pp塑料碗注塑模具設(shè)計(jì)
pp塑料碗注塑模具設(shè)計(jì),pp,塑料,注塑,模具設(shè)計(jì)
It is the new-type inject by shaping technology
1. inject by shaping altogether( inject shaping of at core layers)
Adopt and inject shaping help and observe and make one unique structure altogether. " first" of plastic is injected and fill and enter some types first, then the plastic: " second" follow " first" inject person who enter one and keep initial to drive pressure field of flowing closely. At epidermis district and core the sizes of one, measure and publish" first" and the materials quantities of" second" according to correct proportionate relationship, Make one at" first" complete at" second" to make one parcel appearance core each. In addition, in cosmetics application, the material is put after" second" material injecting to have" first" of epidermis of the small part, So that the epidermis of the part of the runner can be totally closed. Inject making one of shaping altogether with the resin of 2 kinds of different colors, form a piece of a layer of blocks of epidermis and core apt to distinguish (Realize inject shaping one as much as all have and have and one very much important this core similar epidermis. )If there is not advanced detection technique, usually difficult to distinguish the epidermis - core area and boundary of layer. Inject shaping a new technology altogether. British ici company began to use this technology in the 1970s early, and had made the basic theory of including, Produce several patents, such as the products and machinery equipment,etc.. Now similar to " mould mould sandwiches" what has been adopted generally ici production technologies,last outer the materials of the epidermis at moulds and in layers is material different on core occasionally, So two a kind of material person who a certain one inclusives, and core require and have high radiations very, issue and steep shaping and retrieve performance of utilizing etc at 100% by layers of material. Should be fixed relatively by the excellent choice to select the material for use. After injecting the shaping technology and come out in 15 altogether, can really just popularize and popularize . One a kind of adoptions inject the thick teeth of shaping fails and produces horizontal cross-section altogether. Material to pack nylon epidermis, and pearl material pack the nylon at - - glass layers of material core. A rate that shrinks material of pearl of glass is extremely low in core one, have good size stabilities. Nylon prevent pearl from grains of material easy problem of denuding that produces by epidermis person who give good and lubricated tooth tooth gear wheel. Already developed several kinds and processed the method of improving new-typly at present on the basis of the basic theory of injecting shaping altogether. At however, in the mould"" and gas assist paint mould mould. Mould have and paint processing method to adopt low molecular weight polymers as the outer material, Gas assist mould mould shaping to adopt the nitrogen or another kind of gas as the core one( or core ones) material. Produce and process equipment constant to perfect and improve, satisfy of different use newly and the new technologies demands with product design, Inject technology and will become the rich and potential industrialized extensive production technology method altogether.
2. inject by - it compress shaping
Inject and compress shaping move perpendicular on dividing into mould line direction by medium-sized s of walls at -. Adopt the method at the shaping, fill mould stage and produce pressure drive melting body flow according to process, But this flowed the degree of depth of one melted variably. At flowing one deeply relatively, pressure drop relatively low, so that heavy areas make pieces of shaping excessive to pigeonhole melting body, And has prevented the material in the twinkling of an eye from responding, these 2 kinds of factors will hinder the flow of the melting body equally. It injects forming process type make pieces of the 14%s of thickness finally by s of degree of depth, After the plastic has been packed 60% - 75% of the type roughly, stop injecting, a of walls of mould is bulldozed at the same time , Until make the wall original shaping of one finally. The final size of making one is defined at this stage . If at mould wall at process fulling of more type before moving, this kind of technology is usually called and cast and press shaping. On the whole, cast and press shaping to adopt pressure that become to making one go on and protect and pigeonhole in one a piece of variable the type ones of volumeses. Cast and press stage to increase the stages of density, density and then in lying between and solid state plastic change melting body. Adopt and cast and press way shaping pre- pressing discs, remaining stress degree of minimising, Make pieces of have remain stress produce and become phenomenon of refracting. It cast and press shaping improvement type activities types types for kinds of new technology in s of walls,inject its make. Already someone call outside gas to assist shaping law the method, actually these are a kind of misunderstanding, Because the gas has not influenced the melting body flow in type of plastic . During routine inject shaping, protecting and press is while a of volume of keeping type does not change , Under the function that the pressure flows, add and enter more plastics. Unite, Being emerged by the runner position of the high pressure and making a defect probably.
3. computers supplementary shaping
Adopt computer assist project( cae) design and analyse and help and shorten design cycle and prevent cost from expensive mechanical fault processing. Commercial emulations daily to indicate size on flowing one code, melt material flows in flowing dishes of system and type with balance, The figure of offeredding and put bestly and runner defining runner at the same time . Calculate pressure of injecting and shut mould want at different processing terms and material fix by tonnage. And warping rate combine initial to flow into too very accurate to estimate out person who shrink. What is important is and want and make the design tool help and analyse personnel process and go on the operation judged while studying or in a certain plan of design skillfully. Understand at results and can't process in order that it is by research object /materials from prerequisite. After consider adopting this kind of method accurate data-in , can make enormous benefit . In addition, economic make design cycle not to be short and needs produce shorter time the analysis. The one that should point out is, commercial cae procedures usually can't be used directly. It fills and imitate and produce valuable experience but the result must rethink its limitation to estimate again . Use modern computers go on and inject shaping simulated test and limited to pure viscidity fluids only( include the melting plastic of viscoplasticity ). One actual flow form measurable melting body person who flow intoes and performance announce etc. structure by speed, If can carry on the viscoplasticity analysis of high accuracy . At present adopt any other to process way reach this advanced competences, And recent years, at emulation the industrial circle person who take the leads of equipment and the research groups of university already made good progress. Have several a of companies make great efforts and probe emulation technology, in order to be be able to be being explained moulding the sex instinct act and process the phenomenon of more reality correctly. For example, get together on the influence that the orientation of the possessive chain is distributed to some physics performance and performance . Processing physics is very complicated, but some viscoplasticity is embodied too alike to still totally understood , Perfect the rational processing way and taking shape slow at present even more. These stronger strong ways will be exceeded the production capacity that will be designed at present greatly .
4. reversal inject shaping
Comparatively speaking, it is that a relatively new inject shaping chooses parameters that the reversal is injected. The greatest difficult point of this technology is lain in when processing the condition suddenly changeses, To the thing that it will be known little about what kind of change behavior plastic melting body will demonstrate . About the rudimentary knowledge of melting body rheology, is not merely the regular shear . Say exactly , the melting body responds( the viscidity and elastic behavior) the characteristic needing expressing, Not only common stable state flow speed or shear speed and temperature, but also including pressure and flow the speed in the twinkling of an eye. These characteristics including a lot of content and very difficult to understand. However, if not in heterotypic materials inject respect make substantive progress, need and make and publish many kinds of different the concrete operational procedures of plasticses. Need and increase a in common use one tired to try on law is in order to getting ripe and accurate control method also another. During routine inject shaping, the type immobilizes in a of walls, some situations are left, Still utilize and filling on the mould and protect and press and fall section and move the mould wall . Can adopt 2 kinds of different methods : Person who move s of perpendicular on dividing into mould line direction wall; Rotate a of walls of the slipping type . Fill stage rotatory type cores with increasing mould. Through this kind of processing technology, the crooked performance and other mechanical performance of making one has gotten great improvement. Polyphenyl drink the water and polypropylene syringe adopt cup the processing method get great to change and break through the ground 2 a piece of products just by second.
新型注射成型技術(shù)
1. 共注射成型（芯層注射成型）
????采用共注射成型有助于觀察到制件中獨(dú)特的結(jié)構(gòu)。塑料“甲”先注射充入部分型腔，然后塑料：“乙”緊跟著“甲”注射進(jìn)入型腔并保持初始推動(dòng)流動(dòng)壓力場(chǎng)。根據(jù)表皮區(qū)和芯層的尺寸大小，按正確的比例關(guān)系計(jì)量出“甲”和“乙”的用料量，可制得1個(gè)內(nèi)芯層為“甲”外表完全由“乙”包裹的制件。
????另外，在化妝品應(yīng)用方面，有小部分的表皮“甲”料放在“乙”料之后注射，以使?jié)部诓糠值谋砥つ芡耆]合。用2種不同顏色的樹(shù)脂進(jìn)行共注射成型的制件，形成一個(gè)容易區(qū)分的表皮和芯層區(qū)間（認(rèn)識(shí)到所有的注射成型件中存在有類(lèi)似的表皮和芯層這一點(diǎn)非常重要。）如果沒(méi)有先進(jìn)的檢測(cè)技術(shù)，通常難以區(qū)分表皮—芯層的區(qū)域及其分界面。
????共注射成型并非一門(mén)新的工藝技術(shù)。英國(guó)ici公司早在70年代就開(kāi)始應(yīng)用這一技術(shù)，并取得了包括基礎(chǔ)理論，生產(chǎn)產(chǎn)品及機(jī)器設(shè)備等幾項(xiàng)專利。現(xiàn)普遍采用的ici生產(chǎn)工藝類(lèi)似“三明治模塑”，由于模塑外層表皮的材料與中間或芯層的材料不同，因此兩種材料必須有一定的相容性，并且芯層材料要求具有可高度輻射、發(fā)泡成型和100%回收利用等性能。選用材料應(yīng)經(jīng)多種選擇比較而定。 共注射成型工藝問(wèn)世15年后，才真正得以普及推廣。一種采用共注射成型的厚齒輸制作橫截面。
????表皮材料是非填充尼龍，而芯層材料是玻璃-珠料-填充尼龍。芯層中玻璃珠粒料收縮率極低，具有良好的尺寸穩(wěn)定性。尼龍表皮賦予齒輪齒牙良好的潤(rùn)滑性并避免了珠粒料容易產(chǎn)生的磨蝕問(wèn)題。
????基于共注射成型的基礎(chǔ)理論目前已開(kāi)發(fā)出幾種新型加工改進(jìn)方法。例如，模內(nèi)“上漆”和氣體輔助模塑成型擴(kuò)大了采用這種工藝的范圍。模內(nèi)上漆加工方法是采用低分子量聚合物作為外層材料，而氣體輔助模塑成型是采用氮?dú)饣蛄硪环N氣體作為芯層（或部分芯層）材料。隨著產(chǎn)品設(shè)計(jì)與生產(chǎn)加工設(shè)備的不斷完善改進(jìn)，將滿足各種新應(yīng)用和新技術(shù)的需求，共注射技術(shù)必將成為富有潛力的工業(yè)化大規(guī)模生產(chǎn)工藝方法。
2. 注射—壓縮成型
????注射—壓縮成型中型腔壁移動(dòng)方向垂直于分模線。采用這種方法成型時(shí)，在充模階段，按工序產(chǎn)生壓力驅(qū)熔體流動(dòng)，但這一個(gè)流道的深度是可變化的。在較深的流道中，壓力下降得較低，以使大面積的制件成型中熔體沒(méi)有過(guò)度受壓，并避免了瞬間的材料響應(yīng)，這2種因素同樣會(huì)阻礙熔體的流動(dòng)。注射成型過(guò)程中，型腔深度可能是最終制件厚度的14%，在塑料填充了大致60%—75%的型腔后，停止注射，模腔壁周?chē)瑫r(shí)受到推壓，直至最終制件的壁原成型為止。制件的最終尺寸在這階段確定。
????如果在模壁按工序移動(dòng)之前充滿了型腔，該種工藝通常稱為鑄壓成型。大體上，鑄壓成型是在一個(gè)可變體積的型腔內(nèi)采用不變的壓力對(duì)制件進(jìn)行保壓。鑄壓階段是增加密度的階段，密度緊接著在介于熔體和固態(tài)塑料之間起變化。采用鑄壓方式成型致密圓盤(pán)，可把殘留應(yīng)力減至最低程度，制件上的殘留應(yīng)力可產(chǎn)生變折射現(xiàn)象。
????鑄壓成型的改進(jìn)型活動(dòng)式型腔壁是一種新技術(shù)，其由注射全體制件固化階段通過(guò)多孔的金屬型腔壁以“保壓”制件。這種方法已有人稱為外部氣體輔助成型法，其實(shí)這是一種誤解，因?yàn)闅怏w并沒(méi)有影響塑料熔體在型腔內(nèi)的流動(dòng)。在常規(guī)的注射成型當(dāng)中，保壓就是在保持型腔體積不變的同時(shí)，在壓力流的作用下，添加入更多的塑料。 聯(lián)同在型腔內(nèi)的保壓流形成了不均勻的壓力分布，有可能在受高壓的澆口位置產(chǎn)生制件缺陷。
3. 計(jì)算機(jī)輔助成型
????采用計(jì)算機(jī)輔助工程（cae）對(duì)加工設(shè)計(jì)及分析有助于縮短設(shè)計(jì)周期并可避免代價(jià)昂貴的機(jī)械失誤。商業(yè)性仿真代碼常用于流道上標(biāo)明尺寸，以平衡熔料在流道系統(tǒng)及型腔內(nèi)的流動(dòng)，同時(shí)確定澆口的最佳開(kāi)設(shè)置和澆口的數(shù)目。計(jì)算注射壓力和合模噸位要根據(jù)不同的加工條件和材料而定。收縮率及翹曲率結(jié)合初始流向也可準(zhǔn)確估算出來(lái)。重要的是要使得這種設(shè)計(jì)工具幫助熟練分析人員在某個(gè)設(shè)計(jì)方案或加工研究時(shí)進(jìn)行判斷的操作。結(jié)果必須理解為以研究對(duì)象和加工/材料為前提。當(dāng)考慮采用這種方法準(zhǔn)確輸入數(shù)據(jù)后，可取得巨大的效益。另外，這種分析經(jīng)濟(jì)性可使設(shè)計(jì)周期更短和所需的生產(chǎn)時(shí)間更短。
????應(yīng)該提醒注意的是，商業(yè)性的cae程序通常是不可直接使用的。充模仿真可產(chǎn)生有價(jià)值的見(jiàn)識(shí)，但結(jié)果必須重新對(duì)其局限性進(jìn)行重新考慮估計(jì)。應(yīng)用現(xiàn)代計(jì)算機(jī)進(jìn)行注射成型模擬試驗(yàn)，僅限于純粘性流體（不包括粘彈性的熔融塑料）?？深A(yù)測(cè)熔體流入型腔的實(shí)際流動(dòng)速率組成結(jié)構(gòu)和性能公布等，如可進(jìn)行高精度的粘彈性分析。目前所采用的任何其它加工方式都不可能達(dá)到這種先進(jìn)水平，并且最近幾年來(lái)，由仿真設(shè)備的工業(yè)界帶頭者和大學(xué)里的研究小組已取得了良好的進(jìn)展。有幾家公司正在努力探索仿真技術(shù)，以求能正確地解釋更多現(xiàn)實(shí)的塑性行為和加工現(xiàn)象。例如，聚合物主鏈的取向?qū)植康奈锢硇阅芎托阅芊植嫉挠绊憽＜庸の锢韺W(xué)是非常復(fù)雜的，而某些粘彈性體現(xiàn)象仍然沒(méi)有完全弄清楚，更完善合理的加工方式目前正緩慢形成。這些更強(qiáng)的有力的方式將獲得大大超過(guò)目前所設(shè)計(jì)的生產(chǎn)能力。
4. 交變注射成型
????相比較而言，交變注射是一個(gè)比較新的注射成型選擇參數(shù)。這項(xiàng)技術(shù)的最大難點(diǎn)在于當(dāng)加工條件突然改變時(shí)，對(duì)塑料熔體將呈現(xiàn)出怎樣的變化行為知之甚少。有關(guān)熔體流變學(xué)的基礎(chǔ)知識(shí)，不僅僅是固定的剪切粘度。確切地說(shuō)，熔體響應(yīng)（粘性和彈性行為）需要表達(dá)的特性，不僅是通常的穩(wěn)態(tài)流動(dòng)速率或剪切速率及溫度，也包括壓力及瞬間流動(dòng)速率。這些特性包括很多內(nèi)容而且十分難于弄清楚。然而，如果在異型材注射方面取得實(shí)質(zhì)性進(jìn)展，將需制訂出多種不同塑料的具體操作規(guī)程。另還需增加通用的累試法，以求得到成熟和精確的控制方法。
????在常規(guī)的注射成型中，型腔壁固定不變，某些情況下，還有利用在充模和保壓陷段移動(dòng)模壁。可采用2種不同的方法：移動(dòng)型腔壁方向垂直于分模線；旋轉(zhuǎn)或滑動(dòng)型腔壁。在充模階段旋轉(zhuǎn)型芯以增加對(duì)制件尤其是表皮部分分子的變軸取向。通過(guò)這種加工工藝，制件的彎曲性能與其它機(jī)械性能得到了極大的提高。聚苯乙飲水杯和聚丙烯注射器就是采用這種加工方法獲得重大改變突破地2個(gè)產(chǎn)品。
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