The problem with a rigidly mounted flexographic plate is that partially excessive printing pressures occur which can only be compensated for by the relief of the printing plate - to the detriment of the printed image.
The solution is provided by "soft mounting". The excess pressure is absorbed by the compressible foam carrier of the plate mounting tape.
The flexographic printer of today faces several obstacles in producing a quality printed product. Such examples may be: using print cylinders in which the TIR is inconsistent, worn gears which may cause vibrations, or tolerance variations of substrates.
The problem with a rigidly mounted flexographic plate is that, although plates and vinyl tapes are available in a limited tolerance range, partially excessive printing pressures occur which can only be compensated for by the relief of the printing plate - to the detriment of the printed image. As the printing pressure adjusts to those parts of the printing plate with the lowest pressure, the pressure of the remaining area is significantly increased. This increased pressure creates the following results:
- Squeezed edges on the leading edge of the plate
- Dirty print on the trailing edge, in reversed type, and in non-image areas
- Plate bounce causing imperfect impressions
- Uncontrolled dot gain
- Halos around printed areas
- Below normal press speeds due to the excessive pressure on the lead edge of the plate
The solution is provided by "soft mounting". The excess pressure is absorbed by the compressible foam carrier of the plate mounting tape. All areas having too much pressure are no longer pushed, bent, or creased by the rotating cylinder, but will compress into results are realized:
- Lines and screens retain their original structure. The guidance of the substrate and register are more accurate
- The leading and trailing edges of the print appear softer and cleaner
- More accurate transitions from solid print to halftone
- Better control of the size and shape of dots
- Machine vibrations and tolerances of the substrate are more easily compensated
- The life of the printing plate is greatly increased
Lohmann Main | Compressible Foam Mounting Tapes | Hard Mounting Tapes | DuploFLEX® 5 EB and 5 EBX | Construction of Lohmann Compressible stickyback | Plate Mounting Techniques