【正文】
—注塑過程——塑件后處理。塑料成型的原理與鑄造成型的過程非常相似,但由于樹脂的熔融粘度極高,僅僅是把其熔融并使之自然地流入模具中固化,是不可能制成完好的制品。冷卻固化后開啟模具取出塑件。注塑成型的過程多是將經(jīng)過干燥處理后的塑料顆粒置于注塑機(jī)料筒中,由螺旋桿或柱塞將其推入到加熱的料筒中,塑料顆粒在料筒中加熱到一定的成型溫度成為熔融狀態(tài),待模具合模結(jié)束以后,啟動注塑機(jī)活塞推動料筒的螺桿以一定的注射力推擠塑料熔體通過澆注系統(tǒng),注入到閉合的模具型腔。這些成型方法都有各自的特定及適應(yīng)范圍。要求塑件精度高時,模具溫度可控制在50~60℃,要求塑件光澤和耐熱時,應(yīng)控制在60~80℃。熔融溫度低,熔融溫度范圍寬。ABS升溫時粘度增高,成型壓力較高,塑料上的脫模斜度宜稍大;還易產(chǎn)生熔接痕,模具設(shè)計(jì)時注意盡量減小澆注系統(tǒng)對料流的阻力;粘度強(qiáng)烈依賴于剪切速率,所以模具設(shè)計(jì)中大都采用點(diǎn)澆口形式。ABS顆粒表面極易吸濕使表面出現(xiàn)斑痕、云紋等,成型前必須進(jìn)行干燥處理。還可用來制作水表外殼、紡織器材、電器零件、文教體育用品、玩具、電子琴及收錄機(jī)殼體、食品包裝容器、農(nóng)藥噴霧器及家具等。由于以上優(yōu)點(diǎn):ABS在機(jī)械工業(yè)上用來制造齒輪、泵葉輪、軸承、把手、管道、電機(jī)外殼、儀表殼、儀表盤、水箱外殼、蓄電池槽、冷藏庫和冰箱村里等。耐候性差,特別是耐紫外線性能不好。經(jīng)過調(diào)色可配成任何顏色,色澤鮮明,可電鍍。ABS在較寬的范圍內(nèi),有極好的抗沖擊強(qiáng)度,良好的機(jī)械強(qiáng)度(硬、韌、鋼)和一定的耐磨性、耐寒性、耐油性、耐水性。根據(jù)應(yīng)用不同可分為超高沖擊型、高沖擊型、中沖擊型、低沖擊型和耐熱型等。從改進(jìn)PS性能角度看,ABS顯著提高了抗沖擊強(qiáng)度和表面硬度,其熱變形溫度比PS、PVC、PA(約高10℃)等都高,具有良好的尺寸穩(wěn)定性,化學(xué)穩(wěn)定性和電氣性能。三組分的各自特性,使ABS具有良好的綜合力學(xué)性能。工程塑料具有易加工、易制造(成型)的特點(diǎn),即使制品的幾何形狀相當(dāng)復(fù)雜,只要能從模具中脫模,都比較容易制作,因而其效率遠(yuǎn)勝于金屬加工,特別是注塑成型制品,經(jīng)過一道工序,即可制造出很復(fù)雜的成品;可根據(jù)需要隨意著色,或制成透明制品,利用塑料可制作五光十色、透明美麗的制品,提高商品的價(jià)值,并給人一種明快的感覺;也可制作為輕質(zhì)高強(qiáng)度的產(chǎn)品,與金屬、陶瓷制品相比,質(zhì)量輕、機(jī)械性能好;特別是填充玻璃纖維后,更可提高其強(qiáng)度;另外,由于塑料質(zhì)量輕,可節(jié)約能源,在未來塑料制品將輕量化。,比水略重,比鋁輕1/2,比鋼輕3/4,約大多數(shù)有色金屬體積質(zhì)量的1/51/8。 to use UG software and threedimensional molding of design to make the assembly drawings。 to analyze the increased taper and other parameters of plastic parts, threedimensional shape and the mass calculation to select injection molding machine。計(jì)算成型零件的尺寸和公差,計(jì)算側(cè)抽芯機(jī)構(gòu)的參數(shù),并對模具使用的注塑機(jī)進(jìn)行校核,保證成型零件的強(qiáng)度、精度滿足要求,并對注塑機(jī)校核,確保塑料量、推出距離、模具安裝尺寸滿足設(shè)計(jì)模具要求。為保證產(chǎn)品質(zhì)量,對塑料成型工藝和塑料模具提出較高要求,采用UG三維軟件進(jìn)行注塑模具設(shè)計(jì)的方法更加適應(yīng)產(chǎn)品更新?lián)Q代和提高質(zhì)量要求,同時便于后續(xù)的數(shù)控加工。塑料產(chǎn)品一般采用模塑成型方法生產(chǎn),因而塑料模具早已成為一種重要的生產(chǎn)工藝裝備,在國民經(jīng)濟(jì)中起著越來越重要的作用。塑料件模具設(shè)計(jì)摘 要塑料作為高分子化學(xué)和材料科學(xué)發(fā)展的重要成果,早已為人們熟悉,塑料產(chǎn)品已經(jīng)成為人類生產(chǎn)和生活中不可缺少的重要組成部分。多年來,塑料產(chǎn)品制造業(yè)一直在迅速發(fā)展,而當(dāng)前全球范圍的以塑料代替金屬的趨勢又進(jìn)一步加速了這一發(fā)展速度。隨著塑料產(chǎn)品在家電、電子、機(jī)械等產(chǎn)品和日常用品中越來越廣泛應(yīng)用。本文從分析塑料件的材料、形狀等進(jìn)行塑料成型工藝分析,對塑件增加拔模斜度等工藝參數(shù),對塑件三維造型,計(jì)算塑件質(zhì)量,初選注塑機(jī);對塑件進(jìn)行模具成型分析,對模具分型面、澆注口位置、主流道、分流道、澆口形式和冷料穴進(jìn)行設(shè)計(jì),結(jié)合產(chǎn)品生產(chǎn)批量,設(shè)計(jì)模具機(jī)構(gòu),對模具的成型零件和功能零件具體設(shè)計(jì)和布置,運(yùn)用UG軟件,設(shè)計(jì)模具的三維造型,繪出模具總裝圖紙;為保證計(jì)算產(chǎn)品質(zhì)量和模具的強(qiáng)度等考慮。關(guān)鍵詞:塑料;UG建模;塑料模具;CADABSTRACTPlastic, as the important achievement of polymer chemistry and material science, has long been familiar with. Plastic products have bee one of the indispensable ponents in human’s production and daily life. Over the years the plastic product manufacturing industry has been development. Generally plastic products are manufactured by molding therefore plastic molds have bee an important production device and play an increasingly important role in the national economy. The use of plastic products in home appliances, machinery and other daily necessities has bee more and more wide and to ensure the quality, the threedimensional software for injection mold design has adapted to the high demand of product upgrading and improving.This paper is to analyze the plastic molding process from the material, shape and ETC. of the shell of electric appliance。 to analyze the parting line, nozzle position, runner, gate forms and cold slug bined with production quantities to design and organize the molding parts and functional parts 。 to ensure calculating the product quality, mold strength and other considerations. In order to make sure the injection volume and the extrusion distance to meet the product requirements, the dimensions and tolerances of molded parts and the side pumping mechanism will be calculated and also the injection molding machine will be checked.Key Word: