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- 电子线束的辐照技术有哪些?
- 本站编辑:杭州企力电子有限公司发布日期:2019-03-18 12:59 浏览次数:
长期以来人们都认为辐照对高分子材料起着破坏作用,直至该世纪50年代人们发现辐 照可使聚烯烃交联及随后出现的将某些单体通过辐照接枝到聚合物上以后,辐照技术在高分子材料中的应用才迅速发展起来。,辐照技术中使用的辐照源主要有两 种:一类为天然或人工放射源,另一类为各种不同类型的加速器。前者如目前广泛应用的射线源及铯137,锶90等;后者如X射线管、直线加速器、回旋加速器 及其他高能装置。
它们的作用原理都是通过高能辐射激发聚合物分子并引起电离;正负离子的分解;电荷的中和,并进i而引发各种化学反应,特别是自由基反应。 由于辐照技术对材料形态,辐照条件没有特殊要求,辐照反应便于控制(可精确控制交联度)、辐照均匀、重现性好。产品纯度高,可进行电线电束的连续化生产, 从而被认为是一种生产效率高、节能省力,工艺成该低而创效大,无公害或少公害的新型加工技术。此外,电子线束照技术还适用于一些化学法无法交联的材料如 PVC、PP等,及具有复杂结构的绝缘和护套,已构咸了对有机过氧化物交联技术的严峻挑战。
由于线束中 有油膏存在,金属复合带会长期与油膏接触,这就需要考虑与油膏的相容性。而相容性所观察的对象是看在油膏中基带与聚合物薄膜是否会起泡或分层。抗腐蚀性是 指复合带在酸性或碱性环境中会不会分层或对基带造成腐蚀。比如复合钢带的基带,通常用镀铬钢带,镀铬层的特点是即在潮湿大气中很稳定,同时在一般酸性环境 中也很稳定。这是因为金属铬该身在大气中极易氧化成一层极薄的钝化层。试验和长期的使用证明,镀铬钢带用在线束复合带中的相当稳定可靠的
For a long time, it has been considered that irradiation has a destructive effect on polymer materials. The application of irradiation technology in polymer materials developed rapidly only after it was discovered in the 1950s that irradiation can crosslink polyolefins and subsequently graft some monomers onto polymers by irradiation. There are mainly two kinds of radiation sources used in radiation technology: one is natural or artificial radiation sources, and the other is accelerators of various types. The former includes widely used radiation sources and cesium 137, strontium 90, etc. The latter include X-ray tubes, linear accelerators, cyclotron and other high-energy devices. Their principle of action is to excite polymer molecules by high-energy radiation and cause ionization. Decomposition of positive and negative ions; Neutralization of electric charges and I initiate various chemical reactions, especially free radical reactions. Because the irradiation technology has no special requirements on the material morphology and irradiation conditions, the irradiation reaction is easy to control (the degree of crosslinking can be accurately controlled), the irradiation is uniform, and the reproducibility is good. The product has high purity and can be used for continuous production of electric wires and bundles, thus being considered as a novel processing technology with high production efficiency, energy saving and labor saving, low production cost, high efficiency, no pollution or less pollution. In addition, the electron beam irradiation technology is also applicable to some materials that cannot be crosslinked by chemical methods, such as PVC, PP, etc., as well as insulation and sheaths with complex structures, which have posed severe challenges to the organic peroxide crosslinking technology. Due to the presence of ointment in the wire harness, the metal composite tape will be in contact with the ointment for a long time, which requires consideration of compatibility with the ointment. The object of compatibility observation is to see whether the base band and polymer film will blister or delaminate in the ointment. Corrosion resistance refers to whether the composite tape will delaminate or cause corrosion to the base tape in acidic or alkaline environment. For example, the base band of composite steel strip is usually chrome-plated steel strip. The chrome-plated layer is stable in humid atmosphere and also stable in general acidic environment. This is because chromium metal is easily oxidized into a very thin passivation layer in the atmosphere. Tests and long-term use have proved that the chrome-plated steel strip is quite stable and reliable in the on-line bundle composite strip.