Nearly 120 delegates attended the Polyurea Development Association (PDA) Europe 2014 conference in Krakow, Poland in November. Jane Denny reports.
The event took place from 5 - 7 November 2014 and included live polyurea demonstrations, exhibition stands promoting the innovations in spray PU machinery and accessories from various firms.
Delegates from a number of companies including BASF, Bayer MaterialScience and Huntsman gave presentations on polyurea applications and developments.
Swedish institute's tyre test unveiled
The relative durability of substrates for car park decks is the subject of an ongoing study of practical tests at the Swedish Cement and Concrete Research Institute (CBI).
The project, to devise an efficient and revealing way to measure the effect of tyre wear and tear on the range of substrate materials used, began in 2013.
Ylva Edwards, a senior researcher at the institute, told delegates about the testing suites and systems put in place for the study to assess the weathering of substrates exposed to studded tyres. The tyres are used in northern winters.
The studies are designed to measure the resistance to scuffing on substrates including PU-based coatings and polyurea. Nine rolling wheel abrasion tests were initially set up at a site in Gothenburg, Sweden in November 2013 and in a further six were installed in Stockholm in 2014. According to Edwards, the testing space is 35m2 the testing process is performed over 3.5 hours.
In one of the institute’s tests, forty steel balls hammer on the test site and at the same time water is sprayed on the tyres. “We think that this modified scuffing system seems very promising,” she said.
Although the testing process, which is continuing and as yet inconclusive, specifically investigated studded tyres in use in Sweden. Edwards, who gave the presentation, said the tests could be adapted to any type of tyre adding that studded tyres are also used in Norway and Russia.
A follow up study is expected continue for at least the next two to three years. Stage one and two have finished and the institute is now looking for further funding. Polyurea from Italian adhesive and sealant producer Mapei and Swiss-based chemicals company Sika is being used.
Robotics solution to bridge coating with polyurea
Murphy Mahaffey, director of international sales at Polyurethane Machinery Corporation (PMC), outlined his company’s capability in bridge waterproofing. According to Mahaffey, more than 220 bridges had already been waterproofed with his company’s Spraybot.
He also said the machine was capable of spraying an area of 280m2 in one day. He added that if the same job were to be carried out by a human they would have to complete two runs for each pass that the robot makes.The machine runs for eight hours on 3.8 litres fuel, said Mahaffey.
Not only is the technology adaptable, sales of the machines are going to many more environments, Mahaffey added. The company is also developing vertical applications based on the technology which will mean that a Spraybot could be used to coat the inside of water treatment work tanks or walls.
Mahaffey claims that contractors are experiencing 10% higher material efficiency when they use robotic machinery to polyurea spray coat substrates compared to using humans.
The mechanical process provides a more “consistent, even application of material” than humans are capable of, Mahaffey said. “Because they are affected by more variables, the same jobs carried out by a human workforce will more likely return variations of the end product,” according to Mahaffey.
“Lastly,” added Mahaffey, “with a robotic process the material is applied to the surface evenly, whether it’s a rise or a valley. The knock on effect, he said, is a minimisation of overspray.
Bridge waterproofing – a Euro-conundrum
Also on bridges, Dirk Uebelhoer’s presentation he explained the industry’s frustration at the apparent impossibility of imposing uniformity on European states’ requirements for carrying out bridge waterproofing work.
The Sika corporate systems engineer said the UK and Germany had expressed their dissatisfaction with the standards drawn up by EU working group members trying to devise a uniform standard for bridge waterproofing. The problem had not been resolved, he added.
Uebelhoer said international engineers were still unsure what they should specify. Businesses had handed over cash to undertake tests, applied for certificates but still there was no harmonisation.
Uebelhoer joked that a uniformed approach to standards for bridge waterproofing remained a dream and that it was something he would not see before his retirement. Uebelhoer feels it will be 2039 before harmonisation on standards for polyurea would emerge from the EU. The end result, he said, is that “innovation is blocked.”
Pitfalls of polyurea use in arctic conditions
Away from bridges and to pipe and container work, the PDA’s former president and Elmico general manager Elisabet Michelson shared her experiences of using polyurea in low temperatures. The material is used to coat pipes and wastewater containers.
Michelson, who set up the Norway-based system house Elmico over a decade ago, told delegates that it is polyurea’s “strength and elasticity, in combination with low temperature properties, which renders the material unmatched at protecting constructions.”
“But,” she said. “We have to take care, this is not a fairytale. Even polyurea has its limitations and to obtain the best results, we need to learn from our experience and mistakes.”
By looking at projects to coat worn concrete substrate in polyurea, Michelson explained why it is vital to ensure that water cannot find its way between the primer layer and polyurea. “If this happens, you have a problem,” Michelson said. “And if the water freezes, you have an even bigger problem,” she added.
For car park polyurea applications, Michelson warned against overlapping the polyurea in turning zones.
New president
BASF’s director, project management new products, Klaus Breuer replaced Michelson as PDA president.
Breuer said: "Next year, we will strive to make polyurea technology more well-known among potential users, designers, specifiers and construction companies," said Breuer.
"We firmly believe that polyurea that applicator industries are not using polyurea to its full potential yet. Secondly, safe and professional application of the technology and equipment is of utmost importance.
“Therefore, we will continue offering educational spray courses as well as provide information and tools on safety-related aspects and best practices for applicators.”
A number of polyurea machinery makers, such as GAMA and Graco exhibited at the three-day event in Poland.
