SubscribeROTATEK is a company with over 30 years of experience in Graphic Arts and has installed more than 1.200 machines all over the world. Rotatek manufactures offset and flexo narrow web printing presses for labels, flexible packaging, cartons, commercial printing, etc.
Traditionally, label and flexible packaging printers use letterpress and flexo presses to manufacture their products. But we should not exclude from the beginning the possibility to print labels with offset presses.
Offset is the most used printing system around the world. Over 70% of all printing jobs are made in offset. It is also well known that offset gives a superior quality to other printing systems such as flexography and letterpress. Why is this so?
Because offset is an indirect printing technology. This means that the offset plate does not transmit the image directly onto the support, it transfers the image to a covered rubber roller called blanket cylinder, and this one transfers the image onto the substrate. In addition, the printing form is flat; this means that there is no relief to differentiate the printing areas from the non-printing areas, as it is the case of letterpress, flexography or rotogravure.
To achieve an ink-repellent effect on the printing plate, offset technology is based on the physical principle that ink and water are not miscible. The non-image areas of the plate are hydrophilic, that is, water-receptive and the ink-accepting surfaces are oleophilic, and are therefore almost totally unreceptive to water. The film of dampening solution prevents the transfer of ink. This means that in an offset printing unit there is a dampening unit and an inking unit to achieve this repellent effect.
What are the advantages of offset printing over other printing systems?
- High printing quality, specially in half tones and vignettes
- High printing quality on a wide range of materials
- Minimum dot gain
- Raster screen of 150 lines/cm or even more
- Better ink control than other printing technologies
- Consistent quality
- Very sharp detail
- Very low cost of the printing plate compared with a flexo or letterpress photopolymer plate (more than 1:7)
- Quick and easy production of printing plates (less than 15 minutes)
- High availability of skilled operators
Why rotary offset?
First of all, there is to mention the high printing quality in any substrate. With offset technology you can print all paper qualities (from a standard couche to rough paper for wine labels), any kind of unsupported film (PP, PE, etc.), carton board, metallic substrates, aluminium, etc. Therefore, in the offset rotary press you can not only print labels but also other types of packaging, such as cartons, sleeves, in-mould labels, yoghurt lids, etc.
Another advantage of the rotary offset press is that the labels will match identically with the visual appearance of other packaging items printed in offset for the same product thus the prepress will be the same.
And finally, you will get the finished product in one single pass. This means that lead times will be shortened and the cost will be substantially reduced. In one single pass the label or any type of packaging can be printed, foil stamped, embossed, die-cut, stripped and rewinded or stacked.
Rotatek offers combinations of different printing technologies such as offset, flexography, silkscreen, rotogravure, cold stamping, hot stamping etc. Each printing press is configured according to the specific requirements of the customer. For further information, please do not hesitate to contact us:
Rotatek, S.A.
Avda. Graells, s/n
08190 Sant Cugat del Vallès (Barcelona)
SPAIN
Tel. +34 93 674 52 50
Fax +34 93 675 19 02
rotatek@rotatek.com
www.rotatek.com