In flexo printing, 'image transfer' refers to the process by which an image is transferred from the image carrier to the substrate it is printed onto. As we have previously covered, this image transfer process is actually one of the main differences between flexo printing and offset printing. In this post, we take a closer look at image transfer.
Direct & Indirect Image Transfer
A guide published by the University of Illinois points out that the method of image transfer is what separates direct and indirect printing processes. Flexo printing is a direct printing process because the image is transferred directly from the image carrier to the substrate. By contrast, indirect printing processes, such as lithography, transfer the image from the image carrier, to an intermediary, then to the substrate.
Image Transfer In Flexo Printing
The basic flexo printing image transfer process occurs as follows:
1) A 3D version of the image to be printed is made on the image carrier, which is typically made from a flexible rubber or polymer material. This 3D image is a 'relief', which is effectively sculpted into the material.
2) Ink is delivered to the anilox, which is the cylinder within the printing system that rolls ink onto the image carrier. Tiny dimples are then precisely engraved into the anilox roller's surface. Excess ink is then removed using a scraper, which is more commonly known as a 'doctor blade'.
3) The anilox transfers ink to the image carrier.
4) The substrate is sandwiched between the image carrier and the impression cylinder, which applies the pressure. This results in the transfer of the image from the image carrier to the substrate.
A Better Choice Of Substrates
One of the major advantages of flexo printing over offset printing is the ability to transfer images onto a wider range of materials. While offset printing is limited to flat surfaces, flexo printing can be used to print onto packaging, bags, wrappers, foil, paper, wallpaper and a variety of additional substrates.
Visit Our Showroom In Nottingham
Modern flexo printing equipment can make printing tasks easier and produce higher quality image transfers. If you would like to find out more, why not visit our showroom for a free demonstration of our printing presses? Call 01949 836223 to book an appointment.