tampon basic forms
All tampons have a curved (convex)
This is necessary to guarantee a rolling movement (see
rolling characteristics) during the ink pick up and subsequent
application which ensures a good printing image and prevents
the inclusion of air bubbles.
The shape of the tampon is usually
determined by the shape of the print image and the geometry
characteristics of the printing part.
The various tampon shapes can be classified into four groups:
- Round tampons
- Oval tampons
- Square tampons
- Elongated tampons
The shape of the pad also determines
the orientation of the print image in regard to the tampon (see
tampon contact point) depends on the tampon shape. Round, oval
and square tampon shapes have a contact point (see print image
Elongated tampon shapes have a contact line (see print image
As a rule, the tampon should not make the initaial contact in
the middle of the print image because the biggest compression
occurs in this area.
the following rules apply
when choosing a tampon:
of the tampon shape
|The steeper or pointed the shape of the tampon,
the harder and bigger the volume, the better the printing result.
||When printing uneven parts, the selection
of the right tampon shape and tampon hardness (see Shore-A) determines
the quality of the print image and the print speed.
||Certain cliché types require the
use of steeper tampon shapes in higher Shore-A areas depending
on the etching depth and / or the halftone.