四大印刷工艺
四大印刷工艺在印刷过程中，除了选择适当的承印物及油墨外，印刷品的最终效果需要通过适当的印刷方式来完成。现代印刷工艺按照不同的标准可以分成许多种类。比如说，根据印刷原理可分为物理性印刷和化学性印刷，而根据印刷色区数可分为单色印刷和彩色印刷。一般来说，人们习惯根据不同的印版将基本印刷方法分为以下四大类：平板，凹版，凸版和孔板。这四类所对应的最常见的主要工业印刷方法分别为：胶印，凹版印刷，柔性版印刷和丝网印刷。胶印是平板印刷的一种，也是最广泛使用的印刷技术，在中国具有绝对的统治地位。由于印版制作简便快速，并能以高精度还原色彩，使得图像清晰明锐，所以胶印具有印刷速度快，质量稳定，印刷周期短等优点。胶印的产品范围非常广泛，书刊，报纸等常见的印刷品都采用胶印的方式。凹版印刷这个词本意就是雕刻，所以它的原理和雕刻印章很相似。凹版印刷效果出色，印品色彩丰富，形象逼真，因此价格相对昂贵，通常适用于高品质的印刷品，比如纸币，股票，邮票等。随着人们对印刷品质量要求的提高，其使用范围也将越来越大。在凸版印刷技术中具有代表性的柔性版印刷是包装常用的一种印刷方式，在印刷各种塑料袋，纸盒，罐头标签等方面具有良好的效果。柔性版印刷可以做到高速多色印刷，并且使用无污染，干燥快的水性油墨，有利于保护环境。丝网印刷是一种孔板印刷技术，适合于制作特殊效果的印件。丝网印刷的灵活性特点是其他印刷方式无法比拟的，除了纸张之外，几乎任何一种材料都可以作为承印物，而且还可以在立体面上施印。在日常生活中，我们所见到的书包，汽水瓶，家用电器电路板等都是采用这种印刷方式。当然，随着科技的发展，印刷方式日新月异，未来一定会出现更优，更强的新技术。Basic Printing MethodsIn addition to choosing suitable printing stock and ink, the final effect of the presswork is determined by choosing appropriate printing method. According to different standards, modern printing methods can be divided into many types. For example, names like physical printing and chemical printing indicates their different printing principle, while under the number of color zone we have single-color printing and multi-color printingGenerally speaking, people used to divide all of these into four basic categories based on their printing image carriers: planographic or lithographic printing, gravure or intaglio printing, relief or letterpress printing and porous printing. And the related four common industrial printing methods are: offset printing, gravure printing, flexography and screen printing. Offset printing is a kind of lithographic printing, it is the most popular printing method，especially in China. Making offset plate is simple and rapid, and this kind of plate can get high-quality color reduction, which makes the image clear, bright and sharp. Therefore the advantages of offset printing include fast printing speed, stable quality and short printing cycle. It has a broad range of printed matter: books, periodicals, newspapers and many other common things are all printed by this method.The word “gravure” just means to carve, so the operation principle of gravure printing is similar to carving. The quality of its production is very high with rich colors and vivid images, thus its price is relatively expensive and it is suitable for those high-quality printed matter like paper money, stocks, stamps, etc. With the improvement of peoples requirements on printing quality, its range of application will be wider and wider.Flexography is typical in letterpress printing, and is frequently applied to package printing. It can achieve very good effect on all kinds of plastic bags, cartons and cans labels. It is generally considered as a kind of high-speed & multi-color printing method. Because the water-based ink used in flexography is pollution-free and quick-dry, this method is conducive to protect the environment.Screen printing belongs to porous printing technology which can produce special effects. Its advantage in flexibility is incomparable. Almost all kinds of material can be used as its printing stock in addition to paper. And this method can be applied on the facade as well. In our daily life, the product of screen printing is everywhere, such as backpacks, bottles, circuit board of household electrical appliances, etc.Of course, with the development of science and technology, printing methods improve rapidly. Newer and better technology is bound to be invented in the future. (420 words)
