User login

Tooling and Techniques for Pad-Printing Irregular Products

(July 2006) posted on Thu Jul 06, 2006

Find out how to manipulate artwork and select the right equipment and consumables to pull off the project successfully.

click an image below to view slideshow

By Linda Huff

Pad support also is essential for providing a sharp print. Some applications require a special fixture that supports the pad during printing to avoid distortion. As the pad strokes downward onto the part, it must be stopped a certain point just past the image; otherwise, it will cause the image to stretch. In other words, the image goes wherever the pad goes. The fixtured part must encourage the rolling effect of the pad through the entire pad stroke. By supporting the pad on all sides of the part, the pad will roll the image onto the part then roll off smoothly.

Part stability is crucial for repeatability of the print position. Unusual objects and difficult shapes are notorious for movement during the print cycle. Machines that are not stabilized (tabletop presses or presses on casters) create movement during continuous-cycle printing. This can cause repeatability problems if your part does not have the appropriate fixture. If fixtures are properly tooled for optimal repeatability, your print jobs will progress smoothly and with fewer scrap parts.

Special tooling

Custom-made tooling (Figure 3) is sometimes required. It may be in the form of a unique pad configuration or a means to provide support on the inside of a part to prevent the part from collapsing. For instance, small plastic bottles my need air pressure to remain inflated during the compression of the pad. If the bottle collapses during the print cycle, your image will be distorted.

Additionally, custom fixtures with the ability to rotate or accept adjustment can be designed for jobs that involve multiple prints on a single object. This type of application-specific tooling will allow the user to move the loaded fixture to the secondary print location with the same optimal repeatability.

Custom fixtures can also support glass and other delicate items. Without proper support, these breakable items can be crushed by the pressure of even the softest pads during the print cycle.

Ink and substrates


Did you enjoy this article? Click here to subscribe to the magazine.