Michelle Moxley, innovation director at M&R Companies and the person behind @NotoriousRandD on Instagram, explains how to get the most out of digital hybrid printing
Digital hybrid printing is the newest technology to disrupt the screen print market. Hybrid printing is when an automatic screen printing press includes a CMYK digital printer on one of the screen print stations. DTG (direct-to-garment) and screen print each have their own unique strengths: DTG is capable of printing short run quantities with minimal ‘make ready‘ and offers efficient printing with easy repeatability. Screen print, on the other hand, offers high production speeds along with the ability to apply special effects, as well as allowing the printing of any ink colour on almost any fabric.
Digital hybrid printing is screen printing a design and adding a digital enhancement. The first step in hybrid printing, exactly like traditional screen printing, is to make the screens. In this step-by-step guide, we used four screens to achieve a full-colour print with a metallic special effect application. The screens were imaged using direct- to-screen (DTS), which involves printing an image directly onto the surface of an emulsion and exposing the screen; we used the M&R I-Image STE I, which is able to generate and expose a full-size image in under a minute. The screens were coated with pure photopolymer emulsion to ensure the screen would be compatible with the high solid water-based screen printing inks we were using. The advantage of using DTS in a hybrid print space is that the digital art board and the DTS art board are shared, streamlining the registration between the two application methods.
The hybrid process lends itself to variable data printing. These prints were made by sending different combinations of car and background images to the digital head
Automatic set up
Next is the set-up on the automatic press. For this print, the rotation was underbase white, flash then cool, tie coat white, digital print using the M&R Digital Squeegee printer, flash then cool, top coat clear, flash then cool and special effect. Once the screens and squeegees, flood bars and screen inks were added to the press and the screens registered, we tested the digital print to check the registration and colour. If the digital print had needed any adjustments (colour, image, etc), we could make the changes and upload the new file within minutes.The press was pre-heated because this helps the ink flow when using a high solid water-based ink. The underbase white was printed, then flashed and cooled. The tie coat white, which bonds to the digital ink, was applied next and then immediately followed by the digital print: this is a wet-on-wet application.
After a digital print it is important to flash the digital ink and then print a top coat of clear so as to create a strong bond between all the elements. After another flash cure and cool, the final special effect screen was printed. We were able to achieve a run rate of over 400 per hour in production. Finally, the shirt was passed through a tunnel dryer at the manufacturer‘s recommended cure times for high solid water- based inks; for this print on a 100% cotton shirt, the cure was 2 1/2 minutes at 160°C. One of the unique points about this application method is the variable data aspect: for this design we printed 20 different garments, each of which contained a different combination of one of five different car images and one of four different backgrounds. Further variation is possible by adjusting the screen application, for example by changing the colours of the ink or adding a new technique such as flock or foil.
Screen print is enhanced by incorporating it into a digital hybrid system because it allows for variable data to be easily applied and offers reduced set-up times. A digital hybrid system also improves on DTG because it allows the application of special effects and exact colour matching along with offering faster production speeds. Hybrid brings the very best of two worlds together.
Step-By-Step: Digital Hybrid Printing
(1) The screen is prepared using the I-Image STE I direct-to-screen system
(2) The image is printed onto the surface of the emulsion and exposed by LED according to the manufacturer‘s recommendations
(3) The screens are aligned and the squeegees, floodbars and inks added
(4) The first white is printed, followed by the flash and cool down stations
(5) The tie coat white is printed
(6) The digital is printed directly onto the wet tie coat
(7) The digital print is flashed to prevent smearing and to create a strong bond
(8) A clear top coat is printed to bind the image together
(9) The special effect is printed followed by another flash and cool down station
(10) The tee is cured in a tunnel gas dryer for 2 1/2 minutes at 160°C