Polyurea, the developments continue, PDA told.

Over 200 delegates attended the ninth annual Polyurea Development Association’s (PDA) Europe conference in Berlin in November, 2015. Jane Denny reports.

Polyurea’s contribution to Rio de Janeiro’s vintage sports stadium the Maracana, the renovation of a shipwrecked sea vessel and an innovative 2K PU injection bonding material were among the highlights of the PDA conference and exhibition.

The industry, which analysts Grand View Research predict will be worth $1.4 bn by 2020, was given a welcome boost an Olympic seal of approval when it was chosen to coat areas of Rio’s Maracana stadium.

The 85,000-seat venue, which will host the opening sequence of the 2016 Olympics, got its polyurea makeover as part of the preparation for the 2014 World Cup, delegates were told.

Over 70,000m²  of seating and walkway area was covered in Huntsman polyurea over the course of three months.

In their joint presentation entitled Range of Raw Materials Set for The Polyurea Industry and Case Study of Maracana Stadium in Brazil, the firm’s application scientist amines Steven Buvens and coatings application specialist Stijn Roekaerts explained the process.

Using three to four polyurea spray machines at the site, the material was applied to the surfaces in a 3mm layer thickness and at temperatures between 70° and 75°C.

According to the pair, Gama’s G30H (with IMAGE) and G50H spray PU machines were used.

Hey, Macarena!

As the team – from key Huntsman customer Radial Quimica - worked, daily rainfall made the job increasingly challenging.

Despite the problems of temperature extremes, the team sprayed 10,000m² of walkway and 60,000m² of seating area with Huntsman polyurea.

The work was part of a EUR239m facelift given to the site in preparation for the 2014 World Cup.

The consortium group behind the event was, according to Huntsman, initially reluctant to use a polyurea coating due to earlier unsuccessful testing by improperly trained and uncertified operators at both the Maracana Stadium and other local construction projects.

To overcome those negative perceptions, Radial Quimica prepared demonstrations and field tested polyurea’s performance using comparisons and audit controls. Those tests yielded positive results for polyurea.

In the stadium restrooms, bars, locker rooms and lounges with a total are of 100,000m² were covered with self-leveling flooring and polyurethane finished coloured flakes. These were sealed with polyaspartic coating.

In all, Radial Quimica’s work took 102 days although, according to Huntsman, the teams often worked through the night to ensure the work was completed in time.

In preparation for the polyurea application, Radial Quimica developed specialised solutions to address the variety of substrates to be coated.

Surface preparation and the polyurea application also presented some challenges, as other contractors were working on simultaneous projects at the Maracana Stadium. To meet the tight deadlines, Radial Quimica used six sets of hydraulic equipment to spray the substrates with primers and fast-drying glues.

Delegates also heard how polyurea was not only making waves in big projects like sports stadium, it also proved vital to the refurbishment of a vessel that had been left for scrap.

Ship A-hoy!

New Jersey, US-based Polyurethane Machinery Corporation explained how it had used PU foam and polyurea in a unique project to breathe life into a two-story, 6m long shipwrecked vessel.

The firm’s director of international sales Murph Mahaffey told delegates how a polyurea coating was used to restore and protect the riverboat after it spent several years lodged in a Texan river bed.

Around 25m³ of PU flotation foam was also added to the hull to increase its buoyancy and allow it to sustain weights up to 22.6kT, Mahaffey told delegates.

In his presentation Riverboat Rehabilitation with Polyurea: Renewing Resources with Technology, Mahaffey said it took a total of nine months to restore the vessel. Polyurea was applied at a thickness of between 3mm and 5mm depending on the level of protection the part required, said Mahaffey.

Back on the land, delegates were shown how, polyurea can be applied to perfection.

 Polyurea for German roads

Sika’s corporate product engineer Dirk Uebelhoer told delegates how his company undertook a project to restore a highways service road in Germany using polyurea.

In his presentation, Polyurea - a Road Surface? – Uebelhoer said that the use of polyurea allowed for the completion of the project to repair the 40m² space within a 24 hour period.

He said the work was such a success that after a year the firm carried out an inspection of the site and found there was no damage. The project was carried out in accordance with German regulation except, said Uebelhoer the thickness of the material was 2.5mm instead of 6 - 8mm usually stipulated. Despite the thinner material, local road authorities were highly satisfied said Uebelhoer.

The material is proving impervious to damage from cars in Scandanavia too, as Ylva Edwards said  a study of car park decking is showing.

Car park deck study continues

Edwards, a senior researcher at The Swedish Cement and Concrete Research Institute, updated delegates on tests suites to assess the weathering of substrates exposed to studded tyres.

The studies are designed to measure the resistance to scuffing on substrates including PU-based coatings and polyurea. She told delegates the study was comparing the results for a number of systems including polyurea and PU at outdoor locations in Sweden during August 2015. Norwegian systems house Elmico supplied materials and carried out the field work site preparation, she said.

The project focuses on the development of a method for evaluating wear resistance of coating systems intended for use on concrete parking decks.

Edwards said: “A total of 22 systems are included in the study. They were all tested in the laboratory and were placed as well on three different parking decks (during 2013 to 2015) for evaluation and comparison to the laboratory test results.”

Edwards continued: “Three of the four polyurea systems tested in the project performed very well in the test. However, wear resistance to studded tyres is only one of several important properties required for a protective coating system on parking decks.”

The test samples will be inspected every year, for at least another five year, Edwards concluded.

The conference showed polyurea’s strengths go far beyond coating and into the competitive world of adhesion.