Digital cylinder printing is when a machine places ink directly onto a curved surface which is generally the wall of an object that has a circular cross section and a constant, conical or variable diameter. Cylindrical digital printing is a method of reproducing black and white or color images and text on cylindrical objects, usually promotional products, through the use of digital imaging systems.
The digital process is by definition faster than conventional screen printing, requiring fewer production steps and less setup time for more colors and more complex jobs. This in turn allows for short stroke lengths.
The ability of digital cylinder presses to print full color in a single pass, including primers, varnishes and specialty inks, allows for multiple design techniques, including:
● Mirror prints: visible on the inside and outside of glass or plastic.
● Tone-on-tone: solid substrate with a matte finish enhanced with a clear ink or varnish
● Tinted glass: color that is opaque enough to see through
The full wrap cylindrical print also benefits from smooth edges with no visual overlap. To facilitate the preparation of the print file, the illustrations of the original design must be reproducible on cylinders and conical elements without the need for manipulation or distortion; that is, flat images will be printed to scale on a curved surface and the software will adapt automatically. The most advanced systems available on the market can handle these needs.
The digital cylindrical printing process involves inserting a cylinder-shaped element, or part, into an accessory, which holds it firmly in place. The part then passes under a printhead mechanism where small droplets of CMYK (cyan, magenta, yellow and black) inks are released in a specific pattern to form an image. Typically, one part is printed at a time and may take 8-45 seconds to complete, depending on the complexity and quality of the graphics. It is then finished with a UV layer to add a glossy finish and protect it from abrasion.
There are three different imaging techniques used by digital cylinder presses: multi-pass, single-pass and helical printing.
Multi-pass – Multi-pass printing is when the print heads or the printed object are moved axially along the part, like a flatbed printer. Movement time is ineffective and can cause sewing artifacts between movements.
Single pass: A single pass involves using a series of printheads to print the full length of the image with a single revolution of the printed object. Typically, different colors are printed at different stations, resulting in increased cost, increased complexity and sensitivity to print nozzle leaks.
Helical printing: Helical printing is a hybrid method between single and multiple pass approaches. The image data is mapped to allow continuous images in a helical pattern with a limited number of printheads. Users can fine-tune the print resolution, speed, and curing controls to optimize image quality or choose a higher speed if quality is not critical. Cones can be viewed at high speed and curved vessels can be managed through the range of controls offered.
Items that can be printed using digital cylindrical processes include cups, glasses, thermos, bottles, makeup containers, machine parts, transport tubes, pens, tubes, jars and others.