模具外文翻譯-開發(fā)注塑塑料零件變形分析的測試方法【中文4190字】【PDF+中文WORD】
模具外文翻譯-開發(fā)注塑塑料零件變形分析的測試方法【中文4190字】【PDF+中文WORD】,中文4190字,PDF+中文WORD,模具,外文,翻譯,開發(fā),注塑,塑料零件,變形,分析,測試,方法,中文,4190,PDF,WORD
【中文4190字】開發(fā)注塑塑料零件變形分析的測試方法作者:J.G. Iovacs*, B. Silclo出處:Department of Polymer Engineering, Budapest University of Technology and Economics, H-1111 Budapest, Mhegyetem rkp. 3, Hungary摘要:描述注塑塑料零件是彎曲的不是標(biāo)準(zhǔn)化的,而且由于彎曲的過程其本質(zhì)是很復(fù)雜的,所以這是很嚴(yán)重的問題。本文提出一種分析和測量注塑塑料零件變形的新方法。在彎曲方面特別介紹了一個特定的部分用一個特殊的模具設(shè)計(jì),用以描述不同的工藝參數(shù)和模具的影響元素設(shè)計(jì)。通過實(shí)驗(yàn)的使用證明了系統(tǒng)的適用性。通過調(diào)查模具溫度的影響,模具溫度的差異,保持壓力和玻璃纖維材料研究使用不同的模具澆口類型。此外,評估彎曲的新的軟件正在開發(fā)。根據(jù)結(jié)果,得出的結(jié)論是,沿著邊緣角的變形長度可以由曲線進(jìn)行描述。 2011愛思唯爾有限公司保留所有權(quán)利。關(guān)鍵詞:注塑模具 注塑變形 彎曲角效果1.介紹 注塑熱塑性塑料部件的質(zhì)量很大程度上取決于所使用的工藝參數(shù)和模具設(shè)計(jì)。注塑塑料零件的一個主要問題是彎曲引起的不均勻收縮。冷卻不均勻,收縮不均勻和取向嚴(yán)重影響了這種變形。幾個研究人員研究了彎曲的形成和特點(diǎn)而且使用各種方法,特別是多種類型的標(biāo)本幾何圖形。許多研究調(diào)查使用矩形板收縮標(biāo)本,并且這個幾何的應(yīng)用程序擴(kuò)展到翹曲測量。唐家璇等用變形的部分確定刻度盤介紹two-cavity,two-plate注塑模具生產(chǎn)丙烯腈丁二烯苯乙烯(ABS)板材彎曲測試,。作者得出結(jié)論,彎曲主要是受熔體溫度的影響, 其次是包裝時間和包裝壓力。熱分析是進(jìn)行檢查模具的熱殘余應(yīng)力的影響。相關(guān)調(diào)查表明彎曲增強(qiáng)熱塑性塑料圓盤和顯示不同的取向引起的各種變形,也就是說,他們觀察了杯和構(gòu)象馬鞍的構(gòu)造。Kikuchi 和 Koyam 還分析了磁盤標(biāo)本和盤子,他們引入了一個彎曲指數(shù)作為一種記錄注塑零件的特征。 鄭先生等人也承認(rèn)由于其簡單的幾何形狀,無法測量彎曲的標(biāo)本注塑零件,并提出應(yīng)該使用更復(fù)雜的形狀。他們繼續(xù)執(zhí)行測量肋板與注塑仿真模型, 但是他們只能想象肋的影響,而不是整個形變。 詹森不僅在盤子里研究了非晶態(tài)材料的彎曲還在l型標(biāo)本不同圓角半徑和尖角。平板產(chǎn)品的翹曲被定位在三個支持評估針和測量長度的垂直位移上作為協(xié)調(diào)長度的函數(shù)。實(shí)驗(yàn)表明, 模在使用非晶聚合物的溫度之間的差異下形變線性增加。結(jié)果還表明,在低壓力下塑料朝熱端的方向彎曲, 而在高壓力下彎向冷端。半徑較大的角落比半徑較小的標(biāo)本對模具溫度差異更敏感。比例角度偏轉(zhuǎn)的長度徑向部分是對結(jié)果的解釋。Akay 等人還分析了彎曲和溫度之間的關(guān)系差異的兩半模具。測量了變形的平板和l型標(biāo)本并且用有限元軟件和坐標(biāo)測試機(jī)進(jìn)行了計(jì)算。然后,分析了使用統(tǒng)一的冷卻和溫度兩個下模之間的區(qū)別。觀察到一個更高的模具腔端的溫度導(dǎo)致增加的角角落的部分。一些調(diào)查使用框幾何分析翹曲 (16、17)。Kabanemi et al。17 用箱形部分分析翹曲。提出了不同情況下顯示的在變形和殘余應(yīng)力下影響的幾何形狀的復(fù)雜性。得出結(jié)論,不對稱熱剖面是負(fù)責(zé)彎曲引起的彎矩。得出結(jié)論,不對稱熱剖面是負(fù)責(zé)彎曲引起的彎矩。Mlekusch18分析了翹曲與各種類型的專門設(shè)計(jì)的部分角落。對于short-fibre-reinforcement的影響進(jìn)行了研究,認(rèn)為是材料的各向異性。多層模型用來計(jì)算圓柱段的冷卻。模型預(yù)測與實(shí)驗(yàn)測量比較顯示,附加彎曲觀察short-fibre-reinforced材料可以歸因于材料的各向異性。里奇- et al。19使用一個有四個角不同的半徑的標(biāo)本。他們得出結(jié)論,造成彎曲有兩種現(xiàn)象: 第一個是不對稱冷卻,第二個是春天的遠(yuǎn)期效果。由于厚度方向的熱膨脹系數(shù)的增大,增強(qiáng)了春天的遠(yuǎn)期效應(yīng)生成纖維材料。變形轉(zhuǎn)角和最初的變形平面是杰出的。experimenu使用聚丙烯(PP),相同的模具溫度誘導(dǎo)兩個模具的顯著角變形為30 - 50。兩模之間的部分有40 0 c的不同引起約1.50的角度的變化。本研究的目的是不僅是創(chuàng)建標(biāo)本,而且是描述彎曲的一個復(fù)雜的方法。主要目標(biāo)是設(shè)計(jì)和創(chuàng)建一個特定的樣品和模具,它允許以不同的方式獲得變形measuremenu。2方法論和測量設(shè)備 描述彎曲的注塑零件的角落,設(shè)計(jì)了一個特殊的部分。主要目標(biāo)是衡量不同技術(shù)參數(shù)在彎曲模具的模具設(shè)計(jì)或材料屬性的影響。生產(chǎn)所謂的V-top標(biāo)準(zhǔn),一個特殊的模具設(shè)計(jì)和多變的變量插入(圖1),構(gòu)造的嵌件注塑滑進(jìn)可快速調(diào)換的框架,并且一個插線孔有兩個可變的澆到體系。模具的固定的側(cè)面僅僅包含了唯一的可變的型腔嵌件;改變這些嵌件允許將部分的壁厚變化,用這些方法,可以選為壁厚1mm或2mm。頂端的門鎖裝置完美的使兩個模具兩等分,保證厚度均勻的部分。圖1 插入移動和固定的模具3十1門在變形中,材料的方向和注射位置的定位有顯著的效果,因此,三個不同的閘口類型在之前的模型中被用作門插入(如圖2)。一個標(biāo)準(zhǔn)的閘口前面的邊緣,一個標(biāo)準(zhǔn)的門的邊緣,或者沿著整個邊緣的電影門。圖2門的設(shè)計(jì):a)標(biāo)準(zhǔn)門在前面的邊緣,b)標(biāo)準(zhǔn)門的中間,c)膜狀澆口沿著整個邊緣 V-top 本近900年一個角度,造成的變形技術(shù)或其他參數(shù)可以通過改變這幾個角度來量化。除了單向的窩洞填充外,雙向的填充可以實(shí)現(xiàn)可旋轉(zhuǎn)的插入的應(yīng)用(如圖3)。在角落,這些特點(diǎn)允許調(diào)查焊線【20 21】的影響。 圖3 插入可旋轉(zhuǎn)的V-top標(biāo)本 變形受冷卻的高度影響,在角落里是非常重要的。模具的核心的散熱速度必須比腔快,否則,內(nèi)部區(qū)域的角落凝固速度較慢,導(dǎo)致它自身被磨角。面對高要求的變形測試,高效的冷卻系統(tǒng)是必須的(如圖4)。對于最高的控制精確度,溫度傳感器將被安裝進(jìn)模具的核心和腔。不僅是溫度,而且壓力控制也很重要。由于這個原因,兩個壓力傳感器將會被安裝;一個距離閘門5mm,一個在年底前流路徑的5mm處。在這些傳感器的幫助下,轉(zhuǎn)換點(diǎn)會被精確的控制,這是基本穩(wěn)定和一致的重要性。 圖4 模具的冷卻系統(tǒng)V-top樣本的變形評估,特殊的圖像分析軟件被開發(fā)。軟件的掃描圖像分析的標(biāo)本和關(guān)閉角沿著邊緣的長度計(jì)算拐角點(diǎn)的步驟(如圖5)。 圖5計(jì)算關(guān)閉角理論的圖像3實(shí)驗(yàn) 在這項(xiàng)研究中,實(shí)驗(yàn)的進(jìn)行證明了測量技術(shù)的效率。整潔的聚丙烯與玻璃纖維和聚丙烯增強(qiáng)不同重量的內(nèi)容為(10、20、30 wt ),在一個廣泛的變形部分檢查全面評估的新方法。矩陣(北歐化工、HD120M0)和玻璃纖維混合在Brabender塑度計(jì)雙螺桿擠出機(jī),和一個Brabender制粒機(jī)是用于生產(chǎn)擠出物的顆粒。V-top標(biāo)本是注塑的Arburg全能球員3200 c 600 - 250注塑成型機(jī)。標(biāo)本被塑造的厚度為2毫米使用所有3門的類型。對玻璃纖維含量的影響,溫度移動一側(cè)的模具(30、50、70 0 c)和壓力的保持(100、300、500條)進(jìn)行分析。所有其他工藝參數(shù)保持不變。熔體溫度是230 0 c,固定的模具的溫度保持時間是5 s,注入率為50 15秒冷卻時間。切換end-of-cavity壓力傳感器達(dá)到25條。4. 結(jié)果與討論 所述空腔之間的區(qū)別被控制體重的測量,顯示出從不同的腔中的樣本的權(quán)重之間的相關(guān)系數(shù)為0.994。因此,可以得出結(jié)論,試件的重量是獨(dú)立的腔體,和變形在上模腔中產(chǎn)生的試樣的外邊緣進(jìn)行分析。 該實(shí)驗(yàn)的典型結(jié)果示于圖6,具有關(guān)閉角為相對邊緣長度的函數(shù)??梢钥闯觯摐y量是準(zhǔn)確的,標(biāo)準(zhǔn)偏差是比較小的在每個測量點(diǎn)。柵型的影響進(jìn)行了分析,其結(jié)果表明,熔體入口點(diǎn)和類型,因?yàn)樗鼈兇┻^材料(圖6)的定向性的影響,結(jié)果不能被忽略。圖6影響關(guān)閉位置角沿著邊緣的相對位置的函數(shù)(模具溫度:70 0 c,纖維內(nèi)容:20%,持有壓力:300條) 下面,一些成果將提交給驗(yàn)證了該方法的廣泛適用性。實(shí)驗(yàn)結(jié)果表明,在保持壓力對純PP(圖7)的變形有很大影響??拷战堑谋3謮毫τ休^小影響,而進(jìn)一步遠(yuǎn)離拐角的角度的增加而增加保持壓力。 圖7在5%和85%位置拐角角度作為一個功能的壓力使用簡潔的公關(guān) 保壓壓力(圖8)的纖維含量分別降低翹曲。然而,兩個半模之間的溫度差對翹曲的影響最大。當(dāng)用于較高的模具溫度對可動模具側(cè),試件的表面之間的閉合角減小為一個較大的變形的結(jié)果。正在分析變形為沿著邊緣的相對位置的函數(shù),它被觀察到,在截止角單調(diào)減少,與角度的依賴于移動模側(cè)的(圖9)的溫度的斜率。圖8持有關(guān)閉壓力角的影響作為相對位置的功能纖維內(nèi)容(模具沿邊緣:50%)圖9 動模側(cè)的溫度的影響在關(guān)閉角的函數(shù)沿邊緣的相對位置(持有壓力:100條)5、總結(jié) 在本論文中,介紹了一種新的測量方法,來分析注塑塑料零件。就是最新引進(jìn)的V-top樣本,允許調(diào)查不同變形工藝的參數(shù)和材料性能的影響。另外一種新的可變形的注塑模具設(shè)計(jì)和建造V-top標(biāo)本的生產(chǎn)。這個新方法是經(jīng)過測試的,并且經(jīng)過了實(shí)驗(yàn)的研究,門類型和位置的影響,材料的玻璃纖維含量,模具溫度不同,限檔壓力也會被研究。基于實(shí)驗(yàn)數(shù)據(jù),得出結(jié)論,翹曲強(qiáng)烈依賴于纖維內(nèi)容和模具溫度,但是當(dāng)使用聚丙烯和玻璃纖維時,這幾乎不依賴于限檔壓力。這些實(shí)驗(yàn)強(qiáng)有力的支持了新的翹曲分析技術(shù),相對于以前的翹曲測量方法有一個很大的優(yōu)勢。確認(rèn) 本文得到了Janos Bolyai匈牙利科學(xué)院的研究獎學(xué)金。作者要感謝Arburg匈牙利有限公司注塑成型機(jī)和東范教授博士從北歐化工聚烯烴GmbH來的材料。 這項(xiàng)工作被連接到的科學(xué)項(xiàng)目“發(fā)展的素質(zhì)和協(xié)調(diào)R + D +我在BME策略和功能模型”項(xiàng)目。這個項(xiàng)目是支持的新匈牙利發(fā)展計(jì)劃(項(xiàng)目ID:TAMOP-4.2.1 / B-09/1 / kmr - 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Eng.Sci. 36 (10) (1996) 1309.14 H. Kikuchi, K. Koyama, The relation between thickness and warpage in a disk injection moulded from fibre reinforced PA66, Polym. Eng.Sci. 36 (10) (1996) 1317.15 R. Zheng, P. Kennedy, IV. Phan-Thien, X.J. Fan, Thermoviscoelastic simulation of thermally and pressure-induced stresses in injection moulding for the prediction of shrinkage and warpage for fibre reinforced thermoplastics, J. IVon-Newton Fluid 84 (2-3) (1999) 159.16 K. Prashantha, J. Soulestin, M.F. Lacrampe, E. Lafranche, P. Krawczak G. Dupin, M. Claes, Taguchi analysis of shrinkage and warpage of injection-moulded polypropylene/multiwall carbon nanotubes nanocomposites, Express Polym. Lett. 3 (10) (2009) 630.17 K.K. Kabanemi, H. Vaillancourt, H. Wang, G. Salloum, Residual stresses, shrinkage, and warpage of complex injection moulded products: Numerical simulation and experimental validation Polym. Eng. Sci. 38 (1) (1998) 21.18 B. Mlekusch, The warpage of corners in the injection moulding of short-fibre-reinforced thermoplastics, Compos Sci. Technol. 1999 (12)(1923)59.19 A. Ammar, V. Leo, G. Regnier, Corner deformation of injected thermoplastic parts, Int. J. Form Proc. 6 (1) (2003) 53.20 J.G.Kovacs, B. Siklb, Experimental validation of simulated weld line formation in injection moulded parts, Polym. Test. 29 (7) (2010) 910.21 B. Solymossy, J.G. Kovacs, The examination of weld line properties in injection moulded PP composites, Mater. Sci. Forum 589 (2008) 263.翻譯時遇到的生單詞Characterisation 特性描述;性格化Standardised 使符合標(biāo)準(zhǔn);使標(biāo)準(zhǔn)化;使統(tǒng)一 Extremely 非常,極其;極端地Warpage 翹曲,彎曲Additionally 此外;又,加之Keyword 關(guān)鍵字Deformation 變形Determined v. 決定;斷定(determine的過去分詞)adj. 決定了的;堅(jiān)決的influencedv. 影響(influence的過去分詞)adj. 受影響的Additional adj. 附加的,額外的guaranteen. 保證;擔(dān)保;保證人;保證書;抵押品vt. 保證;擔(dān)保significantn. 象征;有意義的事物adj. 重大的;有效的;有意義的;值得注意的;意味深長unidirectional adj. 單向的;單向性的Switchover n. 轉(zhuǎn)換;替換Experiments n. 試驗(yàn) 實(shí)驗(yàn)(experiment的復(fù)數(shù))Test MethodTest method development for deformation analysis of injection mouldedplastic partsJ.G.Kovcs*,B.SiklDepartment of Polymer Engineering,Budapest University of Technology and Economics,H-1111 Budapest,Muegyetem rkp.3,Hungarya r t i c l e i n f oArticle history:Received 9 March 2011Accepted 19 April 2011Keywords:WarpageCorner effectInjection mouldingDeformationInjection moulda b s t r a c tThe characterisation of warpage of injection moulded plastic parts is not standardised andis extremely problematic due to the complex nature of the warping process.This paperpresents a novel method for the analysis and measurement of the deformation of injectionmoulded plastic parts.A specific part with a special mould design was introduced for thecharacterisation of the effect of different technological parameters and different mouldelement design on warpage.The applicability of the system was demonstrated via itsexperimental use.The effects of mould temperature,mould temperature difference,holding pressure and the glass fibre content of the material were investigated usingdifferent gate types in the mould.Additionally,new software was developed to evaluatewarpage.Based on the results,it was concluded that the deformation of the corner alongthe edge length can be described by a curve.?2011 Elsevier Ltd.All rights reserved.1.IntroductionThe quality of injection moulded thermoplastic parts islargely determined by the process parameters and themould design used.One of the main problems with injec-tionmouldedplasticpartsiswarpagecausedbynon-uniformshrinkage.Thisdeformationisstronglyinfluenced by non-uniform cooling,differential shrinkageand orientation effects 1.Several researchers have investigated the formation andcharacteristics of warpage using various methods,partic-ularly multiple types of specimen geometries.Many studieshave investigated shrinkage using rectangular plate speci-mens 2,3,and the application of this geometry wasextended to warpage measurements 49.Tang et al.10,11 introduced a two-cavity,two-plateinjection mould producing acrylonitrile butadiene styrene(ABS)plates for warpage testing,with deformation of theparts being determined with a dial gauge.The authorsconcluded that warpage was mostly influenced by melttemperature,followed by packing time and packing pres-sure.Thermal analysis was performed to check the effect ofany thermal residual stress in the mould.Fahy 12 investigated the warpage of reinforced ther-moplastics on a circular disk and showed that differentorientation caused various deformations;namely,theyobserved cup-and saddle-shaped conformations.Kikuchiand Koyama 13,14 also analysed disk specimens andplates,and they introduced a warpage index as a means ofrecording the characteristics of injection moulded parts.Zheng et al.15 acknowledged that plate-like speci-mens were incapable of measuring warpage of injectionmoulded parts because of their simple geometry,andproposed that a more complex shape should be used.Theycontinued to perform measurements with the injectionmoulding simulation on a ribbed plate model,but theywere only able to visualise the effect of the rib and not theentire deformation 15.Jansen 8 studied the warpage of amorphous materialsnot only on plates but also on L-shaped specimens withdifferent corner radii and sharp corners.The warpage of flatplate products was assessed by positioning the plate on*Corresponding author.Tel.:36 14631440.E-mail addresses:kovacspt.bme.hu(J.G.Kovcs),siklopt.bme.hu(B.Sikl).Contents lists available at ScienceDirectPolymer Testingjournal homepage: front matter?2011 Elsevier Ltd.All rights reserved.doi:10.1016/j.polymertesting.2011.04.011Polymer Testing 30(2011)543547threesupportingpinsandmeasuringtheverticaldisplacement as a function of the length coordinate.Theexperiments showed that deformation linearly increasedwith the difference between the temperatures of the mouldhalves when using amorphous polymers.The results alsoshowed that at low holding pressure the plates curvedtowards the hot side,whereas at high holding pressure theplates curved towards the cold side.The corners with largerradiiweremoresensitivetomould temperaturedifferencesthan were specimens with smaller radii.The result wasexplained by the proportionality of the angle deflection tothe length of the radial section.Akay et al.9 also analysed the relationship betweenwarpage and the temperature difference of the two halvesof the mould.The deformation of both the flat plate andthe L-shaped specimens was measured and calculatedwith finite element software and a coordinate-measuringmachine.Then,it was analysed using uniform cooling andalso with temperature difference between the two mouldhalves.It was observed that a higher mould temperature onthe cavity side resulted in increase of the angle in thecorner of the part.Some investigations used box geometry for warpageanalysis 16,17.Kabanemi et al.17 analysed warpage onbox-like parts.Different cases were presented to show theinfluence of the geometrical complexity of the shape on thedeformations and residual stresses.It was concluded thatthe asymmetrical thermal profile was responsible for thebending moment that caused warpage.Mlekusch 18 analysed the warpage on a specificallydesigned part with various types of corners.The effect ofshort-fibre-reinforcement was studied and attributed tothe anisotropy of the material.A multi-layer model wasused to calculate the cooling of a cylindrical segment.Themodel predictions were compared with experimentalmeasurementsshowingthattheadditionalwarpageobserved for short-fibre-reinforced materials could beattributed to the anisotropy of the material.Ammar et al.19 used a specimen with four cornerswith different radii.They concluded that two phenomenacaused warpage:the first was asymmetrical cooling andthe second was the spring forward effect.The springforward effect was generated in fibre-reinforced materialsdue to the higher thermal expansion coefficient in thethickness direction.The deformation around the cornerand the deformation of the initially flat surfaces weredistinguished.Using polypropylene(PP)in their experi-ments,equal mould temperatures in both mould halvesinduced a significant angle deformation of 3?and 5?.A difference of 40?C between the two mould halves causedan angle variation of about 1.5?.The aim of this research was to create not only a spec-imen but also a complex method for warpage character-isation.The main goal was to design and create a specificsample and mould,which allows deformation measure-ments to be obtained in different manners.2.Methodology and measuring equipmentTo characterise the warpage at the corners of injectionmoulded parts,a special part was designed.The main goalwas to measure the effect of varying technological param-eters,mould design or material properties on warpage.To produce the so called V-top specimens,a specialmould was designed with changeable and variable inserts(Fig.1.).The constructed insert mould slides into a quick-change frame and has two cavities with a variable runnerFig.1.The moving and stationary sides of the mould with the 3 1 gate inserts.Fig.2.Gate designs:a)standard gate at the front of the edge,b)standardgate at the middle of the edge and c)film gate along the whole edge.J.G.Kovcs,B.Sikl/Polymer Testing 30(2011)543547544system.The stationary side of the mould contains only thechangeable cavity inserts;changing these inserts allowsthe parts wall thickness to be varied.In this way,the wallthickness can be chosen as either 1 mm or 2 mm.Top locksguarantee the perfect closing of the two mould halvesassuring a uniform part thickness.The orientation of the material and the positioning ofthe injection location have significant effects on thedeformation.Therefore,three different gate types can beused by changing the gate inserts in the mould(Fig.2.):a standard gate at the front of the edge,a standard gate atthe middle of the edge or a film gate along the whole edge.The sides of the V-top specimen close an angle of 90?,and the deformation caused by the technological or otherparameters can be quantified by changing this angle.Inaddition to unidirectional cavity filling,bidirectional fillingcan be achieved with the application of rotatable inserts(Fig.3.).This feature allows investigation of the influence ofthe weld lines 20,21 at the corners.Warpage is highly influenced by cooling and is verysignificant at corners.The coreof the mould has todissipateheat faster than the cavity;otherwise the internal area ofthe parts corner solidifies slower and causes a sharpeningof the corner itself.To meet the high requirements ofwarpage tests,an efficient cooling system is required(Fig.4.).For the highest control precision,temperaturesensors were installed into both the core and the cavity ofthe mould.Not only the temperature but also the pressurecontrol is important.For this reason,two pressure sensorswere mounted;one at a distance of 5 mm from the gate(PGS;post-gate-sensor)and one at a distance of 5 mmbefore the end of the flow path(EOC;end-of-cavity sensor).With the help of these sensors,the switchover point can becontrolled precisely,which is of fundamental importancefor a stable and consistent cycle.To evaluate the warpage of the V-top specimen,specialimage analysis software was developed.The softwareanalysed scanned images of the side of the specimens andcalculated the closing angle along the edge length from thecorner point(Fig.5.)in 5%steps.3.ExperimentalIn this study,experiments were carried out to prove theefficiency of the novel measuring technique.Neat poly-propylene and polypropylene reinforced with glass fibre ofdifferent weight contents(10,20,30 wt%)were examinedto comprehensively evaluate the new method in a widerange of deformed parts.The matrix(Borealis,HD120MO)and the glass fibreswere mixed on a Brabender Plasticordertwin-screw extruder,and a Brabender pelletizer was usedto produce pellets from the extrudate.From these mate-rials,V-top specimens were injection moulded on anArburg Allrounder 320?C 600250 injection mouldingmachine.The specimens were moulded with a thickness of2 mm using all 3 gate types.The effects of glass fibrecontent,temperature of the moving side of the mould(30,50,70?C)and holding pressure(100,300,500 bar)wereanalysed.All other technological parameters were keptFig.3.V-top specimen with rotatable inserts.Fig.4.The cooling system of the mould.Fig.5.Theoretical image for the closing angle calculation.Fig.6.The influence of injection location on the closing angle as a functionof the relative position along the edge(mould temperature:70?C,fibrecontent:20%,holding pressure:300 bar).J.G.Kovcs,B.Sikl/Polymer Testing 30(2011)543547545constant.The melt temperature was 230?C,the tempera-ture of the stationary side of the mould was 50?C,theholding time was 5 s,the injection rate was 50 cm3/s andthe cooling time was 15 s.The switchover took place whenthe end-of-cavity pressure sensor reached 25 bar.4.Results and discussionThe difference between the cavities was controlled withweightmeasurements,showingthatthecorrelationbetween the weights of the samples from the differentcavities was 0.994.Therefore,it was concluded that spec-imen weight is independent of the cavity,and deformationwas analysed on the outer edge of the specimens producedin the upper cavity.A typical result of the experiments is shown in Fig.6,with the closing angle as a function of the relative edgelength.It can be seen that the measurement is accurate andthestandarddeviationisrelativelysmallateachmeasurement point.The influence of gate type was ana-lysed,and it was shown that the melt entrance point andtype cannot be neglected because they influenced theresults through the orientation of the material(Fig.6).Below,some results will be presented to demonstratethe wide applicability of the method.The experimentalresults showed that the holding pressure had a consider-able effect on the deformation of neat PP(Fig.7.).Close tothe corner the holdingpressurehad a minoreffect,whereasfurther away from the corner the angle increased withincrease in holding pressure.Fibre content decreased warpage independently ofholding pressure(Fig.8.).However,the temperaturedifference between the two mould halves had the biggesteffect on warpage.When higher mould temperatures onthe movable mould side were used,the closing anglebetween the faces of the specimen was decreased asa result of a larger deformation.Analysing the deformationas a function of relative position along the edge,it wasobserved that the closing angle decreased monotonically,with the slope of the angle depending on the temperatureof the moving mould side(Fig.9.).5.ConclusionsIn this paper,a new measurement method was intro-duced for the deformation analysis of injection mouldedplastic parts.The newly introduced V-top specimen allowsinvestigation of the effects of different technologicalparameters and material properties on its deformation.Moreover a novel transformable injection mould wasdesigned and built for the V-top specimens production.The new method was tested and analysed with experi-mental research,in which the effects of gate type andlocation,glassfibrecontentofthematerial,mouldtemperature difference and holding pressure were inves-tigated.Based on the experimental data,it was concludedthat warpage strongly depended on the fibre content andon mould temperatures,but that it was nearly independentof the holding pressure when using PP with glass fibre.These experiments strongly support the new warpageanalysis technique in having a significant advantage overpreviously used warpage measuring methods.AcknowledgementsThis paper was supported by the Jnos Blyai ResearchScholarship of the Hungarian Academy of Sciences.Theauthors would like to thank Arburg Hungaria Ltd.for theinjection moulding machine and Dr.Tung Pham from Bor-ealis Polyolefine GmbH for the material.This work is connected to the scientific program ofthe Development of quality-oriented and harmonizedRDIstrategyandfunctionalmodelatBMEproject.ThisprojectissupportedbytheNewHungaryDevelopmentPlan(Project ID:TMOP-4.2.1/B-09/1/KMR-2010-0002).Fig.7.Corner angle as a function of holding pressure at 5%and 85%positionusing neat PP.Fig.8.The influence of the holding pressure on the closing angle asa function of the fibre content(mould temperature:50?C,relative positionalong the edge:50%).Fig.9.The 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