油管接頭注塑模具設(shè)計(jì)【一模兩腔】【說明書+CAD+PROE+仿真】

油管接頭注塑模具設(shè)計(jì)【一模兩腔】【說明書+CAD+PROE+仿真】,一模兩腔,說明書+CAD+PROE+仿真,油管接頭注塑模具設(shè)計(jì)【一模兩腔】【說明書+CAD+PROE+仿真】,油管,接頭,注塑,模具設(shè)計(jì),說明書,仿單,cad,proe,仿真 河南機(jī)電高等?？茖W(xué)校畢業(yè)設(shè)計(jì)說明書油管接頭注塑模具設(shè)計(jì)前 言塑料制品在日常生活中是常常見到的，如在家用電器、儀器儀表、建筑器材、汽車工業(yè)、日用五金、通信器材以及醫(yī)療器械等眾多領(lǐng)域，塑料制品的使用比例正迅猛增加。這主要是因?yàn)橐韵略颍旱谝唬芰吓c金屬材料相比有許多優(yōu)點(diǎn)：容易加工，生產(chǎn)效率高；節(jié)約能源，絕緣性能好；質(zhì)量輕，相對密度為1.01.4，比鋁輕一半，比鋼輕3/4，比強(qiáng)度高，具有突出的耐磨、耐腐蝕性等；第二，在日用和工業(yè)產(chǎn)品中，一個設(shè)計(jì)合理的塑料制品往往能代替多個傳統(tǒng)金屬結(jié)構(gòu)件，加上利用工程塑料特有的性質(zhì)，可以一次成型非常復(fù)雜的形狀，并且還能設(shè)計(jì)成卡裝結(jié)構(gòu)，從而減少產(chǎn)品中裝配的各種緊固件，降低了金屬材料消耗量和加工及裝配工時；第三，注塑加工是塑料加工中普遍采用的方法之一。該方法使用與全部熱塑性塑料和部分熱固性塑料，制品數(shù)量比其他常規(guī)的金屬成型方法要大得多。由于注塑成型加工不僅產(chǎn)量多，而且適用于多種原料，能夠成批、連續(xù)的生產(chǎn)，并且具有穩(wěn)定的尺寸，容易實(shí)現(xiàn)生產(chǎn)的自動化和高速化，具有極高的經(jīng)濟(jì)效益。因此目前工業(yè)產(chǎn)品非金屬化、金屬制品塑料化的趨勢日益明顯。獲得注塑制品的過程，稱之為注塑成型或者注射成型，或者簡單的稱之為注塑。注塑成型的基本過程是：顆粒狀的高分子材料（以下簡稱為塑料）經(jīng)過注塑機(jī)螺桿的擠壓和加熱，成為熔融狀態(tài)的可以流動的熔體。在螺桿的推動下，塑料熔體通過注塑機(jī)的噴嘴、模具的主流道、分流道和澆口進(jìn)入模具型腔，成型出具有一定形狀和尺寸制品的過程。注塑的結(jié)果是生產(chǎn)出符合用戶要求的塑料制品。要想取得合格的制品，必須要有設(shè)計(jì)合理、制造精良的模具，還需要有何該模具配套的先進(jìn)的注射設(shè)備（注塑機(jī)）以及合理的加工工藝。因此人們常將，模具、注塑機(jī)以及工藝稱之為注塑過程得以順利進(jìn)行的三個基本要素。作為注塑成型加工的主要工具之一的注塑模具，在質(zhì)量、精度、制造周期以及注塑成型過程中的生產(chǎn)效率等方面的惡水平高低，直接影響產(chǎn)品的質(zhì)量、產(chǎn)量、成本及產(chǎn)品的更新?lián)Q代，并最終決定著企業(yè)在市場競爭中的反映能力和速度。與其他機(jī)械行業(yè)相比，模具制造業(yè)主要有以下三個特點(diǎn)：第一，模具不能像其他機(jī)械產(chǎn)品那樣可作為基本定型的商品隨時都可以在機(jī)電市場上買到。這是因?yàn)槊扛蹦＞叨际轻槍μ囟ǖ乃芰现破返囊?guī)格而產(chǎn)生的，由于塑料制品的形狀、尺寸各異，差距甚大，其模具結(jié)構(gòu)也是大相徑庭，所以模具制造不可能形成批量生產(chǎn)。換句話說，模具是單件生產(chǎn)的，重復(fù)加工的可能性很小。因此，模具的設(shè)計(jì)、制造成本都較高。第二，因?yàn)樽⑺苣＞呤菫楫a(chǎn)品中的塑料制品而訂制的，作為產(chǎn)品，除質(zhì)量、價格等因素之外，很重要的一點(diǎn)就是需要盡快地投放市場，所以對于為塑料制品而特殊訂制的模具來說，其制造周期一定要短。第三，模具制造時一項(xiàng)技術(shù)性很強(qiáng)的工作，其加工過程集中了機(jī)械制造中的諸多先進(jìn)技術(shù)的部分精華與鉗工技術(shù)的手工技巧，因此要求模具工人具有較高的文化技術(shù)水平，特別是對于企業(yè)來說要求培養(yǎng)“全能工人”（即多面手），使其適應(yīng)多工種的要求，這種技術(shù)工人對模具單件生產(chǎn)方式組織均衡生產(chǎn)來說是非常重要的。注塑機(jī)也是注塑成型必需的要素之一。一般來說，市場上供應(yīng)的各種形式和規(guī)格的注塑機(jī)，但是在實(shí)踐中，必須根據(jù)模具的實(shí)際情況和注塑廠家的設(shè)備情況進(jìn)行選擇。對于采用注塑成型加工方法生產(chǎn)塑料制品來說，合理的成型工藝既是三個基本要素中的加工工藝。所謂成型工藝，簡單來說就是將壓力、溫度、時間（速度）三大要素組成最合理的搭配。在成型過程中，尤其是精密制品的成型，要想確立一組最佳的成型條件決非易事，因?yàn)橛绊懗尚蜅l件的因素很多，除制品的形狀、模具結(jié)構(gòu)、注塑設(shè)備、原材料等之外，電壓的波動、環(huán)境溫度的變化對成型都有一定的影響。到目前為止，建立最佳的成型工藝尚無簡便可靠的辦法，大多需要操作者具有很豐富的實(shí)踐經(jīng)驗(yàn)與耐心，根據(jù)塑料制品在成型過程出現(xiàn)的具體文言體認(rèn)真調(diào)查，才能確立一個理想的成型工藝，高效率、高質(zhì)量地生產(chǎn)出合格的塑料制品。如前所述，注塑過程得以實(shí)現(xiàn)的三個基本要素是：注塑機(jī)、注塑模具以及加工工藝，它們?nèi)币徊豢?。隨之市場競爭的激烈化，客戶對于產(chǎn)品的質(zhì)量要求越來越高，生產(chǎn)速度要求越來越快。這些要求推動人們不斷設(shè)計(jì)技術(shù)更加先進(jìn)，生產(chǎn)效率更加高的注塑機(jī)，同時設(shè)計(jì)結(jié)構(gòu)更加合理，性能更加穩(wěn)定的注塑模具，并尋求更為合理的注塑工藝，以滿足這方面的要求。但是要做到上述三個方面并不容易。因?yàn)閺闹破焚|(zhì)量方面講，塑料模具以及注塑成型工藝對其影響甚大；從制品的生產(chǎn)效率方面講，注塑機(jī)、模具以及生產(chǎn)工藝則發(fā)揮著巨大的作用。而整個注塑的工藝又是有制品的形狀和大小、塑料的種類、模具的結(jié)構(gòu)以及注塑機(jī)的類型來決定的。為了能夠使我們在畢業(yè)后的工作過程中能夠獨(dú)立分析和解決實(shí)際問題，在三年的學(xué)習(xí)將要結(jié)束的時候，學(xué)校安排了“畢業(yè)設(shè)計(jì)”這個環(huán)節(jié)。本設(shè)計(jì)題目為“油管接頭注塑?！?在設(shè)計(jì)中經(jīng)過分析選用了“一模兩腔”的型腔排列方式，能夠滿足中等批量的生產(chǎn)任務(wù)；澆口的設(shè)計(jì)中根據(jù)模具結(jié)構(gòu)選擇了潛伏式澆口，在開模過程中能夠自動切斷澆口凝料，提高了生產(chǎn)效率；由于制件有側(cè)孔，需要設(shè)置側(cè)向分型抽芯機(jī)構(gòu)，本模具中采用了斜導(dǎo)柱抽芯機(jī)構(gòu)；在頂出機(jī)構(gòu)的設(shè)計(jì)中，由于制件包緊在型芯上造成脫模力較大，為保證塑件質(zhì)量，采用了頂管脫模；頂管必須在側(cè)型芯滑塊回位時提前退會復(fù)位，為避免側(cè)型芯與頂管在合模過程中發(fā)生干涉，設(shè)置了彈簧式優(yōu)先復(fù)位機(jī)構(gòu)，需要注意的是選用的彈簧要有迫使頂出機(jī)構(gòu)復(fù)位的足夠力矩.畢業(yè)設(shè)計(jì)是塑料模設(shè)計(jì)課程重要的綜合性和實(shí)踐性教學(xué)環(huán)節(jié)。通過這個環(huán)節(jié)使我能夠綜合運(yùn)用塑料模具設(shè)計(jì)課程和其他先修課程的知識，分析和解決塑料模具設(shè)計(jì)問題，進(jìn)一步鞏固、加深和拓寬所學(xué)知識，逐步樹立正確的設(shè)計(jì)思想，增強(qiáng)創(chuàng)新意識和競爭意識，熟悉掌握塑料模具設(shè)計(jì)的一般規(guī)律，培養(yǎng)分析問題和解決問題的能力；通過設(shè)計(jì)計(jì)算、繪圖以及運(yùn)用技術(shù)規(guī)范、標(biāo)準(zhǔn)、設(shè)計(jì)手冊等有關(guān)設(shè)計(jì)資料，進(jìn)行全面的塑料模具設(shè)計(jì)基本技能的訓(xùn)練。在設(shè)計(jì)過程中得到了楊占堯老師的大力指導(dǎo)與幫助，此外還參考了有關(guān)同學(xué)的設(shè)計(jì)內(nèi)容和資料，他們?yōu)槲业脑O(shè)計(jì)提供了許多寶貴意見，在此我表示衷心的感謝！第1章 模塑工藝規(guī)程的編制塑件的工藝性分析塑件的原材料分析塑件的材料采用聚甲醛（POM），屬熱塑性塑料，是一種具有優(yōu)異綜合性能的工程塑料。從使用性能上看，該塑料具有硬度大、耐磨性強(qiáng)、彈性好、化學(xué)穩(wěn)定性高、尺寸穩(wěn)定性好，其耐油性能與溫度、濕度等外界條件無關(guān)等優(yōu)點(diǎn)，并且具有突出的耐溶劑性和良好的耐熱性【2】。從成型性能上看，該塑料熔料的流動性較好，受溫度變化的影響較小，而受壓力的影響比較敏感，在注塑成型時只要控制壓力的大小就可獲得適合的流動性，使得成型較容易。但是制件的成型收縮率較大，使得成型后制件上易產(chǎn)生折皺、凹痕、斑紋、熔接痕等缺陷，因此應(yīng)注意注塑工藝的合理控制，例如在成型時應(yīng)采用較高注射壓力，適當(dāng)延長保壓時間以減小收縮率等。塑件的結(jié)構(gòu)和尺寸精度及表面質(zhì)量分析（1） 結(jié)構(gòu)分析。 從零件圖上分析，該零件總體形狀類示一個三通管道，在下端有一個直徑為35mm，深度為3mm的凹坑。在上端有一個外徑為40mm，內(nèi)徑為30mm，高度為3mm的凸緣。在三通的一端是一段M12mm的螺紋，其長度為10mm。因此，模具設(shè)計(jì)時必須設(shè)置側(cè)向分型抽芯機(jī)構(gòu)，該零件屬于中等復(fù)雜程度。（2） 尺寸精度分析。 從零件圖可知，該零件各個尺寸均未注明公差，為提高經(jīng)濟(jì)效益，則按未注明公差尺寸來處理。根據(jù)表215【1】查得POM材料的適用未注公差等級為MT6級(GB/T14486-1993)。從以上分析可見，該零件的尺寸精度等級不高，對應(yīng)的模具相關(guān)零件的尺寸加工容易保證。從塑件的壁厚上來看，壁厚最大處為9mm，最小處為5mm，壁厚差為4mm,相差較大，成型時可能會在塑件內(nèi)部產(chǎn)生縮孔和殘余應(yīng)力，應(yīng)在成型工藝上采取措施，比如延長保壓時間和冷卻時間，改善澆注系統(tǒng)，開設(shè)冷卻水道，使模具冷卻均勻等，防止缺陷的產(chǎn)生。（3） 表層質(zhì)量分析。 該零件的表面要求沒有缺陷、毛刺，內(nèi)部表面應(yīng)光潔，以利于液體的流動。除此之外沒有特別的表面質(zhì)量要求，故比較容易實(shí)現(xiàn)。綜上分析可以看出，注塑時在工藝參數(shù)控制的較好的情況下，零件的成型要求可以得到保證。計(jì)算塑件的體積和重量為了選用注塑機(jī)型號及確定模具型腔數(shù)，應(yīng)該先確定塑件的質(zhì)量。計(jì)算塑件的體積：用分割法求得塑膠體積= 25680（具體過程略）。計(jì)算塑件的質(zhì)量：根據(jù)設(shè)計(jì)手冊【3】查得POM的密度為，故塑件的質(zhì)量為： = 256801.41= 36.2g 采用一模兩件的模具結(jié)構(gòu)，考慮其外形尺寸，注塑時所需壓力等情況，初選用注塑機(jī)XSZY250型。塑件注塑工藝參數(shù)的確定由于聚甲醛塑料的熱穩(wěn)定性較差，在210下停留時間不得超過20min,在正常加工溫度范圍內(nèi)受熱時間稍長也會發(fā)生分解。所以在保證物料流動性的前提下，盡量采用較低的成型溫度和較短的停留時間。查相關(guān)文獻(xiàn)資料，聚甲醛的成型工藝參數(shù)可作如下選擇【2】：（試模時，可根據(jù)實(shí)際情況作適當(dāng)調(diào)整）注塑溫度：包括料筒溫度和噴嘴溫度。料筒溫度：后段溫度選用165； 中段溫度選用175； 前段溫度選用185；噴嘴溫度：選用175；注塑壓力：選用100Mpa;注塑時間：選用40s；保 壓：選用40Mpa;保壓時間：選用10s；冷卻時間：選用35s。另外，為了提高制品的尺寸穩(wěn)定性和減少內(nèi)應(yīng)力，可將注塑成型后獲得的制件置于120130的環(huán)境中進(jìn)行空氣浴，停留時間約4小時，然后緩慢冷卻至室溫。第2章 注塑模的結(jié)構(gòu)設(shè)計(jì)2.1 分型面的選擇根據(jù)分型面選擇原則和塑件的成型要求選擇分型面。該塑件為油管接頭，表面質(zhì)量無特殊要求，分析后可取如下圖所示的分型面，它是塑件最大截面，大孔在開模方向上成型，而小孔在側(cè)面，便于抽芯。若選圖1所示的分型方式即可降低模具的復(fù)雜程度，減少模具加工難度又便于成型后取件。故選用如圖1所示的分型方式較為合理。圖1 分型面的選擇（1）圖 2 分型面的選擇（2）若采用圖2所示的分型方式，雖然側(cè)向抽芯距大大減小，但要想使制件脫模，模具的開模行程將增加很多，模具結(jié)構(gòu)也成倍增大，所需設(shè)備要有很大的開模行程才行，勢必降低生產(chǎn)效率。2.2 確定型腔的排列方式本塑件在注塑時采用一模兩件，即模具需要兩個型腔。綜合考慮澆注系統(tǒng)、模具結(jié)構(gòu)的復(fù)雜程度等因素，擬采取如圖3所示的型腔排列方式。圖 3 型腔排列方式（1）采用圖3所示的型腔排列方式能夠適應(yīng)生產(chǎn)批量的需求，模具結(jié)構(gòu)也不復(fù)雜，容易保證塑件的質(zhì)量。若采用圖4所示的型腔排列方式，雖然較圖3在模具結(jié)構(gòu)上少了一側(cè)的抽芯機(jī)構(gòu)，但將兩個側(cè)型芯放在同一側(cè)，由于側(cè)型芯較細(xì)小，并且抽芯距較長，造成抽芯力大，抽芯機(jī)構(gòu)相對復(fù)雜，并且模具縱向尺寸將隨之增大，模具制造成本提高。 圖4 型腔排列方式（2）另外一種型腔排列方式如圖5所示，一模四件對稱布置，生產(chǎn)效率最高，但是在模具上有四個側(cè)型芯，側(cè)向分型抽芯機(jī)構(gòu)設(shè)置相對復(fù)雜，抽芯力大，將成倍增大模具結(jié)構(gòu)的復(fù)雜程度。圖5 型腔排列方式（3）2.3 澆注系統(tǒng)設(shè)計(jì)（1） 主流道設(shè)計(jì)。 根據(jù)設(shè)計(jì)手冊【1】查得XSZY250型注塑機(jī)噴嘴的有 關(guān)尺寸：噴嘴前端孔直徑：=4mm；噴嘴前端球面半徑：=18mm；根據(jù)模具主流道與噴嘴的關(guān)系【1】：=+（12）mm=+（0.51）mm取主流道球面半徑=19mm；主流道的小端直徑=5mm。為了便于將凝料從主流道中拔出，將主流道設(shè)計(jì)成圓錐形，其斜度取為，經(jīng)換算得主流道大端直徑=9.5mm，為了使熔料順利進(jìn)入分流道，可在主流道出料端設(shè)計(jì)半徑=6mm的圓弧過渡。（2） 分流道設(shè)計(jì)。 分流道的形狀及尺寸，應(yīng)根據(jù)塑件的體積、壁厚、形狀的復(fù)雜程度、注塑速率、分流道的長度等因素來確定。本塑件形狀不算太復(fù)雜，熔料填充型腔比較容易。根據(jù)型腔的排列方式可知分流道長度較短,為了便于加工起見，選截面形狀為梯形的分流道，查有關(guān)文獻(xiàn)【1】初確定梯形尺寸=9mm,=6mm。（3） 澆口設(shè)計(jì)。 根據(jù)塑件的成型要求、型腔的排列方式及模具結(jié)構(gòu)，擬選潛伏式澆口較為理想，可以自動切除澆口凝料，提高生產(chǎn)率，模具結(jié)構(gòu)孔也不復(fù)雜。根據(jù)設(shè)計(jì)手冊初步確定澆口尺寸，澆口長度= 2mm，直徑= 1.2mm，試模時修正。2.4 抽芯機(jī)構(gòu)設(shè)計(jì)制件的一側(cè)有一個側(cè)孔，垂直于脫模方向，阻礙成型后塑件從模具脫出。因此成型油管接頭的零件必須做成活動的型芯，即須設(shè)置抽芯機(jī)構(gòu)。本模具采用斜導(dǎo)柱抽芯機(jī)構(gòu)。2.4.1 斜導(dǎo)柱尺寸的確定（1） 確定抽芯距。 抽芯距一般應(yīng)大于成型孔的深度，本題目中塑件側(cè)孔深度為45mm，另加3mm的抽芯安全系數(shù)，可取抽芯距=48mm.（2） 確定斜導(dǎo)柱傾角。 斜導(dǎo)柱傾斜角與抽拔力以及抽芯距有直接關(guān)系。本題取為=。（3） 確定斜導(dǎo)柱的尺寸。 根據(jù)抽拔力及其傾斜角度，按設(shè)計(jì)資料的有關(guān)公式進(jìn)行計(jì)算。本題中經(jīng)驗(yàn)估值，斜導(dǎo)柱的直徑mm。確定最小開模行程【1】取固定凸肩，暫選安裝斜導(dǎo)柱的定模板厚=50mm,則斜導(dǎo)柱總長可按下式計(jì)算【1】：如果設(shè)計(jì)中有變化，則就修正的長度。2.4.2 滑塊與導(dǎo)滑槽設(shè)計(jì)（1） 滑塊與側(cè)型芯的連接方式設(shè)計(jì)。 本題中側(cè)向抽芯機(jī)構(gòu)主要是用于成型零件的側(cè)向孔，由于側(cè)向孔的深度較大，考慮到型芯強(qiáng)度和裝配問題，采用組合式結(jié)構(gòu)。型芯和滑塊的連接采用鑲嵌方式，并用螺釘加固。其結(jié)構(gòu)如圖6所示（2） 滑塊的導(dǎo)滑方式。 本題中為使模具結(jié)構(gòu)緊湊，降低模具裝配復(fù)雜程度，擬采用整體式滑塊和整體式導(dǎo)向槽的形式。其結(jié)構(gòu)如圖7所示。為提高滑塊的導(dǎo)向精度，裝配時可對導(dǎo)向槽或滑塊采用配磨、配研的方法。圖6 型芯的連接方式圖7 滑塊的導(dǎo)滑方式（3） 滑塊的導(dǎo)滑長度和定位裝置設(shè)計(jì)。 導(dǎo)滑長度要保證側(cè)向抽芯后，滑塊與導(dǎo)滑槽的配合長度不小于其總長度的，滑塊的限裝置采用彈簧滾珠形式。其結(jié)構(gòu)如圖8所示。 圖8 滑塊的限位方式圖9 型腔的組合方式1-定模板 2-主型芯 3-澆口套 4-定模鑲塊 5-滑塊6-導(dǎo)滑槽 7-動模鑲塊 8-動模板 9-推管 10-側(cè)型芯2.5 成型零件結(jié)構(gòu)設(shè)計(jì)（1） 凹模的結(jié)構(gòu)設(shè)計(jì)。 本題中模具采用一模兩件的結(jié)構(gòu)形式，由于制件上面有螺紋需要成型，考慮加工的難易程度和材料的價值利用率等因素，型腔擬采用鑲拼式結(jié)構(gòu)，將成型螺紋的工作零件做成瓣合模形式，可以在其損壞后很容易的更換。此外，由于開模后塑件包緊型芯的力比較大，為確保脫模過程中制件的完好無損，擬采用推出力比較平穩(wěn)的推管形式推出制件，塑件不易發(fā)生變形，所以推管頂部也構(gòu)成了型腔的一部份。其結(jié)構(gòu)形式如圖9中件9所示。根據(jù)本題中分流道與澆口的設(shè)計(jì)要求，分流道設(shè)置在動模板上，而澆口設(shè)置在定模板上。其結(jié)構(gòu)如圖9所示。（2） 凸模結(jié)構(gòu)設(shè)計(jì)。 凸模主要是與凹模相結(jié)合構(gòu)成模具型腔，其凸模和側(cè)型芯的結(jié)構(gòu)形式如圖9中件2、10所示。第3章 模具設(shè)計(jì)的有關(guān)計(jì)算本題中成型零件工作尺寸計(jì)算時均采用平均尺寸、平均收縮率、平均制造公差和平均磨損量來計(jì)算。查表【5】得聚甲醛的收縮率為= 1.4%2.0%，故平均收縮率為=（1.4+2.0）%/2=1.7%，模具制造公差取=/3（為塑件公差）。3.1 型腔和型芯工作尺寸計(jì)算型腔、型芯工作尺寸計(jì)算見表1。3.2 螺紋瓣合塊的尺寸計(jì)算3.2.1 螺紋瓣合塊型腔側(cè)壁厚度及底厚計(jì)算（1） 螺紋瓣合塊型腔側(cè)壁厚度計(jì)算。 螺紋瓣合塊型腔側(cè)壁厚度的計(jì)算應(yīng)根據(jù)組合式矩形型腔側(cè)壁厚計(jì)算公式【6】進(jìn)行計(jì)算。式中 型腔壓力（MPa）模具材料的彈性模量（MPa）剛度條件，即允許變形量（mm）本題中取 =40MPa（選定值）； =8mm； =20.17mm（根據(jù)表1型腔工作尺寸計(jì)算得長、寬尺寸，取大值進(jìn)行計(jì)算）； =2.110MPa; =0.040.05mm,取=0.045mm。代入公式計(jì)算得考慮到瓣合塊需要由螺釘固定，故取螺紋瓣合塊的外形尺寸為50mm15mm.考慮到加工和裝配時的實(shí)際情況，可取動、定模瓣合塊的厚度分別和對應(yīng)的動、定模板相匹配以方便用螺釘固定。螺紋瓣合塊的結(jié)構(gòu)形式如圖10所示。圖10 螺紋瓣合塊（一對）第4章 模具冷卻與加熱系統(tǒng)的計(jì)算本塑件在注射成型時不要求有太高的模溫（約80左右即可），因而在模具上可不設(shè)加熱系統(tǒng)，而采用模具溫度控制器來對模具溫度進(jìn)行控制，自動實(shí)現(xiàn)模具冷卻、加熱的交替，使模具在成型過程中達(dá)到較好的熱平衡。是否需要冷卻系統(tǒng)可作如下設(shè)計(jì)計(jì)算： 設(shè)定模具平均工作溫度為80，用20的常溫水作為模具的冷卻介質(zhì)，其出口溫度為25，產(chǎn)量為(初算每2分鐘一套)2.17kg/h。（1） 求塑件在硬化時每小時釋放的熱量Q3，查有關(guān)文獻(xiàn)【5】得聚甲醛的單位熱流量為42J/kg（2） 求冷卻水的體積流量V【1】式中 冷卻水的體積流量（m/min）； 單位時間內(nèi)注入模具內(nèi)的塑料熔體的質(zhì)量(kg/h)； 塑料成型時在模具內(nèi)釋放的熱焓量（J/kg）； 冷卻水的比熱容J/（kgK）； 冷卻水的密度（kg/m）； 冷卻水的出口溫度（）； 冷卻水的進(jìn)口溫度（）。由體積流量V查表【1】可知所需的冷卻水管的直徑d為12。為達(dá)到較好的冷卻效果，根據(jù)模具整體結(jié)構(gòu)設(shè)置4個冷卻水道，平均布置在制件周圍，其結(jié)構(gòu)見裝配圖。第5章 模具閉合高度的確定在支撐和固定零件的設(shè)計(jì)過程中，根據(jù)經(jīng)驗(yàn)確定：定模座板：=32mm,考慮模具整體結(jié)構(gòu)的協(xié)調(diào)取定模板：=50mm，動模板：=40mm，支撐板：=32；動模座板：=32mm。根據(jù)推出行程和推出機(jī)構(gòu)的結(jié)構(gòu)尺寸確定墊塊高度=80mm因而模具閉合高度： + =32+50+40+32+80+32=266mm第6章 注塑機(jī)有關(guān)參數(shù)的校核本模具的外形尺寸為315mm440mm266mm. XSZY250型注塑機(jī)拉桿間距為448mm370mm，故能滿足模具的安裝要求。由上述計(jì)算模具的閉合高度=242mm，XSZY250型注塑機(jī)所允許模具的最小厚度=200mm，最大厚度=350mm，即模具滿足的安裝條件【1】： 經(jīng)查資料XSZY250型注塑機(jī)的最大開模行程S=500mm，滿足下式【1】頂出塑件的要求： 此外，由于側(cè)向分型抽芯距較大，需校核開模距離的增加量。按照式【1】mm=144mm式中 最小開模行程，本題中取=134mm。經(jīng)校核，注塑機(jī)的開模行程足夠，XSZY250型注塑機(jī)能滿足使用要求，故可采用。第7章 繪制模具總裝圖和非標(biāo)準(zhǔn)零件工作圖本模具的總裝圖見裝配圖所示。非標(biāo)準(zhǔn)件工作圖見零件圖。本模具的工作原理：模具安裝在注塑機(jī)上，定模部分固定在注塑機(jī)的定模板上，動模固定在注塑機(jī)的動模板上。合模后，注塑機(jī)通過噴嘴將熔料經(jīng)流道注入型腔，經(jīng)保壓、冷卻后塑件成型。開模時動模部分隨動模板一起運(yùn)動漸漸將分型面打開，與此同時在斜導(dǎo)柱的作用下側(cè)抽芯滑塊向兩邊分離并脫離塑件，完成側(cè)向抽芯動作，當(dāng)分型面打開到144mm時，動模停止運(yùn)動，在注塑機(jī)頂出裝置作用下，推動推管運(yùn)動將塑件從型芯上頂出。合模時，推管在彈簧的彈力作用下首先復(fù)位，隨著分型面的閉合滑塊帶著側(cè)型芯復(fù)位。圖11 油罐接頭注塑模三維圖第8章 注塑模主要零件加工工藝規(guī)程的編制(1) 主型芯。主型芯如零件圖01所示，其加工工藝過程見工藝規(guī)程卡片1。(2) 定模板。定模板如零件圖02所示，其加工工藝過程見工藝規(guī)程卡片2。圖12 油管接頭注塑模1-定位環(huán) 2-定模座 3-定模板 4-動模板 5-支撐塊 6-動模座 7-推管 8-推板 9-推管固定板 10-墊板 11-滑塊 12-壓緊楔 13-斜導(dǎo)柱 14-瓣合塊 15-主型芯 16-澆口套 17-導(dǎo)軌 18-側(cè)型芯第9章 注塑模的裝配本模具在裝配時的主要要求如下：（1） 模具上下平面的平行度偏差不大于0.05mm,分模面處需密合。（2） 推件時推管和頂桿動作要保持同步。（3） 彈簧要有足夠的力矩。 裝配時以分型面密合作為該模具的裝配基準(zhǔn)，裝配順序如下【8】：（1） 裝配前按圖檢驗(yàn)主要工作零件及其他零件得尺寸。（2） 鏜導(dǎo)柱、導(dǎo)套孔。將定模板3、動模板4疊合在一起，使分模面緊密接觸并夾緊，鏜導(dǎo)柱、導(dǎo)套孔，在孔內(nèi)壓入工藝定位銷后，加工側(cè)面的垂直基準(zhǔn)。（3） 加工模板。用定模側(cè)面的垂直基準(zhǔn)確定定模上型腔中心的實(shí)際位置，并以此作為加工基準(zhǔn)，分別鏜小型孔和線切割用的穿絲孔2-mm，銑矩形臺肩73mm80mm，并以兩個孔為基準(zhǔn)，線切割主型芯孔。按照定模板的實(shí)際中心位置尺寸在動模板4上鏜型孔，并按照定模板上對應(yīng)位置的實(shí)際尺寸線切割滑塊的讓位矩形孔73mm80mm。（4） 壓入導(dǎo)柱、導(dǎo)套。在定模、動模板上分別壓入導(dǎo)套、導(dǎo)柱，使導(dǎo)向可靠，滑動靈活。（5） 裝配支撐板和墊塊。將動模板4、墊塊5、動模座板6和墊板10疊放在一起，用定模側(cè)面的垂直基準(zhǔn)確定連接緊固的螺釘孔，鏜螺釘過孔，并在動模板上攻出螺紋。（6） 裝配型芯。將定、動模板合攏，把型芯放入型孔內(nèi)，用螺孔復(fù)印法和壓銷套法使型芯緊固在墊板上。（7） 在動模座板上鉆緊固型芯的螺紋通孔，并用螺釘將型芯固定在動模座板上。（8） 通過型芯引鉆頂板上的頂桿孔及推管孔，安裝推管及頂桿。組裝定出系統(tǒng)。（9） 組裝墊塊，支撐板、定模座板。（10） 加工定模座板。加工螺紋孔、銷釘孔和壓緊楔孔，并將澆口套壓入定模座板。（11） 定模和定模座板的裝配。用平行夾頭把它們夾緊。通過定模座板的孔引鉆在定模上，拆下后，在定模上鉆、攻螺紋孔，然后用螺釘和銷釘將定模和定模座板緊固。（12） 完成裝配后進(jìn)行試模，并交驗(yàn)入庫。第10章 試模（1） 試模前，必須對設(shè)備的油路、水路及電路進(jìn)行檢查，并按規(guī)定保養(yǎng)設(shè)備，做好開機(jī)前的準(zhǔn)備。（2） 原料應(yīng)合格。根據(jù)推薦的工藝參數(shù)將料筒和噴嘴加熱。由于制件大小、形狀和壁厚的不同，以及設(shè)備上熱電偶位置的深度和溫度表的誤差也各有差異，因此資料上介紹的加工某一塑料的料筒和噴嘴溫度只是一個大致范圍還應(yīng)根據(jù)具體條件試調(diào)【7】。判斷料筒和噴嘴溫度是否合適的最好辦法，是在噴嘴和主流道脫開的情況下，用較低的注射壓力，使塑料自噴嘴中緩慢地流出，以觀察料流。如果沒有硬塊、氣泡、銀絲、變色，而是光滑明亮者，即說明料筒和噴嘴溫度是比較合適的，這時就可以開始試模。（3） 在開始試模時，原則上選擇在低壓、低溫和較長的時間條件下成型，然后按壓力、時間、溫度這樣的先后順序變動。最好不要同時變動二個或三個工藝條件，以便分析和判斷情況。壓力變化的影響，馬上就可以在制件上反映出來，所以如果制件充不滿，通常首先是增大注射壓力。當(dāng)大幅度提高注射壓力仍無顯著效果時，才考慮變動時間和溫度。延長時間實(shí)質(zhì)是使塑料在料筒內(nèi)受熱時間加長，注射幾次后若仍然未充滿，最后才提高料筒溫度。但料筒溫度的上升以及塑料溫度達(dá)到平衡需要一定的時間，一般約15min左右，不是馬上就可以在制件上反映出來的，因此必須耐心等待，不能把料筒溫度升得太高，以免塑料過熱甚至發(fā)生降解。（4） 注射成型時可選用高速和低速兩種工藝。一般在制件壁薄而面積大時，采用高速注射，而壁厚面積小者采用低速注射，在高速和低速都能充滿模腔的情況下，除玻璃纖維增強(qiáng)塑料外，均易采用低速注射【7】。（5） 對黏度高和熱穩(wěn)定性差的塑料，采用較慢的螺桿轉(zhuǎn)速和略低的背壓加熱和預(yù)塑，而黏度低和熱穩(wěn)定性好的塑料可采用較快的螺桿轉(zhuǎn)速和略高的背壓。在噴嘴溫度合適的情況下，采用噴嘴固定的形式可提高生產(chǎn)率。但當(dāng)噴嘴溫度太低或太高時，需要采用每成型周期向后移動噴嘴的形式。 在試模過程中應(yīng)作詳細(xì)記錄，并將結(jié)果填入試模記錄卡，注明試模是否合格。如需返修，則應(yīng)提出返修意見。在記錄卡中應(yīng)摘錄成型工藝條件及操作之一要點(diǎn)，最好能附上加工出的制件，以供參考【8】。 試模后，將模具清理干凈，涂上防銹油，然后分別入庫或返修。小 結(jié)這次畢業(yè)設(shè)計(jì)是我們進(jìn)行完了三年的模具設(shè)計(jì)與制造專業(yè)課程后進(jìn)行的，它是對我們學(xué)完三年來所學(xué)課程，繼而進(jìn)入工作崗位獨(dú)立工作前的最后一次深入、系統(tǒng)的綜合性的復(fù)習(xí)，也是一次理論聯(lián)系實(shí)踐的訓(xùn)練。它在我們的學(xué)習(xí)中占有重要的地位。通過這次設(shè)計(jì)使我在復(fù)習(xí)先修知識的同時又學(xué)到了許多新知識，對一些原來一知半解的理論也有了進(jìn)一步的的認(rèn)識。特別是原來所學(xué)的一些專業(yè)基礎(chǔ)課：如機(jī)械制圖、模具材料、公差配合與技術(shù)測量等有了更深刻的理解，使我進(jìn)一步的了解了怎樣將這些知識運(yùn)用到實(shí)際的設(shè)計(jì)中，同時還使我更清楚了模具設(shè)計(jì)過程中要注意到的問題。如怎樣使制造的模具既能滿足使用要求又不浪費(fèi)材料，保證加工的經(jīng)濟(jì)性，加工工藝的合理性。由于能力有限，設(shè)計(jì)中難免有疏漏之處，懇請老師給予批評指正。致謝注塑成型技術(shù)是材料加工技術(shù)中不可缺少的重要加工手段之一，目前在國內(nèi)正處于蓬勃發(fā)展時期，具有廣泛的發(fā)展前景。在大學(xué)三年學(xué)習(xí)即將結(jié)束之際，能夠按照老師的指導(dǎo)并綜合運(yùn)用三年來的所學(xué)所知設(shè)計(jì)一套注塑模具,必將為日后的獨(dú)立工作創(chuàng)造一個良好的開始。在畢業(yè)設(shè)計(jì)過程中楊老師一直扮演著導(dǎo)向者的角色，從接到設(shè)計(jì)題目那一刻起就給我指明了方向，讓我明白了設(shè)計(jì)要求、設(shè)計(jì)流程、設(shè)計(jì)中可能遇到的問題以及解決方法等，并不厭其煩的糾正設(shè)計(jì)中的錯誤，詳細(xì)檢查設(shè)計(jì)中的細(xì)節(jié)及重點(diǎn)，對設(shè)計(jì)方案提出了寶貴的修正意見，一步步完善了我的設(shè)計(jì)。在此對楊老師表示衷心的感謝！此外在設(shè)計(jì)過程中參考了一些同學(xué)的設(shè)計(jì)實(shí)例，并向他們請教，得到他們的大力幫助，為我提供了許多有關(guān)設(shè)計(jì)的資料,在此一并表示深深的謝意！參考文獻(xiàn)1 塑料注塑模結(jié)構(gòu)與設(shè)計(jì) 楊占堯主編 北京：清華大學(xué)出版社2 塑料模具技術(shù)手冊 北京：機(jī)械工業(yè)出版社3 塑料工業(yè)手冊 翟金平 黃漢雄 吳舜英主編 北京：化學(xué)工業(yè)出版社4 注塑模設(shè)計(jì) 張克惠主編 西北工業(yè)大學(xué)出版社5 工程塑料 金國珍主編 北京：化學(xué)工業(yè)出版社6 實(shí)用注塑模設(shè)計(jì)手冊 賈潤禮 程志遠(yuǎn)主編 中國輕工業(yè)出版社7 注射模具與注射成型實(shí)用手冊 美 J.B.戴姆著 化學(xué)工業(yè)出版社8 模具制造技術(shù) 翟德梅主編9 模具材料 高為國主編 北京：機(jī)械工業(yè)出版社10 模具設(shè)計(jì)手冊之四塑料模具設(shè)計(jì) 北京：機(jī)械工業(yè)出版社第 26 頁 共 26 頁目錄前 言1第1章 模塑工藝規(guī)程的編制41.1 塑件的工藝性分析41.2 計(jì)算塑件的體積和重量51.3塑件注塑工藝參數(shù)的確定5第2章 注塑模的結(jié)構(gòu)設(shè)計(jì)62.1 分型面的選擇62.2 確定型腔的排列方式72.3 澆注系統(tǒng)設(shè)計(jì)82.4 抽芯機(jī)構(gòu)設(shè)計(jì)92.5 成型零件結(jié)構(gòu)設(shè)計(jì)11第3章 模具設(shè)計(jì)的有關(guān)計(jì)算133.1 型腔和型芯工作尺寸計(jì)算133.2 螺紋瓣合塊的尺寸計(jì)算13第4章 模具冷卻與加熱系統(tǒng)的計(jì)算16第5章 模具閉合高度的確定17第6章 注塑機(jī)有關(guān)參數(shù)的校核18第7章 繪制模具總裝圖和非標(biāo)準(zhǔn)零件工作圖19第8章 注塑模主要零件加工工藝規(guī)程的編制20第9章 注塑模的裝配21第10章 試模22小 結(jié)23致 謝24參考文獻(xiàn)25- 2 -附 錄圖1 注塑模裝配圖 圖2 注塑模開模圖圖3 定模 圖4 動模桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)（論文）外文翻譯譯文 第10頁 共22頁編號： 畢業(yè)設(shè)計(jì)(論文)外文翻譯（原文）學(xué) 院： 國防生學(xué)院 專 業(yè)： 機(jī)械設(shè)計(jì)制造及其自動化 學(xué)生姓名： 匡鵬來 學(xué) 號： 1000110105 指導(dǎo)教師單位： 機(jī)電工程學(xué)院 姓 名： 曹泰山 職 稱： 講 師 2014年 3 月 9 日桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)（論文）外文翻譯譯文 第27頁 共28頁 technical note on the characterization of electroformed nickel shells for their application to injection molds aUniversidad de Las Palmas de Gran Canaria, Departamento de Ingenieria Mecanica, Spain AbstractThe techniques of rapid prototyping and rapid tooling have been widely developed during the last years. In this article, electroforming as a procedure to make cores for plastics injection molds is analysed. Shells are obtained from models manufactured through rapid prototyping using the FDM system. The main objective is to analyze the mechanical features of electroformed nickel shells, studying different aspects related to their metallographic structure, hardness, internal stresses and possible failures, by relating these features to the parameters of production of the shells with an electroforming equipment. Finally a core was tested in an injection mold. Keywords: Electroplating; Electroforming; Microstructure; Nickel 1. IntroductionOne of the most important challenges with which modern industry comes across is to offer the consumer better products with outstanding variety and time variability (new designs). For this reason, modern industry must be more and more competitive and it has to produce with acceptable costs. There is no doubt that combining the time variable and the quality variable is not easy because they frequently condition one another; the technological advances in the productive systems are going to permit that combination to be more efficient and feasible in a way that, for example, if it is observed the evolution of the systems and techniques of plastics injection, we arrive at the conclusion that, in fact, it takes less and less time to put a new product on the market and with higher levels of quality. The manufacturing technology of rapid tooling is, in this field, one of those technological advances that makes possible the improvements in the processes of designing and manufacturing injected parts. Rapid tooling techniques are basically composed of a collection of procedures that are going to allow us to obtain a mold of plastic parts, in small or medium series, in a short period of time and with acceptable accuracy levels. Their application is not only included in the field of making plastic injected pieces 1, 2 and 3, however, it is true that it is where they have developed more and where they find the highest output. This paper is included within a wider research line where it attempts to study, define, analyze, test and propose, at an industrial level, the possibility of creating cores for injection molds starting from obtaining electroformed nickel shells, taking as an initial model a prototype made in a FDM rapid prototyping equipment. It also would have to say beforehand that the electroforming technique is not something new because its applications in the industry are countless 3, but this research work has tried to investigate to what extent and under which parameters the use of this technique in the production of rapid molds is technically feasible. All made in an accurate and systematized way of use and proposing a working method. 2. Manufacturing process of an injection moldThe core is formed by a thin nickel shell that is obtained through the electroforming process, and that is filled with an epoxic resin with metallic charge during the integration in the core plate 4 This mold (Fig. 1) permits the direct manufacturing by injection of a type a multiple use specimen, as they are defined by the UNE-EN ISO 3167 standard. The purpose of this specimen is to determine the mechanical properties of a collection of materials representative industry, injected in these tools and its coMParison with the properties obtained by conventional tools. Fig. 1.Manufactured injection mold with electroformed core.The stages to obtain a core 4, according to the methodology researched in this work, are the following: (a) Design in CAD system of the desired object.(b) Model manufacturing in a rapid prototyping equipment (FDM system). The material used will be an ABS plastic.(c) Manufacturing of a nickel electroformed shell starting from the previous model that has been coated with a conductive paint beforehand (it must have electrical conductivity).(d) Removal of the shell from the model.(e) Production of the core by filling the back of the shell with epoxy resin resistant to high temperatures and with the refrigerating ducts made with copper tubes.The injection mold had two cavities, one of them was the electroformed core and the other was directly machined in the moving platen. Thus, it was obtained, with the same tool and in the same process conditions, to inject simultaneously two specimens in cavities manufactured with different technologies. 3. Obtaining an electroformed shell: the equipmentElectrodeposition 5 and 6 is an electrochemical process in which a chemical change has its origin within an electrolyte when passing an electric current through it. The electrolytic bath is formed by metal salts with two submerged electrodes, an anode (nickel) and a cathode (model), through which it is made to pass an intensity coming from a DC current. When the current flows through the circuit, the metal ions present in the solution are transformed into atoms that are settled on the cathode creating a more or less uniform deposit layer. The plating bath used in this work is formed by nickel sulfamate 7 and 8 at a concentration of 400ml/l, nickel chloride (10g/l), boric acid (50g/l), Allbrite SLA (30cc/l) and Allbrite 703 (2cc/l). The selection of this composition is mainly due to the type of application we intend, that is to say, injection molds, even when the injection is made with fibreglass. Nickel sulfamate allows us to obtain an acceptable level of internal stresses in the shell (the tests gave results, for different process conditions, not superior to 50MPa and for optimum conditions around 2MPa). Nevertheless, such level of internal pressure is also a consequence of using as an additive Allbrite SLA, which is a stress reducer constituted by derivatives of toluenesulfonamide and by formaldehyde in aqueous solution. Such additive also favours the increase of the resistance of the shell when permitting a smaller grain. Allbrite 703 is an aqueous solution of biodegradable surface-acting agents that has been utilized to reduce the risk of pitting. Nickel chloride, in spite of being harmful for the internal stresses, is added to enhance the conductivity of the solution and to favour the uniformity in the metallic distribution in the cathode. The boric acid acts as a pH buffer. The equipment used to manufacture the nickel shells tested has been as follows: Polypropylene tank: 600mm400mm500mm in size. Three teflon resistors, each one with 800W. Mechanical stirring system of the cathode. System for recirculation and filtration of the bath formed by a pump and a polypropylene filter. Charging rectifier. Maximum intensity in continuous 50A and continuous current voltage between 0 and 16V. Titanium basket with nickel anodes (Inco S-Rounds Electrolytic Nickel) with a purity of 99%. Gases aspiration system.Once the bath has been defined, the operative parameters that have been altered for testing different conditions of the process have been the current density (between 1 and 22A/dm2), the temperature (between 35 and 55C) and the pH, partially modifying the bath composition. 4. Obtained hardnessOne of the most interesting conclusions obtained during the tests has been that the level of hardness of the different electroformed shells has remained at rather high and stable values. In Fig. 2, it can be observed the way in which for current density values between 2.5 and 22A/dm2, the hardness values range from 540 and 580HV, at pH 40.2 and with a temperature of 45C. If the pH of the bath is reduced at 3.5 and the temperature is 55C those values are above 520HV and below 560HV. This feature makes the tested bath different from other conventional ones composed by nickel sulfamate, allowing to operate with a wider range of values; nevertheless, such operativity will be limited depending on other factors, such as internal stress because its variability may condition the work at certain values of pH, current density or temperature. On the other hand, the hardness of a conventional sulfamate bath is between 200250HV, much lower than the one obtained in the tests. It is necessary to take into account that, for an injection mold, the hardness is acceptable starting from 300HV. Among the most usual materials for injection molds it is possible to find steel for improvement (290HV), steel for integral hardening (520595HV), casehardened steel (760800HV), etc., in such a way that it can be observed that the hardness levels of the nickel shells would be within the mediumhigh range of the materials for injection molds. The objection to the low ductility of the shell is compensated in such a way with the epoxy resin filling that would follow it because this is the one responsible for holding inwardly the pressure charges of the processes of plastics injection; this is the reason why it is necessary for the shell to have a thickness as homogeneous as possible (above a minimum value) and with absence of important failures such as pitting. Fig. 2.Hardness variation with current density. pH 40.2, T=45C.5. Metallographic structureIn order to analyze the metallographic structure, the values of current density and temperature were mainly modified. The samples were analyzed in frontal section and in transversal section (perpendicular to the deposition). For achieving a convenient preparation, they were conveniently encapsulated in resin, polished and etched in different stages with a mixture of acetic acid and nitric acid. The etches are carried out at intervals of 15, 25, 40 and 50s, after being polished again, in order to be observed afterwards in a metallographic microscope Olympus PME3-ADL 3.3/10. Before going on to comment the photographs shown in this article, it is necessary to say that the models used to manufacture the shells were made in a FDM rapid prototyping machine where the molten plastic material (ABS), that later solidifies, is settled layer by layer. In each layer, the extruder die leaves a thread approximately 0.15mm in diameter which is compacted horizontal and vertically with the thread settled inmediately after. Thus, in the surface it can be observed thin lines that indicate the roads followed by the head of the machine. These lines are going to act as a reference to indicate the reproducibility level of the nickel settled. The reproducibility of the model is going to be a fundamental element to evaluate a basic aspect of injection molds: the surface texture. The tested series are indicated in Table 1. Table 1. Tested series Series pH Temperature (C) Current density (A/dm2) 14.20.2552.2223.90.2455.5634.00.24510.0044.00.24522.22Fig. 3 illustrates the surface of a sample of the series after the first etch. It shows the roads originated by the FDM machine, that is to say that there is a good reproducibility. It cannot be still noticed the rounded grain structure. In Fig. 4, series 2, after a second etch, it can be observed a line of the road in a way less clear than in the previous case. In Fig. 5, series 3 and 2 etch it begins to appear the rounded grain structure although it is very difficult to check the roads at this time. Besides, the most darkened areas indicate the presence of pitting by inadequate conditions of process and bath composition. Fig. 3.Series 1 (150), etch 1.Fig. 4.Series 2 (300), etch 2.Fig. 5.Series 3 (300), etch 2.This behavior indicates that, working at a low current density and a high temperature, shells with a good reproducibility of the model and with a small grain size are obtained, that is, adequate for the required application. If the analysis is carried out in a plane transversal to the deposition, it can be tested in all the samples and for all the conditions that the growth structure of the deposit is laminar (Fig. 6), what is very satisfactory to obtain a high mechanical resistance although at the expense of a low ductibility. This quality is due, above all, to the presence of the additives used because a nickel sulfamate bath without additives normally creates a fibrous and non-laminar structure 9. The modification until a nearly null value of the wetting agent gave as a result that the laminar structure was maintained in any case, that matter demonstrated that the determinant for such structure was the stress reducer (Allbrite SLA). On the other hand, it was also tested that the laminar structure varies according to the thickness of the layer in terms of the current density. Fig. 6.Plane transversal of series 2 (600), etch 2.6. Internal stressesOne of the main characteristic that a shell should have for its application like an insert is to have a low level of internal stresses. Different tests at different bath temperatures and current densities were done and a measure system rested on cathode flexural tensiometer method was used. A steel testing control was used with a side fixed and the other free (160mm length, 12.7mm width and thickness 0.3mm). Because the metallic deposition is only in one side the testing control has a mechanical strain (tensile or compressive stress) that allows to calculate the internal stresses. Stoney model 10 was applied and was supposed that nickel substratum thickness is enough small (3m) to influence, in an elastic point of view, to the strained steel part. In all the tested cases the most value of internal stress was under 50MPa for extreme conditions and 2MPa for optimal conditions, an acceptable value for the required application. The conclusion is that the electrolitic bath allows to work at different conditions and parameters without a significant variation of internal stresses. 7. Test of the injection moldTests have been carried out with various representative thermoplastic materials such as PP, PA, HDPE and PC, and it has been analysed the properties of the injected parts such as dimensions, weight, resistance, rigidity and ductility. Mechanical properties were tested by tensile destructive tests and analysis by photoelasticity. About 500 injections were carried out on this core, remaining under conditions of withstanding many more. In general terms, important differences were not noticed between the behavior of the specimens obtained in the core and the ones from the machined cavity, for the set of the analysed materials. However in the analysis by photoelasticiy (Fig. 7) it was noticed a different tensional state between both types of specimens, basically due to differences in the heat transference and rigidity of the respective mold cavities. This difference explains the ductility variations more outstanding in the partially crystalline materials such as HDPE and PA 6. Fig. 7.Analysis by photoelasticity of injected specimens.For the case of HDPE in all the analysed tested tubes it was noticed a lower ductility in the specimens obtained in the nickel core, quantified about 30%. In the case of PA 6 this value was around 50%. 8. ConclusionsAfter consecutive tests and in different conditions it has been checked that the nickel sulfamate bath, with the utilized additives has allowed to obtain nickel shells with some mechanical properties acceptable for the required application, injection molds, that is to say, good reproducibility, high level of hardness and good mechanical resistance in terms of the resultant laminar structure. The mechanical deficiencies of the nickel shell will be partially replaced by the epoxy resin that finishes shaping the core for the injection mold, allowing to inject medium series of plastic parts with acceptable quality levels. References1 A.E.W. Rennie, C.E. Bocking and G.R. Bennet, Electroforming of rapid prototyping mandrels for electro discharge machining electrodes, J. Mater. Process. Technol. 110 (2001), pp. 186196. 2 P.K.D.V. Yarlagadda, I.P. Ilyas and P. Chrstodoulou, Development of rapid tooling for sheet metal drawing using nickel electroforming and stereo lithography processes, J. Mater. Process. Technol. 111 (2001), pp. 286294. 3 J. Hart, A. Watson, Electroforming: A largely unrecognised but expanding vital industry, Interfinish 96, 14 World Congress, Birmingham, UK, 1996. 4 M. Monzn et al., Aplicacin del electroconformado en la fabricacin rpida de moldes de inyeccin, Revista de Plsticos Modernos. 84 (2002), p. 557. 5 L.F. Hamilton et al., Clculos de Qumica Analtica, McGraw Hill (1989). 6 E. Julve, Electrodeposicin de metales, 2000 (E.J.S.). 7 A. Watson, Nickel Sulphamate Solutions, Nickel Development Institute (1989). 8 A. Watson, Additions to Sulphamate Nickel Solutions, Nickel Development Institute (1989). 9 J. Dini, Electrodeposition Materials Science of Coating and Substrates, Noyes Publications (1993). 10 J.W. Judy, Magnetic microactuators with polysilicon flexures, Masters Report, Department of EECS, University of California, Berkeley, 1994. (cap. 3). How Surface Treatments Keep Molds Operating LongerImportant tips and information about mold coatings to help you achieve the level of production that you and your customers desire. By Steven . Bales Mold making technology January 2006AbstractTheres an awful lot to know these days about molding plastic and how to get the very best performance from the valuable tools you build or run. This guide has been written to provide important tips and information about mold coatings. After reading this, you should have a very good idea of what coatingsfrom the very traditional to the very latestwill help you to achieve the level of production you and your customers desire. After all, these tools are an investment and they need to be protected for the life of the products they mold.Key Wordsmold coatings preventive maintenance (PM) program benefit nickel Cobalt diamond-chrome nickel-PTFE nickel-boron nitride electroless nickel textureThe Key Role of CoatingsBefore introducing you to the wide range of coatings on the market today, its important to note the role coatings can play in an effective preventive maintenance (PM) program.PM is really the key to protecting your tooling, your investment. Why? Because it saves time and money. Once you invest in a mold coating to improve tool performance, then a PM program is always a good idea to ensure you get the maximum benefit. These two steps should be a given in any shop.Remember, no coating lasts forever, and producing substandard parts from a mold with a worn coating is no way to win customers and stay profitable. PM is probably the most cost-effective strategy you can put in place. The key is to educate your personnel on how mold coatings wear during production. Every coating is different, so its of benefit to have employees learn how to tell when the coating is showing deterioration, especially in high-wear areas such as gates and runners. For example, wear in and around gate areas plated with hard chrome is the first sign that your mol