Heidelberg Prosetter

Chicago 2001 was a significant milestone for Heidelberg. The German manufacturer chose the Print '01 show to unveil its entry into violet platesetting technology.
Three formats were available in its new violet diode platesetter range: the P102 for the 8pp B1 market, the 4pp P74 for the B2 sector and the 2pp P52 targeting the smaller B3 segment. The beauty of the P52 was that it was designed with the same footprint and architechture as the P74, which meant that when a customer needed to go up a size they could simply upgrade the machine to the 4pp P74 with only a few alterations. Scaling up to a P102, however, wasn’t quite as simple; the machine’s larger drum necessarily created a larger footprint.
In 2003, Heidelberg went even further in developing the Prosetter range, incorporating a more powerful 30MW laser diode compared to the previous 5MW. This gave customers the option to expose photopolymer violet plates as well as silver halide plates. The new laser head could also be switched during operation back to the original 5MW.The Prosetter Fast versions, for the P74 and P102s, were introduced in October 2005. Both versions could handle an additional four plates per hour (pph). The PF74 went up to 24pph while the PF102 moved up to 20pph.It was mainly smaller print firms snapping up these systems at the start, according to Guy Elliott, Heidelberg’s UK product manager for Prinect workflow and CTP. This was because visible-light CTP kit was cheaper than thermal machines. And the Prosetter had some clever features for those taking their first steps into CTP, including temperature compensation, which allows a plate to be imaged or re-imaged without the aluminium expanding. The light-sensitive plates could also be processed under yellow light allowing for almost daylight conditions, which is better for the operator.
With all the Prosetter models, the printing plate is aligned in a half-shell and held in place by a vacuum as it is imaged. The laser spot is then guided with a rotating prism. A single-cassette loader can be fitted, which allows up to 150 plates to be held. An optional multi-cassette loader can also be added, holding up to four cassettes, each able to hold 150 plates for up to four different press sizes. Heidelberg will buy back an old model or take it back as part exchange. Before taking the plunge it’s worth getting an engineer to check the laser life of the machine and to see whether it has its original or the more powerful 30MW laser heads. It is also advisable to check the service history of the kit. Secondhand prices start from £10,000.

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SPECIFICATIONS

Printing plate format Min 370x323mm; Max 670x525mm (P52 and P74); 811x1,055mm (P102)Speed at 2,540dpi P52: 25pph; P74: 20pph; PF74: 24pph; P102: 16pph; PF102: 20pph Resolution 2,032-3,386dpi

Plate thickness 0.15-0.30mm

Footprint P52/P74: 1,730x1,385mm; P102: 2,050x1,385mm

Weight P52/P74: 475kg; P102: 575kg;

Price Used from £10,000

What to look for

• Service record

• Laser life