by Liz White, editor
Despite the obvious difficulties of doing business over the last year, the German polyurethanes sector is in a positive mood and has seen encouraging developments in sales and turnover recently.
This was highlighted by Dr Albrecht Manderscheid of Cannon Deutschland, opening the seventh international polyurethanes meeting of the FSK eV (Germany’s Specialist Association for Foamed Plastics/Polyurethanes), which he chairs.
“We must think positively,” said Dr W.Alexander Strietholt of Dow Deutschland GmbH & Co. OHG, chairman of the FSK’s polyurethane group, reinforcing this optimism.
More than 160 participants at the 10-11 Nov meeting in Würzburg, Germany, heard Streitholt pointing out that, “Now in November, sales are starting to rise,” after a period earlier this year when sales dipped by 20 or 30 percent.
Some PU companies have been bankrupted by the crisis, Strietholt said, but he thinks expertise has stayed within the sector: expertise it needs to continue to innovate.
“I feel very positive we can grow faster than the rest of the market,” Strietholt said, stressing the need for good networking and efficient use of resources. This is more crucial now, he said, as companies become ever leaner, and so rely on fewer experts than before.
The good news is that the most difficult period — from Q4 08 to Q1 09 — is now past, although the FSK estimates that 2009’s figures will show a 25-30 percent drop in German PU production for the whole year, pointed out Dr Hans-W. Schloz, managing director of the association, in his review of the year. This will translate into is a 30-percent cut in value and a 25-percent cut in volume for 2009, Schloz said.
In a European plastics market of 60 million tonnes, polyurethane forms about 5.6 percent at 3.5 million tonnes, but in Germany, the PU focus is stronger so that polyurethane represents about 7.5 percent of the German plastics market (2008 data), with 929 kilotonnes of material out of a total of 12 million tonnes of plastics, Schloz pointed out.
In technical uses, Germany has many companies using small amounts of PU in specialities, said Schloz: these high-specification, high-value uses form 14 percent of the German PU total, compared with only 8 percent of the PU market within Europe overall.
In automotive, the decline has been obvious in Europe: the European Automotive Manufacturers’ Association, ACEA, estimates that total European car registrations fell 5 percent for the ten months to the end of October, to 12.2 million, while Germany’s registrations rose by 26 percent to 3.3 million vehicles.
The German rebate scheme for early scrapping helped raise the volume of small cars purchased, Schloz said.
noted. Buses remain a buoyant market, while the truck business “has seen an incredible decline,” he said.
In 2008, Germany’s “building sector decline accelerated,” in housing, said the FSK director, adding that the commercial segment still had good growth till the end of 2008.
While renovation and refurbishing are thought to be rising, Schloz noted how hard it is to get figures to back-up this view. A lot of new regulations have been passed on use of insulation and this is affecting roofing materials strongly: “If you want to re-roof you must insulate,” said Schloz, noting that PU is fighting with mineral wool here.
The comfort foam sector – flexible foam in furniture and bedding – is an important one for Germany at 22 percent of the total sector, and the country remains one of Europe’s major foam-producing nations, making about 204.4 kilotonnes a year.
New energy offers PU potential
Several papers at the Würzburg meeting addressed the theme of PU uses in alternative energy sources, ranging from solar to wind power, with uses in coatings, composites and adhesives — and potential in the rotor blades.
One speaker was able to give some answers to the crucial question: “Is PU a suitable material for blades for wind turbines?” There is some potential, indicated Dr Martin Knops, director of rotor blade development with REpower Systems AG (see box above left).
Blades are challenging constructions: they can be up to 61-m long and from 7-20 tonnes in weight, said Knops. These composite structures, reinforced with glass fibre or carbon fibre are huge components and very demanding as far as engineering is concerned, he said. They experience many millions of load changes, along with vibrations and swings, hurricane winds, salt water, rain, ice, and also have to handle sudden emergency stops — needed if the power network fails, Knops said.
Such load conditions – with the load always on the back edge of the blade — must be considered in design, he said. The blade edge suffers a lot of stress and wear and tear, and is exposed to rain, sun, salt, ice, and routine maintenance is difficult, he added.
Material specifications include heavy load handling, and bending demands – up to 11 m deformation can occur on the end of a 40-m long part, he stressed.
Rotor blades form 20-25 percent of the cost of a system, at €2 million for a 5MW system, or €12/kg of blade, Knops said.
Since failure in use would be so costly, both financially and in terms of poor image, intense validation is carried out before series production commences, Knops explained. Qualification of new materials is always a challenge in blade manufacture, he noted, along with development of suitable processes and tight cost control.
REpower uses glass-fibre reinforced epoxy resin, not carbon fibre, in the blade construction, Knops added. Carbon fibre is expensive, the stability is not much higher, and availability has been an issue here, he stressed.
The shells also contain integral sandwich elements based on balsa wood and PVC foam.
Polyester foam is a new material being used here and there is some potential for exploiting PU foam also, Knops said.
REpower also uses thick adhesive layers 1-10 mm thick for bonding the shell to the frame, “an unusual technology,” he said. At the moment it uses epoxy adhesives but is moving towards using PU for faster bonding, he added.
Manufacture of the rotor blade is either by resin-infusion technology, or uses pre-preg sheets. The former starts with a dry glass inlay, and the sandwich is infused with resin using vacuum technology, Knops said.
For pre-preg processes using resinimpregnated glass-fibre layers, there is interest in testing PU as the resin, Knops noted.
Blades are produced in parts (halves) and glued together, in layers up to 100 mm thick.
Henkel has been active in developing materials for thick-layer PU adhesives, Knops said.
Balsa wood is used in the sandwich for its very high layer stability which is important in thrust stability, Knops explained.
“For us the challenge with new materials is thrust stability,” Knops said. “Tests with existing foams show that PU is not that optimal here, although higher density foams can compensate for this,” he noted.
Green coatings needed for green energy
Discussing coating materials for rotor blades, Martin Kaune of Relius Coatings GmbH & Co., part of the BASF group, said they form 5 percent of the total cost of a blade, 1 percent of the complete turbine costs and 0.5 percent of the costs of a complete wind park.
With prepreg process, an in-mould gel coat is always used, said Kaune. Generally, he said, “using green products for green energy is a major issue for the wind energy sector.” Hence all gel coats are solvent-free liquids.
Coatings must last a blade’s life time of 20 years, and PU coatings are now almost the only option, Kaune observed, with solvent-free PU superior to epoxy ones in UV resistance and superior in shrinkage to polyester coatings. PU coatings are also better than both in elastomeric properties, Kaune added.
PU coatings are compatible with epoxy resins, give excellent UV and weather resistance, and are fast curing, although this can be a disadvantage as pot life is short, Kaune pointed out. Foaming can cause problems and a lowgloss product is difficult to achieve with PU.
Topcoats also need to be water-soluble and solvent-free. Relius has high-solids systems which meet the current EU VOC (volatile organic compound) limits of <420g/l, he said.
A transparent in-mould gel coat can be applied by roller, Kaune said, noting that these are big moulds — 35-m long. Transparent coatings allow the user to see problems such as cracks and repair them, he said.
After demoulding and bonding the blade parts together, they are sanded down and PU putty is used to improve shape and cover large defects — 2 to 3-mm deep, Kaune said. This putty sets rapidly so that processors can sand the blade after 90 min and continue processing – “epoxy takes much longer,” he said.
PU gelcoats can be applied by roller or sprayed. “Some companies spray manually, some automatically,” Kaune said. One option is to use a low-viscosity material for “very fast spraying and a one-hour work-over time,” with the process repeated to give the right thickness.
Finally, said Kaune, users have “the perfect finish – with a matte surface for no reflection.” Looking forward, Kaune mentioned the potential for exploiting nano-materials in coatings. And there is increasing use of “riblet or sharkskin,” effects, where a surface is ribbed to increase aerodynamic efficiency, he added.
Other advances include hydrophobic and anti-icing effects, and self-healing coatings, Kaune concluded.
Photovoltaics in solar energy
Polyurethane is being used as the frame for photovoltaic (PV) panels for solar energy collection, as described by Dr Hubert Ehbing of Bayer MaterialScience. The biggest potential for wider use of PV technology lies in private households, he said, noting that it is not easy to pinpoint future growth in PV use, with levels of between 8 and 23 percent predicted.
Some countries have passed laws encouraging solar panel use. Here Ehbing pointed out the slump in the Spanish solar power market, where large financial incentives were mandated for feeding solar energy back into the grid, and the resulting weight of demand caused the scheme to collapse.
Similar incentive schemes for solar energy exist in France and the US, said Ehbing.
China is now “a very interesting location,” said Ehbing. In the last three to four years many suppliers of PV equipment have outsourced production to China, and this trend is likely to continue as costs rise, he said.
The standard framing for PV panels is “efficient but not attractive,” said Ehbing, noting that PV panels are usually integrated as part of a building’s façade, or installed on roofs, in the same way as solar panels.
PV panels are made by laminating PV cells (wafer-based crystalline silicon or thin-film cadmium telluride or silicon) between foils using hot-melt adhesives, and then between glass plates. But they cannot be mounted on buildings in this way, Ebbing said; and are framed first, traditionally with aluminium.
“Our approach is to replace the aluminium with a plastic frame,” for higher design freedom, and more colour options, Ehbing said. The frame’s function is in mounting, sealing and connecting the PV panel, he continued.
“We have very cost-sensitive technology and are looking to cut production costs,” while ensuring a 20-25-year life for the PV modules, Ehbing said. The aim is for highly automated production that can be moved to Asia, he said.
BMS has been working on this use with Berlin-based supplier of PV panels, SOLON SE.
Ehbing showed an example of a unit 1.8 m high and 27 mm thick, with 72 cells. This has a black elastomeric PU frame, with sealing elements integrated into the frame. Such units can seal the whole roof in one step, he said.
The panels can be screwed directly to the roof battens, making mounting onto the roof very simple, Ehbing said. A further metal sealing around the complete roof is the last step.
Tests by BMS/SOLON include those for thermal shock resistance on modules at -40°C to +85°C for 350 days.
Snow load testing at 700 kg load for 168 h indicated little deflection.
Two PU systems, aromatic or aliphatic, are possible, with some filler used to give the necessary rigidity and with flame retardant added to both.
Aromatic systems are state-of-the-art, Ehbing observed, with an inmould coating (IMC) recommended. No IMC is needed with aliphatic systems, which have intrinsically better UV resistance, Ehbing said. A mould temperature of 85°C is needed for aromatics, and of 65°C for aliphatics.
Both types bond well to inserts and the aromatic type has gained TUV certification. The aliphatic type is available but is more expensive, Ehbing added.
Answering questions, Ehbing said the PV market grew for a long time but is now stagnating. Suppliers are working to raise the efficiency of PVs, which is currently about 14 percent, he added.
Asked how long it takes to amortise the €20 000-€30 000 costs for PV panels for a domestic dwelling, Ehbing said that, on a southern-facing roof, this can take 12-14 years.
Russia still has great potential Although Russia is one of the favoured BRIC (Brazil, Russia, India, China) economies for foreign investment, Eugenio Toccalino, marketing manager for plastics with Dow Automotive, noted that the country is currently in recession, with a sharp decline in GDP this year of about 6 percent.
GDP growth of around 8 percent for 2006/7 was followed by 5.6 percent growth in 2008, he noted, in another presentation at the FSK event.
As elsewhere, government measures have been taken to stabilise the economy, Toccalino said. But for sustained recovery, Russia needs global growth, especially for its oil/gas sectors, he added.
Before the downturn Russia had high annual growth in automotive sales — 18.4 percent combined annual growth rate (CAGR) from 2002 to 2008 to a level of 3 million — and was expected to overtake Germany as the top market in Europe in 2009. But the market fell 50 percent in the first half of 2009, with all OEMs affected, he added. Sales dropped from 1.455 million in H1 2008 to 735 000 in H1 2009, Toccalino said.
The top three best-selling brands are currently Ladas from Avtovaz, which has a 24- percent share of the market, followed by Hyundai with 13.7 percent, General Motors with 10 percent and Volkswagen with 9 percent.
In five years’ time, the top-ten best-selling brands are likely to be completely different, Toccalino said. What is certain, he stressed, is that there is still huge potential for growth, with Russian per-capita car ownership now at just above 0.2, way below that in Western Europe, which averages about 0.6.
Russia’s automotive market will see growth again in 2010 and by 2015 it is expected to catch up with or surpass the levels of 2008, he added.
He also noted that currently, international car makers have invested heavily in the Russian market — but that “they have built plants that so far have been standing still.” In the PU market, volumes will also develop rapidly in Russia, with 2008’s volumes reached again by 2012, Toccalino said.
Looking at Russia’s auto components sector, Toccalino said production of instrument panels, seats and carpets, will become more localised, with increased PU content driven by both foreign and domestic brands, Toccalino said. Local production will rise, using the worldwide model of the Tier 1s partnering with local module manufacturers, he added.
PU-intense uses will be among the first to localise, he added, and this means that the PU market will grow faster than car production.
In seating, headliners and steering wheels, growth will be at the rate of the market, but in instrument panels, acoustics and components for NVH (noise, vibration, harshness) reduction, PU growth will be rapid because there is low use in these parts currently, he said.
In seating there will be a focus on emission reduction to meet the specifications of the Japanese and German OEMs, and an emphasis on better comfort (see box above).
In commercial vehicles growth will not only be in the typical PU uses in cars: major growth potential lies in innovations such as in-mould painted LFI (long-fibre injected) parts for large exterior body panels, and low-density RRIM (reinforced-reaction-injection moulded) parts for high-quality interior trim, at low capital investment, Toccalino said.
Dow is active in the PU sector in Russia through its NPP Izolan joint venture in Vladimir, 180 km from Moscow, whose PU solutions can support all uses. For example, a large part of Izolan’s production is devoted to rigid foam systems for insulation/construction uses, Toccalino said. Izolan is currently building a second, state-of-the-art plant, due to start production by the end of this year, he added.
Discussing security in intellectual property and in ownership rights for foreign companies investing in Russia, Toccalino said it is possible to minimise risk in a JV, pointing out that “any investment involves a certain risk level.” In a separate interview, Toccalino noted that Russia has to import isocyanates, but that some polyols are made locally.
And discussing recovery, he pointed out that, “with 2009 as a baseline then it is not difficult to improve on that.”
Wind turbine manufacturer REpower Systems AG, headquartered in Hamburg, was set up in 2001, with 260 people and had €142 million turnover.
Now it employs 1775 people and turnover has reached €1200 million, so the company has “grown dramatically,” said Dr Martin Knops, director of rotor blade development, with REpower Systems AG.
This year REpower also expects sales and profits to grow, he added. Delivery times are a couple of months, now there is spare capacity as market expansion has slowed, Knops pointed out.
REpower is strong in offshore, and installed a 5MW system in the Belgian Nordsee in 2004, which has been running well for five years now.
Knops commented that this is a “very promising market.”
WIND POWER RISING FAST
During 2009, “the wind energy market receded a little: China is growing and the US and Europe dipped a little,” noted Dr Martin Knops, director of rotor blade development, with REpower. “Early in 2008, dramatic growth in 2009 was expected. That did not happen, but the sector expects good growth still,” he said.
In 2008, some 24000 MW of new wind energy capacity was installed, split fairly evenly between North America, Europe and Asia Pacific. This is likely to drop to 22 000 MW this year, then rise to over 48 000 MW of new capacity in 2013, bringing the world total to over 300 000 MW, from around 150 000 MW now, said Knops.
In 2008, the top ten markets accounted for 88 percent of all new wind energy capacity, Knops added. In 2008, the US installed 8360 MW, China 6300 MW, Spain, Germany and India 1600-1800 MW, and Italy, France and the UK around 1000 MW of new capacity each.
Martin Kaune of Relius Coatings said that growth in windfarms has been high in Europe, particularly in Germany, but also noted that potential in China, which “needs an enormous amount of energy right now,” and must look at wind energy, he said. China will probably overtake the US as the largest market for wind energy this year, he said.
Discussing what alternative energy routes it would be wise to invest in, Knops said “wind energy is very competitive now and markets are good almost everywhere where there is wind energy compensation.” But location of wind farms is certainly an issue that has to be dealt with, he noted.
Kaune agreed, commenting that a lot of potential still exists in offshore wind installations, while onshore ones are bedevilled by noise issues and disputes on location.
“In Germany, the sector is stagnating for the moment, so there will be fewer [windfarms] built,” he said, adding that there is, however, likely to be “some replacement of old installations by by new, bigger and more efficient ones.”
PU USE IN ROTOR BLADES?
• As coating — already an established use.
• As thick-film adhesive (Makroplast K8340 developed by Henkel) —This has the potential for shorter cycle times versus epoxy, higher productivity and better overall economics.
Challenges: process security, workability, cost.
• As matrix system in the laminate — Potentially higher strength against intermediate fibre break.
Challenges include long flow distances, impregnation behaviour, viscosity development.
• As sandwich layer material (structural foam) — Has potential to cut costs. Challenges include firmness, fatigue resistance, binding of laminate.— Martin Knops of Repower
ETCHING RESISTANT PU
A recent Relius innovation is a coating for masking large aluminium aircraft interior parts when shapes are being thinned by chemical etching, with the aim of a 30-35 percent weight saving. The copolymer used for coating is dissolved in toluene or methylene chloride and up to three layers are spray-applied and dried, said Martin Kaune of Relius.
A computer-controlled laser then cuts the coating to the desired shape, with the cut edges forming a natural seal. The coating on the parts to be etched away “can then be stripped off by hand,” Kaune said.
When the entire part is dipped in sodium hydroxide, the uncoated areas are etched and thinned from 6 mm to 3 mm. Meanwhile, the areas protected with the masking paint are unharmed.
A new masking material had to be environmentally friendly and decrease process time and costs, Kaune said. The solution was a new solvent-free two-component PU-based coating.
This cuts processing time and costs, by hardening in seconds, and is knife and lasercuttable after 30 minutes, Kaune said.
Also, users can pull it off and dispose of it in the normal trash, he said. It also has the necessary strong resistance to caustic soda, he added.
Relius Coatings, part of the BASF group, has its headquarters in Oldenburg, with sites across Europe. Relius employs 680 people, in five divisions; general industrial, powder coatings, wind energy, liquid industrial protective, and aircraft coatings.
PU is a standard coating material in automotive OEM refinish, for trucks and trailers and commercial transport generally, Kaune said. Other typical uses might be floor coatings for kindergartens and garages, and topcoats for steel for industrial machinery.
Russian automotive trends:
*Production will localise. In 2008 locally made models formed 40% of the market, but by 2015 this will rise to 70%.
* Value of locally made cars will rise through a shift from lower content domestic brands to higher content western or Asian brands; and
* Domestic brands will close the gap with foreign brands in terms of perceived quality (acoustic, comfort, aesthetics, harmony, odour), increasing the PU content of vehicles.
Trends in automotive foam in Russia
•Low VOC/ low emissions Seat, head/armrest,a NVHb. St wheelsc
•Improved comfortc Seat, head/armrest
•improved NVH/Acousticsc NVH, IPIT foam
•low applied density/fast demoulding NVH, IPIT foam, St wheels
a. German, Japanese OEMS.
b. German OEMs.
c. Domestic brands NVH - heavy layers, acoustic foams. IPIT - instrument panels and interior trim.