外文翻譯--塑料注塑成型的實驗室實驗與實踐

附錄 附 1：外文文獻翻譯 Practice vs. laboratory tests for plastic injection moulding M. Van Stappen, K. Vandierendonck, C. Mol, E. Beeckman and E. De Clercq Abstract:Different types of anti-sticking coatings have been applied industrially on injection moulds for various types of plastics. Very often these tests are being done on a trial-and-error basis and results obtained are difficult to interpret. WTCM/CRIF has developed laboratory equipment where the injection moulding process can be simulated and demoulding forces and friction coefficients can be measured. These measurements were compared with surface energy calculations of the coated surfaces and of the plastic materials in order to find a correlation. Using this approach it must be possible to make an easy and cheap selection of promising coatings towards plastic injection moulding. Another important advantage is that the understanding and modelling of the mouldplastic interface becomes possible. This new way of coating selection for plastic injection moulding has been demonstrated for various PVD coatings and verified for different industrial injection moulding applications. Author Keywords: Injection moulding； PVD coating； Modeling； Surface energy Article Outline 1. Introduction 2. Experimental details 3. Results and discussion 4. Conclusions References 1. Introduction PVD coatings have found their way into industry for several applications like metal cutting and deep drawing. Their use in plastic injection moulds has given both positive and negative results. The unreproducible character of the results hinders further implementation in industry. To valorise the intrinsically good coating properties like chemical inertness vs. plastics to enhance demoulding, more insight is needed into the mechanism of interaction between the mould surface and the plastic material during injection moulding. To our knowledge, a systematic study of the influence of mould surface roughness, mould coating, properties of the polymer like Youngs modulus, surface energy, polarity, structures, etc. on possible binding mechanisms between the mould surface and the plastic material has never been carried out. This makes it practically impossible to understand demoulding mechanisms and, as a consequence of this, to select a proper coating for the injection mould. The purpose of this work was to try to simulate the injection moulding process in the laboratory and to correlate the results with surface energy measurements of the coated mould and of the plastic material. This could result in an approach to select the proper coating for a certain kind of plastic to be injected. 2. Experimental details Laboratory equipment has been built to measure demoulding forces and friction coefficients. The mould itself is made out of tool steel 1.2083 and has a diameter of 64 mm and a height of 30 mm (Fig. 1). The thickness of the moulded part is 2 mm. A pressure sensor measures the demoulding forces. The temperature inside the mould is measured by thermocouples as presented in Fig. 1. All moulds were hardened to a hardness of 56 HRC. Fig. 1. A cylindrical plastic part injection moulded around a mould. After a running-in period of 40 injections, the demoulding force was measured 10 times for each coatingplastic material combination. Surface energy was measured on the surface of the coating and on the surface of the plastic material using the model of Owens and Wendt. A Digidrop GBX apparatus has been used based on water and di-iodomethane as testing liquids. To measure the total surface energy, the dispersive surface energy and the polar surface energy are measured. Injection moulding was carried out as follows. In the first application, a polyurethane plastic material with tradename DESMOPAN 385 S was injection moulded using uncoated moulds and moulds coated with, respectively, a TiN and a CrN coating. In the second application, three types of polymers were tested on a TiN coated mould and an uncoated mould. Two elastomers (trade name HYTREL G 3548 W, which is a block-copolyester, and SANTOPRENE 101-73, which is a blend of polypropylene and EPDM), and EVOPRENE, which consists of polystyrene and butadiene. 3. Results and discussion The demoulding forces measured for the first application are given in Table 1. Table 1. Demoulding forces (N) for DESMOPAN The demoulding forces for the second application are given in Fig. 2. Fig. 2. Demoulding forces (in N) for three materials: HYTREL, EVOPRENE, SANTOPRENE. This demoulding behaviour has also been observed in industrial practice, so the demoulding laboratory apparatus is a good simulation of reality. To explain these results, an attempt was made to find a correlation with the surface energy measurements. Both total surface energy as well as polar surface energy in mJ/m2 were compared for both coated surfaces and plastic materials. Fig. 3. Total surface energies (mJ/m2) of the different coatings and plastic materials. In order to explain the demoulding behaviour, an attempt was made to make a correlation between demoulding forces measured and the surface energy values. It should be expected that when the surface energy of the coated surface is lower than the surface energy of the plastic material, an easy demoulding behaviour could result as a consequence of low material affinity between coating and plastic material. Because the ratio of polar vs. dispersive surface energy varies for the different plastic materials, both surface energy values are taken into account. For the demoulding forces measured in the first case (Table 1), it could be seen that a CrN coating, especially, could offer good demoulding behaviour. When we compare ( Fig. 3) the surface energy values of DESMOPAN with the values for the mould surfaces STAVAX (=uncoated), CrN and TiN then it can be seen, for both total surface energy as polar surface energy, that the measured values for DESMOPAN are lower compared to the mould surface values. This means that there is no correlation between the demoulding forces measured and the surface energy values. It seems, however, that a CrN surface has the lowest surface energy compared to a TiN coated surface and an uncoated surface. When one looks to the total surface energy values (Fig. 3), one can see that SANTOPRENE has the lowest value and HYTREL the highest. If our hypothesis was correct from the beginning, we should conclude that the demoulding force for HYTREL should be small and should be large for SANTOPRENE. One can see from Fig. 2. that this is not the case. Fig. 4. Polar surface energies (mJ/m2) of the different coatings and plastic materials. When one looks at the polar surface energy values (Fig. 4), the three plastic materials have a lower value than the mould surface and SANTOPRENE and EVOPRENE have a lower value than HYTREL. Even when other surface energy criteria are used, e.g. the lower the energy of the mould surface the lower the demoulding force (3), even then no correlation can be found. It can be seen that a TiN coating always increases the surface energy and, on the other hand, good demoulding is sometimes seen, e.g. for HYTREL and DESMOPAN, and sometimes bad demoulding results, e.g. for EVOPRENE. Hence, we can conclude that, based on the surface energy values measured, no correlation could be found within the demoulding forces. Obviously, other parameters, such as roughness and injection temperature, also play an important role in explaining the demoulding behaviour. In order to continue the research work to explain the demoulding behaviour, we will focus on five industrial demonstrations and try to incorporate all relevant parameters: coating properties, plastic material properties and injection parameters. 4. Conclusions No correlation could be found between the demoulding behaviour of plastics vs. coated moulds and the measured surface energy values. Other parameters must also influence this demoulding behaviour. Further research will focus on other parameters like coating properties, plastic properties and injection parameters. References 1. Annonymous, Big savings made with coated injection moulding tool, Precision Toolmaker 6 (1998),138. 2. O. Kayser , PVD-Beschichtungen schtzen werkzeug und schmelze. Kunststoffe 7 (1995), p. 98. 3. M. Grischke , Hartstoffschichten mit niedriger Klebneigung. JOT 1 (1996), p. 15. 譯 塑料注塑成型的實驗室實驗與實踐 M. Van Stappen, K. Vandierendonck, C. Mol, E. Beeckman and E. De Clercq 摘 要 ： 對于不同類型的塑料， 不同類型的防粘涂料已應(yīng)用于注塑模具 工業(yè)。 很多時候 ,這些試 驗正在做一個 反復(fù)試驗， 依據(jù)和結(jié)果都難以解釋 .WTCM/CRIF 開發(fā)了 可以模擬注射成型 過程的實驗室設(shè)備 ， 并且 可以通過測量得到脫模力 和摩擦系數(shù)。 這些測量數(shù)據(jù) 與 計算所得的 涂層表面 和塑料 材料 的表面能量值進行比較，以找到相關(guān)聯(lián)系。 使用這種方法 可能 為注射成型的涂料 作出方便和廉價的選擇 。 另一重要好處是 使了 解和塑造 模具成型 塑料 的 接口變得可能。 這一為塑料注射成型選擇涂料新的方法已經(jīng)應(yīng)用于各種 PVD 涂料，并且這種方法在塑料注射成型工業(yè)中也得到了時間。 關(guān)鍵詞 ：注射成型； PVD 涂層 ； 塑造 ； 表面 能 文章綱要 1介紹 2 實驗內(nèi)容 3. 結(jié)果和討論 4. 結(jié)論 參考文獻 1.介紹 PVE 涂層在工業(yè)中得到了一些應(yīng)用，如 金屬切口和深沖壓。他們在塑料 注射模具中的應(yīng)用產(chǎn)生了 正面和 負面的 結(jié)果 。它的不可再生的性質(zhì)阻礙了它在工業(yè)中的更廣泛的應(yīng)用。確定性質(zhì)好的 涂 料性能，如對塑料的化學(xué)惰性，來幫助脫模，關(guān)于找到模具型腔 表面和塑料材料之間的 在注射成型 期間 的相互化學(xué)作用機理，需要 更多 的研究。 就我們所知， 有系統(tǒng)的研究模具表面粗糙度、模具涂層和 熱性能 的影響 ，如 楊氏模量 、表面能量 、 極性 、 結(jié)構(gòu) 等，在模具表面和塑料材料之間找到一個可能的關(guān)聯(lián)機制還從 沒有進行過。這使得了解脫模機理和為注塑模具選擇一個合適的涂料幾乎不可能 。 這項工作的目的 是 在實驗室里設(shè)法模仿 注射成型 的過程 ，并且找到涂層模具的表面能測量結(jié)果和塑料材料的表面能測量結(jié)果的相互關(guān)系。 這 樣可以得到一種方法去 選擇適當(dāng)?shù)耐繉訛槟骋槐蛔⑸?的 塑料。 2.實驗內(nèi)容 實驗試里建立了實驗設(shè)備來測量脫模力和摩擦系數(shù)。 模 具用 工具鋼 1.2083 做 成，直徑64 毫米和 高 30 毫米 (如圖 1)。成型塑件的厚度是 2mm。壓力傳感器測量脫模力。模具里的溫度由熱電偶測得。模具被淬硬到 56HRC。 圖 1.圓柱形塑料零 件的注射成型 在經(jīng)過 40 次跑合注射以后，每個涂層與塑料的結(jié)合的地方的脫模力被測量了 10 次。通過 在涂層的表面和在塑料材料的表面使用 Owens 和 Wendt 模型 測量表面能。一種以水和 鄰苯二甲酸二碘甲烷 作 為測試液體的 Digidrop GBX 設(shè)備被使用，去測量表面總能量、分散的能量和集中的能量。 注射成型的執(zhí)行過程如下，在 第一 步中 ,將 商品 名 DESMOPAN 385 S 的 聚氨酯塑料材料 分別注入生產(chǎn)時沒有上涂層的模具、涂上 TiN 的模具和涂有 CrN 涂層 的模具。第二步，將三種類型的聚合物分別在涂他 TiN 的模具和未上涂層的模具上進行測試。 二個彈性 材料 (商標(biāo)HYTREL G 3548 W， 是一個塊聚酯 和 SANTOPRENE 101-73，是聚丙烯和 EPDM的混合 )和 EVOPRENE，包括 聚苯乙烯和丁二烯 。 3.結(jié)果和討論 第一步中測量的脫模力如表 1 表 1. DESMOPAN 的脫模力（ N） 第二步 中三種材料的脫模力如圖 2 圖 2.HYTREL、 EVOPRENE、 SANTOPRENE 三種材料的脫模力（ N） 這 種 脫模行為 ,也出現(xiàn)在工業(yè)實踐中 , 所以脫模實驗室儀器 可以做一個 很好的現(xiàn)實模擬 。 試圖去找到 一種 與 表面能量測量 相關(guān)聯(lián)的因素來解釋這個結(jié)果，不同涂層模具和不同塑料材料的總表面能和集中表面能（ mJ/m2）將進行比較。 圖 3.不同涂層和塑料材料的總表面能 為了解釋脫模 過程， 有人企圖 把測定的 脫模力和表能量值 聯(lián)系起來。正如所 預(yù)料到 的那樣 ,當(dāng)涂層表面 的 表面能低于塑 料 材料 的 表 面 能 時，從 易脫模 行為可以得出一 個結(jié)論就是涂料和塑料材料的低親和性。因為集中對分散的表面能比率為不同塑性材料而改變 ,因此兩個表面能值都應(yīng)被考慮到。 從第一步中所