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Options and Accessories for Productive Pad Printing

(March 2007) posted on Wed Mar 07, 2007

Examine some of the solutions on the market today.

click an image below to view slideshow

By John Kaverman

Automated closed-cup machines can have thinner-metering systems added to continuously add thinner to the ink cup. These systems simply drip a predetermined amount of solvent into the top of the ink cup at regular intervals. Unless the ink cup has some feature that allows the thinner to be mixed into the ink, the thinner just sits on top of the ink, having very little effect on viscosity.

Pad shuttles

Pad shuttles can be a less-expensive alternative to the purchase of a larger machine in some applications. Using a split pad, a pad shuttle can, in some cases, print an image that would otherwise exceed the cliche or ink cup's maximum image area. For example, let's say you have two images of the same color that must print with their respective centerlines being 45 mm apart. When etched separated by this dimension, the two images don't fit within your machine's maximum image area. If these two images fit when separated by, for example, 30 mm, then you could etch them that way, pick them up with two pads butted together, and then shuttle the two pads apart to achieve the desired 45-mm separation prior to image transfer.

Pad shuttles can also be used to print two images on two different sides of the same part when both images, etched side by side, are picked up at the same time by two separate pads. After image pick up, the pads move along the X-axis to position the first print. After the first print, the nest rotates while the pad shuttles into position for the second print. In order for this to work, your machine needs to be able to pick up once and print twice, and you must have both a pad shuttle and a rotating nesting fixture (Figure 3). You can also print two colors this way if you have a two-color ink well on a one-color machine.

Nesting fixtures


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