What is flexography?
Flexography is a form of printing using flexible photopolymer plates or sleeves with a 3D relief to transfer an image to a given material. A wide variety of inks, including fast drying water-based inks, can be printed onto a wide variety of materials, including plastic, metallic foils, cellophane, and paper. It is designed for printing small or large quantities quickly and is also well suited to printing large areas of solid color. The main applications are within the packaging industry such as labels, flexible plastic and paper packaging, corrugated cardboard, plastic bags and folding carton.
Why use flexographic print?
Flexography is the most popular process used to print packaging and product labels, as it is cost effective when printing small or large quantities and offers superb quality. Fine details and a rich palette of colors are attainable with the precision obtained by using flexographic plates. This attention to detail and quality is particularly important in food packaging, as it is the image on the package which attracts the customer and sells the product.
Flexographic printing produces high quality impressions with images at 133, 150 or 170 line screen onto a wide variety of substrates, and is often used to print images with 6, 7 or more different colors of ink, instead of being limited to the traditional 4 colors used in other types of printing. This enables flexographic prints to achieve a brightness and depth of color with a wider gamut compared to standard CMYK color printing.
Why use flexographic printing for making flexible packaging?
Flexographic (flexo) printing is ideal for printing on flexible packaging due to the excellent image quality, the high printing speeds and the ability to print on non-porous materials, which are ideal for food packaging.
Glunz & Jensen Degraf offers an extensive selection of prepress plate making equipment for flexible packaging. We offer exposure units, processors, dryers and light finishers for the entire range of flexible packaging plate sizes, e.g. 900 x 1200 mm (36 x 47”), 1200 x 1530 mm (47 x 60”) and 1320 x 2030 mm (52 x 80”). In addition, our portfolio includes mounting tables for precision plate positioning and tables to measure the relief depth of the plate.
What is the difference between flexographic plates and sleeves?
Flexographic plates are flat, rectangular flexible photopolymer plates which can be imaged with a laser or by exposing it to a UV light through a film negative (light sensitive plates). All major plate manufacturers in the flexo industry make their own versions of flexo plates and the corresponding dedicated equipment and, if necessary, the chemicals which are required to create the finished plates. Glunz & Jensen Degraf is the major supplier of this dedicated prepress equipment to the majority of the industry’s plate manufacturers.
Before they can be used on press, flexographic plates must be mounted onto a sleeve using double-sided tape on a mounting table. The mounting tables produced by Glunz & Jensen Microflex offer remarkable accuracy, ensuring excellent registration on press.
Cylindrical flexographic sleeves are essentially flexographic plates which have been pre-mounted onto a fibreglass form. Compared to plates, sleeve technology offers the advantage that there is no plate mounting required, saving time and delivering perfect register. In addition, the flexo sleeves which are currently on the market use thermal imaging, meaning that they are extremely fast to create and require no chemistry to process. This system is ideal for long run lengths.
Glunz & Jensen offers an extensive range of prepress equipment for making sleeves, including processors and dryers. In order for our customers to be competitive, we offer a multiple sleeve mounter and easy-to-use sleeve trimmer, allowing the printer to use only the required part of the sleeve and avoid waste, thereby saving money.
What are the advantages of automation in flexography?
Dedicated automation equipment and in-liner assemblies in flexo prepress reduce operator intervention during plate production, increasing efficiency, while reducing production waste and time. Though automation in flexo prepress is in its infancy, Glunz & Jensen has many years experience and expertise in creating fully automated systems for the offset industry and has begun pioneering projects in the flexo industry.