Which pad printing pad shape?
Printing International has more than 2200 different shapes of pad printing pads. There are four basic shapes: round, roof-shaped (saddle), rectangular and square. All standard pad printing pad shapes have one common characteristic: the printing surface is convex and angled from the sides to the print area in the centre. This convexity is a factor influencing the ink transfer, whereby the lateral angles provide the stability necessary to obtain smudge free prints. A semi-circular, tapered pad is the ideal shape. It can be rolled to all sides equally well, thus preventing the formation of air bubbles. This rolling motion allows the ink to be easily transferred from the printing plate to the object to be printed. The above described shape, however, does not lend itself to all objects or print motifs. Square or rectangular pads are sometimes necessary. When square pad printing pads are used, it is still important for the central area to be tapered in order to insure that the pad rolls well. The results produced by rectangular (bar-shaped) pad printing pads are generally less desirable, as the pads themselves can only be rolled laterally in two directions. Special pad printing pads with unique shapes can be made for specific applications.
Which size of pad printing pad?
In order to guarantee sharp, smudge free print, the pad printing pad selected should be as large as possible. The less the pad printing pad is deformed, the sharper the printed motif. It must be larger than the actual motif to be printed, particularly with “problem prints”, where corners are to be reproduced at an exact angle. The disadvantage of the large pad printing pad volume is that a very large pad requires a large press, and, such a large pad is more subject to the vibration caused by the movement of the press than one of smaller mass. Besides this, the price is considerably higher, as the main factor in pricing pad printing pads is the weight of the material.
In which hardness (durometer) should I order a pad printing pad?
Choosing the pad printing pad hardness should be done by the print engineers of Printing International. However, it is always a good idea to be somewhat aware of the process. The following is a list of our top tips for choosing pad printing pad durometers:
- Use hard pad printing pads for textured surfaces. You can also use them when you need to print an image in a lower-levelled area next to a raised surface. The pad will have to roll over the “step”.
- Hard pad printing pads can be used in a pad “nest” or matrix, when you need to use one machine with many pads that are placed with small gaps between them e.g. when printing computer keyboards.
- Softer pad printing pads are ideal when printing onto heavily contoured surfaces and fragile items.
- Use a softer pad printing pad if the power of your machine can’t compress the pad adequately to achieve a satisfactory rolling action.
- Try as much as possible to avoid using pad printing pads of different hardness on the same application. The thickness of the ink deposit will vary on the substrate. This is particularly true when dealing with a pad matrix.
For more information about choosing the correct pad durometer, please contact Printing International.
Download THE BROCHURE
Please fill in your contact details