ABOVE: Thinh Thieu, Kiet Tran and Wilco van Zwieten with Panoval’s GEW UV curing system.
More than 60% of the global volume of pressure-sensitive adhesive labels are produced in the Far East, including those for electronic, medical and pharmaceutical applications. This is the main reason why the company has been founded in Vietnam, although the overall ownership remains European. Despite having just the one production site, Panoval work internationally with resellers and direct customers, and have built a business with global presence. Their production agility and reputation for flexibility has led to them becoming a leading supplier of specialist, non-standard label stock. Typical customers are flexible packaging resellers, label converters and conventional printers.
Panoval employs 25 people currently and is steadily expanding. The management team consists of seasoned and internationally operational professionals with extensive experience in developing and producing label stock laminates for the most demanding applications. Director Wilco van Zwieten joined Panoval as a Sales Manager in 1993 and is now a key part of that team. His remit is to drive new business and he sees technological advancement and innovation as being pivotal to their success.
As he explains: “In such a competitive market, it is the relatively small size of the company and the operation of two very different coating lines that enables us to be so successful. In addition to the higher volume mainstream work we do, our production team are able to run a multitude of smaller specialist jobs, sometimes changing product three or four times in a shift. We use the very latest UV hot melt technology to back up our rubber-based systems. This UV technology is the only one that can potentially replace solvent-based coatings… not right away, but in 10 to 15 years. To do this, you need to have a top of the range UV-curing solution with all the bells and whistles, that backs that technology up. And that is what we designed, in collaboration with the machine manufacturers and GEW, so we can cater for all of our needs in the next five to ten years. We are future-proofed.”
Designed and manufactured in the UK by GEW, Panoval’s custom-built UV curing system includes five NUVA2 lampheads, with capacity to fit up to seven lampheads in all, mounted against a Ø1000mm chilled roller on a Sung An Machinery (SAM) coating line. The lamps are mounted around the drum on a solid frame assembly, which is separate from the roller assembly and slides away from its engaged position on rails. This allows access to the roller surface and underside of the lamphead assembly.
When initially searching for a UV-curing solution, van Zwieten was directed towards GEW by a Malaysian associate who had recently worked with GEW for the design and installation of a UV curing system for release coating applications. Van Zwieten recalls: “I visited the Malaysian factory to see the installation at first hand, and then began talking to GEW. Slowly at first, as we knew we needed a complex, engineered solution with a high level of customisation.” Gradually the momentum built as he worked through Panoval’s requirements with GEW’s ‘Specialist UV’ division. He comments: “We were impressed with the people at GEW… their responsiveness and their ability to answer all of our questions, however technical. It’s all about working with the right people.”
Van Zwieten then visited GEW’s UK production facility during the system build, which provided both parties with the opportunity to discuss the system in further detail and to ensure that it was on track to meet all requirements and expectations. Regarding the design, installation and ongoing technical support for the system, van Zwieten is unreserved: “The whole process was seamless, we have had no issues at all. If a technical issue does arise, we have GEW’s remote monitoring in place to assist us – but we really have had a good experience with this system. He continues: “To date, the only demand we have had for the remote monitoring service is the weekly reports that we automatically receive, which show us useful management information such as running time, lamp hours, energy usage and efficiency. It also gives us peace of mind because we know that if a problem were to arise, it would immediately be flagged up by the monitoring platform.”
As van Zwieten points out, no expense was spared in the specification of the new UV curing system, to ensure that it will meet every demand for years to come. He comments: “A typical laminator will install one or two lamp stations and then be happy. We have differed here and installed a series of five lamps in tandem, which means we can modify the distance between chemical application and curing from one job to the next, enabling us to cater for many different markets that cannot currently be catered for with this technology. This is why we chose to work together with the people at GEW, they have the technical expertise and experience for such a complex system. We now look forward to a rapid return on our investment, with the energy savings and the new work the UV system is bringing in for us.”
Panoval’s target markets are the pharmaceutical and electronics industries, which require a cleaner label with lower residual outgassing properties. Van Zwieten explains: “Residual outgassing is where a product continues to emit gases after production, and this can be a serious problem for manufacturers. In the electronics world, for example, outgassing can cause electronic failure and if you are manufacturing expensive items such as optical drives, then any failure factor needs to be reduced to an absolute minimum, if it cannot be eradicated completely.” He continues: “This is where the UV curing system really sets us apart. We have tried and tested our curing process in our ISO 6 clean room production environment, and we can produce laminates with much, much lower outgassing properties. This enables us to offer a cleaner and far superior product to these specialised manufacturers and their converters.”
With the bespoke UV system designed specifically for Panoval, the distance between the coating heads and the curing lamps can be precisely controlled. This means that the optimum exposure can be achieved for a multitude of different applications. Furthermore, the UV system has been designed with seven lamphead housings and five repositionable lamp cassettes, meaning that the lampheads can be placed in a number of different positions, to effectively control the dwell time. By increasing the time between the application of chemicals to the substrate, and the point at which those chemicals are cured, this allows more time for unwanted gases to escape prior to lamination. It also affects the speed at which the machine can run; the longer outgassing period enables effective and safe curing to be achieved at up to 50% faster running speeds. As van Zwieten says: “This gives us an enormous competitive edge over many US and European companies, who are limited to running at slower speeds.”
Demonstrating the company’s pursuit of the perfect solution, Panoval have also invested in having five GEW multi-point UV monitoring (mUVm) sensors fitted to each of the UV lampheads, and linked to their ERP system. These can measure at the central position of the lamp, and at the extreme edges of a 500mm web and a 1050mm web. In addition to particle meter readings which accurately measure outgassing levels immediately after curing, mUVm enables the production team to measure and verify that the correct level of UV dose and intensity has been administered throughout the production run. With mUVm it is possible to generate a UV curing certificate for every batch by recording live UV outputs for every lamp. Real time UV output data is exported via a RESTful API interface.
However, van Zwieten’s aim is to further develop the benefits of the UV monitoring system by using its reporting capability to research and establish optimal energy levels for initial tack, adhesion and release of the company’s core range of products. This UV sensor information will then be used to create a 3D cure map of every jumbo roll of product, offering a high level of traceability to end user manufacturers. While this data is particularly crucial to customers in the pharmaceutical, electronics and aerospace industries, it can also be used to set up repeat productions runs, quickly and efficiently.
Wilco van Zwieten’s team have also had to overcome technical difficulties created by the local conditions in Ho Chi Minh City. The 18,000 m³/hr of air used for cooling is drawn into the clean room from outside of the building at an ambient temperature of around 35° C. They have fitted two-stage filtration and some 25 meters of additional inlet ducting to reduce the air temperature, humidity, and any contaminant particles within, before it reaches the lampheads.
The production team are collectively driven by a pioneering mindset; their focus is using research and development to create products that offer the end user a commercial advantage. An example of this is their production of substrate for tyre labels, using a refined UV hot melt process. As van Zwieten explains: “We would not use conventional hot melt for tyre labels as it is quite unstable, particularly at higher grammage. This results in the converter having to reduce the converting speed as the die-cutting blades quickly become contaminated with adhesive. Instead, we have perfected the UV hot melt process whereby we can slightly overcure, to create a low-tack adhesive that has a very high final adhesion. This means that the converter can produce his labels much faster and cleaner. It’s a win-win situation for both of us.”
It is the downstream commercial benefits that differentiate their UV products from the conventional, and more than compensate for the somewhat higher cost of UV-based raw materials. Added to this, van Zwieten points to a market trend that is also working in their favour: “More and more coatings manufacturers are producing UV-based polymers and we are seeing the prices falling quickly… they have already come down over 40% in the past three years. It’s a matter of time until UV takes over.”
Panoval’s five lamp system enables the team to tailor the curing process for each and every job, to achieve undercure and overcure at will. As van Zwieten explains: “For certain jobs we need to undercure and we can do this by simply using one lamp at the end of the path. The advantage of this is that it extends the path by up to 130cm, and this allows time for the outgassing to take place before the coating hits the UV station. So we can produce labels for highly demanding medical applications, for example, without slowing down our coating line.”
To quantify this speed increase in terms of competitive advantage, van Zwieten continues: “We can run these particular jobs at up to 40 mpm, which is way above the norm for this type of specialist product. They are commonly running in Europe and the US at 25 mpm, and as a result are significantly more expensive on like-for-like products.”
Labelling for medical applications is often required on non-woven substrates, which absorb far more radiation than polyesters and polypropylenes. This means that high UV curing power is also a regular requirement, and overcuring is easily achieved with up to 108kW of UV power on tap. UV overcuring is used to mimic the more desirable properties of solvent-based adhesives, whereby the coating is cured to become low-tack and touch-dry, but at the same time it remains a highly cohesive adhesive that ages extremely well. This process has other advantages, as van Zwieten explains: “The initial tack is low and even allows for repositioning, but the final adhesion is very strong – easily in excess of 50 newtons – as is required for high performance labelling. And then we go back to the advantages in conversion, which becomes a much quicker process with UV cured coatings.” He concludes: “We can achieve all of the benefits of solvent-based coatings but without the outgassing and the extractables, which are of such concern to the medical, aerospace and electronics industries.”
Panoval also have GEW ‘HiC’ quartz windows fitted to the UV lampheads, which are particularly suited to hot melt applications. This special grade of quartz allows significantly more UVC energy to pass through to the coating, compared to conventional quartz. As van Zwieten comments: ”We did not cut any corners in the specification of our UV system and we have yet to find a job that it cannot do. Because we run a broad and diverse range of demanding, short-run jobs, we had to be sure that we will always be able to achieve what we want to do. And if we do ever find that we need more power, we can easily add two more lamphead cassettes into the vacant housings.” He adds: “However, as it stands, we can run at 220 mpm on this line. We are achieving double the production speed of an equivalent, solvent-based application. As an example, we recently produced a removable polyester label with a low silicone release liner at 100 mpm with a low coatweight coverage, and zero outgassing… and that, as far as I am aware, is a new world record.”
“The GEW system has achieved what we wanted it to, precisely. It overcures, it undercures perfectly. We are saving huge amounts in terms of electricity consumption and reducing our carbon footprint. If you imagine our old water-based system required almost 40 metres of ovens heated to 200 degrees, in order to get the water out… we were consuming around 1,800kW an hour. With water-based coatings, about 40% of every kilo is water that has to be extracted. Now with UV we can run at 220 metres per minute and the maximum we consume is around 600kW per hour. So it’s a third."
However, there are other considerations to be taken into account when adopting UV curing processes, as van Zwieten points out, "You need better trained, dedicated staff to work with and understand UV, and you need better equipment to begin with. To compare, there are over 1,100 solvent-based laminators in China alone, and they are basic, low-cost machines that are simple to operate. You don’t need a laboratory. But it is a dangerous game – it is toxic and polluting, and it costs a lot of energy.” Contrasting this with the benefits of UV, he concludes, “With UV you don’t need an incinerator, it’s not toxic, you don’t have the fire risk, and the energy savings and environmental benefits are very impressive.” He concludes: “We have found a very competent and responsive partner in GEW. To anyone looking for a UV solution for hot-melt adhesive, I would suggest giving them a call.”
More info: www.gewuv.com