外文翻译--塑料注塑成型的实验室实验与实践

附录 附 1：外文文献翻译 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. 译 塑料注塑成型的实验室实验与实践 M. Van Stappen, K. Vandierendonck, C. Mol, E. Beeckman and E. De Clercq 摘 要 ： 对于不同类型的塑料， 不同类型的防粘涂料已应用于注塑模具 工业。 很多时候 ,这些试 验正在做一个 反复试验， 依据和结果都难以解释 .WTCM/CRIF 开发了 可以模拟注射成型 过程的实验室设备 ， 并且 可以通过测量得到脱模力 和摩擦系数。 这些测量数据 与 计算所得的 涂层表面 和塑料 材料 的表面能量值进行比较，以找到相关联系。 使用这种方法 可能 为注射成型的涂料 作出方便和廉价的选择 。 另一重要好处是 使了 解和塑造 模具成型 塑料 的 接口变得可能。 这一为塑料注射成型选择涂料新的方法已经应用于各种 PVD 涂料，并且这种方法在塑料注射成型工业中也得到了时间。 关键词 ：注射成型； PVD 涂层 ； 塑造 ； 表面 能 文章纲要 1介绍 2 实验内容 3. 结果和讨论 4. 结论 参考文献 1.介绍 PVE 涂层在工业中得到了一些应用，如 金属切口和深冲压。他们在塑料 注射模具中的应用产生了 正面和 负面的 结果 。它的不可再生的性质阻碍了它在工业中的更广泛的应用。确定性质好的 涂 料性能，如对塑料的化学惰性，来帮助脱模，关于找到模具型腔 表面和塑料材料之间的 在注射成型 期间 的相互化学作用机理，需要 更多 的研究。 就我们所知， 有系统的研究模具表面粗糙度、模具涂层和 热性能 的影响 ，如 杨氏模量 、表面能量 、 极性 、 结构 等，在模具表面和塑料材料之间找到一个可能的关联机制还从 没有进行过。这使得了解脱模机理和为注塑模具选择一个合适的涂料几乎不可能 。 这项工作的目的 是 在实验室里设法模仿 注射成型 的过程 ，并且找到涂层模具的表面能测量结果和塑料材料的表面能测量结果的相互关系。 这 样可以得到一种方法去 选择适当的涂层为某一被注射 的 塑料。 2.实验内容 实验试里建立了实验设备来测量脱模力和摩擦系数。 模 具用 工具钢 1.2083 做 成，直径64 毫米和 高 30 毫米 (如图 1)。成型塑件的厚度是 2mm。压力传感器测量脱模力。模具里的温度由热电偶测得。模具被淬硬到 56HRC。 图 1.圆柱形塑料零 件的注射成型 在经过 40 次跑合注射以后，每个涂层与塑料的结合的地方的脱模力被测量了 10 次。通过 在涂层的表面和在塑料材料的表面使用 Owens 和 Wendt 模型 测量表面能。一种以水和 邻苯二甲酸二碘甲烷 作 为测试液体的 Digidrop GBX 设备被使用，去测量表面总能量、分散的能量和集中的能量。 注射成型的执行过程如下，在 第一 步中 ,将 商品 名 DESMOPAN 385 S 的 聚氨酯塑料材料 分别注入生产时没有上涂层的模具、涂上 TiN 的模具和涂有 CrN 涂层 的模具。第二步，将三种类型的聚合物分别在涂他 TiN 的模具和未上涂层的模具上进行测试。 二个弹性 材料 (商标HYTREL G 3548 W， 是一个块聚酯 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.结果和讨论 第一步中测量的脱模力如表 1 表 1. DESMOPAN 的脱模力（ N） 第二步 中三种材料的脱模力如图 2 图 2.HYTREL、 EVOPRENE、 SANTOPRENE 三种材料的脱模力（ N） 这 种 脱模行为 ,也出现在工业实践中 , 所以脱模实验室仪器 可以做一个 很好的现实模拟 。 试图去找到 一种 与 表面能量测量 相关联的因素来解释这个结果，不同涂层模具和不同塑料材料的总表面能和集中表面能（ mJ/m2）将进行比较。 图 3.不同涂层和塑料材料的总表面能 为了解释脱模 过程， 有人企图 把测定的 脱模力和表能量值 联系起来。正如所 预料到 的那样 ,当涂层表面 的 表面能低于塑 料 材料 的 表 面 能 时，从 易脱模 行为可以得出一 个结论就是涂料和塑料材料的低亲和性。因为集中对分散的表面能比率为不同塑性材料而改变 ,因此两个表面能值都应被考虑到。 从第一步中所