It is vital to clean print rollers if you wish to continue to get premium quality prints. No wonder many print-shops take utmost care and spend a lot of money on the best cleaning solution and equipment. Chemical cleaners are available in almost all shops selling printing supplies.
Baking Soda Systems
Sodium bicarbonate or baking soda blast systems utilize air pressure to deliver the baking soda media to the print roller. A vacuum unit is then used to recover the spent media. The principle of re-fracture is used in baking soda blasting. Bigger crystals of sodium bicarbonate are smashed into smaller ones upon impact. The blasting pressure may reach 20 to 25 psi for mechanically engraved and chrome rollers. Laser engraved rollers need 30 to 35 psi. The soda gets to inside of the cells to break up the dried ink. This process is good for removing dried ink and stains. It can be used to clean the wide web rolls either on the press or off it. This is for narrow web rolls' press only.
Off press cleaning needs a blast cabinet. The latter must be enclosed. The on-press cleaning units are portable. They can be taken from one press to another. On-press systems are used by corrugated box printers. The roll rotates while the nozzle travels mechanically across roll at the time of cleaning. The units are safe, effective, and quick.
The plastic bead systems utilize plastic and air bead media to impact upon the cylinder surfaces. Air pressure of 35 to 70psi are used. Such systems are generally off press units which come with enclosed cabinets. The roll gets rotated while the nozzle journeys the entire length. The dried ink is broken up by the poly or plastic beads.
Ultrasonic And Chemical Cleaning
The ultrasonic cleaning systems use sound energy. This makes for the cleaning action. The system is monitored by ultrasonic generators controlled by timers. These are utilized to restrict the exposure time and also to minimize damage done to cells. Too much exposure will damage the cylinder. Shorter clean times are needed for higher line engravings. This is as they are more vulnerable to damage.
The chemical cleaners fund daily use in the printing industry. They are effective for most part. Majority of such cleaners are caustic and permit a thorough and quick clean. The chosen chemical must comply with OSHA and EPA guidelines. Data-sheets and guidelines must also be reviewed.