包装技术基础11.pptxVIP

Lesson 11Package Printing 第11课 包装印刷 Introduction The objective of package printing and decorating is to create a visibly identifiable image, consistently, for a large number of impressions. these have been divided into two groups: Printing in the context of this discussion refers to flexography, lithography and gravure--the methods that account for the vast majority of all packaging graphic art. Each of these methods has a number of variations. Decorating is used to describe a number of special methods such as screen printing, hot foil stamping, embossing, and pad printing. Printing Methods Printing an image requires the ability to transfer fluid ink or another marking medium onto the substrate in the desired pattern. There are dozens of ways of doing this, but the bulk of package printing can be grouped in three basic categories based on the fundamental geometry of the printing plate: Relief : Variations are flexography (commonly referred to as flexo), letterpress, and offset letterpress (commonly referred to as dry offset) Printing MethodsPlanographic: The process is known as offset lithography and commonly referred to as lithography, offset or litho Gravure: The process is rotogravure, sometimes called roto and occasionally referred to as intaglio Printing presses have the following features in common regard1ess of the actual printing method used: An accurate material feed system that will present substrate to the printing station in precise register. An ink reservoir or ink fountain and a method of introducing ink into the printing train. Printing MethodsA means of metering ink so that the amount applied is consistent over the print run. A way of configuring the ink to the required pattern. This is done by the printing plates, one for each color. A means of transferring ink to the substrate by pressing the substrate between the ink-bearing surface and an impression roll. Since inks are applied as fluids, a means of drying or ]solidifying them. Printing