Understanding the Pad Printing Pad

Hardness of the Pad Printing Pad

The hardness of the pad is normally determined by the amount of silicon oil used when the pad is moulded. The harder the pad, the less silicone oil that was added. Four basic pad hardnesses are standard in the industry and cover most applications. Customs pad hardnesses are available through most pad suppliers. Many pad manufacturers colour code the four standard hardnesses by adding pigment to the silicone itself or by colouring the pad base. Not all manufacturers use the same code, but the typical colour designations by pad hardness are:

As a general rule, the harder the pad, the better the performance. However, a hard pad may be impractical in some applications, such as when using a low-power machine or printing onto a delicate item. Choosing the proper pad hardness for a job is a matter of experimentation and experience.

Special 550 Shore pads are available for printing onto abrasive substrates and textured finishes. Two such applications include the turn-signal control arms and windshield-wiper control arms of automobiles, which are moulded in glass-filled nylon. A heavy white ink is required, and the pad must resist the abrasive nature of the substrate.

A useful tool for all pad printers is a durometer gauge for determining pad hardness. This simple tool (the same one you would use to measure the Shore hardness of a squeegee) is available through silicone-rubber suppliers and many general-service dealers in the screen - and pad-printing industries. You can now purchase pads with a "ready to use" finish.

Maintaining accurate pad hardness can be problematic for some pad manufacturers, making the durometer gauge an ideal quality-control device for incoming pads.

Use the following guidelines for pad hardness when selecting your pads:

  • Hard pads are most suitable for textured surfaces you can also use them when you need to print an image in a recessed area next to a raised surface and the pad will have to roll over the "step."
  • You can also use hard pads in a pad "nest" or matrix, when you must fit a single rnachlne with numerous pads that are spaced with small gaps between them (for example, when printing computer keyboards).
  • Use softer pads when printing onto heavily contoured surFaces, Also use them when printing onto fragile items.
  • You must use a sofler pad is the power of your machine can't compress the pad sufficiently to achieve a satisfactory rolling action.
  • Avoid using pads of different hardnesses on the same application, or the thickness of the ink deposit will vary on the substrate. This js particularly true when dealing with a pad matrix.

Shape and Size of The Pad Printing Pad.

Shape is the most important variable in selecting a pad.

Hardness of the Pad Printing Pad

The hardness of the pad is normally determined by the amount of silicon oil used when the pad is moulded.

Surface Finish of the Pad Printing Pad

Throughout the pad-printing industry, the custom practice among pad manufacturers is to furnish pads with a high gloss finish.

Material of the Pad Printing Pad

This topic refers not only to the material of the pad itself, but also the base onto which the pad is mounted.

Special Printing Pads for Large Images

In some situations, a large image area must be printed and the machine does not have the power to compress such a heavy pad in a smooth motion.

Quality Control of Pad Printing Pads

Poor-quality consurnables like pads can destroy the performance of the printing machine.

Pad Printing Pad Life

Next to "What should I use?", the most difficult question to answer is "How long should a pad last?"