Case study video
Introduction
The Riverside Flooring plant occupies a vast manufacturing site at Thornaby-on-Tees in northern England. The company was acquired by the James Halstead Group in 2010, enabling the group’s expansion into heterogeneous floor coverings. Riverside primarily manufactures vinyl flooring in roll form at 4-metres wide, for the commercial market and also for residential use. Its products are sold through the Polyflor brand, another James Halstead Group company, all across the world.
Mark Raine, Production Director at Riverside Flooring, outlines the scope of the Polyflor range: “We have a wide covering of all markets, not just the heterogeneous that we provide here, but homogeneous and also LVT tile. We’re quite design-led and we’re very active in the market. We pride ourselves on getting material to customer really quickly, to help them deliver their projects on time, to the highest quality.”
He continues: “In the factory itself here, we produce sheet flooring using various plastisols to create a floor with a unique design that we print on the sheet in-house, making up a whole range of products – from safety flooring, to standard compact flooring, to acoustic versions.”
The need for change
All Riverside products are coated with UV-cured polyurethane (PUR) lacquers to enhance their durability, their appearance and, most importantly, their stain resistance. The PUR lacquer is also used to control the gloss or the matt effect, and can also aid slip resistance. As every square metre of product is UV coated, it is imperative that Riverside has a highly dependable UV curing system to rely upon. By 2024, Raine and his production team knew that it was time to replace what they had, as he explains: “The UV system that we had in place had been in for a good number of years. That system was coming to end of life, the technology it was built on, and because we now use PUR coatings on everything we make here, we needed something robust that we could use all the hours that we’re producing.”
He goes on to explain the procurement process in more detail: “So when it came to replacing the system, we had three different suppliers that we wanted to speak to. We approached the original supplier and then we also had contact with GEW and asked them to come and discuss the project with us. It’s always a very tricky thing to take a plunge with a new supplier. You know, you have to be more than 100% sure. you really have to have a lot of confidence to jump and make the change to somebody new. So, we really had to think long and hard and do a lot of due diligence and a lot of work with GEW, as well as visiting the factory and talking to the guys and looking at the design to gain that confidence in order to get us to move. It’s very critical to us because we’re making quite a wide sheet and we have to have certain things in place to ensure that the UV is cured in the right way. It was key for us to make sure that GEW both understood that and demonstrated that they’ve done that in the past.”
Design and procurement
David Lyus, International Sales Manager at GEW, was the key contact for Riverside throughout the procurement cycle. He worked closely with GEW’s extensive Design and Engineering teams over many months, to ensure that the customer’s requirements were met at every stage. He comments: “We understood the parameters of the material they were making, the width, the speed, what type of coating they’re using, etc. How many lamps there were. But in this case, there’s a lot more to it in terms of the functionality and some of the parameters of the finished product, which are very highly influenced by the UV system itself.”
At the same time, Mark Raine was keen to seize the opportunity to upgrade the UV system, and to improve several aspects of the way that they worked: “We had an option here to do something totally different, with different technology, that could help us from a maintenance point of view, help us start and stop the line a bit more efficiently and also create a bit more space in the area where the plant was to allow us to see the sheet more, to help us with any problem solving. So there was really an opportunity here to change the way we did things.”
No going back
Neal Richardson is Engineering Manager at the Thornaby plant, and was responsible for planning the successful execution of the UV system replacement during a brief factory shutdown: “My main task of this whole project was to get the new system fitted within a very tight time frame. From my experience in putting many projects in, you’ve got to have a relationship with the supplier. Prior to us actually getting any equipment on site, there’s been a lot of work done behind the scenes. In order to fit any new system in, we had to basically remove the existing system. That meant that the new system was going to have to work. There was no going back.”
Ensuring perfect product
A further consideration for the Riverside team was the technical aspects of achieving a successful, even cure across such a wide web, as Raine explains: “Part of the difficulty in trying to cure PUR on a sheet four metres wide is there aren’t any four-and-a-half metre wide lamps. So whatever system you put in place, you have to have some overlap of the lamps to cover the width of the sheet.”
Lyus adds detail: “What happens at the points where the lamps overlap was a particular concern for Riverside Flooring because if that’s not done very carefully, you get a difference in irradiance, in intensity and the dose, the quantity of energy. And if that happens, then you can get differentials in your gloss level across the material. And if it’s a piece of flooring four metres wide, then rather obvious to see that once it’s installed and it doesn’t look good.”
Additionally, GEW had to ensure precise control of oxygen levels at the point of curing to achieve a consistent finish, as Lyus explains: “Equally, from the UV lamps point of view, they cure under an inert atmosphere. So there’s nitrogen that’s introduced into the area where the final curing lamps take place. And it was important to make sure that the level to which the residual oxygen in that chamber is reduced is consistent because again if it’s not then you get differential gloss / matt patterns across the material, which is not acceptable.”
He leads on to GEW’s methodology: “We sent up some of our specialists to do an audit on the line to measure what is the radiometric profile on each bank of three lamps and what’s the total dose, what’s the irradiance that’s produced by these lamps at various positions across the width and we’re looking for how uniform, how consistent it is now, so we probed up the nitrogen chamber there, measured up how consistent the oxygen levels were inside there, and that’s our minimum target for consistency of irradiance and dose in our solution.”
Prototype testing
The final stages of Riverside’s due diligence process involved comprehensive prototype testing at GEW’s main manufacturing facility in West Sussex, which ultimately led to the project getting the go-ahead from Raine and his team: “We did quite a lot of testing on the product. We looked at lamp overlap and we looked at checking the curing process. We had one of our PUR suppliers involved. They did some independent testing for us and once we’d established the lamp technology and the setup could deliver what we wanted, we pressed the green light to go.”
Manufacturing of the UV system then began in earnest and the Riverside team were very much involved in the process, as Richardson says: “We did several visits with our technical people down to GEW to see the whole system being built. We looked at the electronics of it, the mechanics of it. Everybody was working together.” Raine agrees: “The interaction with the technical team was excellent, with the design team was excellent.”
Successful installation
The UV system replacement was scheduled to coincide with an annual factory shutdown and had to be executed with military precision due to the very limited time available. Richardson sets the scene: “The day came, we ripped out the old system completely. That was a nearly a five-day job just to take them out. GEW people were on site. We worked very well with them. Put the new system in. A lot of mechanical work, a lot of hours spent.” Raine concludes with the outcome: “We hit the deadline, producing grade one material on the day we said we would be after the shutdown.”
Expected enhancements
After many years of working with the outgoing UV system, the team had a clear picture of improvements that needed to be made with any incoming replacement, and they worked closely with GEW to ensure that these enhancements were achieved through intelligent design. David Lyus begins by outlining the system configuration: “So the present setup today is the coating’s applied with a coater to the web. The web rises up another floor level. It passes underneath a gantry with three lamps on it. These are three overlapping 150 centimetre UV lamps which forms the pre-gelling station. After that the web moves to the final curing position which consists of three gantries of three overlapping lamps each. All of that area underneath those nine lamps is fully inertised. So there’s a nitrogen rich atmosphere there which depletes the oxygen down to a specified level to ensure enhanced surface properties of the finished coating.”
The first requirement was to design the system to make UV lamp changes much faster and more efficient, as Raine explains: “On the old system, we have to turn the whole system off and then run production to a stop in order to get into the machinery to change a lamp… something in the region of an hour and a half’s production disruption. Whereas on the GEW design solution, 10 minutes… we can effectively change a lamp on the run.”
This major advancement was simply achieved by astute design, as Richardson explains: “We can switch the GEW lamps off and isolate them. We don’t have to access the lamps from underneath. We can access the lamps from on the top. So all of the undershielding and everything stays in place. We can pull a cassette out. We can replace it with another cassette, start the lamps back up again. There’s no need to wait for the nitrogen to purge through the system.” Raine agrees and adds a quick conclusion: “Which saves us a significant amount of time in production. And that’s for us reduced downtime, reduced scrap and reduced maintenance interaction.”
Cleaning and maintenance improvements
The second targeted requirement was to improve upon the intensive cleaning and maintenance regime that was necessary to keep the outgoing UV system in service. Richardson highlights this: “The older system was very maintenance intensive from a technical point of view and also from a cleaning point of view. The new system’s arrived and both parts of that are dramatically reduced. That time has less than halved, and the technical side of having to change anything out is so much easier.”
Raine adds a comment: “So previously when we would clean the system, it was very difficult to get into all the areas you needed to clean. We would drop the undershield and go underneath, do the cleaning, move reflectors and be in and amongst the workings, which gave you an opportunity to damage things or catch lamps.”
Again, intelligent design has been employed to great effect, as Richardson says: “With the new system there is a glass plate between the fume and all of the technical side of the lamps and everything. So none of the lamps, none of the reflectors ever come in contact with the fume. So therefore, it’s just literally the glass has to be cleaned. We’ve ran this now for some time and we have not had any contamination at all onto the lamps or the reflectors.” Raine concludes succinctly: “The contamination can’t get to the places on the lamps where it can affect quality. So we’ve made a real step forward in that area as well.”
Lyus goes on to describe the lamp and extraction functionality in more detail: “We mounted the UV lamps above a quartz glass window and then beneath the window is the inerted atmosphere. So the lamps in the inerted area are separated from each other physically by a quartz glass barrier. So the radiation from the lamps shines down through the quartz and exposes the coating on the material. To keep completely separated any contamination that could be occurring in the factory, we don’t actually extract any air from the production room at all.”
He continues: “We bring in air from outside the building which is drawn through a dedicated filter panel and introduced into the UV lampheads under a light positive pressure. So there’s no chance for any contaminants in the air within the factory to enter into the lamp… and then the air from the lamp, the warm air, the ozone gas is discharged to the outside of the building. GEW provide the supply air fans, the exhaust air fans and a system of ducting which we designed ourselves and installed to transport the air to and from the UV lampheads.”
Reliability and support
A further, crucial benefit that the new UV system has brought is the constancy of operation, backed by superb technical support from the manufacturer. Richardson comments on this: “Reliability is phenomenally better. We’ve had phenomenally less breakdowns and we’ve been able to rectify them very quickly. If we’ve needed some technical backup from GEW, it’s a phone call and within 10 minutes, quarter of an hour, somebody technical will contact you back. They’ve probably had a look at the history of what’s gone on, and every time they’ve been able to point us in the right direction and we’ve been able to rectify it on site.”
Return on investment
On the all-important topic of energy savings, Raine is clear: “We’re confident that we are saving… the amount of power we were drawing on the panels, the warm-up and the setup time of the new lamps is considerably shorter. So even first thing on a morning, we’re not having to switch everything on as early for the product to get ready. So we are definitely confident we’re saving.”
Summary
Raine goes on to praise those involved in this major project for the company: “To sum up the project, it’s been a very satisfying, successful process. The team achieved its goal on such a big project, a crucial project that if it went wrong would mean no production out of Riverside. A really good achievement by both GEW and Riverside people working together.”
For further information on GEW’s high power NUVA2 curing system, visit www.gewuv.com/nuva2
For more about Riverside / Polyflor, visit: https://www.polyflor.com/
