Innovations highlighted at annual Foamed Plastics and Polyurethane annual conference

The Association of Foamed Plastics and Polyurethanes annual conference highlighted innovations including those it honoured as the industry's 2013 ‘lighthouse’ ideas.

Polyurethane wound care

Petra Hertel outlined how a polyurethane solution can provide a lifeline to people recovering from wounds.

Hertel, of Ausbuttel and Co, told delegates how wound management could be a life-changing experience and that badly-managed care could lead to severe disfigurement.

Longer life expectancy and demographic change had impacted the wound care sector, which she said has grown by more than 85% since 2007.

Hertel spoke of the growing medical devices market and raised the prospect of a 3D dressing for special wounds which she believes could arise out of the combination of current know-how for molding with innovative materials.

Hertel said: “The speed of healing is quicker within a moister environment. With this in mind, the very first hydrcolloid wound dressing was developed - an absorbent carboxymethylcellulose-coated on a polyurethane film.”

She told the audience that further materials, such as polyurethanes foams and alginates followed. Hertel said the technological interaction that occurs within this combination of foam, film and adhesive provides “outstanding medical products.”

Sustainable energy production

A joint presentation by BASF’s Christopher Hebette and Holger Ruckdaschel outlined the company’s applications for wind energy plants and composites. Hebette told delelgates that further significant growth is expected within the windfarm sector in the coming years.

Both Hebette and Ruckdaschel agreed that polyurethane had proved its “feasibility” in early applications but it remained to be seen how the quickly the material might replace other well-established materials.

Hebette’s presentation provided insight into the fatigue characteristics of polyurethane. Understanding performance will be important for efficiently manufacturing rotary blades for the world’s (roughly) quarter of a million turbines.

According to the pair, there is certainly scope for polyurethane sales in the wind energy sector. When windfarms were still in their infancy during the 1980s blades measured 50m in length – today they are 200m. Offshore wind turbines will utilise 250m blades said Hebette.

“There is a demand for innovative processes and design. All this points to the efficiency of the plant and at BASF we want to focus on the chemical development of materials. On the other hand without design and without knowledge it will not work,” he added.

Pultruded polyurethane-based composites and polyurethane foams as core materials

Polyurethane-based structural inserts for the root section of the blade were developed in a collaboration between BASF and Danish pultrusion company Fibreline.

According to Ruckdaschel, the fibre volume content, fibre orientation, impregnation, curing and resulting material performance have all been improved by using the polyurethane resin Elastocoat from BASF. Core materials are used as sandwich applications in rotor blades to provide buckling resistance at minimum weight.

Established core materials based on PET and PVC, said Ruckdaschel, have lower foam densities which do not achieve the required performance. As an example of the good mechanical performance, the fatigue characteristics of different polyurethane-based core materials were compared to PVC foams. “By choosing and combining different polyurethane systems, the stiffness-to-ductility ratio can be balanced and adjusted to fit the application.

The reactive foaming potentially offers the opportunity to mould complex, near net shape parts and to simplify the manufacturing process,” said Ruckdaschel.

Unequivocal about the benefits of a polyurethane base to rotary blade composition, their presentation highlighted polyurethane-based material's high fatigue resistance, good adhesion to other composite materials and fast curing during processing properties. “Prefabricated structural inserts can be used for wind turbines and for composites in general,” Ruchdaschel added.

Rail applications

The use of polyurethane in rail applications is becoming more widespread. As with the automotive industry, the material's ability to reduce the overall weight of vehicles is a significant factor in its popularity. Co-managing directors Resch & Vogt GmbH have developed an entirely different application for the material within rail than weight reduction.

As regulatory change on the acceptable levels of noise and vibration emissions around urban rail and tram infrastructure becomes a greater issue, Andreas Vogt and Johann Resch will be keeping a very close eye on developments.

Vogt told delegates how his company had “successfully applied polyurethane to reduce noise and vibration emissions, as well as stray electrical currents, from urban transport systems.

"Installing polyurethanes in urban railways and trams is a great challenge to the material itself because conditions at the construction site change all of the time. For example it can be dry and dusty or wet and raining. “It is important to continue improving the positive properties of the material for those requirements,” he added.

Raw materials and sustainability

Christoph Gurtler, who currently heads a Bayer AG competence centre dedicated to new catalytic processes, outlined his company’s involvement with a project to harvest C02 as a polyurethane feedstock.

Gurtler said the issue of whether CO2 could be made use of was an important question for chemists and the world. “We think it is a sensible choice because there is so much of it available.

To use the fossil resources of the world a little less is a bit of the solution to global warming and climate change.” He said research undertaken by BMS’s Dream Production – a project funded by the German Ministry of Education and Research – had already shown CO2-based polyurethane foam properties to be superior to those of conventionally-produced material.

From early 2013, the new method for chemically converting CO2 to a polyol (and later into a polyurethane) moved on from batch quantities to continuous production. He said it was a key moment for the polyurethane industry as it allowed for industrial-scale production of CO2-based polyurethane.

Gurtler told delegates how Bayer had found a suitable catalyst for which experts had searched for more than 40 years. It enabled the efficient reaction of CO2 – a resource that is usually slow to react. He added that further research was underway at the CAT Catalytic Centre, an additional Bayer project partner.

Waste conifer bio-foam

BioFoamBark is a bio-based rigid foam was developed as an insulation material for homes by a research team at Germany's University of Freiberg. The end product comprises more than 80% recycled biomass, mainly conifer tree bark. In addition, said BioBark team member Prof Marie-Pierre Laborie, the material also shares a similar conductivity to conventional insulation materials but is non-combustible.

Three-dimensional print for polyurethane surfaces

Delegates were next impressed with Saip’s creative method for printing on three-dimensional surfaces. The company has developed its process for printing on paintable polyurethane surfaces. Among its range of four hundred prints are camouflage, animal print and a wood veneer finish.