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       TIPS ON STORING ROLLERS  
 

Roller care commences the day new rollers arrive from the supplier. Manufactures usually recommended against storing new rollers. If possible, put them to immediate use, which offers at least one important benefit and two safeguards for the lithographer determined to continue an effective roller maintenance programme. If possible, locate the storage rack in the pressroom, eliminating the time needed to adjust to its temperature and humidity.

Placing new rollers into immediate use guarantees the longest possible on-press mileage from them. The synthetic rubber material will experience deterioration prior to the rollerís first printing assignment.

The press operator will have an opportunity to examine the rollers for roundness, evenness of caliper or diameter, possible core distortions and durometer (hardness)

Each of these factors bears on the life span and efficiency of a lithographic roller. Discovering any deficiencies as soon as possible will ensure against future downtime and roller-related presswork problems to enable the operator to return defective rollers to the manufacturer earlier rather than later.

In addition, depending on the urgency of roller replacement request as perceived by the manufacturer, a new or replacement roller may not have received the normal aging or stress relief measures prior to the finishing process. Such a roller almost invariably develops high or low spots if left in storage for any length of time between its receipt and its initial use.

It may prove expedient, nevertheless, to store new rollers at least temporarily before putting them on the press. If so, be sure to leave the rollers wrapped in the special paper provided to protect them from sunlight, ozone and airborne contaminants.

The location of the storage rack also will affect the longevity and efficiency of a roller- old or new- left off the press for extended periods of time. If possible, locate the storage rack in the pressroom, eliminating the time needed to adjust to pressroom temperatures and humidities prior to installation on the press. Avoid situating the storage rack near an ozone producing electric motor or close to any source of high heat.

The design of the storage rack also is important to the well being of rollers. Storage racks may be constructed to hold small rollers by the ends of their shafts; large, heavy rollers fare better if stored vertically.

Vertical storage of rollers prevents the rubber of composition material from separating from the core. Rollers stored horizontally should be turned 180 degrees periodically to prevent the "storage sag" rollers may experience over time while in storage.

The storage rack also should provide ample clearance between the rollers and any part of the rack or of any nearby structure or machinery. Probably the most common cause of low spots in offset rollers is allowing them to rest for prolonged periods while in contact with a solid surface or with another roller.

Some minimal preparation of a roller going into storage helps prevent roller deterioration or damage. It is vital to clean a roller taken from the press and slated for storage. Be sure to remove all traces of ink. If necessary, use a deglazing compound on the roller to lift any film of hardened ink and gum.

It also pays to protect a roller earmarked for lengthy storage. Wrap it in heavy paper or apply a film of non-detergent grease or roller lubricant to the rollerís surface. The film of lubricant will protect the roller from the harmful consequences of any humidity/temperature fluctuations in the storage area.

A chart kept near the storage rack will prove helpful in keeping track of a rollerís age and length of storage. The chart should list the date of purchase of arrival of a new or reconditioned roller, the date of its consignment to storage and a simple one-to-five rating of the rollerís condition at the time of storage.

It is important to guard against careless handling of rollers being prepared for storage. While not the primary press rollers, rollers kept in storage nevertheless comprise important adjuncts to the printing process and are vital to the continued proficient operation of the pressroom. They must be ready for immediate use on the press in case of damage or functional failure of one of the newer rollers.

Avoid banging a roller against a solid object, especially against sharp table corners, workbenches and projections of machinery. The synthetic rubber material comprising the rollerís pliable, laminated outer layers easily can suffer irremediable damage - permanent low spots may result from heavy blows.

All press rollers should either be on the press in use or in the storage rack, except when removed from the press for purposes of cleaning or examination. A roller left untended on a workbench or left learning a wall, table or piece of machinery is particularly subject to damage. A roller thus left accidentally for any prolonged period of time should be thoroughly examined for any signs of damage.

 

 

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