Roller Cleaning & Care
Printing rollers are the "heart" of the printing press and require regular attention, care and maintenance. In optimum/clean condition, on-press rollers will feel soft, pliable, velvet-like and deliver top quality printing results every shift. The ultimate success of the printing process depends on control of ink distribution. A press roller with dried ink, gum. laze, paper lint and calcium carbonate on the surface or ground-in the grooves or valleys (nap) of the roller, will not have the ability for fine-film ink pickup or lay-down. The "nap" of a glazed roller has been filled and covered with different particles accumulated from all the materials that have passed over the roller such as:
- Water-soluble particles
- solvent-soluble particle
- Insoluble contaminates
|Clean Rubber Roller Surface||Glazed Rubber Roller Surface|
The nap of a glazed roller is filled and covered with different particles accumulated from all of the materials that pass over the roller: water-soluble particles (gums, coatings, dust), solvent-soluble particles (inks, etc.), and insoluble residue (mineral deposits, clays, soap deposits). The particles are mixed and bound together, trapping each other into the tiny grooves. To restore the roller, you need to flush all of these particles out of the grooves one step at a time.
Use a three step system to clean the rubber roller surface:
- Use a water miscible wash (solvent mixed with water) to remove both the solvent-soluble and water-soluble particles that are near the top of the deposit layer. This leaves the insoluble particles.
- Use a non-grit roller paste to remove the insoluble particles. Be sure to use a paste that is designed and tested for the type of rollers you have. Never use a paste with grit, for this will damage the rubber.
- With the layer of insoluble particles removed, most of the remaining soluble particles will be exposed and can be washed out with a second water-miscible rinse.
- For Strong dirt, you should use volatile, residueless cleaners.
- In order to preserve the surface structure of the roller, cleaners containing ester or ketone, and especially methyl acetate or acetone, must not, under any circumstances, be used.
The most important
- In storage the roller must be supported only on the shafts and should never rest on the covering surface.
For longer storage time the covering should be protected from direct light and should be ideally stored at temperatures between + 20 °C and + 30 °C at about 65 % relative humidity.
- The original TRAD Rollers wrapping paper provides the required barrier to light,
and should not be removed until shortly before the roller is used.