Developments in inks and dispensing systems are aimed at consistent quality
Having the right ink just in time for the press is a key issue for the cost effective converter of today. Says David Holmes, managing director of Inovex Systems: “In-plant ink dispensing systems have been widely accepted by all sectors of the ink and printing industry as offering substantial financial, logistical and practical benefits to both converters and ink suppliers.
“For converters, a key benefit to their day-to-day operation is the ability automatically to produce spot colours from a database of formulations on a just in time – right first time basis without recourse back to their ink supplier. For the ink supplier, the tremendous logistical problems of supplying a wide range of types of inks and colours to their customers is reduced to supplying bulk quantities of base colours and additives.”
He told Converting Today: “The converter is able to achieve a high degree of flexibility in production planning, and offer a faster, more flexible service to its customers. Shade matching and batch ink production is carried out on site and only the amount of ink required to complete the job is produced. Press-returns can be stored on the system’s database for use on subsequent jobs or re-worked using in-built software tools with a resulting decrease in ink wastage and cost. In addition, accurate job cost analysis can be undertaken as the ink quantity and value per job is automatically logged on a job-by-job basis.”
But isn’t dispensing only suitable for larger converters? “That’s a common misconception,” he says. “With advances in computer and control system technology it is now economically viable to install such systems in small to medium sized converters. Dispensing systems have come a long way since the large tank farms and expensive dispensing heads prevalent 10 years ago. A typical system can now be installed from as little as £18,000, with features and benefits not even realised by those much larger and more expensive systems.
Probably the largest step forward in recent years has been software. “With the development of modern relational database technology with easy to use and intuitive graphical interfaces the software of today makes that available ten years ago look antique. With the application development systems available, based on industry standard platforms, in-house rapid development of ‘tailor made’ software is possible. Combining this with the latest technology in plcs and state of the art dispense valves has enabled the development of dispense systems having higher levels of accuracy and repeatability, integrated with sophisticated manage- ment systems at a much lower cost than that even thought possible in recent years.”
Choice of systems
The Inovex Systems ink dispensing range includes systems suitable for solvent based, water based and UV curing technologies. They range from the Aquablend 16 ingredient water based system to the newly introduced Colorblend 36, which is suitable for multi technology water or solvent based ink systems on a single fixed head.
Now with over 700 installations around the world, Inkmaker is offering two new automatic dispensing systems. The P18 system was conceived to offer an affordable solution to small-medium size printers. Says the company: “It enables the printer to reproduce any colour at any time and to obtain the desired quantity of ready to use ink with a notable reduction in waste.
The system can handle water based and solvent based liquid inks.” The P32 system allows medium size production by means of a downsized, complete, compact unit. The machine manages liquid water based or solvent based colours. It is said to allow the production of the required quantity of colour in a fast and reliable way, from a formulation stored in the database of the system.
Rexson has released its Colorweigh Compact 32 dispense system suitable for up to 32 solvent based, water based and UV inks. Able to dispense into five gallon pails and 55gal barrels, the Compact 32 and its smaller sister unit, the Compact 18 features Rexson’s Impress dispense and management packages. These allow the equipment to be easily accessible to networks and the Internet for cost effectiveness, quality management and data sharing between sites, for example.
Reducing downtime during job changes is a top pressroom goal, says Graymills. Available in an automatic or manual version, its new IF-NW system supplies ink and flushes the system. Using a plc with graphic interface, the press operator can control multiple stations at once, or individually.
The system comprises a PPS pump, two one or two gallon containers, air operated valves and controls. First the pump supplies ink to the press station. At the end of a run, the operator pushes a “button” to start the automatic process. In step two the pump reverses and draws the ink in the system back to the ink container. The valves activate and switch to the flush container and then the pump begins to circulate the flush solution through the entire system. After a pre-set (but variable) time, the pump reverses and draws the flush solution back to its container. Finally the process stops – ready for the next run.
“A typical printer can spend a large proportion of its day filling ink ducts and checking ink levels at regular intervals. There is also a considerable amount of ink that is wasted when changing inks,” says technotrans. The company supplies a broad range of inking systems that are said to eliminate the time consumption and waste involved in ink control. They are also claimed to enhance the quality.
Its products are offered both for cartridge ink dispensing, up to ink levelling through a barrel or container pumped ink supply systems. Cartridge dispensing is available through a manual filling product (easy.fill) through a semi automatic on press cartridge system (handy.fill) to the fully automated ink.line cartridge dispensers. The range extends to offer combination barrel pumping by ink.line cartridge systems, through to ink.trac or vario.fill ink levelling, supplied by integrated container to tank systems (ink.supply).
“Printers working in a challenging market can’t afford to turn their backs on any developments which will increase efficiency and throughput, and minimize quality errors. We are seeing a huge growth in inking supply systems, especially in the B1 and B2 sheet-fed and web markets,” says Peter Benton, operations manager of technotrans.
When Tesco decided to raise further the profile of its Finest range of premium own brand products, it included a specially developed, high brilliance silver ink in the packaging designs. The ink systems are part of a range of finishes developed using vacuum metallized pigments.
In order to maintain consistency across the broad range of labels, cartons, pots, sleeves, and flexible packaging, Tesco exclusively commissioned the services of Intercolor to assist as project manager for the supply of the finished ink products. Given the number of printers involved, Tesco took the “unprecedented step of nominating a preferred ink supplier to handle several aspects of this demanding project, but most importantly, to administer the distribution logistics in order to ensure the Tesco specified products are available to all its suppliers”.
The entire system is based upon the new development by Intercolor of a method of measuring, with the use of a specialized spectrophotometer. The colour and brilliance of the silver is expressed as a ‘Lustre Index’ through a computer programme that the companies have developed together. Until now, measurements had been carried out using a gloss meter only. The method identifies both brilliance of reflection and the colour (because the reflections from a silver are not totally neutral in colour) and clearly defines whether the print is within the agreed specification.
According to Intercolor, the system has been working so well that Tesco is highly commending its work. The authority to approve and reject printed work has now been passed to the ink maker. Control has been applied to all packaging, whether film, carton or container and, in the four months since the system was established, the majority of samples submitted by converters is reported as having been within the specification.
Key to the operation is the website, www.intercolorfinest.co.uk that has been established so that all parties concerned have access to the necessary information.
“We are always asking the ink makers to play catch-up,” says Jill Woods, ink products manager at inkjet technology developer Xaar. “But now with partnerships with ink makers we will develop the printhead and ink alongside.” Partnerships include those with Sunjet, Sericol and Avecia. The company has recently completed testing of a UV ink developed by SunJet for flexible substrates in the reel to reel wide format market, she reveals.
Sericol and Xaar announced the Black+ ‘blacker than black’ solvent ink in September, designed for coding and marking bar codes which will not fade when printed. “It was particularly needed in automated warehouses where there is only one chance to get the scan right. Those products that don’t scan are sent back to the producer,” emphasised Jill Woods. It is geared for absorbent surfaces such as paper and board, and the use of a low volatility solvent allows the ink to dry rapidly once printed. As well as coding, the Black+ will be available for other areas of packaging.
“We are also working with Sericol on solvent inks for our new printheads” she continues. “I can’t comment now, but we shall be announcing something shortly.” Another long term partner, Avecia, is working on the development of UV high performance inks. “Our focus is on developing inks for the packaging market, wide format and for some industrial niche markets,” adds Jill Woods. In particular, we are having a big push on UV inks for our Leopard greyscale printhead.”