Sheetfed offset printing & UV curing

What is sheetfed offset printing?

In sheetfed offset, printers are feeding the press with individual cut sheets as opposed to a continuous web. The sheetfed offset, or offset lithographic (litho), printing process is known as offset because the image is ‘offset’ from the lithographic plates to the blanket, before finally going onto the paper. Printing plates are made using a CTP (Computer-to-Plate) system. These plates are used to apply each of the four CMYK colours (cyan, magenta, yellow, black) to the rubber blankets mounted on the cylinder, which then applies the print image evenly to the substrate.

The ink used in this process is very viscous and it is applied to the print rollers individually. This means that litho printing can use special spot colours, metallics and Pantone mixes. Litho presses are able to print on a wide range of substrates, from lightweight paper all the way up to thick board, Metpol (foil board) and plastics.

Sheetfed offset printing is typically split into two sectors – commercial sheetfed offset printing and packaging sheetfed offset printing. You can find out more about these below.

Commercial sheetfed offset printing

In this sector, the print itself is the core product. It usually then undergoes post processing to generate items such as magazines, brochures, books, transactional / direct mailing, leaflets, catalogues, letterheads and business cards, etc. Some commercial printers are further diversifying their product range by printing on new materials with the adoption of LED UV curing.

Packaging sheetfed offset printing

This sector typically produces paper or board packaging e.g. boxes, cartons, sleeves or labels. These are used in a broad range of consumer markets including FMCG, cosmetics, food, healthcare, labels, drinks and confectionery. Arc UV has already been widely adopted in this sector with LED UV curing an emerging technology that has major benefits when printing special substrates such at PET, PP and foil board.

What can a UV curing retrofit do for your sheetfed offset business?

UV benefits for sheetfed offset printers

Faster turnaround – Instant ink drying enables immediate finishing and despatch of jobs. Sheets can be folded, cut, bound and processed right away, reducing work-in-progress and significantly shortening lead-times.
Print without limitations – UV and UV LED inks enable printing on almost all stock types including PE, PET, PU, synthetic paper etc. and bring added value and increased product diversity with coated and uncoated papers, plastics and foil laminated sheets.
No marking, no sealer or spray powder – Marking of sheets in the delivery or perfecting process is eliminated and machine varnish or sealer is no longer necessary. No spray powder is required, removing widespread contamination and associated cleaning and maintenance.
Sharper dots and vibrant colours – UV curing retrofits achieve sharper dots, more vibrant colours and a higher quality finished product.

UV LED benefits for sheetfed offset printers

Print without limitations – Unlike UV lamps, LEDs emit little infrared heat towards the substrate. This avoids common issues such as high pile temperatures, curling of heat-sensitive materials and loss of moisture in paper.
Ultimate productivity and peace of mind – No moving parts for low maintenance and no warmup/cool-down mean less UV related downtime, which increases press productivity. Furthermore, GEW offers up to 3 years’ LED warranty, irrespective of running hours.
Reduced energy consumption – LED instant on-off means that no energy is consumed when the press is idle. The higher electrical efficiency of LEDs and the purity of UV output allow typical energy savings of up to 70%, compared to H-UV or IR lamp systems.
No marking, no sealer or spray powder – UV LED inks and varnishes are 100% cured instantly after the LED lamp.

GEW products for sheetfed offset printers

GEW has two main offerings for sheetfed offset printers, depending on whether your needs require a UV LED or mercury arc curing system. You can find out more about these two options below:

LeoLED2

LeoLED2 takes LED performance to new heights over GEW’s already highly-acclaimed, water-cooled LeoLED system. Offering a 55% increase in electrical power (140W / cm), a 50% increase in UV dose (300mJ / cm²) and a 45% increase in UV irradiance (44W / cm²) compared to its predecessor, LeoLED2 is GEW’s next generation UV LED curing system that guarantees the best performance on the market for the most challenging curing applications.

As with the generation 1 model, LeoLED2 is available in both a cassette version and a compact version, depending on the requirements of the customer, their equipment and their application. Both models are designed to interchange with every current arc lamp model in GEW’s range. This patented ArcLED technology gives ultimate flexibility on press, no matter the application.

LeoLED2 is GEW’s next generation, water-cooled, highest power UV LED curing system. It comes in a compact and a cassette version, designed for the toughest applications.

LeoLED2 also comes in two power level options, offering ultimate customisability to customers, depending on their application and energy saving needs, whilst providing faster printing speeds alongside GEW’s renowned process reliability.

This lamp can be used in the delivery position alongside GEW’s E4C, giving printers access to GEW’s ArcLED technology. To see this in action, watch the video below.

Find out more about LeoLED2 on our product page or download the LeoLED2 brochure:

Download the LeoLED2 brochure

E4C

E4C offers the highest power available from the GEW mercury arc range, to support the most demanding UV curing applications and the fastest printing speeds on sheetfed machines. It performs to the harshest cure test procedures and is suitable for low migration applications.

E4C has optically tuned reflectors to maximise curing power and operates quietly, with minimal air requirements. Water flow monitoring technology ensures water flow at all times, and the E4C’s water-cooled reflectors support the highest UV power whilst limiting heat transfer to the substrate, making it safe for a broad range of heat-sensitive materials.

It is designed to operate with the lowest level of maintenance and is engineered for fast, easy lamp changes. All replaceable components are plug-and-play, and the reflectors can be cleaned and fully replaced without breaking the water seals. Furthermore, the reflector mechanisms and seals are tested to millions of operations to ensure reliability.

Find out more about E4C on our E4C product page or download the E4C for sheetfed brochure:

Download the E4C sheetfed brochure

One lamp – any position (with our Modular Lamp Array)

LeoLED’s Modular Lamp Array offers the ultimate in flexibility and enables GEW to deliver the highest energy dose in the market, at the best value.

All lamps on the press have identical designs and can be freely moved between print stations to change curing configuration and adapt to the job at hand. For highly demanding applications (such as B1 LED coating at 18,000sph) multiple lamps can be placed in tandem at the end of the press.

ArcLED compatible

ArcLED hybrid UV technology allows interchanging of a UV Arc lamp or
LED array in the same housing.

Optimise your press with a mixture of Arc and LED curing on any station, for the ultimate flexibility.

GEW have held granted patents covering this technology internationally since 2016.

To find out more about how LeoLED2 and E4C’s ArcLED capabilities can benefit your business, download our brochure:

Download ArcLED brochure

Why trust GEW to retrofit your sheetfed offset press?

GEW has over 30 years’ experience engineering UV curing systems. We have a large engineering and design team who are trained extensively to ensure seamless integration with all sheetfed offset printing presses, such as Heidelberg, Komori, KBA, Manroland, RMGT etc. In situations where GEW has not previously retrofitted to a specific make or model, we use precision laser scanning technology to custom design your integration, ensuring seamless installation to your press.

Watch this video to find out more about our retrofitting process:

Remote Monitoring and service support

GEW’s 4.0 IoT Remote Monitoring technology, which is controlled via the RHINO HMI Control system, comes as standard with every new retrofit. With over 21,000 lamps being monitored worldwide, GEW is able to record all system data, send monthly reports to customers, perform remote updates and proactively deal with system issues before customers even notice there is a problem.

We have offices in the UK, United States and Germany, as well as a worldwide network of distributors, that allow for 24-hour, 7-day technical support, with a team of dedicated service technicians and customer service support staff available to deal quickly and efficiently with customer questions.

Watch our video to find out more about our Remote Monitoring system and how our team will support you post-installation:

What do our sheetfed offset customers say?

Speak directly to a sales representative

If you are unsure about which UV curing system best suits your requirements, we are here to help. Please contact one of our sales representatives directly.