Pad Printing Explained
Take a look at a detailed explanation of the pad printing process for many different industries on the Unique Assembly & Decorating blog. Click to read!
Of all the product decorating services that we offer, we get the most questions about pad printing. We thought it would be a good idea to share some information about this versatile printing method.
Product Decorating Services – Pad Printing
Pad printing is a printing method that allows the transfer of an image onto a 3-dimensional object. Although forms of pad printing had existed for some time, pad printing brought about a significant change in the watchmaking industry in the late 40’s and 50’s; watchmakers were able to transfer an image onto the curved surface of the watch face for the first time. Today, pad printing is used to decorate parts of various shapes, sizes, and materials in many industries.
The modern-day pad printing process is fairly simple. While the ink cup (think of a cup of ink turned upside down on a razor blade like edge) sits over an etched image on the printing plate, ink is flooded into the recessed image. During the print cycle, the ink cup moves away from the etched image and exposes the ink-filled image while clearing away the excess ink. Next, the silicone printing pad compresses over the image and plucks the image out of the printing plate. Then, as the pad moves towards the part to be printed, the ink cup moves back over the etched image and floods the image with ink for the next cycle. Finally, the silicone printing pad compresses on the part and transfers the image onto the part. Then the process repeats. Click the video tab of this page for a video of pad printing a medical device.
Technology is in the Printing Pad, but the Art is in Choosing the Right Pad for the Job
Most people think the image is molded on the pad like a rubber stamp used to mark a piece of paper, but it is not. The process is more accurately called transfer pad printing or pad transfer printing — a better description of the process because the printing pad transfers the image from the printing plate to the part. The unique properties of the silicone pad enable us to lift the image from a flat printing plate and transfer it to a variety of surfaces — flat, cylindrical, spherical, compound angles, textures, concave or convex — with little image distortion. Printing pads are made in a variety of sizes, shapes, and durometer. While the science of the process is in the pad, the art of the process lies in matching the right pad size, shape, and durometer with the right surface to provide the best results. It can take years of experience to develop the skill to choose the correct pad for each project.
Inks for Nearly Every Material
Pad printing inks are formulated to match the type of material to be printed. Ink lines are developed to provide adhesion and durability for a variety of material such as plastic, glass, metal, wood or ceramic. However, matching ink to the substrate does not stop here. Ink lines are available for nearly every plastic material including (but not limited to) ABS, Acrylic, HIPS, polycarbonate or nylon, and for various coatings or paint used on metal products. With pre and post-treatment procedures, more difficult materials such as polypropylene, polyethylene, Delrin or Urea can also be pad printed. For most applications, inks are either solvent-based, which are cured with time or by adding heat to improve adhesion or durability for some substrates, or UV based using ultra-violet light for an instant cure.
Pad Printed Parts in Every Industry
Pad printing is used to decorate plastic, glass, and metal products — practically any rigid part that requires a logo or marking — from many industries including automotive, medical, electronic devices, cosmetic / health & beauty, plastic molders and manufacturers.
Unique’s Pad Printing Capability
At Unique, we offer the following pad printing capability
- Single Color Pad Printing
- Multicolor Pad Printing – 2 to 5 Spot Color Images
- 5-Color Process Pad Printing (4 color process plus a white for non-white substrates)
- Automation for High Volume Projects
- Rotational Pad Printing
I hope this information has given you with a better understanding of the pad printing process and how it works as well as how it relates to your project or industry. Feel free to contact us to learn more.