Which presses does BFS stock rollers for?
We stock a broad variety of rollers for ALL leading press manufacturers.
BFS and its expertise of rubber compounds has become synonymous with knowledge and innovation when it comes to roller manufacture in the UK. Both original manufacturers of printing machinery as well as printers rely upon BFS’s craftmanship and innovation.
How much do your offset printing press rollers really cost?
The price you pay for a new or re-covered roller is only one factor in the “true cost” of the roller. The life of the roller measured in the total number of impressions is another factor—a roller that lasts longer is obviously cheaper in the long run. And, the performance operating costs are another very important factor. To compare costs you need to consider how long the roller will last—how many impressions you will get from it during its life. Then you need to consider if the roller will shrink and glaze easily, forcing expensive down time to reset and clean. If the roller will not hold its shape, or changes properties by running too hot, you need to consider the cost of wasted ink, paper, and time tweaking the press to force it to print.
Can I refurbish my offset printing press rollers?
At BFS we recover your used rollers and also offer an exchange program for the most popular used items, which is a great way to get rollers shipped to you quickly. You simply call us and we send your new rollers to you immediately. You send us your old rollers or if you are on our regular pick-up route we will collect. We then recover the rubber on your roller (a fraction of the cost of a new roller) and keep it on the shelf for the next exchange customer. Our roller exchange service is unrivalled and means that you do not suffer downtime waiting for rollers to arrive. All rollers are press ready to slot straight into your machine. This means they are fitted with new bearings and spacers so you are assured properly aligned rollers.
Why do offset printing press rollers shrink?
Sooner or later all rollers change size, but poor practices and poor rollers speed up the process, requiring frequent downtime for press adjustments. In fact, shrinkage is the leading cause of roller resetting. Running with shrunken rollers leads to ink/water balance problems, colour variation, and excessive downtime. Shrinkage can be caused by excess heat, usually from the settings being too high, from insufficient lubrication, bad bearings or the usage of inappropriate roller care cleaning products. The heat causes a chemical reaction in the rubber that breaks the long molecule chains (specifically the plasticizers) which give the rubber compound its flexibility and ability to hold its shape. This breakdown occurs naturally as a result of the constant flexing of the rubber during normal operation, which is why even the best rollers won’t last forever. But excessive heat speeds up the deterioration process. It can also be caused by the plasticizers leaching out of the rubber over time.
Using an inappropriate roller for the job can cause shrinkage too. The rubber compounds on rollers will be specific for each application, which each have their own conditions; such as the speed at which they will be running (higher speeds generate more heat) and the types of chemicals or UV they will be exposed to.
How should I store my offset printing press rollers?
New rollers can be damaged if not stored correctly. To avoid creating flat spots in the rubber, do not lean them against the wall or store them flat on a shelf or the floor. They need to be suspended from the journals, keeping the rubber surface free of any pressure or load. Heat and light can cause the rubber compounds to break down prematurely. Keep the paper cover on the rollers and store them in a cool place away from heat sources and direct sunlight. The UV light in sunlight, or emanating from fluorescent lights, can also damage the rubber. Be careful not to store rubber rollers near electric motors unless the area is well ventilated. This is because the ozone generated by motors can also break down the rubber compound.
Am I using the right offset printing press roller cleaning products?
Using the wrong chemicals on your rollers can contribute to the deterioration of the rubber. BFS can advise you as to which would be safe and formulated especially for the type of roller that you are using.
What is the best offset printing press roller cleaning product?
Always us chemicals recommended by the manufacturer. BFS offer a full range of approved chemicals, with instructions. Never test new chemicals on your rollers. It can be an expensive mistake.
What’s the best way to install bearings onto an offset print roller?
Bearings must be mounted using a specialist press. This is the only way to get perfect alignment and not damage the bearings or the journal in the process. Never, use a hammer! No hammer can deliver the balanced force that is necessary to mount bearings correctly. Tapping on the floor is a crude technique that almost guarantees the pressure will be uneven and the bearings damaged. All BFS rollers arrive “press ready,” with the bearings factory installed.
Can I reuse offset printing press roller bearings?
Don’t risk damaging your expensive press? An imperfection too small to feel could be enough to cause serious problems. The bearing is ruined just by pulling it off the journal because the seals are forced against the rows, causing them to be permanently indented and obstruct the free turning of the bearing balls. This can cause the journal to grab, leading to indexing, stripe-width changes around the roller, and inconsistent ink transfer and colour variations.
How much pressure should I use when I set my offset printing press rollers?
As little as possible! Never tighten the rollers beyond the press manufacturer’s specifications. Setting rollers with too much pressure is a common mistake, and an expensive one. Some think that the pressure is what moves the ink and water, but actually it’s the shearing forces generated by the different speeds of rollers with different diameters that do the work. More pressure can reduce print quality and lead to unnecessary downtime. Always back rollers off a little before inserting new ones because new rollers will most likely be slightly fatter than the used rollers. Set the new ones by coming forward until making contact with any surface, never by backing off.
What’s the best way to clean an offset printing press roller?
- Use a water miscible wash to remove the top layer of solvent-soluble and water-soluble particles from the nap of the roller. 2. Use a non-grit roller paste to remove the insoluble particles. 3. Finally, wash a second time with a water-miscible wash to remove the remaining soluble particles. Talk to one of BFSs Technical Sales Managers to advise you when it comes to roller care products.