滾輪注塑模具設計（全套含說明書和CAD圖紙）

滾輪注塑模具設計（全套含說明書和CAD圖紙）,滾輪,注塑,模具設計,全套,說明書,仿單,以及,cad,圖紙 Journal of Materials Processing Technology 187188 (2007) 690693Adaptive system for electrically driven thermoregulation of moulds for injection moulding B. Nardin a, , B. Zagar a, , A. Glojek a , D. Kri aj bzaTECOS, Tool and Die Development Centre of Slovenia, Kidri eva Cesta 25, 3000 Celje, Sloveniac b Faculty of Electrical Engineering, Ljubljana, SloveniaAbstract One of the basic problems in the development and production process of moulds for injection moulding is the control of temperature con-ditions in the mould. Precise study of thermodynamic processes in moulds showed, that heat exchange can be manipulated by thermoelectricalmeans. Such system upgrades conventional cooling systems within the mould or can be a stand alone application for heat manipulation withinit. In the paper, the authors will present results of the research project, which was carried out in three phases and its results are patented in A6862006patent. The testing stage, the prototype stage and the industrialization phase will be presented. The main results of the project were total and rapidon-line thermoregulation of the mould over the cycle time and overall inuence on quality of plastic product with emphasis on deformationcontrol. Presented application can present a milestone in the eld of mould temperature and product quality control during the injection moulding process. 2006 Elsevier B.V. All rights reserved.Keywords: Injection moulding; Mould cooling; Thermoelectric modules; FEM simulations1. Introduction, denition of problem Development of technology of cooling moulds via thermo-electrical (TEM) means derives out of the industrial praxis andproblems, i.e. at design, tool making and exploitation of tools.Current cooling technologies have technological limitations.Their limitations can be located and predicted in advance withnite element analyses (FEA) simulation packages but not com-pletely avoided. Results of a diverse state of the art analysesrevealed that all existing cooling systems do not provide con-trollable heat transfer capabilities adequate to t into demand-ing technological windows of current polymer processingtechnologies. Polymer processing is nowadays limited (in term of short-ening the production cycle time and within that reducing costs)only with heat capacity manipulation capabilities. Other produc-tion optimization capabilities are already driven to mechanicaland polymer processing limitations 3.1.1. Thermal processes in injection moulding plasticprocessing Plastic processing is based on heat transfer between plasticmaterial and mould cavity. Within calculation of heat transferone should consider two major facts: rst is all used energywhich is based on rst law of thermodynamicslaw of energyconservation 1, second is velocity of heat transfer. Basic taskat heat transfer analyses is temperature calculation over timeand its distribution inside studied system. That last depends onvelocity of heat transfer between the system and surroundingsand velocity of heat transfer inside the system. Heat transfer canbe based as heat conduction, convection and radiation 1.1.2. Cooling time Complete injection moulding process cycle comprises ofmould closing phase, injection of melt into cavity, packing pres-sure phase for compensating shrinkage effect, cooling phase,mould opening phase and part ejection phase. In most cases, thelongest time of all phases described above is cooling time. Cooling time in injection moulding process is dened astime needed to cool down the plastic part down to ejectiontemperature 1.Corresponding authors. Tel.: +386 3 490920; fax: +386 3 4264612.E-mail address: Blaz.Nardintecos.si (B. Nardin).0924-0136/$ see front matter 2006 Elsevier B.V. All rights reserved.doi:10.1016/j.jmatprotec.2006.11.052B. Nardin et al. / Journal of Materials Processing Technology 187188 (2007) 690693691Fig. 1. Mould temperature variation across one cycle 2.Fig. 2. TEM block diagram. The main aim of a cooling process is to lower additionalcooling time which is theoretically needless; in praxis, it extendsfrom 45 up to 67% of the whole cycle time 1,4. From literature and experiments 1,4, it can be seen, that themould temperature has enormous inuence on the ejection timeand therefore the cooling time (costs). Injection moulding process is a cyclic process where mouldtemperature varies as shown in Fig. 1 where temperature variesfrom average value through whole cycle time.2. Cooling technology for plastic injection moulds As it was already described, there are already several differ-ent technologies, enabling the users to cool the moulds 5. Themost conventional is the method with the drilling technology,i.e. producing holes in the mould. Through these holes (coolinglines), the cooling media is owing, removing the generated andaccumulated heat from the mould 1,2. It is also very convenientto build in different materials, with different thermal conductiv-ity with the aim to enhance control over temperature conditionsin the mould. Such approaches are so called passive approachestowards the mould temperature control. The challenging task is to make an active system, which canalter the thermal conditions, regarding to the desired aspects,like product quality or cycles time. One of such approaches isintegrating thermal electrical modules (TEM), which can alterthe thermal conditions in the mould, regarding the desired prop-erties. With such approach, the one can control the heat transferwith the time and space variable, what means, that the temper-ature can be regulated throughout the injection moulding cycle,independent of the position in the mould. The heat control isdone by the control unit, where the input variables are receivedfrom the manual input or the input from the injection mouldingsimulation. With the output values, the control unit monitors theTEM module behaviour.2.1. Thermoelectric modules (TEM) For the needs of the thermal manipulation, the TEM modulewas integrated into mould. Interaction between the heat and elec-trical variables for heat exchange is based on the Peltier effect.The phenomenon of Peltier effect is well known, but it was untilnow never used in the injection moulding applications. TEMmodule (see Fig. 2) is a device composed of properly arrangedpairs of P and N type semiconductors that are positioned betweentwo ceramic plates forming the hot and the cold thermoelectriccooler sites. Power of a heat transfer can be easily controlledthrough the magnitude and the polarity of the supplied electriccurrent.2.2. Application for mould cooling The main idea of the application is inserting TEM moduleinto walls of the mould cavity serving as a primary heat transferunit. Such basic assembly can be seen in Fig. 3. Secondary heattransfer is realized via conventional uid cooling system thatallows heat ows in and out from mould cavity thermodynamicsystem. Device presented in Fig. 3 comprises of thermoelectricmodules (A) that enable primarily heat transfer from or to tem-perature controllable surface of mould cavity (B). Secondaryheat transfer is enabled via cooling channels (C) that deliverconstant temperature conditions inside the mould. Thermoelec-tric modules (A) operate as heat pump and as such manipulatewith heat derived to or from the mould by uid cooling sys-tem (C). System for secondary heat manipulation with coolingchannels work as heat exchanger. To reduce heat capacity ofcontrollable area thermal insulation (D) is installed between themould cavity (F) and the mould structure plates (E).Fig. 3. Structure of TEM cooling assembly.692B. Nardin et al. / Journal of Materials Processing Technology 187188 (2007) 690693Fig. 4. Structure for temperature detection and regulation. The whole application consists of TEM modules, a temper-ature sensor and an electronic unit that controls the completesystem. The system is described in Fig. 4 and comprises of aninput unit (input interface) and a supply unit (unit for electronicand power electronic supplyH bridge unit). The input and supply units with the temperature sensor loopinformation are attached to a control unit that acts as an exe-cution unit trying to impose predened temperate/time/positionrelations. Using the Peltier effect, the unit can be used for heatingor cooling purposes. The secondary heat removal is realized via uid coolingmedia seen as heat exchanger in Fig. 4. That unit is based oncurrent cooling technologies and serves as a sink or a sourceof a heat. This enables complete control of processes in termsof temperature, time and position through the whole cycle.Furthermore, it allows various temperature/time/position pro-les within the cycle also for starting and ending procedures.Described technology can be used for various industrial andresearch purposes where precise temperature/time/position con-trol is required. The presented systems in Figs. 3 and 4 were analysed from thetheoretical, as well as the practical point of view. The theoreticalaspect was analysed by the FEM simulations, while the practicalone by the development and the implementation of the prototypeinto real application testing.3. FEM analysis of mould cooling Current development of designing moulds for injectionmoulding comprises of several phases 3. Among them is alsodesign and optimization of a cooling system. This is nowa-days performed by simulations using customized FEM packages(Moldow 4) that can predict cooling system capabilities andespecially its inuence on plastic. With such simulations, moulddesigners gather information on product rheology and deforma-tion due to shrinkage as ell as production time cycle information. This thermal information is usually accurate but can still beunreliable in cases of insufcient rheological material informa-tion. For the high quality input for the thermal regulation ofTEM, it is needed to get a picture about the temperature distri-bution during the cycle time and throughout the mould surfaceand throughout the mould thickness. Therefore, different processsimulations are needed.Fig. 5. Cross-section of a prototype in FEM environment.3.1. Physical model, FEM analysis Implementation of FEM analyses into development projectwas done due to authors long experiences with such packages4 and possibility to perform different test in the virtual envi-ronment. Whole prototype cooling system was designed in FEMenvironment (see Fig. 5) through which temperature distributionin each part of prototype cooling system and contacts betweenthem were explored. For simulating physical properties inside adeveloped prototype, a simulation model was constructed usingCOMSOL Multiphysics software. Result was a FEM modelidentical to real prototype (see Fig. 7) through which it waspossible to compare and evaluate results. FEM model was explored in term of heat transfer physicstaking into account two heat sources: a water exchanger withuid physics and a thermoelectric module with heat transferphysics (only conduction and convection was analysed, radiationwas ignored due to low relative temperature and therefore lowimpact on temperature). Boundary conditions for FEM analyses were set with thegoal to achieve identical working conditions as in real test-ing. Surrounding air and the water exchanger were set at stabletemperature of 20 C.Fig. 6. Temperature distribution according to FEM analysis.B. Nardin et al. / Journal of Materials Processing Technology 187188 (2007) 690693693Fig. 7. Prototype in real environment. Results of the FEM analysis can be seen in Fig. 6, i.e. temper-ature distribution through the simulation area shown in Fig. 5.Fig. 6 represents steady state analysis which was very accuratein comparison to prototype tests. In order to simulate the timeresponse also the transient simulation was performed, showingvery positive results for future work. It was possible to achieve atemperature difference of 200 C in a short period of time (5 s),what could cause several problems in the TEM structure. Thoseproblems were solved by several solutions, such as adequatemounting, choosing appropriate TEM material and applyingintelligent electronic regulation.3.2. Laboratory testing As it was already described, the prototype was produced andtested (see Fig. 7). The results are showing, that the set assump-tions were conrmed. With the TEM module it is possible tocontrol the temperature distribution on different parts of themould throughout the cycle time. With the laboratory tests, itwas proven, that the heat manipulation can be practically regu-lated with TEM modules. The test were made in the laboratory,simulating the real industrial environment, with the injectionmoulding machine Krauss Maffei KM 60 C, temperature sen-sors, infrared cameras and the prototype TEM modules. Thetemperature response in 1.8 s varied form +5 up to 80 C, whatrepresents a wide area for the heat control within the injectionmoulding cycle.4. Conclusions Use of thermoelectric module with its straightforward con-nection between the input and output relations represents amilestone in cooling applications. Its introduction into mouldsfor injection moulding with its problematic cooling constructionand problematic processing of precise and high quality plasticparts represents high expectations. The authors were assuming that the use of the Peltier effectcan be used for the temperature control in moulds for injectionmoulding. With the approach based on the simulation work andthe real production of laboratory equipment proved, the assump-tions were conrmed. Simulation results showed a wide area ofpossible application of TEM module in the injection mouldingprocess. With mentioned functionality of a temperature prole acrosscycle time, injection moulding process can be fully controlled.Industrial problems, such as uniform cooling of problematicA class surfaces and its consequence of plastic part appear-ance can be solved. Problems of lling thin long walls can besolved with overheating some surfaces at injection time. Further-more, with such application control over rheological propertiesof plastic materials can be gained. With the proper thermalregulation of TEM it was possible even to control the meltow in the mould, during the lling stage of the mould cav-ity. This is done with the appropriate temperature distributionof the mould (higher temperature on the thin walled parts of theproduct). With the application of TEM module, it is possible to signif-icantly reduce the cycle time in the injection moulding process.The limits of possible time reduction lies in the frame of 1025%of additional cooling time, describe in Section 1.2. With the application of TEM module it is possible to activelycontrol the warping of the product and to regulate the amountof product warpage in the way to achieve required product tol-erances. The presented TEM module cooling application for injectionmoulding process is a matter of priority note for the patent, heldand owned by TECOS.References c1 I. Cati , Izmjena topline u kalupima za injekcijsko preanje plastomera,s Drutvo plasti ara i gumaraca, Zagreb, 1985.sc c2 I. Cati , F. Johannaber, Injekcijsko preanje polimera i ostalih materiala,s Drutvo za plastiku i gumu, Biblioteka polimerstvo, Zagreb, 2004.s3 B. Nardin, K. Kuzman, Z. Kampu, Injection moulding simulation resultss as an input to the injection moulding process, in: AFDM 2002: The Sec- ond International Conference on Advanced Forming and Die Manufacturing Technology, Pusan, Korea, 2002.4 TECOS, Slovenian Tool and Die Development Centre, Moldow Simulation Projects 19962006.5 S.C. Chen, et al., Rapid mold surface heating/cooling using electromag- netic induction technology: ANTEC 2004, Conference CD-ROM, Chicago, Illinois, 1620 May, 2004.