V M Traders


Harnessing the Power of Electronic media for the Print media

      Rollers for offset printing

  The inking and dampening rollers in the offset machine are very important components for transporting the ink and to dampen the printing plate. Due to their various functions in the machine the rollers are subject to various demands and require special care and maintenance.
  Hardened rollers or rollers with surfaces damaged by solvents are frequently important sources of trouble. It is therefore necessary to check their Store-hardness. This hardness test according to standard DIN 53505 (“shore A”) is carried out with a handy test instrument, whereby a truncated cone-shaped needle is pressed into the surface of the roller covering by means of a spring. The maximum depth of penetration is measured. The readings on the indicator are from 0 to 100 in steps of 5 Shore hardness units each.
  Depending on the function of the roller, the required Shore hardnesses vary.
  Careless use of cleaning agents to clean the rollers also frequently causes printing problems. Fluids, which are injurious to rubber, must never be removed with unsuitable tools such as a wire brush or emery cloth.
  Detailed guidelines for care and maintenance of rubber products are given in standard DIN 7716.
  The industry has developed special cleaning and maintenance materials, which give excellent results, even in extreme cases and which help to preserve the roller covering. 
  Instructions from the roller manufacturers concerning the treatment and storage - before and during use - of rollers covered with elastic materials should also be strictly observed.  Only well maintained inking and dampening rollers guarantee good and consistent printing quality, long working life and permit rapid ink changes.  

Copyright ©  printingindia.com  All rights reserved
Website designed and Hosted by Quartette InfoTech Pvt. Ltd.