Printing plates and flexible printing.
by bigbag, Sat Dec 28, 2013 at 03:38:44 AM EST
Printing processes such as offset lithography use printing plates to transfer an image to paper or other substrates.The plates may be made of metal, plastic, rubber, paper, and other materials. The image is put on the printing plates using photomechanical, photochemical, or laser engraving processes. The image may be positive or negative. Typically, printing plates are attached to the plate cylinder in the press. Ink is applied to the plate's image area and transferred directly to the paper or to an intermediary cylinder (blanket) and then to the paper. In screen printing, the screen is the equivalent of the printing plate. It can be created manually or photochemically and is usually a porous fabric or stainless steel mesh stretched over a frame.
Flexible printing is including flexible packaging film and label printing. Types include two sides, the image printed on your PP woven bags(also named as PP bags) and PE film etc., will always appear in the same position from one item to the next. The number of printing plates needed for a job where printing is done on both sides of the sheet of paper is determined not only by the number of colors of ink but also by how the sheets are imposed and fed into the printing press.
Ink is applied to a plastic surface through flexible rubber or polymer plates. This printing uses quick-to-dry inks. The inks dry through evaporation.Flexible printing does work by imprinting lettering and imagery on the surface of a stand up pouch. The letters and images are engraved onto flexible rubber or polymer plates. They are engraved in the form of tiny indentations. Ink is rolled onto the plates which in turn are joined with letterpress cylinders. The small indentations in the plates hold the ink. The ink is transferred to plastic or other printing surface when it comes into contact with the inked plates.A big advantage of using flexographic printing is the time it takes to make custom printed flexible pouches. It is quicker to make custom stand up bags with flexography than with rotogravure printing. Another big advantage of the technique is that it has been tried and tested. It has been around since the late 19th century. It has evolved a lot in during the 20th century. Thirteen years into the 21st century, and it remains a popular printing technique.