Die-cutting and creasing are pre-requisites for jobs with complex shapes, such as folding cartons and self-adhesive labels, as well as a great way to add value to other print work.
If you produce die-cut work or complex creasing and perforating in-house, it's likely to be on an elderly platen or cylinder that's clunking away at a couple of thousand sheets per hour. Alternatively, many printers opt to outsource the work.
With the Inline Offset Cutting (IOC), Kocher + Beck (K+B) offers a way to do the die-cutting on-press and inline at the same time as the printing.
This is not unique. There are other systems that also convert a spare printing or coating unit on a press to cut, crease and perforate, including Cito's RSP and the PPP system distributed by Pomeroy Pressroom Products. All share the benefits of working inline with printing at the running speed of the press, slashing total production time by combining two processes into one and support a range of formats and suppliers of litho presses.
Where K+B differs from its rivals is that its heritage is as a precision die-maker, including flexible rotary dies. In the narrow-web label printing world, the latter have become ubiquitous, converting self-adhesive labels by on-press kiss-cutting, eliminating an additional process.
Hard times
According to K+B UK managing director David Morris, flexible dies took off during the last recession, as firms looked for a way to streamline their operations. Fast forward and K+B, believes that today's tough conditions are right for a similar revolution in rotary die finishing in sheetfed litho.
K+B comes at it from a different angle to its rivals. As a die-maker, it banks on the recurring revenue stream of customers buying new dies.
"The underpacking is not a way to make money, our money comes from the dies," says UK sales director Steve Horne.
Underpacking costs £210 for B3, £280 for B2 and £350 for B1, while the protective sheets to ensure your impression cylinder remains mark free are a maximum of £65 for B1 steel sheets.
The integrity and stability of the die is at the heart of IOC. K+B argues that systems that use plastic sheets with metal dies stuck to them create issues with accuracy and make-ready time. IOC dies are made from a single sheet of steel, or in the case of larger press formats, multiple sheets pin registered together to ensure accuracy and stability. The firm argues solid steel makes for a more accurate and robust die.
"It's about makeready time on-press," says sales executive Mal Nicholas-Jones. "When time is money, you don't want to be fiddling around. Ten minutes makeready time is acceptable, but two hours is not."
Conversion rates
Makeready time on press is one issue, but what about how long it takes to turn your artwork into a usable die? Morris says a typical turnaround time is two working days, but depending on the complexity of the die and the client's needs, it is possible to reduce that.
"Increasingly, people are asking for same-day," he says. "Having enough capacity is essential to turn jobs around. When I started, it was a five-day lead time, now it's possible to be one day or even less."
K+B says its model of making the whole die to tight tolerances from the printer's artwork ensures the die will register perfectly with the print and that the pressures will be even across and around the sheet. It argues that rivals' DIY die mounting onto a plastic sheet means more tinkering with position and pressure, leaving the press idle as makeready time mounts up.
An experienced operator can get register and pressure perfect in as little as 11 sheets, and it's possible to re-use sheets used for colour makeready to set up the IOC, reducing waste.
The two factors that need to be adjusted on-press are fit and pressure. Gross adjustment to fit is done by moving the whole sheet in the clamps horizontally and vertically, while fine controls can then be done using the press controls. Setting the pressure is a matter of gradually bringing up the pressure until it is cutting or creasing to the required depth and no more. When it's new to the operator, it will take slightly longer due to trial and error, but if you have regularly used stocks and dies, you can record previous settings and use very few sheets just to tweak the parameters.
The cost of a die is a result of its complexity and the total length of the rules, rather than the size of the sheet. K+B claims that die costs for the IOC are the same, or at worst only marginally higher, than rivals' machines.
Fitting is simple. You remove the blanket and back-off the pressure on the plate and impression cylinders. Some presses, including Heidelberg's, have controls for inline finishing to make this even simpler. The die and the underpacking, which is a combination of steel, aluminium and plastic sheets to give the perfect blend of lateral stability, flexibility and thickness, are mounted on the blanket cylinder. Once in place, and when the clamps are tight and after register and pressure adjustments, you're ready to go.
Dies are manufactured at K+B's Coalville, Leicestershire factory. From the proprietary CAD system, which takes common file formats including Illustrator and PDF. Files are cleaned up to ensure the die can be made and will work on press and then ripped to create a layout.
UV-sensitive etch-resist film is first laminated onto a sheet of steel and then exposed using a UV CTP system. Unhardened areas are scrubbed off in the processor and the etch-resist is hardened by baking.
Price comparison
Etching leaves the die proud of the background. At this stage, the lines are several millimetres wide. The next stage is the milling process that produces the necessary edge profiles for cutting, perforating or creasing. The optimal profiles are determined by the substrate type and thickness being processed. Milling is the process that takes the time - and therefore has the most impact on cost. Price is affected by the length of the die-lines and the complexity - straight lines and right angle corners are straightforward, while compound curves add complexity and cost because it takes longer for the milling tools to produce these shapes. Whether it's a B3 or a B1 sheet makes little difference, but the length of line and its complexity determine the cost.
Milling is carried out using machines developed in-house to accuracy better than 10 microns per metre.
But it's not just the X-Y dimension that is important - the height of the die is also crucial to ensure even results around the cylinder. A second machining stage back-grinds (polishes out any fluctuations in height) the die to an accuracy of +/- three microns.
Dies for tough stocks are laser hardened and are tested using the specified substrate before backing and despatch. For the IOC system, blanket bars are attached to the plate to enable mounting on the blanket cylinder of a printing or coating unit.
Neither K+B's IOC or its rivals are as versatile as a flatbed's support of automatic cutting and stripping. However, for simple jobs, such as folders and any other work that can be guillotined to free the final job, they are ideal. They're also a boon for kiss-cut work on self-adhesive stock where you can create complex dies that couldn't be handled by a flatbed.
It would be hard for a printer to ignore the potential to achieve added-value with so little capital expenditure.
SPECIFICATIONS
Format
B3, B2 and B1
Press manufacturers supported
KBA, Komori, Heidelberg, Manroland, Mitsubishi and Ryobi
Components
Steel die, underpacking kit comprising sheets of aluminium and plastic and impression cylinder protection sheets
Prices
Dies: From £150 depending on complexity and length of rules
Underpacking: B3 £210, B2 £280 and B1 £350
Protective sheets:
Steel: B3 £45, B2 £50, B1 £65
Plastic: B3 £15, B2 £18, B1 £25
Contact
Kocher + Beck 01530 812400 www.kocher-beck.co.uk
THE ALTENATIVES
Cito RSP
Like the IOC, this is a cylinder-mounted cutter and creaser. It uses a plastic sheet to hold processing rules with lateral, vertical and diagonal adjustment of the grid to a pin bar registration. It has a higher upfront cost, but Cito claims the processing rules are cheaper than creating new dies. Fits all Heidelbergs and selected KBA, Komori and Manroland machines.
Format B3-B1
Price From £1,200
Contact Cito UK 01773 521852 www.citouk.co.uk
PPP
Another cylinder-mounted cutter, creaser and perforator. Like the Cito, it's based on a plastic sheet. PPP says the system is as happy on web as sheetfed machines too.
Format B3-B1
Price from £3,000
Contact Pomeroy Pressroom Products 01594 837474 www.pomeroy.co.uk
Kama ProCut 53
Kama is carving a niche in smaller-format cutters and finishing machines. Not a direct competitor, as it's offline, but if you want more finishing options, one machine can cut, kiss cut, crease and emboss, blind emboss and optionally can ‘hot cut' plastics, hot foil and apply holograms. In addition to the B3 53, there is also a B2 machine.
Sheet size 400x530mm
Speed 6,000sph
Price from £150,000
Contact Kama UK 01527 522392 www.kama.info
Kluge EHF
If you want an offline system and a more versatile, albeit slower, machine then the Kluge offers cutting, creasing and perfing, foiling and embossing. These are mechanical beasts that require a skilled operator to set up.
Sheet size 356x559mm
Speed up to 3,300sph
Price from £60,000
Contact Kluge 01453 836522 www.kluge.biz
