The Secret Lies in the Surface Structure

Thin coatings have a big impact on productivity and quality

Heidelberger Druckmaschinen AG (Heidelberg) unveiled more than 50 customer-focused product innovations at drupa 2004, thereby underlining its commitment to pioneering technology. Heidelberg takes the full range of parameters into account when designing a new press or enhancing existing ones. In addition to ink and blankets, a number of factors are key at high production speeds in determining the quality of sheet travel and, consequently, print quality. These include cylinder geometries, cylinder surfaces and the properties of these surfaces.

Productivity and quality can only be maintained and even enhanced by using special print-protecting surfaces for all transfer and impressions cylinders after the perfecting stage. These specially coated, exchangeable jackets - known at Heidelberg as TransferJacket Plus and PerfectJacket Plus - are available for both Printmaster and Speedmaster multi-color models. TransferJacket Plus cuts cleaning times by up to 80 percent in some cases. On perfecting presses, the jackets ensure the familiar high quality on both sides of the paper. This is one of the reasons for the success of Speedmaster SM 102 models used as long perfectors. Heidelberg is the market leader par excellence in this sector, having a global market share in excess of 70 percent. This corresponds to an installed base of over 900 machines in the 70 x 100 centimeter format alone.

TransferJacket Plus - technologies of the future deliver top results
When transported through the press, the freshly printed sheet may deposit ink on Superblue, stuck-down films or the jackets of the transfer cylinders, leading to a build-up of ink. This ongoing soiling may even lead to marking on the print sheets. This is an all too familiar story for printers - under some circumstances these surfaces have to be cleaned or even exchanged after just a short period of use. TransferJacket Plus with its ink-repelling coating has significantly reduced the amount of washing required since it was first unveiled at drupa 2004.

Heidelberg is the first and - to date - only manufacturer to supply transport cylinder jackets treated with an innovative coating technology based on nanotechnology (see site promotion). This technology employees a special, ink-repelling Sol-Gel coating.

Once Heidelberg's developers had identified the optimum surface coating through extensive studies and laboratory tests, the coating underwent practical trials. The results at all four field test customers were extremely positive and more than satisfied the requirements of the performance specification. Customers state that, in some cases, wash-up times have fallen by up to 80 percent for long large-format perfectors.

Requirements from performance specification	SM 52	SM 74	SM 102	SM 102
Reduction in washup times as %	50 - 60%	60%	70%	80%
Prevent ink drying on within up to 2 hours	•	•	•	•
Surface cleaned completely - without residues	•	•	•	•
Wash-up chemicals: - 50 %, better environmental impact	•	•	•	•
Corrosion-resistant surface	•	•	•	•
Coating service life of at least 1 year	•	•	•	•

Table: Compliance with performance specification; feedback from field testers

Heidelberg installed a new production facility at its Wiesloch site specifically for this innovative coating process and has been series-producing its "nano coating" there since March 2004. Several thousand jackets have already been supplied. A quality check constantly ensures that the properties profile required by the customer is being adhered to. Feedback from print shops that have used this new product has been positive throughout.

Customer benefits from TransferJacket Plus:

• Better print quality in both recto and verso printing, particularly with con-tones and solids.
• Increased productivity through reduced wash-up times.
• Increased flexibility through a broader bandwidth of printing stock.
• Faster production speeds.

PerfectJacket Plus - perfecting at its very best
There are very few innovations which have revolutionized the throughput time for each job as significantly as perfecting technology, which can reduce processing time by up to 50 percent. Heidelberg's tried-and-tested perfecting technology is based on three-drum perfecting, consisting of a reversing, storage and transfer drum. The challenge lies in transferring the sheet reliably with register accuracy to the next printing unit - at speeds of up to 13,000 sheets an hour. This is where Heidelberg's 30 years of experience really comes into its own. The unique selling points are the storage drum with its eccentric rotary suckers and the reduced-diameter reversing drum. The reversing drum also uses a patented pincer gripper system which ensures the familiar level of register accuracy at any speed. Experts at Heidelberg developed special ceramic jackets to guarantee high quality and smooth sheet travel. These jackets have been fitted as standard since drupa 2004. The PerfectJacket Plus exchangeable jacket gives the impression cylinders downstream of the perfecting device an extremely ink-repellent and finely structured surface. Here, too, Heidelberg makes full use of its manufacturing expertise which, honed through many years of development work and standardized production processes, ensures uniform, consistently high quality coating over the entire surface.

Customer benefits from PerfectJacket Plus:

• Virtually identical high quality on both sides of the paper, even with critical paper grades and thick ink coatings.
• The ink-repelling properties prevent the ink from smearing. It is therefore possible to process a wide range of printing stocks and achieve high productivity through simple cleaning.
• High press availability thanks to this innovative jacket.

The three-drum perfecting offered by Heidelberg and the use of PerfectJacket Plus is a cross-format feature which is used in small, medium and large formats. It is the secret behind the success of the One Pass Productivity philosophy and is synonymous with high print quality and flexibility, register accuracy and stability in the production run.

Image 1:
The illustration shows the differences in the ink-repelling properties of the old surface (left: chrome) and the new TransferJacket Plus surface (right: Sol-Gel nanotechnology coating) with a colorless test liquid simulating the properties of ink.

Image 2:
The new TransferJacket Plus serves as a sheet transport surface in the press. A liquid with ink-simulating properties illustrates the drip-off qualities of the new Sol-Gel nanotechnology surface on a transfer cylinder.

Image 3 +4:
This direct comparison clearly shows the difference between the finer surface structure of PerfectJacket Plus and the earlier PerfectJacket technology.