汽車儀表蓋內(nèi)飾標(biāo)識(shí)罩注射模設(shè)計(jì)【說明書+CAD+UG】

汽車儀表蓋內(nèi)飾標(biāo)識(shí)罩注射模設(shè)計(jì)【說明書+CAD+UG】,說明書+CAD+UG,汽車,儀表,蓋內(nèi)飾,標(biāo)識(shí),注射,設(shè)計(jì),說明書,仿單,cad,ug 新型注塑模具冷卻通道設(shè)計(jì) 作者 A B M Saifullah, S.H. Masood 和 Igor Sbarski 摘要 注塑成型是大規(guī)模生產(chǎn)塑料零件時(shí)最通用并且最重要一種操作方法。在此項(xiàng)工藝當(dāng)中,冷卻系統(tǒng)的設(shè)計(jì)好壞是非常重要的,因?yàn)樗艽蟪潭壬蠜Q定了零件的生產(chǎn)周期。一個(gè)良好的冷卻系統(tǒng)設(shè)計(jì)可減少生產(chǎn)周期,并保證零件的尺寸穩(wěn)定性。本文敘述的是一個(gè)注塑膜的冷卻通道系統(tǒng)的橫切面內(nèi)容。對(duì)這些新的冷卻通道系統(tǒng)進(jìn)行模擬實(shí)驗(yàn)。工業(yè)園區(qū)采用比較分析法，用注塑仿真分析軟件分析塑料內(nèi)部，內(nèi)部有常見的冷卻通道。微注射成型機(jī)的塑料零件已得到實(shí)驗(yàn)驗(yàn)證。用模具表面溫度的分布情況和塑料零件的冷卻時(shí)間，或是凝固時(shí)間相比較分析得到的。結(jié)果表明，均勻的溫度分布可減少凝固時(shí)間，從而減少塑料零件成型周期。 1.介紹 注塑成型的方法廣泛使用于塑料部件的工藝生產(chǎn)當(dāng)中 [1]。注射成型的基本原理是,一個(gè)固體聚合物熔化后,注入到模具型腔內(nèi)，冷卻之后脫模。因此，主要階段是注射成型，過程包括填充、冷卻和脫模。塑模周期決定生產(chǎn)成本效益高低，而冷卻過程是尤為重要的一步。冷卻周期決定部件生產(chǎn)效率。因此，在現(xiàn)代工業(yè)當(dāng)中，生產(chǎn)成本和生產(chǎn)時(shí)間有密切關(guān)系，生產(chǎn)部件的時(shí)間越久，成本越高。減少冷卻時(shí)間可在根本上增加生產(chǎn)效率，并且減少生產(chǎn)成本。因此，理解和優(yōu)化典型的成型過程即內(nèi)傳熱是很重要的。熱交換率是塑料注射制品和模具的決定性因素，影響注塑模具的生產(chǎn)業(yè)績(jī)。 A B M Saifullah是工業(yè)研究機(jī)構(gòu)的一名博士生會(huì)員, 就讀于斯威本國(guó)立科技大學(xué)，澳大利亞墨爾本人，電子郵件：msaifullah@swin.edu.au。 IAENG. S. H. Masood的是斯威本國(guó)立科技大學(xué)機(jī)械制造工程系的一名教授, 澳大利亞墨爾本人。聯(lián)系電話:+ 61-3-9214 8260,傳真:+ 61-3-9214 5050,電子郵件:smasood@swin.edu.au Igor Sbarski博士是斯威本國(guó)立科技大學(xué)機(jī)械制造工程系的一名高級(jí)講師，澳大利亞墨爾本人。電子郵件:isbarski@swin.edu.au)。 熱量必須從塑膠材料上移開，直到達(dá)到穩(wěn)定狀態(tài)為止后,才可允許脫膜。此過程中需要完成冷卻時(shí)間或是凝固時(shí)間。對(duì)于最佳熱傳遞過程來說，在熔融的塑料材料和模具間，恰當(dāng)?shù)睦鋮s系統(tǒng)設(shè)計(jì)是很有必要的。在模具型芯和型腔內(nèi)安裝直井眼然后注入冷凍液也就是冰水，使熔融的塑料散熱。此方法用于常規(guī)機(jī)械加工過程中，使用直鉆制造這類小孔,而卻不能生產(chǎn)像通道或是3D空間這類復(fù)雜的孔狀。 一個(gè)冷卻系統(tǒng)的替代方法, 在注射模具的過程當(dāng)中，符合或適合于模具型腔形狀和核心形狀，才能提供更好的熱傳遞，從而得到最優(yōu)生產(chǎn)周期。這種方法是用不同橫截面相同通道，盡量貼近模具表面減少熔融塑料的熱量。這確保零件均勻冷卻效率更佳。目前，隨著快速成型技術(shù)的來臨，例如：直接金屬沉淀工藝，直接金屬激光燒結(jié)工藝，還有許多先進(jìn)的計(jì)算機(jī)輔助工程軟件的,可以給模具設(shè)計(jì)并制造許多復(fù)雜布局和復(fù)雜橫切面的更高效冷卻通道[2、3、4]。本文介紹了一種方形截面的冷卻通道注塑壓模，并模仿這種方法生產(chǎn)一種圓形塑料碗，并與使用模擬仿真分析軟件制作的直線形冷卻通道相比較。用這個(gè)方形冷卻通道和傳統(tǒng)的直線形冷卻通道壓模來完成這項(xiàng)驗(yàn)證性試驗(yàn)，是為了用微注射成型機(jī)制作的模具將一個(gè)圓形通道分為兩種塑材。結(jié)果表明方形冷卻通道壓模的冷卻時(shí)間和溫度分布都比直線形冷卻通道壓模有優(yōu)勢(shì)。 零件和模具設(shè)計(jì)方面 1. 零件設(shè)計(jì) 用聚丙烯制成的圓形塑料碗，如圖1(a)，采用Pro-Engineer CAD軟件設(shè)計(jì)的。輸出初始圖形規(guī)格模具表面圖形文檔，在輸入到MPI中進(jìn)行分析。塑料零件體積是177.90和質(zhì)量是162.3mg。試驗(yàn)測(cè)試零件如圖1(b)，此零件使用Pro-Engineer軟件設(shè)計(jì)出來的。使用Pro-Engineer CAD軟件對(duì)聚丙烯和丙烯腈這兩種類型的塑料材料已做了大量的實(shí)驗(yàn)驗(yàn)證。測(cè)出零件體積是8.8,聚丙烯部分和丙烯腈部分質(zhì)量分別為8.58mg和8.13mg。 2 .模具設(shè)計(jì) 模具設(shè)計(jì)當(dāng)中利用Pro / Molde 設(shè)計(jì)Pro / Engineer 系統(tǒng)組件。采用計(jì)算機(jī)數(shù)控技術(shù)制造模具。圖2中所示的模具有兩個(gè)部分型心和型腔。采用電腦數(shù)控技術(shù)將方形冷卻通道一半設(shè)計(jì)在型腔部分和另一半設(shè)計(jì)在型心部分。然后將這兩部分用螺絲連接，并用液態(tài)填料密封以免漏水。 圖- 1：CAD模型（a）圓形塑料碗，（b）被測(cè)試部分。 圖- 2 ：CAD模型的核心（上）和兩個(gè)型腔。 3．分析結(jié)果 MPI仿真軟件被用來零件分析[5]。用聚丙烯塑料材料分析注入、冷卻、變形這三步順序。對(duì)比分析出方形冷卻系統(tǒng)通道與傳統(tǒng)的直線形冷卻通道的區(qū)別。直線形通道的直徑為12mm，方形通道長(zhǎng)度為12mm（圖3）。0.995cm周長(zhǎng)的聚變嚙合已被應(yīng)用到工業(yè)當(dāng)中。直線形通道和方形通道的嚙合元素的數(shù)量分別為12944個(gè)和12291個(gè)。這兩種情況下均使用25°標(biāo)準(zhǔn)海水，雷諾數(shù)為10000，熔煉溫度是230℃的冷卻介質(zhì)。比較分析MPI結(jié)果如圖4，從圖中看出，直線形通道溫度分布比方形通道更為均勻些，而方形通道所需冷卻時(shí)間相對(duì)直線形較少。直線形冷卻通道除了頂頭部分很小以外，大部分零件冷卻時(shí)間需要大概24秒，而方形冷卻通道圖解表明其冷卻時(shí)間要少于20秒。直線形冷卻通道的凝固時(shí)間大概在0.46-93.7秒之間，方形冷卻通道冷卻時(shí)間在0.3-87.15秒之間。因此,使用方形冷卻通道，需要5秒的冷卻時(shí)間，冷卻時(shí)間減少了35%。 圖- 3 MPI分析，（a）：直線型冷卻通道，（b）：方形冷卻通道 圖4比較二者冷卻時(shí)間，（a）：方形冷卻通道（b）直線形冷卻通道。 4.實(shí)驗(yàn)驗(yàn)證結(jié)果 對(duì)一個(gè)圓形的塑料零件用模具加工機(jī)器實(shí)驗(yàn)驗(yàn)證結(jié)果如圖5所示。零件直徑是40mm，厚度是7mm。模具標(biāo)準(zhǔn)尺寸是10x10x2.5。 模具材料是低碳鋼。用TECHSOFT迷你模具加工機(jī)即一個(gè)小型注塑機(jī)進(jìn)行實(shí)驗(yàn)驗(yàn)證如圖6。兩個(gè)采用PICO技術(shù)生產(chǎn)的TC08 K型熱電偶已被用來測(cè)量被測(cè)試零件的上下表面溫度。聚丙烯和丙烯腈的熔解溫度均是250°C。標(biāo)準(zhǔn)海水已被用來作為冷卻介質(zhì),由于室溫25℃,所以叫做冷卻水。冷卻通道直徑是5mm,正方形冷卻通道和直線型冷卻通道標(biāo)準(zhǔn)截面尺寸是5mm。每隔一秒測(cè)試一下兩個(gè)熱電偶的表面溫度。圖7記錄了丙烯腈-丁二烯-苯乙烯塑的方型通道頂部和底部的表面比直線型通道更早冷卻。方形冷卻通道的頂部和底部的表面溫度在特定時(shí)間立即注射后最高記錄是52.1和53.36℃，30秒后溫度分別降低到42.47℃和43.07℃,而直線形冷卻通道頂部和底部最高溫度記錄分別是53.24℃和52.01℃,30秒后降到溫度分別為47.72℃和47.47℃。所以，采用方形通道溫度平均可降低4到5℃。用聚丙烯作為零件的材料時(shí)實(shí)驗(yàn)也發(fā)現(xiàn)有類似的結(jié)果。從圖8可看出使用方形冷卻通道時(shí), 溫度可能降低2 到3℃。實(shí)驗(yàn)測(cè)試出20個(gè)樣品是由丙烯腈-丁二烯-苯乙烯材料制成的，發(fā)現(xiàn)樣品都具有相同的數(shù)據(jù)。圖9記錄了丙烯腈-丁二烯-苯乙烯樣品試驗(yàn)和聚丙烯實(shí)驗(yàn)驗(yàn)證結(jié)果 圖- 5：（a）低碳鋼核心（左）（b）低碳鋼直線形和正方形冷卻通道模具型腔 圖6測(cè)試注塑實(shí)驗(yàn)裝置，左：迷你裝置，右： PC輸出溫度。 圖7 ABS溫度比較圖 圖- 8：聚丙烯溫度比較圖 圖- 9抽樣檢測(cè)，左：ABS塑料，右：聚丙烯塑料。 4.結(jié)論 注射成型過程轉(zhuǎn)換到冷卻過程是至關(guān)重要的一步,因?yàn)槔鋮s時(shí)間通常約占總周期的一半，從而直接影響到模具塑料產(chǎn)品的收縮和彎曲程度。因此,在模具設(shè)計(jì)當(dāng)中一個(gè)良好的冷卻通道系統(tǒng)是至關(guān)重要的,因其影響生產(chǎn)效率和產(chǎn)品質(zhì)量。MPI仿真結(jié)果和實(shí)驗(yàn)驗(yàn)證表明使用方形冷卻通道可減少35%的冷卻時(shí)間，總周期20%的時(shí)間可大大提高注射模零件的生產(chǎn)效率和生產(chǎn)質(zhì)量。 鳴謝 這些作者都要感謝來自沃森工業(yè)工程學(xué)院的Meredith女士和Phil Watson。他們得到了斯威本國(guó)立科技大學(xué)的電腦數(shù)控生產(chǎn)模具技術(shù)的支持。 參考文獻(xiàn) [1] D.V.Rosato, D.V.Rosato和M.G. Rosato，注塑成型手冊(cè)第三頁,波士頓,英文文獻(xiàn)(2003)。 [2] X. Xu, E. Sach 和S.Allen,注塑模具冷卻通道的適形設(shè)計(jì)，聚合物工程科學(xué)，4, 1, 1269-1272，(2001)。 [3] D.E. Dimla, M. Camilotto, and F. Miani:注射成型冷卻通道的工具的設(shè)計(jì)和優(yōu)化,J.變形。材料科學(xué)論壇,容量: 561-565,聚丙烯。1999-2002, (2007)。 [4]一個(gè)B和s . h . Masood M Saifullah、優(yōu)化設(shè)計(jì)和熱分析冷卻通道的注射模塑料零件模具,材料科學(xué)論壇,由561-565 1999 - 2002年,頁。(2007)。 [5 A B Saifullah, S. H. Masood和Igor Sbarski，塑料注射成型時(shí)使用新型冷卻通道優(yōu)化周期時(shí)間和改進(jìn)零件質(zhì)量。ANTEC@NPE 2009年,美國(guó)。 Proceedings of the World Congress on Engineering 2009 Vol I WCE 2009, July 1 - 3, 2009, London, U.K. New Cooling Channel Design for I njection Moulding A B M Saifullah, S.H. Masood and Igor Sbarski Abstract— Injection moulding is one of the most versatile and important operation for mass production of plastic parts. In this process, cooling system design is very important as it largely determines the cycle time. A good cooling system design can reduce cycle time and achieve dimensional stability of the part. This paper describes a new square sectioned conformal cooling channel system for injection moulding dies. Both simulation and experimental verification have been done with these new cooling channels system. Comparative analysis has been done for an industrial part, a plastic bowel, with conventional cooling channels using the Moldflow simulation software. Experimental verification has been done for a test plastic part with mini injection moulding machine. Comparative results are present ed based on temperature distribution on mould surface and cooling time or freezing time of the plast ic part. The results provide a uniform temperature distribution with reduced freezing time and hence reduction in cycle time for the plastic part. Index Terms—Conformal cooling channel, Cycle time Moldflow, Square shape. I. INTRODUCTION Injection moulding is a widely used manufacturing process in the production of plastic parts [1]. The basic principle of injection moulding is that a solid polymer is molten and injected into a cavity inside a mould which is then cooled and the part is ejected fro m the machine. Therefore the main phases in an injection moulding process involve filling, cooling and ejection. The cost-effectiveness of the process is mainly dependent on the time spent on the moulding cycle in which the cooling phase is the most significant step. Time spent on cooling cycle determines the rate at which parts are produced. Since, in most modern industries, time and costs are strongly linked, the longer is the time to produce parts the more are the costs. A reduction in the time spent on coo ling the part would drastically increase the productio n rate as well as reduce costs. So it is important to understand and optimize the heat transfer process within a typical moulding process. The rate of the heat exchange between the injected plastic and the mo uld is a decisive factor in the economical performance of an injection mould A B M Saifullah is a research doctoral student at Industrial Research Institute Swinburne (IRIS), Swinburne University of Technology, Melbourne, Australia (e-mail- msaifullah@swin.edu.au), also Member, IAENG. S. H. Masood is a Professor of Mechanical & Manufacturing Engineering at Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Melbourne, Australia. (Corresponding author, ph:+61-3-9214 8260, fax: +61-3-9214 5050, e-mail: smasood@swin.edu.au) Dr Igor Sbarski is a Senior Lecturer at Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Melbourne, Australia.(e-mail: isbarski@swin.edu.au ). 3 .Heat has to be taken away from the plastic material until a stable state has been reached, which permits demolding. The time needed to accomplish this is called cooling time or freezing time of the part. Proper design of cooling system is necessary for optimum heat transfer process between the melted plastic material and the mould. Traditionally, this has been achieved by creating several straight holes inside the mould core and cavity and then forcing a cooling fluid (i.e. water) to circulate and conduct the excess heat away from the molten plastic. The method s used for producing these holes rely on the conventional machining process such as straight drilling, which is incapable of producing complicated contour-like channels or anything vaguely in 3D space. An alternative method of coo ling system that co nforms or fits to the shape of the cavity and core of the mould can provide better heat transfer in injection moulding process, and hence can result in optimum cycle time. This alternative method uses contour-like channels of different cross-section, constructed as close as po ssible to the surface of the mould to increase the heat absorption away from the molten plastic. This ensures that the part is cooled uniformly as well as more efficiently. Now-a-days, with the advent of rapid p rototyping technology such as Direct Metal Deposition (DMD), Direct Metal Laser Sintering (DMLS) and many advanced computer aid ed engineering (CAE) software, more efficient co oling channels can be designed and manufactured in the mould with many complex layout and cross-sections[2,3,4]. This paper presents a square section conformal co oling channel (SSCCC) for injection moulding die. Simulation has been done for an industrial p lastic part, a circular plastic bowel for these SSCCC and compared with conventional straight cooling channels (CSCC) with Moldflow Plastic Inside (MPI) software. Comparative experimental verification has also been performed with SSCCC and CSCC die for a circular shape test part with mini injectio n moulding machine for two plastic materials. Result shows that SSCCC die gives better cooling time and temperature distribution than that of CSCC dies. II. DESIGN OF THE PART AND MOULDS A. Part design The part circular plastic bowl made of polyprop ylene (PP) thermoplastic, as shown in Fig 1(a) has been designed with Pro -Engineer CAD software. It was then exported to IGES (Initial Graphics Exchange Specification) file surface model to impo rt in MPI for analysis. Material volume of the plastic part is 177.90cm and its weight is 162.3 gm. Experimental test part as shown in Fig 1(b) has also been d esigned with Pro-Engineer software. Experimental ISBN: 978-988-17012-5-1 WCE 2009 Proceedings of the World Congress on Engineering 2009 Vol I WCE 2009, July 1 - 3, 2009, London, U.K. verification has b een done with two types of plastic materials, PP and ABS (Acrylonitrile Butadiene Styrene). Test part volume was 8.8 cm3, and part weight for ABS and PP were 8.68 gm and 8.13gm respectively. (a) (b) (a) (b) Fig-1 CAD model of (a) Circular plastic bowel, (b) Test part. B. Mould Design Mould design has been done using Pro/Moldesign module of the Pro /Engineer system. This mould is then manufactured with Computer Numerical Control (CNC) machine. The mould shown in Fig 2 has two parts, the core and the cavity. Square section conformal cooling channel (SSCCC) has been produced around the cavity by CNC machining of one half of the channel on cavity part and the other half on the core part. Both halves are then joined with screws and sealed with liquid gasket (Permatex) to avoid water leakage. Fig-2 Assembly CAD model of mould with core (top ) and two cavity parts. III. ANALYSIS AND RESULTS MPI simulation software has been used for part analysis [5]. Analysis sequence was flow-cool-warp. Polyprop ylene plastic material has been used for analysis. Comparative analysis has been done with conventional straight coo ling channel (CSCC) and SSCCC. The diameter of CSCC was 12 mm and the length of SSCCC section size was 12 mm (Fig 3). Fusion meshing with global edge length of 0.995 cm has been used . The numbers of mesh elements used were 12944 and 12291 for CSCC and SSCCC respectively. 3 Fig-3 Analysis setting in MPI (a) CSCC (b) SSCCC Both cases used cooling medium as normal water of 25°C. Reynolds number was 10000, melting temperature was 230 °C. Comparative analysis result from MPI as shown in Fig 4 shows that SSCCC shows better temperature distribution and (a) (b) Fig-4 Comparative freezing or cooling time (a) CSCC (b) SSCCC. less part freezing time than CSCC. In case of CSCC, most of the part cools in about 24 second except the top few areas, while on the other hand SSCCC diagram shows that it is less than 20 seconds. And also CSCC shows the time to freeze range to be 0.4 6-93.7sec and SSCCC shows this to be 0.3-87.15sec. So, using SSCCC, 5 second of cooling time has been reduced which is 3 5% reduction of cooling time. IV. EXPERIMENTAL VERIFICATION AND RESULTS Experimental verification has been done with a circular shap e plastic test part using the machined mould as shown in Fig 5. Part diameter was 40 mm and thickness was 7 mm. The mould dimension was 10x10x2.5 cm . Mould material was mild steel. Experiment has been done with a mini (a) (b) Fig-5 (a) Mild steel Core (left) and cavity with SSCCC (b) CSCC of mild steel. ISBN: 978-988-17012-5-1 WCE 2009 Proceedings of the World Congress on Engineering 2009 Vol I WCE 2009, July 1 - 3, 2009, London, U.K. injection moulding machine of TECHSOFT mini moulder (Fig 6). Two thermocouples TC08 K type of PICO technology have been used to measure temperature of top and bottom surface of the test part. Melting temperature was 250°C fo r both ABS and PP. Normal water has been used as a cooling medium, room temperature has been measured as 25 °C, so is cooling water. Cooling channel diameter was 5 mm for CSCC and SSCCC section size was 5 mm. With two thermocouples, surface temperature of the test part has been measured for every second. Fig-8 Comparative temperature plot for PP In experimental tests, twenty samp le test parts have been produced for ABS and PP material for experimental verification and in every case almost the same data has been found. Fig 9 shows the sample test parts in ABS and PP, which have been produced fo r experimental verification. Fig-6 Experimental setup for test injection moulding, left: mini moulder, right: temperature outp ut in PC. Fig 7 and Fig 8 show the comparative temperature distribution for top and bottom surface of the plastic parts for 30 second. Fig-9 Sample test part prod uced for experimental verification Left: ABS right: PP plastic. V. CONCLUSION The cooling process is one o f the most important sub processes in injection moulding because it normally accounts for approximately half of the total cycle time and affects directly the Fig-7 Comparative temperature plot for ABS From Fig 7 it is noted that for the ABS plastic, using SSCCC, the top face and bottom face of test part cooled earlier than that with CSCC. In case of SSCCC, maximum top and bottom surface temperature recorded at particular time immediately after injection were 53.36 °C and 52.1°C. After 30 second, this temperature reduced to 42.47 °C and 43.07 °C, whereas, for CSCC they were 53.24, 52.01 and 47.47, 47.72 °C. So in average, 4 to 5 °C reduction in temperature happens using the SSCCC. Similar results also have been found when using PP as the part material. From Fig 8, it can be shown that using SSCCC, about 2 to 3 °C reduction in temperature can be possible. shrinkage, bending and warp age of the moulded plastic product. Therefore, designing a go od cooling channel system in the mould is crucial since it influences the production rate and quality. The results of MPI simulation and experimental verification show that using square shape conformal cooling channels gives up to 35% reduction in cooling time and 20% of the total cycle time can b e obtained, thus greatly improving the production rate and the production quality of injection moulded parts. ACKNOWLEDGMENT These authors are grateful to Mrs. Meredith and Phil Watson of Faculty of Engineering and Industrial Science, Swinburne University of Technology for their technical support for die making with CNC machining. ISBN: 978-988-17012-5-1 WCE 2009 Proceedings of the World Congress on Engineering 2009 Vol I WCE 2009, July 1 - 3, 2009, London, U.K. REFERENCES [1 ] D.V. Rosato, D.V. Rosato and M.G. Rosato, Injection Moulding Handbook-3rd ed , Boston, Kluwer Academic Publishers, (2003). [2 ] X. Xu, E. Sach and S.Allen, The Design of Conformal Cooling Channels In Injection Moulding Tooling,Polymer Engineering and Science, 4, 1, pp 1269-1272, (2001). [3] D.E. Dimla, M. Camilotto, and F. Miani: Design and optimization of conformal cooling channels in injection moulding tools, J. of Mater. Processing Technology, 164-165, pp 1294-1300, (2005). [4] A B M Saifullah and S. H. Masood, Optimum cooling channels design and Thermal analysis of an Injection moulded plastic part mould, Materials Science Forum, Vols. 561-565, pp. 1999-2002, (2007). [5] A B Saifullah, S. H. Masood and Igor Sbarski, cycle time optimization and part quality improvement using novel cooling channels in plastic injection moulding. ANTEC@NPE 2009, USA. ISBN: 978-988-17012-5-1 WCE 2009