How do you use your UV curing system?

Rahul Kumar talks to print service providers from Delhi-NCR who are making a difference using conventional UV systems, even as LED UV is being hailed as the future of print finishing.

18 Apr 2018 | By Rahul Kumar

The buzz is definitely on LED UV. It’s the latest cutting-edge version of a technology which has found its footing in the industry. Today, customers want UV finishing in jobs as varied as high-end packaging items and wedding invitation cards and everything in between. Meanwhile, print service providers are looking to retrofit UV systems on their existing machines. 
While LED UV is, undoubtedly, the technology of the future, industry experts believe it will take time for LED UV to be popular in India due to its high cost of initial investment and unavailability of raw material, which is again expensive. On the plus side, however, LED UV is a green technology, consumes less power and its lamp life is more compared to conventional UV, besides it being an easy to operate plug and play system. 
So, for now, conventional UV curing and coating will have to do. 
Like every technology, it has its pros and cons. On the positive side, it gives attractive results with less investment and operating cost and people in printing facilities are familiar with its behaviour. The best part is, pre-owned printing presses are more suitable for retrofit UV systems, especially Heidelberg, as its metallurgy is strong. On the negative side, it requires more space; power consumption is high (almost the same or more than a printing press) and requires additional air conditioning, exhaust and chilling systems.
And there are number of options to choose from. Among Indian manufacturers, we have Alpna Visual Packaging Aids, APL Machinery, UV Graphic Technology, Unique UV & Light, Dizario Machinery, and few others. These solutions are customisable and easy on the pockets for Indian printers. On the other hand, we also have the best of the overseas manufacturers available in India. These include companies like IST Metz, GEW, AMS Spectral UV and Phoseon Technology.
At the end of the day, however, a technology is a means to an end. It all depends on how a printer plans to harness its potential, as we will see in the following pages. But before that, an important question, why UV curing and coating?
Why UV?

New Delhi-based Standard Cartons specialises in UV jobs for pesticides manufacturers. According to Basram Bairwa of Standard Cartons, the demand for UV comes from customers and its requirements vary from job to job. “Most of the time, we match customers’ samples with our print products,” he says. 

Bairwa says the demand is for something different to attract attention. “Most of our customers ask for hybrid printing, while demand for UV also comes in conventional printing,” he adds. The run lengths of most of UV jobs at Standard Cartons are around 10,000 sheets per job. The company delivers them in less than two hours. 
Based in Patparganj Industrial Area in Delhi, Vee Aar Packers is a print firm which was established by Rakesh Gupta in 1998, accompanied by Mudit Gupta in 2008. The firm has a Heidelberg specialised unit of a 5 color + coater machine and a two-colour printing presses. And even before UV was introduced in India, the company was in the forefront of print enhancement. Gupta from the very beginning had a passion for printing on metPET and started metallic printing in 2002. “It was conventional printing on metPET and the drying time was minimum two days. The technology was not good but managed to produce satisfactory results,” It was in 2006, when their dreams came true when UV printing technology for offset came to India and when they adapted to UV, there was a tremendous quality satisfaction which was the need of the hour. 
Gupta says the company’s existing customers from diverse segments such as garments, cosmetics, fragrances, hardware and FMCG, pushed the company to upgrade and invest. For Gupta, cost of UV coating is less than conventional lamination and the results are far better. The only hitch is that on corrugated boxes, it creates problems on creasing.
Gupta believes, today, UV is the best technology for value addition. “We want to make things beautiful. We want to produce new textures of UV varnishes and focus more on coating compared to printing. Value addition is our prime focus. Print buyers want new things and we always work towards delivering these,” he adds.
How to use UV?
The rise of UV coating can be traced back to the rise of packaging. As the consumer market exploded, there was a need to have distinct product differentiation on the shelves. UV coating helped. For one thing, it could be easily applied to traditional packaging substrates such as duplex, polypropylene, and metPET, among others, besides paper. UV coating also lends the package a tactile feel. 
Naresh Malhotra of Ipack, the sister concern of VK Box Industries, which invested in UV to cater to the emerging mobile phone packaging market, says that its ratio of UV and conventional jobs is fifty-fifty. 
“Somewhere in 2011-12, our customers from the mobile industry and sweet manufacturers started demanding UV jobs because big companies were doing it and a few people were importing it from China. Big players like Haldiram and Bikaner launched UV cartons at the same time and proved that attractive and eye-catching packaging enhance the value of packaged material,” Malhotra explains. 
Malhotra recounts how during the initial days printers did not have the complete setup for UV and even production was less, around 5,000 sheets per day.
Now, the things have changed, and how? These four print firms showcase how to use UV.

Standard Cartons

Standard Cartons is a Gurugram-based corrugation unit which established a printing unit in Okhla Industrial Area, New Delhi, around a decade ago. Basram Bairwa, who is responsible for print production at Standard Cartons, says the company prints on metallised boards and other flexible media, adding, since there is UV curing and coating, printing substrates hardly matters.

Standard Cartons has installed UV curing and coating systems from APL Machinery on its six-colour Heidelberg CD 102 printing press. Bairwa says printing substrates, printing inks, setting of lamps and lamination play major roles. Thus, all these must be in an accurate manner to produce best jobs.

“Most of our jobs are on metPET sheets and for this, UV curing is a must. We do UV coating on four-colour commercial jobs too. These days, we are witnessing a demand for textured hybrid UV coating on conventional jobs to make it attractive,” he adds. Currently, the company prints on duplex, polypropylene (PP) and paper.

The company runs both conventional and UV jobs on the same press. “It gives us time for changeover and it keeps our rollers and blankets in good health. When we change printing press from conventional to UV, we clean the printing press with caution, rubber rollers and blankets too. Combi blankets and rollers are also available in the market,” Bairwa says. However, with each job, chiller water and IP value are changed. In some jobs, the company uses full gloss. For this impact, five-colour printing is the same, with five printing plates and no plate for gloss.

The system has five UV lamps. First is after the first printing unit which prints white, two floating lamps can be installed in any of the print stations and the rest two are at end of the press.

Sairam Creations

Sairam Creations is a partnership entity. Mukesh Munjal, Ashok Nagpal and Rajesh Gupta are the three partners. The company, which got into UV curing in 2015, has specialisation in pharma printing. Around 95% of its print production is for this segment. The rest 5% has a mix of customers.

The company has installed four UV lamps from APL Machinery on a pre-owned six-colour Heidelberg CD 102 printing press. Khurram Suhaib Hasan, production head, Sairam Creations, who has two decades of hands-on experience in printing, says, earlier lamination was used but UV is both cheaper and faster than lamination.

The first lamp is after the first printing unit (to cure white), the second lamp is installed at one of the four-colour printing units and rest two are at the end of the printing press. Two lamps are at end of the press to cure the entire sheet.

“Our ratio between conventional and UV jobs is around 40:60. We have two print production units in the same industrial area and one is dedicated for UV print production,” Hasan says. “Most of our jobs are short-run and the number is high. The average run length of the job is 5,000 sheets per job.”

More than 95% of these jobs are on metPET. The company also prints on polypropylene. “We have printed jobs for Thums Up on metallised sheets,” he says, adding that processes vary from jobs to jobs but usually, the company goes for metallised polyester lamination first, then five-colour printing and later hybrid UV.

“We advise our customers for UV applications and today, around 40% of our customers opt for UV. Polypropylene is in demand because of UV curing and coating,” he says.

Hasan adds that metPET UV jobs are ten times expensive compared to conventional printing due to the cost of metallised polyester coating, higher cost of printing inks and consumption of more electricity.

Again, using UV on a shopfloor is a specialised job. “Thus, it has to be used with precautions. We ensure that our operators are equipped with essential tools like mask, glasses and the facility has proper air conditioning,” he adds.

Ipack (VK Box Industries)

Established in 1975, by Manohar Lal Malhotra, VK Box started using UV by printing jobs for mobile manufacturing companies, especially for accessories like headphones, batteries and others. This was handled by a sister concern Ipack, started by the second generation Naresh Malhotra in 2011 to focus on the rising mobile packaging market.

For this, last year, the company scaled up its UV business in terms of quality and quantity by bringing in a six-colour Heidelberg CD 102 plus coater printing press and installing six UV lamps from Alpna Visual Pakcaging Aids. Of these, three are interdeck and rest are at end of the printing press.

“We wanted to produce UV jobs at the speed of 10,000 sheets an hour or more. So we put three lamps at the end of the press. Sometimes it becomes tough to dry at high speed. Three interdeck lamps are located after first, fifth and sixth printing units,” Naresh Malhotra says. “We installed the Heidelberg so that we can finish drip-off UV jobs in one go. And thus, we could increase quality and quantity both.”

The company has four printing presses and three of them are equipped with retrofitted UV curing and coating systems. The company has a capacity to print 1,00,000 sheets per day but presently are running the system at 50%.

“We have dedicated presses for UV jobs because change-over takes time. And cleaning the press is a challenge. If it is not cleaned properly, it will reflect in the next job,” he adds. For conventional jobs, the company uses non-baked printing plates and for UV, it uses baked plates. “During interchange, conventional printing plates did not work and we had to use baked plates for conventional too. It was a waste of time and an unnecessary expense. Later, we decided to dedicate a printing press for UV jobs only,” he explains. “Initially, jobs were not sufficient to run the machine, but nowadays, we are running only UV jobs on it.”

Malhotra says metallised printing was the first where UV curing was required. Now, flexible materials like PP (polypropylene), PVC (polyvinyl chloride) and PET (polyethylene terephthalate) and to a certain extent polycarbonate are in demand. Met vinyl is also in demand.

On the subject of coating, two of the company’s presses are with anilox rollers, which help to decide the volume of coating. The rest are without anilox. This gives the company a better control in print production and costing. It does flood coating/ flat coating/ full UV, drip-off with gloss. Plus, design possibility increases because of UV coating. “We have a strong infrastructure for UV curing and coating, including professionally trained graphic designers,” he says.

Next, the company is focusing on flexible media and for this it will have to switch to LED UV. “Flexible printing substrates are heat-sensitive and its shapes can change because of the temperature of UV lamps. Since there is no heat in LED, it is the best solution for flexible substrates,” Malhotra says. He, however, agrees that LED printing inks are expensive and flat and drip-off coatings are not available for LED.

Vee Aar Packers

Last year, Vee Aar Packers installed a five-colour Heidelberg CD 102 online plus coater printing press and with UV lamps from Alpna Visual Packaging Aids. Mudit Gupta of Vee Aar Packers says because of UV, the company can now print on PP (Polypropylene), metPET and other substrates.

“The extended delivery in the machine also gives us an edge as it helps in higher gloss in UV coating, which is not possible with short delivery machines even when the same UV varnish is being used,” Gupta says.

He adds that for UV, funds and electricity are the major challenges when you opt for an up-to-date fully equipped UV curing system to attain faster curing, better quality and higher production. 

Hybrid, texture and drip-off are common nowadays but demand now is for good quality UV printing jobs. “We have a ratio of 80:20 in UV and conventional. We do not want to focus on non-UV jobs because changeover is time consuming,” Gupta says, adding, “We are growing more than 20% year-on-year. In the current year, it will be more than 100% because of the new five-colour press.

"With the new Heidelberg machine, our capacity to print UV has now increased from 6,000 sheets per hour to a whopping 16,000 sheets per hour, which helps complete a UV Job within 48 hours," he adds.

As the saying goes, one bird in hand is worth two in the bush. So until LED UV becomes affordable and easily available, it is possible to do impressive print enhancement work with conventional UV. This is exactly what’s happening. Currently, conventional UV is popular in India, and it will continue for a while. The idea is to do it intelligently, focusing on the work you are doing and how UV can help enhance it. 

Also, UV needs to be handled with precautions. So, protective gears like masks and glasses for all the workers are mandatory. It also needs an excellent exhaust system on the shopfloor so that employees of these firms are not affected by toxic fumes.