Technical Tutorial

The Carbon Trust defines a carbon footprint as being all the greenhouse gas emissions produced across the lifecycle of a product, including production, actual use and disposal of the product once it has outlived its usefulness.

The whole idea of carbon footprinting has quickly developed from being an interesting concept jumped on by a few a leading firms to a practical reality in the printing industry, and increasingly clients are requesting the carbon footprint details of particular jobs to help them measure their own environmental impact.

As a result, footprinting is growing in popularity because not only is it seen as beneficial to the environment and to printers, but it’s actually being used as a marketing tool and an important ‘value add’. To enable printers to measure and communicate their impact there are a number of carbon calculators to help work out the footprint of different printed publications.

Typically the print process accounts for 10-20% of a job’s carbon footprint, including energy used and materials. Unsurprisingly, paper is the main contributor to a publication’s carbon footprint, typically 50-70% of the total.

To really understand a carbon footprint, the full print supply chain has to be analysed with two key factors affecting the total footprint: the paper’s source (country of origin) and the ultimate source of the paper pulp and wastage levels.

The Carbon Trust can help print businesses to measure their footprint and identify ways to reduce it. Its leaflet ‘How to monitor your energy use’, shows businesses how to record information on energy use, and outlines simple techniques to help a business use the data to spot money-saving opportunities.

Set up a good energy monitoring system. This will allow you to understand where and how energy is being used, identify areas where you can reduce energy consumption and save money.

For more information, visit www.carbontrust.co.uk

 Mezzanine capital is a funding option that stands between a bank loan and an equity investment and commonly takes the form of a debt investment. The repayment priority of lenders of mezzanine capital in the event of a company falling into administration is lower than that of the normal debt lender.
As a result of the subordinated nature of the debt, interest rates on mezzanine debt are generally higher than other loans from traditional lenders. Mezzanine capital is sometimes invested by parent companies or major shareholders into a business at lower interest rates in order to provide a cash injection without breaching the terms of existing lending packages.
Aside from a debt investment, for listed companies, mezzanine capital can take the form of preferred stock, non-voting shares which rank over common shares in the payment of dividends or in the event of the liquidation of a company. Mezzanine capital will commonly be structured as a convertible bond, which allows a company to take an equity stake in the business in the event of any breach of the debt agreement.
Mezzanine capital will frequently form part of a funding package provided to a management buyout and enables many smaller companies to raise the total funds needed to buy the business. As it is paid off in one go at the end of an agreed term, it does not represent a drain on a company’s cashflow and is registered on balance sheets as equity rather than debt.
The importance and use of mezzanine capital has increased over the past decade alongside the boom in private equity-backed leveraged buyouts.
Companies hoping to attract mezzanine finance will need a solid business plan, a strong management team and a good track record.   
By William Mitting

William Mitting is news editor at PrintWeek

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 The inking systems on conventional offset presses have continued to evolve with new types of rubbers being introduced to run alongside steels or other compounds.
A standard inking system consists of a number of rollers which are used to transfer ink from the ink duct onto the plate. A press will generally have four forme rollers which should all be different diameters to allow replenishment of the ink at different rates; this helps to prevent the appearance of stripes which can affect the quality of the print.
Oscillation within the ink train is essential to help smooth out the ink film. This includes the main distributors and the inking forme rollers which will, in conjunction with the ability to alter roller timings, give better rollout from grip-to-leave.
Any press running for long periods on multiple shifts will benefit immensely from having ink temperature control, as it will improve the flow consistency by managing the press’s integral heat.
Another important factor in the design of an inking system is the accessibility to the rollers for adjustment and removal. It saves time if the press settings are not lost by removing rollers for unnecessary maintenance checks.
Modern presses tend to have pre-settings for attaining optimum colour quickly, something which can be enhanced with workflow that enables the press to be set up using characteristic values with the ideal dot gain. This is where a closed-loop colour system becomes an important part of the printing process, seamlessly linking pre-press and press. It ensures that colour quality is controlled consistently. Modern colour measurement isn’t left to the press minder any more – it is generally accepted that a spectro-photometric measurement device will give a more objective result.
By Mike Lambert

Mike Lambert is a technical specialist demonstrator at Heidelberg UK

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 Productivity, the number of sheets produced in a given time, is greatly influenced by ‘feeder stability’ and so it is a critical area to assess when making a press investment.
Some 15 years ago, feeders were tedious to set up with lots of manual adjustments. The press minder had to take the time to settle the feeder to run at a moderate speed, maybe 5,000 sheets per hour (sph). Top press speeds rarely went above 8,000sph. The technology used front-feeders which picked up sheets at the fore-edge and advanced each one completely before the next could be lifted.

Today, time is money and most sheetfed presses pick up at the rear of the sheet in a shingle mode. Subsequent sheets are moved as soon as the previous one is advanced. Now, 18,000sph is feasible.
With shorter run lengths, make-readies can be a large proportion of the job and the need for a stable feeder is essential.

Design can play a big part by giving an operator the confidence that it’s easy to use with plenty of tolerance. If a feed-board is deluged by brushes and wheels, manual intervention is inevitable.
With format changes from job to job, automation becomes even more attractive. Even smaller presses come with preset values and characteristic curves for the setting of suction or air. Suction pull-lays are essential to attain the highest, most consistent speeds. Instead of belts, the use of servo motors and Venturi air transfer now combine to eliminate sheet distortion at the front-lays and prevent ‘doubling’.

Modern press feeders could go faster, but if one mis-feed reduces productivity, does it make sense for short-run work? The difficulty is stopping the sheet in the delivery, as well as ensuring it arrives unmarked, but that’s a whole new story...

By Mike Lambert

Mike Lambert is a technical specialist demonstrator at Heidelberg UK

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Concentric is an AM screening technique for offset litho. The difference is that thin concentric rings are inserted in the screen dots. Dividing up the dot surface on the plate reduces the ink film thickness, which means ink use can be reduced. It can also produce cleaner, more saturated colours.

The ink saving you can achieve will vary depending on the substrate and on the kind of work. For example, a heatset web magazine printer I know of saved 22%, while a large food carton converter saved about 15% on ink. As a rule, a saving of 10% on your annual ink cost is a good target to aim for.

Because concentric limits ink film thickness, it also improves print stability. Changing inking on press makes very little difference to TVI (dot gain) and so it is much easier to get consistent colour.

Although introducing a new technology to the pressroom can be a challenge, operators cope well with concentric thanks to this stability, as well as the fact that it uses rosettes like conventional screening.

Another way to save ink is by using grey component replacement (GCR). This works by taking some or all of any neutral (grey) component of a colour made from a mixture of coloured inks (CMY) and replacing it with a single black ink (K).

GCR can be an effective way of saving ink, but the potential saving depends on the content of the original separations. If the job already has a long black separation, GCR will not be effective.

GCR can also only be effective in colours with a neutral component. In bright saturated colours, there is no neutral to replace. The concentric effect applies to both saturated and neutral colours. I know of at least one web offset printer that is using concentric and GCR together as they complement each other well.
By Paul Bates

Paul Bates is UK business manager at EskoArtwork

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The concept behind the incorporation of an inline sheet inspection system is to offer the printer the tools to create the perfect printed stack – finished printed sheets without any flaws. This should be of particular interest to any printers producing work for the high-end markets, but particularly exciting for those involved in such areas as pharmaceuticals, where quality is an absolute essential.

A typical inspection system will use a very high-speed camera, positioned after the last printing unit, linked to an equally high-speed computer. The system will compare the image on the printed sheet to the image of a sheet passed by the customer and held within the computer.

These operations happen at very high speeds – Manroland’s InlineInspector, for example, examines every 0.5mm portion of a B1 image six times as the sheet passes through, while still printing at up to 16,000 sheets per hour.

If any errors are spotted on the sheet – such as hickies, dust spots, filling in, creasing, colour quality issues, ink problems, or even substrate problems – the operator will be alerted, a tab inserted in the stack at that point, and an on-screen image of the sheet will appear with the problem area highlighted. This then allows remedial action to be taken.

Working hand-in-hand with the inspector system, some manufacturers will also provide an automated sorting system that actually diverts the imperfect sheets away from the finished stack and into a reject delivery pile. Where this is not employed, the automatically inserted tabs will highlight to an operator where problems occurred during the run, and which sheets should be manually removed from the finished stack.
By Gary Doman

Gary Doman is sales director for sheetfed products at Manroland GB

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Print workers who use inks, wash-up solutions and the like are at a higher risk of developing dermatitis than workers in general. So it’s important to be aware of the risks and recognise the warning signs.
Some clues to a work-related cause are: that it is primarily on the hands and face, the condition improves away from work and that it affects more than one person handling the same materials or working in the same area.
You should read COSHH Essentials for Printers. This guidance is written specifically for the printing industry. It describes in more detail how to control exposure to chemicals in a range of common print processes and tasks.
If an outbreak does occur, you need to understand the underlying causes and observe what happens in your workplace. Have there been any changes, such as new processes, materials handled or skin care products? Have you done everything you can to avoid contact? Are existing ‘exposure control’ measures still working? Have you provided the right type of gloves? Are employees using them correctly? Are employees protecting their skin by washing, drying and moisturising properly? Have they had sufficient training?
If you are unable to identify an obvious cause and any actions to improve preventative measures have been unsuccessful in dealing with dermatitis, it may be necessary to call in specialist help.
Finally, if you have confirmed cases of work-related dermatitis at your site, then the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations, 1995 require you to report this to the Health and Safety Executive.
For more, visit www.hse.gov.uk/printing/dermatitis. For general information on work-related skin disease, see www.hse.gov.uk/skin.
By Bob Rajan

Bob Rajan works for the Health and Safety Executive

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Humidity control is essential component in printing, but why do we need it in the cold wet UK?

Temperature control is easy and we know that temperature and humidity are linked, so if you change one, the other will also change –frequently in the wrong direction for the printer trying to produce a quality product.

If you heat cold air as it enters your factory, the relative humidity plummets as the moisture-carrying capacity of the air increases. Like a sponge released from your grasp, as the air heats up, it’s ability to hold  water increases so the water contained within it becomes proportionally less. So a humidifier is required.

In the summer, moisture has to be replaced as a result of the air conditioning. As the air temperature drops below its dew point, condensate forms and the humidity is reduced as the air cools. This moisture needs to be replaced to maintain the humidity.

Not maintaining a constant humidity level while printing has numerous consequences. They range from erratic dimensional stability, low paper strength, static charges, paper curl, plus poor employee comfort and paper conditioning.

Humidifiers come in various shapes and sizes however moisture can only be added to air in one of three ways - evaporation, spray and steam. It will depend on the application as to which method will be the most cost-effective solution.

Payback period of such a system is short, allowing the use of thinner paper, faster machines, less down-time, beter paper stability and increased register accuracy. All press manufacturers advise a stable and constant humidity of around 50% relative humidity (rh) to ensure their machines achieve maximum performance.
By John Barker

John Barker is sales director at Humidity Solutions

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The blanket is a key consumable, an intermediary between the image on the plate and the ink on the paper. Blanket performance is critical to finished results – they have to be able to perform well in a demanding environment. Presses have become faster and the range of chemistry used is increasing, including new alternatives to alcohol.

Inks, too, can affect the choice of blanket. Printers must choose the right surface texture for the results they want. The adoption of compressible layers in blankets has also helped reduce smashes.

There are a number of layers to a blanket using fabric, rubber, compressible elements etc. The durability of a blanket varies greatly depending on application, maintenance and sometimes even plain luck but a guideline is one to three million impressions.

Blanket quality has improved over the years. To achieve optimum reproduction quality the printer wants minimum stretch. The tensioning of the blanket is important and there is a correct formula for optimum fit (width between bearers (mm) x 0.06 = the number of Newton metres required). Printers shouldn’t use overly aggressive wash up chemistry because this can destroy the surface of the blanket.

When buying a blanket the printer should look at its surface tension, surface roughness, compressibility, ink acceptance and ink transfer behaviour, tone value transfer characteristics, the setting/swelling, release behaviour, hardness and dimensional stability.

Blankets should be stored covered and rolled up in boxes or tubes or laid flat in cool, dark and dust-free conditions. Metal-edged blankets have adhesive tape around their corners, which should not be removed as it prevents the metal bars from scratching the blanket’s surface. Clean blankets thoroughly with warm water before first use.
By Mick Simmonds

Mick Simmonds is technical specialist, print and quality systems at Heidelberg

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Using grey component replacement (GCR) or under-colour removal (UCR) can reduce ink usage by up to 12-15%. For a commercial printer, with say 20 printing units running double days and producing mainly four-colour work, the annual ink spend could be in the region of £100,000, so ink reduction could result in a saving of as much as £15,000.

GCR and UCR are not new, they were very familiar terms in the days of scanner operators. They are ways of replacing the chromatic colours (cyan, magenta, yellow) in the grey component with black.

The key advantages are reduced ink consumption, speedier drying, reduced set-off (marking) and better overall control.

GCR/UCR has become popular again because printers have embraced device link profiles.

Historically if a printer was given a CMYK image they would be reluctant to re-separate it to get a higher GCR/UCR in case there was a colour change. Now, with device link profiles, printers can change the GCR/UCR with no risk to the visual colour but all of the cost and quality advantages outlined above.

With the increasing requirement for colour management and the implementation of ISO and Fogra standards as marketing tools and ways of reducing waste and downtime, ink reduction by
GCR/UCR is attracting renewed interest.

Some suppliers offer this as a hot folder to work alongside a workflow, whereas Heidelberg has integrated it. GCR/UCR is available in Prepress Manager, ColorEditor, or in Metadimension. Anyone with these tools can make these savings with no additional investment.

Given the current emphasis on cost-cutting there is no doubt GCR/UCR is a hot topic and Heidelberg is fielding an increasing number of questions in this area. Although it could benefit any printer, it is the high-speed, high-output players that will benefit the most.
By Steve Fowler

Steve Fowler is a technical support specialist at Heidelberg UK

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Ask any printer what the benefits are of anilox coating and they will almost certainly say: “Consistent quality”. So, can the principle be applied to an inking unit? Well, if anyone thinks that anilox is a new concept, think again. It was used in flexo printing by the Second World War and was incorporated into offset in the 1980s.

Back then it was a waterless concept with the need to run specialist inks and waterless plates that were not widely available and this held the technology back. Recently it’s been shown that anilox can have broader appeal by incorporating dampening.

The use of conventional printing plates, regular inks and offset solvents etc, means anilox is increasing in popularity. With paper accounting for over 65% of any job cost, anilox can be made ready quickly and minimise waste paper in ways that other systems cannot, even digital. This means it has environmental benefits as less stock finds its way to the scrap bin, operating time and power are cut, running costs kept low and a consistent product is delivered.

Anilox inking doesn’t have the usual ink train. The secret lies in the engraving of the anilox roller and the short ink path. To alter ink density, temperature is used to change the ink viscosity. Warmth increases density strength, while chilling has the opposite effect. It’s not necessary to run stock while achieving colour, so vast alterations can be made and all without paper waste.

Printers know the importance of high-quality pre-press when running conventional offset, but it‘s even more important when running anilox. Mediocre plates on a conventional press will eventually produce a mediocre job. It will take time, waste stock and could ultimately lose business. With colour-managed pre-press and plates, anilox can deliver the very highest quality.
By Richard Bradley

Richard Bradley is marketing manager of B2 and B3 products for Heidelberg UK

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Guillotine safety inspections have now been mandatory for a decade, following the implementation of Regulation 6 of the Provision and Use of Work Equipment Regulations 1998. However, it is also important to comply with the materials handling elements which are covered by regulation nine of the Lifting Operations and Lifting Equipment Regulations 1998 (LOLER).

This piece of legislation covers a plethora of lifting devices and it talks of ‘regular’ inspections.

In reality, guillotines have to be checked every six months. The lifting and loading equipment around the guillotine usually only requires an annual check.

Heidelberg this year extended its service agreement offerings to cover safety examinations on peripheral materials handling equipment as well as guillotine safety inspections. It’s not expensive. Annual guillotine safety inspection and preventative maintenance agreements are available for less than £500 and for peripheral equipment from around £80.

In addition to keeping printers within the law, such inspections also report on the wear and tear of chains, lifting gears and cylinders that could cause performance or quality issues and therefore help to avoid downtime. It’s of particular importance given how today’s printers have to ‘sweat’ their assets, leaving insufficient time for regular maintenance.

Other manufacturers and third party engineers also offer inspection services. Users should check the qualifications, experience and up-to-date knowledge of the supplier.

Britain has been at the forefront of safety regulation in Europe. It was the first market to introduce 10-cell light curtains and the first to make full-function monitors, where safety checks are an inherent part of the machine’s control structure, mandatory. This emphasis on safety is unlikely to disappear.

By Steve Rickman

Steve Rickman works in post-press technical centre support at Heidelberg UK

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Unlike printers that specialise in publication printing and deal with the same customers all the time, commercial printers have a wide range of different clients. Some of these clients are well versed in how to create digital files for print, but unfortunately most are not and this is a problem.

For a print job to run smoothly, files need to meet exacting standards and this requirement is bound to be difficult for clients to comply with, and for printers to enforce.

Fortunately, these days, creating good files is a lot easier thanks to the work of organisations like Ghent Workgroup (GWG, www.gwg.org) and the commitment that its member organisations have made.

Most of the common professional desktop design applications are now shipped either with the ability to create files properly built-in or can be updated from files downloaded from the GWG website.

This didn’t happen by chance – it required an unprecedented level of co-operation from many companies in the industry.

If your clients use a professional graphic arts package, such as InDesign, Illustrator or QuarkXPress, then it has never been simpler to create good files.

But not everyone uses these programs. Clients may well create files in common office applications, such as Microsoft Word, Excel or PowerPoint, which can’t be so easily processed. Once again, help is freely available on the GWG website.

With such a wealth of information available, it’s unfortunate that many file creators still get it wrong. Pointing your clients to the GWG website is a good place to start, but some of them won’t bother to look or make the effort to try to understand what it is they should be doing because they don’t see the value in it.

I believe the challenge for many printers is to make it clear to their clients how they can benefit from getting to grips with this technology.
By Andy Psarianos

Andy Psarianos is a director of FE Burman

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Colour quality management (accuracy and consistency) is a challenge whatever print technology you use. Accuracy is getting the colour appearance to where it should be, which usually means matching a standardised print appearance like ISO 12647, or matching a previously printed example or a proof. Consistency means maintaining that accuracy during the course of the print run, and from run to run.

Most variables in the printing process can be measured and therefore controlled. This means that either a calibration process can be implemented that improves accuracy, or good housekeeping and maintenance programmes can be developed to improve colour consistency. There isn’t a printing technology that has significantly fewer variables than any other but they each have different variables.

In offset lithography, there are about 20 variables that affect print appearance, with paper type, ink/water and temperature at the top of the list. With digital printing technology, what constitutes good housekeeping depends on the device, as well as whether it uses dry toner, such as Xerox, or liquid toner, such as HP Indigo. However, both score highly for convenience when compared with offset. The manufacturers of high-end digital presses include sophisticated calibration software in their packages and recommend strict housekeeping procedures to improve consistency.

Basic calibration consists of printing a test sheet. Then the operator should measure the colour swatches on the sheet against whichever standard is being used in the print shop and recalibrate accordingly. At the high end, some machines allow for a degree of internal calibration, which can be done automatically for each job. However, this will generally only handle colour drift of, say, 5-10%. Any more will need to be addressed through external calibration.

By Alan Dresch

Alan Dresch is founder of
Mellow Colour

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For those investmenting in laser-cutting technology, the challenge is to source machines that are well matched to the application.
Laser-cutting has advanced a great deal and low-cost systems today have superior capabilities to the top-of-the-range kit of only a few years ago. Modern systems can cut more intricate designs in a wider range of substrates and with tighter tolerances than ever before.
To begin sourcing the best system for your operation, contact several manufacturers to request samples run on your materials using a few of your part configurations.
The manufacturers should then be able to recommend a system that is correct for cutting your parts from your materials.
If a system integrator insists on using particular components, such as lasers, scan heads, etc, consider it a red flag that they are not set up to match laser technology to real application requirements.
After receiving your cut samples and model recommendations, request a personal visit to manufacturers of interest to see actual cutting of your parts and materials. A day spent on site will give you a feel for the degree of difficulty cutting your parts and to examine the ease of use of importing drawings of parts into the laser cutter and converting the drawings into a useable cutting path.
As with any equipment purchase, it’s also advisable to determine the extent of service support that is available from each manufacturer, as this can make the difference between a relatively short period and a much longer period of downtime in the future. Better quality laser cutters include remote diagnostic capabilities. You should also look to get use of your chosen manufacturers’ contract manufacturing services. These would provide proof of concept and allow their software integrators to fine-tune operations to meet your needs.
By Markus Klemm

Markus Klemm is R&D software engineer for US-based die-cutting specialist Spartanics

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