【正文】 n the melting resin and mold. During cooling near the mold cavity will be nonuniform temperature region. During cooling, cooling channels near the area than the area far from the cooling channels to cool faster. This temperature difference will cause uneven shrinkage of the material to heat stress. The strong thermal stresses can cause warping problem. Therefore, it is an imitation of the important stage in the molded parts during the cooling area of the thermal residual stress. Understand the characteristics of the thermal stress, causing deformation of presimulation. In this article, the injection mold is designed to produce warping of test samples and perform the thermal analysis presented in the mold on the role of the residual thermal 天津科技大學(xué)外文資料翻譯 17 stress. After the pletion of the mold design and manufacture of, tryout injection warp specimens there are many defects. Including a short shot, splash and warping. The solution of a short shot by milling out the additional pores to drain the trapped air in the corner of the cavity. At the same time, reducing the injection pressure can reduce the occurrence of splashing. Warpage control can be controlled by many factors, such as injection time, injection temperature and dissolved material temperature. After these trimming, mold can produce lowcost highquality warp specimens, these specimens need to go through a simple polishing. 3. Obtaining an electroformed shell: the equipment Electrodeposition [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 ing 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 400 ml/l, nickel chloride (10 g/l), boric acid (50 g/l), Allbrite SLA (30 cc/l) and Allbrite 703 (2 cc/l). The selection of this position 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 50 MPa and for optimum conditions around 2 MPa). 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 surfaceacting 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 天津科技大學(xué)外文資料翻譯 18 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: 600 mm 400 mm 500 mm in size. ? Three teflon resistors, each one with 800 W. ? 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 50 A and continuous current voltage between 0 and 16 V. ? Titanium basket with nickel anodes (Inco SRounds 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 22 A/dm2), the temperature (between 35 and 55 176。 45 4 177。 Electroforming。 最后，還要根據(jù)材料的收縮率留出足夠的公差補(bǔ)償 。 設(shè)計(jì)這個(gè)模具時(shí)，選用了截面為拋物面形式的流道，可以 只在公模板上方便的加工。壓板的最大區(qū)域取決于兩系桿之間的距離， 這對(duì)于注塑機(jī)來(lái)說(shuō)是一個(gè)限制。 天津科技大學(xué)外文資料翻譯 7 天津科技大學(xué)外文資料翻譯 8 這 種現(xiàn)象表明，在低電流密度和高溫條件下工作，得到更小的晶粒尺寸和殼重現(xiàn)性好，就是所需要的足夠的應(yīng)用程序。因?yàn)檫@是一個(gè)負(fù)責(zé)內(nèi)部壓力的塑料注射液，這種方式與環(huán)氧樹(shù)脂灌漿將遵循它，相反對(duì)低韌性的殼補(bǔ)償，這就是為什么它是必定盡可能的外殼厚度均勻，并沒(méi)有重要的原因，如 腐蝕。 模具的設(shè)計(jì)和 制造完成后，試模注塑出來(lái)的翹曲試樣會(huì)存在很多缺陷。灌漿階段就是在 注射溫度下用融解的熱塑料注入模腔。 天津科技大學(xué)外文資料翻譯 3 該階段取得 的 核心 [4]， 根據(jù)這一方法 研究了這項(xiàng) 工作 ,有 如下 : a,利用 CAD 系統(tǒng) 設(shè)計(jì) 的理想目標(biāo) b 模型制造 的快速成型設(shè)備 (頻分多路 系統(tǒng) ). 所用 材料 是一個(gè) ABS 塑料 c 事先涂有導(dǎo)電涂料的一個(gè) 電鑄 鎳殼 (必須有導(dǎo)電 ). d 無(wú)外殼 模型 e 核心的生產(chǎn) 是背 面 環(huán)氧樹(shù)脂的抗高溫 外殼 與 具有制冷的銅管管道 . 注塑成型是世界上最常見(jiàn)的方法生產(chǎn)復(fù)雜。因?yàn)樗麄兒芏鄷r(shí)候是互為條件。這種方法在 控制成型過(guò)程中，嚴(yán)重依賴(lài)于運(yùn)營(yíng)商的直覺(jué)和幾個(gè)“拇指規(guī)則”運(yùn)營(yíng)商的發(fā)展而用不同的材料工作過(guò) 一段時(shí)間，壓力，溫度和時(shí)間設(shè) 置是不同的。熱感應(yīng)強(qiáng)度的增 強(qiáng)主要在模塑零件的冷卻階段，主要因?yàn)樗牡蛯?dǎo)熱性和在溶融樹(shù)脂和模具之間的溫差。 同時(shí) 這種添加劑也增加 了殼的 阻力 . Allbrite703 是 一種可生物 降解水溶液表 使用劑 氯化鎳 ,有利于 解決金屬 統(tǒng) 一 分布在陰極產(chǎn)生的導(dǎo) 電性的問(wèn)題。 45 3 177。 7 校驗(yàn) 注塑模具 試驗(yàn)已進(jìn)行 了 各種代表性熱塑性材料如聚丙烯、高密度聚乙烯和 PC、 并進(jìn)行了注射部件性能的分析，如尺寸，重量，阻力，剛度和柔性。所以，在產(chǎn)品的表面只會(huì)留下一條分型線(xiàn)的痕跡。 合適起氣孔設(shè)計(jì)可以使空氣釋放出來(lái)不會(huì)出現(xiàn)零件不 完整的現(xiàn)象。n, Revista de Pl225。 nevertheless, such operativity will be limited depending on other factors, such as internal stress because 天津科技大學(xué)外文資料翻譯 19 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 200–250 HV, 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 300 HV. Among the most usual materials for injection molds it is possible to find steel for improvement (290 HV), steel for integral hardening (520–595 HV), casehardened steel (760–800 HV), etc., in such a way that it can be observed that the h