)出版社，2002 [14] 廖念釗，古瑩蓭，莫雨松，互換性技術(shù)與測量，第五版，北京：中國計量出版社，2007.6 [15] 李慶余，張佳，機械制造裝備設(shè)計，北京：機械工業(yè)出版社，2003.8 [16] 大連組合機床研究所，組合機床設(shè)計參考圖冊，北京：機械工業(yè)出版社，1975.11 [17] Kollmann F. G. Rotating Elasto-Plastic Interference Fits. Trans. ASME, 80-C2/DET-11. [18] Mechanical Drive(Reference Issue). Machine Design.52(14),1980 [19] Frank W. Wilson, Philip D. Harvey & Charles B. Gump. 2nd ed. Die design handbook[M]. McGraw-Hill Book Company.1965 temperature Pujos, Cedex, great molding numer cooling is to effect and quality fastest lar industrie increase well known economically mer melt sufficiently so that the part can be ejected without any significant deformation 2. An efficient cooling system design of the cooling channels aiming at reducing cycle time must minimize such undesired defects as sink marks, differential shrinkage, ther- mal residual stress built-up and part warpage. During the post-fill- ing and cooling stages of injection molding, hot molten polymer touches the cold mold wall, and a solid layer forms on the wall. tion to the coolant moving through the cooling channels and by natural convection to the air around the exterior mold surface. The coolant is flowing through the channels at a given flow rate and a given temperature which is considered constant throughout the length of the channel. In this work, time-dependent two-dimensional model is considered which consists of an entire computational domain of the cavity, mold and cooling channel surfaces. The cyclic transient temperature distribution of the mold and polymer T-shape can be obtained by solving the transient energy equation. * Corresponding author. Tel.: +330540006348; fax: +330540002731. Applied Thermal Engineering 29 (2009) 17861791 Contents lists available E-mail address: hassanenscpb.fr (H. Hassan). cess where polymer is injected into a mould cavity, and solidifies to form a plastic part. There are three significant stages in each cy- cle. The first stage is filling the cavity with melt hot polymer at an injection temperature (filling and post-filling stage). It is followed by taking away the heat of the polymer to the cooling channels (cooling stage), finally the solidified part is ejected (ejection stage). The cooling stage is of the greatest importance because it signifi- cantly affects the productivity and the quality of the final product. It is well known that more than seventy percent of the cycle time in the injection molding process is spent in cooling the hot poly- distribution of the mold and polymer, therefore, their effect on the solidification degree of that polymer. A fully transient mold cooling analysis is performed using the finite volume method for a T-shape plastic mold with similar dimensions to 5, as shown in Fig. 1. Different cooling channels positions and forms are studied. 2. Mathematical model The heat of the molten polymer is taken away by forced convec- 1. Introduction Plastic industry is one of the worlds ranked as one of the few billion-dol injection molded parts continues to plastic injection molding process is cient manufacturing techniques for precision plastic parts with various shapes at low cost 1.The plastic injection molding 1359-4311/$ - see front matter C211 2008 Elsevier Ltd. All doi:10.1016/j.applthermaleng.2008.08.011 growing industries, s. Demand for every year because as the most effi- producing of and complex geometry process is a cyclic pro- As the material cools down, the solid skin begins to grow with increasing time as the cooling continues until the entire material solidifies. Over the years, many studies on the problem of the opti- mization of the cooling system layout in injection molding and phase change of molding process have been made by various researchers and ones which focused intensity on these topics and will used in our system design and validations are 36. The main purpose of this paper is to study the effect of the cooling channels position and its cross section shape on the temperature Cooling system leads to minimum cooling time is not achieving uniform cooling throughout the mould. C211 2008 Elsevier Ltd. All rights reserved. Effect of cooling system on the polymer during injection molding Hamdy Hassan * , Nicolas Regnier, Cedric Lebot, Cyril Laboratoire TREFLE-Bordeaux1-UMR 8508, Site ENSCPB, 16 Av. Pey Berland, 33607 Pessac article info Article history: Received 15 November 2007 Accepted 19 August 2008 Available online 30 August 2008 Keywords: Polymer Solidification Injection molding abstract Cooling system design is of is crucial not only to reduce ity of the final product. A performed. A cyclic transient of the mold cooling study cooling system design. The ture distribution of the mold tivity of the process, the cooling should be necessary for the Applied Thermal journal homepage: www.elsevi rights reserved. Guy Defaye France importance for plastic products industry by injection molding because it cycle time but also it significantly affects the productivity and qual- ical modeling for a T-mold plastic part having four cooling channels is analysis using a finite volume approach is carried out. The objective determine the temperature profile along the cavity wall to improve the of cooling channels form and the effect their location on the tempera- the solidification degree of polymer are studied. To improve the produc- time should be minimized and at the same time a homogeneous cooling of the product. The results indicate that the cooling system which and solidification at ScienceDirect Engineering dissipation of the heat through phase change process. This tech- plicit/implicit technique already validated in previous studies by Vincent 8, and Le Bot 9 that is based on the technique New Source” of Voller 10. This method proposes to maintain the nodes where phase change occurs to the melting temperature. This solu- tion is repeated until the convergence of the temperature with the source term equals to the latent heat. The source term is discret- ized by: S c qL f of s ot qL f f n1 s C0f n s Dt 5 The solid fraction which is function of the temperature is line- arized as: Nomenclature C P (J/kg K) specific heat at constant pressure f s solid fraction h (W/m 2 K) heat transfer coefficient K number of the internal iterations L latent heat of fusion, J/kg n number of the external iterations N normal direction S c source term T (K) temperature t (s) time H. Hassan et al./Applied Thermal Engineering nique is applied on fixed nodes and the energy equation in this case is represented as follow: qC P oT ot r:krTS c 2 And the source term S c is represented by: S c qL f of s ot 3 where f s (T) = 0.0 at TC31T f ,(full liquid region) 0C30 f s C301, at T = T f (iso- thermal phase change region) and, f s (T)=1 at TC30T f (full solid region). On the whole domain, the following boundary conditions are applied C0k oT oN h c T C0T c 2C 1 ; and C0k oT oN h a T C0T a 2C 2 : 4 3. Numerical solution The numerical solution of the mathematical model governing the behavior of the physical system is computed by finite volume method. The equations are solved by an implicit treatment for qC P oT ot r:krT1 In order to take into account the solidification, a source term is added to the energy equation corresponding to heat absorption or heat release 7, which takes in consideration the absorption or the the different terms of the equations system. When we take in con- sideration the solidification effect, the energy equation is solved with a fixed point algorithm for the solid fraction. For each, itera- tion of that fixed point, we use discretization with time hybrid ex- 0.2 0.4 0 .2 0.004 0.03 0.004 P2 P3 P4 P1 P6 P7 P5 Exterior air, free convection, h a Cooling channels, forced convection, h f Fig. 1. MoldstructurewithaT-shapeproductandfourcoolingchannels(Dim.Inm). Greek symbols k (W/m K) thermal conductivity q (kg/m 3 ) density C 1 interior surface of the cooling channels C 2 exterior surface of the mold Subscripts a ambient air c cooling fluid f phase change 0.01 0.01 0.01 0.01 0.01 0.02 A1 A2 A3 A4 A5 A7 B1 B2 B3 B4 B5 B7 C1 C2 C3 C4 C5 D1 D2 D3 D4 D5 0.04 0.02 0.01 0.015 Polymer Fig. 2. Different cooling channels positions (Dim. In m). 29 (2009) 17861791 1787 f n k1 K s f n k K s dF s dT C18C19 n k K T n k1 K C0T n k K 6 Then, we force the temperature to tend to the melting temper- ature where the source term is not null by updating the source term: S k1 c S k c qC p T C0T f Dt 7 The energy equation is discretized as follow: qC P Dt C0 qL f Dt dF dT C18C19 n k K ! T n k1 K C0r:krT n k1 K qL f Dt f n k1 K s C0f n s C0 qL f Dt dF dT C18C19 n k K T f qC P Dt T n 8 With: dF dT !C01 if 0 C30 f n k K s C30 1 and dF dT 0iff n k K s 0or1 9 This process allows differentiating the temperature field and so- lid fraction calculated at the same instant and the linear system is solved by central discretization method 11. For each internal iter- ation, the resolution of that equation provides f n k1 K s and T n k1 K . The convergence is achieved when the criteria of the solid fraction and temperature are verified by: f n k1 K s C0f n k K s C13 C13 C13 C13 C13 C13C302 f and; T n k1 K C0T n k K C13 C13 C13 C13 C13 C13C302 T 10 Further details on the numerical model and its validation are presented in 9. the horizontal direction (between positions B2 and B5 or positions A2 and A5 which have the maximum solidification percent). When we compare the solidification percent for different locations of the upper positions C and D, we find that as the channel approaches to the product in the horizontal direction the solidification percent increases, and the cooling rate increase rapidly compared with the effect of lower position. We notice that, the effect of the cooling channel position on the temperature distribution and solidification decreases as the cooling time augments to higher value and its ef- 1788 H. Hassan et al./Applied Thermal Engineering 4. Results and discussion A full two-dimensional time-dependent mold cooling analysis in injection molding is carried out for a plate mould model with T-shape plastic mold and four cooling channels as indicated in Fig. 1. Due to the symmetry, half of the mold is modeled and ana- lyzed. All the cooling channels have the same size and they have diameter of 10-mm each in case of circular channels. The cooling operating parameters and the material properties are listed in Ta- bles 1 and 2, respectively, and they are considered constant during all numerical results 5,7. Each numerical cycle consists of two stages, cooling stage where the cavity is filled with hot polymer initially at polymer injected temperature, the ejection stage where the cavity is filled with air initially at ambient temperature. Figs. 3 and 4 show the cyclic transient variations of the mould tempera- ture with time for 16 s mold cooling time at locations; (P1,P2,P3,P4) beside the mould walls and P5 to P7 inside the mould walls, respectively (Fig. 1) and that in case of applied the solidifica- tion and without applied solidification. They are simulated for the first 30 cycles in case of circular cooling channels position (A5, D3) as shown in Fig. 2. We find that, the simulated results are in good agreement with the transient characteristic of the cyclic mold tem- perature variations described in 5. It is found that there is a slightly difference in temperatures values between the two results, thus due to the difference in numerical method used and the accu- racy in the numerical calculations. The figures show that, the rela- tively temperature fluctuation is largest near the cavity surface and diminishes away from the cavity surface. We find that the maxi- mum amplitude of temperature fluctuation during the steady cycle can reach 10 C176C without applying solidification and 15 C176C in case of applying the solidification. 4.1. Effect of cooling channels form An efficient cooling system design providing uniform tempera- ture distribution throughout the entire part during the cooling pro- cess should ensure product quality by preventing differential shrinkage, internal stresses, and mould release problems. It also should reduce time of cooling and accelerate the solidification pro- cess of the product to augment the productivity of the molding Table 1 Cooling operating parameters Cooling operating parameter Cooling operating parameter Coolant fluid temperature 30 C176C Ambient air temperature 30 C176C Polymer injected temperature 220 C176C Heat transfer coefficient of ambient air 77 W/ m 2 K Temperature of fusion of polymer 110 C176C Heat transfer coefficient inside cooling channel 3650 W/ m 2 K Latent heat 115 kJ/ Mold opening time 4 s kg process. To demonstrate the influence of the cooling channels form on the temperature distribution throughout the mould and solidi- fication process of the product, we proposed three different cross sectional forms of the cooling channels, circular, square, rectangu- lar1 with long to width ratio of 0.5 and rectangular 2 with width to long ratio of 0.25. Two cases are studied; first case, all the cooling channels have the same cross sectional area, and the second case, they have the same perimeter. The comparison is carried out for the same cooling channels position (A5, D3). Fig. 5 shows the solidification percent (calculated numerically as the summation of the solid fraction of each element multiplied by the area of that element to total area of the product) for differ- ent forms with different cooling time. The figure indicates that the effect of cooling channels form on the cooling rate decreases with increasing the cooling time. It also shows that the cooling channel form rectangle 2 has the maximum solidification percent for case 1, and in case 2 the changing of the cooling channels form has not a sensible effect on the solidification percent. The same results can be obtained when we compared the solidification in the prod- uct and the temperature distribution though the mould for differ- ent forms with the same cross sectional area at the end of the cooling stage for cooling time 24 s for cooling cycle 25, as shown in Figs. 6 and 7, respectively. The results indicate that the cooling process is improved as the cooling channels tend to take the form of the product. 4.2. Effect of cooling channels position To investigate the effect of the cooling channels position, we di- vided the proposed positions into four groups, groups A and B for different positions of the bottom cooling channel, with a fixed po- sition of the top cooling channel, and with vice versa for groups C and D for the same cooling channel form (circular) as illustrated in Fig. 2. Fig. 8 represents the effect of different cooling channel positions on the of solidification percent at the end of 25th cooling cycle for groups A and B (lower cooling channel effect), C and D (upper cool- ing channel effect) with cooling time. It indicates that for lower cooling channel position effect, the cooling rate increases and hence the solidification percent of the polymer increases as the cooling channel approaches the polymer in the vertical direction (position B has solidification percent greater than position A, and with the same positions C and D). The figure shows also the most efficient cooling rate is obtained as the cooling channel takes the position between 20% and 50% through the product length for Table 2 Material properties Material Density (kg/m 3 ) Specific heat (J/kg K) Conductivity (W/m K) Mould 7670 426 36.5 Polymer 938 1800 0.25 Air 1.17 1006 0.0263 29 (2009) 17861791 fect on the cooling rate of the product is not the same for different positions. Engineering 60 65 ab H. Hassan et al./Applied Thermal The solidification degree distribution through the product at the end of cooling stage at the end of cooling time 24 s and 25th cool- ing cycle for different locations of cooling channel is shown in Fig. 9, and the temperature distribution throughout the mould and the polymer at the same instant for different cooling channels Temperature, o C Time, s 0 200 400 600 30 35 40 45 50 55 P1 P2 P3 P4 Fig. 3. Temperature history of the first 30 cycles at locations Time,s 30 35 40 45 50 55 60 65 P5 P6 P7 ab Temperature, o C 0 200 400 600 Fig. 4. Temperature history of the first 30 cycles at locations Solidification percent Coolingperiod (constant perimeter -) Coolinvgperiod (constant area ) + + + + + + + + + + + + + + + 16 1618202224262830 0.68 0.72 0.76 0.8 0.84 0.88 0.92 0.96 Circle Rectangle1 Rectangle2 Square Circle Rectangle1 Rectangle2 Square + + 30282624222018 Fig. 5. Changing the solidification percent of the polymer part with cooling time for different cooling channel forms. 70 75 29 (2009) 17861791 1789 position is shown in Fig. 10. When we examine the solidification degree of the product and the temperature distribution throughout the mold for different positions, we find that as the cooling channel position moves toward the products, the homogeneity of the tem- perature distribution throughout the polymer and the mold during Temperature, o C Time, s 0 30 35 40 45 50 55 60 65 P1 P2 P3 P4 600500400300200100 P1 to P4 (a) without solidification (b) with solidification. Time,s 30 35 40 45 50 55 60 65 70 75 P5 P6 P7 Temperature, o C 0 200 400 600 P5 to P7 (a) without solidification (b) with solidification. Fig. 6. Solidification percent distribution through the product for different cooling channels forms (a) rectangular 2 and (b) circular having the same cross sectional area. 3 8 4 0 4 0 4 0 4 2 4 2 4 5 45 4 5 4 5 4 5 5 0 5 0 5 0 5 5 55 60 6 0 5 65 70 70 80 80 9 90 X Y 0 0.05 0.1 0.15 0.2 0 0.05 0.1 0.15 0.2 35 35 3 7 37 3 8 3 8 38 4 0 4 0 4 0 40 4 2 42 4 2 4 2 4 2 5 45 4 5 4 5 45 5 0 5 0 55 55 60 60 65 65 70 70 809 X Y 0 0.05 0.1 0.15 0.2 0 0.05 0.1 0.15 0.2 ab Fig. 7. Temperature distribution through the mould for different cooling channels forms (a) circular and (b) rectangular 2 having the same cross sectional area. Time, s Solidification percent + + + + + + + + + + 20 0.82 0.84 0.86 0.88 0.9 0.92 0.94 0.96 0.98 1 B1,D3 B2,D3 B3,D3 B5,D3 B7,D3 A1,D3 A2,D3 A3,D3 A5,D3 A7,D3 + + Solidification percent 0.82 0.84 0.86 0.88 0.9 0.92 0.94 0.96 0.98 1 B2,C1 B2,C2 B2,C3 B2,C5 B2,D1 B2,D2 B2,D3 B2,D5 3028262422 Time, s 20 3028262422 ab Fig. 8. Changing the solidification percent of the polymer part with cooling time for different cooling channel positions (a) lower cooling channel positions A and B and (b) upper cooling channel positions C and D. Fig. 9. Solidification percent distribution through the product for different cooling channels positions for cooling time 24 s and 25th cooling period (a) B7, D3 (b) B2, D3, (c) B2, C5, and (d) B2, C3. 1790 H. Hassan et al./Applied Thermal Engineering 29 (2009) 17861791 37 3 8 3 8 38 4 0 4 0 4 0 4 2 4 2 2 4 2 45 45 4 5 4 5 4 5 5 0 5 0 5 0 50 60 60 7 70 8 80 90 90 100 100 110110Y 0.05 0.1 0.15 0.2 3 5 3 7 37 3 8 3 8 38 4 0 4 0 4 0 4 2 4 2 4 5 4 5 4 5 5 0 50 5 0 5 55 5 5 60 6 0 65 65 5 70 70 75 7 80 80 9Y 0.05 0.1 0.15 0.2 a b positions H. Hassan et al./Applied Thermal Engineering 29 (2009) 17861791 1791 the solidification process decrease for example positions (B2, D3) and (B2, C3). The figure indicates that as the channel approaches the product in the horizontal direction and vertical direction, the temperature distribution throughout the polymer divided into two regions during the cooling process (B7, D3), (B2, D3), (C5, B2), (C3, B2) and thus has the same effect on the solidification pro- cess. These two areas of the temperature distribution and that dif- ferent cooling rate through the cooling process lead to different severe warpage and thermal residual stress in the final product which affect on the final product quality. 5. Conclusion The variation of the temperature of the mould through a num- ber of molding cycles is carried out. The simulated results are in good agreement with the transient characteristic of the cyclic mold temperature variations described in 5 and It is found that there is a slightly difference in temperatures values between the simulated results and those described in 5. The effect of cooling channels form and the effect of its position on the temperatures distribution throughout the polymer and the solidification of 7 4 2 X 0 0 0.20.150.10.05 Fig. 10. Temperature distribution through the mould for different cooling channels the product are studied. The results indicate that as