La polyvalence du polyuréthane

Peu de produits peuvent atteindre le niveau de  polyvalence et la popularité du polyuréthane. De l'isolation aux planches de surf, et des airbags aux mastics des fenêtres, le polyuréthane occupe une place prépondérante dans notre vie de tous les jours.

Son succès grandissant et son utilisation accrue sont renforcés par le fait qu'il s'agit d'une matière abordable, sans danger et recyclable; et ce sont précisément ces qualités qui en font le produit de prédilection des fabricants et détaillants dans le monde entier. Le polyuréthane peut répondre aux exigences les plus strictes des consommateurs, d'où sa popularité grandissante. Contrairement à d'autres matières qui pourraient avoir des fonctions identiques, on le trouve en grande quantité et il peut être fabriqué suivant des spécifications précises. Par exemple :

  • Les fabricants de matelas exigent une plus grande fermeté de la mousse qu'ils utilisent, aussi les fabricants de polyuréthane pourraient-ils travailler avec des concepteurs de matelas pour répondre à ces exigences spécifiques.
  • Les constructeurs automobiles sont contraints par la loi de garantir à l'intérieur des véhicules des niveaux sonores ne dépassant pas un certain plafond, aussi pourraient-ils collaborer avec les producteurs de polyuréthane pour y parvenir. Les portières peuvent être intégralement fabriquées à partir de polyuréthane en raison des diverses formes que cette matière peut adopter.

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Etudes de cas

Polyurethanes in a heartbeat: the total artificial heart [11 November 2011]

 

The Total Artificial Heart(TAH) is a mechanical device which treats total biventricular heart failure. The TAH can act as a valuable bridge to transplant, prolonging patient lives until a heart becomes available. The first successful bridging operation was performed in 1985 using a Jarvik 7 Total Artificial Heart. A typical TAH uses a segmented polyurethane solution to build the ventricles and internal diaphragms of the heart. It also uses an external battery, a compressed air pump and a blood sac to pump blood around the body.

Current industry standard

The leading provider of Total Artificial Heart Systems is Syncardia Systems. Based on the CardioWest TAH, a 10-year trial found that 79% of patients who received a TAH survived to transplant of a donor heart. Over 950 people have received TAH’s, with the longest TAH currently in use being in place for over 1300 days. Syncardia also produces the ‘freedom portable’ TAH, which is powered by batteries and carried in a back-pack and therefore allows stable patients to leave the hospital while awaiting a donor heart. 

AbioCor

A recent innovation in TAH systems is the AbioCor heart, which is a fully implantable heart. The ventricles and valves of the AbioCor are produced from ‘AngioFlex’, a polyether-based polyurethane plastic; this material has been tested to withstand at least 180 million beats over a period of five years. This heart, which operates entirely internally, is powered by electromagnetic forces which pass through the skin. The materials and design allow it to combat issues of calcification and clotting which have affected earlier artificial heart systems.

Further developments

The current Syncardia TAH is 70cm3; however a smaller 50cm3 heart is planned which should allow more women to access the technology than previously. Further research in portable and internal heart systems should allow greater mobility for patients when awaiting transplants, while further testing could allow the TAH to become a long term solution for patients who cannot access, or reject, donor hearts.

The total artificial heart is a nother example of how polyurethanes innovation contributes to improving lives and protecting the planet in new ways everyfday.

For more on the total artificial heart, read our blog
Formula One adopts Polyurethane safety blocks to replace tires [17 August 2011] [17 August 2011]

Singapore, Monaco, Barcelona or Abu Dhabi- all these cities have at least two things in common: they all host Formula 1 races and were among the first to adopt a new technology from BASF France, to replace the racks of old tires as safety barriers on Formula 1 races.

Spectacular overtaking manoeuvres and high-speed duels between virtuoso pilots are what the public yearn for, unfortunately this is not a risk-free sport and accidents happen. Research on how to install higher security measures for drivers has long focused on the car’s cockpit. However, a new system was recently introduced that significantly improves safety on the racing track. Old tires are indeed being gradually replaced by a new generation of safety blocks which make spinning off the track less dangerous.

These safety blocks are made of polyurethane foam with impact absorption properties up to 40 times higher than tires. Each block weighs 120kg and measures 1.5 x 1.2m. In order to make them easily interlocked, they always have a convex and a concave end. The polyurethane block is shaped around a steel sheet, which is then filled with polyurethane rigid foam. Filling the block is the most complicated part of the production process because the manufacturer needs to avoid any deformation. The block must also be held together tight for another 15 minutes after the filling, to allow polymerization.

In the wake of the safety blocks’ great success on the racing track, tests are currently carried out on how to extend the use of this special foam. Thanks to its specific characteristic, it is easily applicable for the production of buoys for example.

From protecting racing drivers to sea navigation; the latest PU foam innovations are further examples of how polyurethanes contribute to improving life and protecting the planet in new ways everyday.

Latest innovations in polyurethane coatings [ 1 June 2011]

On 24-26 May, the city of Frankfurt hosted Tech Textil 2011, an international trade fair devoted to textiles. Tech Textil is a platform for companies to showcase the latest innovations in textile production. This time around the main surprise came from new polyurethane coatings.

The Coating covers a surface (substrate) in order to improve the substrate’s properties, such as appearance, adhesion, wetability, corrosion resistance, wear resistance, and scratch resistance. The process of coating has existed for thousands of years. Ancient Egyptians used varnishes and enamels based on beeswax, gelatin and clay, at least as early as 3000 BC. Over the years, traditional coating has been replaced with an advanced thin film layer, which ranges from fractions of a nanometer (monolayer) to several micrometers in thickness. Coating is essential for a number of industrial and every day products. Unsurprisingly, some of the best coating layers are polyurethane films.

The latest evidence of this was provided by scientists from Epurex Films, a subsidiary of Bayer MaterialScience. They presented LPT 5901, a polyurethane hot-melt adhesive film, which could become a new standard for thermal coatings. This thin polyurethane film is easy to transport and simple to apply on any type of material (versatility is a key property for flexible materials). With application and cross-linking process over, PU film shows excellent levels of thermal resistance. This innovation allows polyurethane film to be used in a wide range of applications, from key rings to thermal protective clothing, such as fire-fighting suits.

Besides textile, Epurex films presented coatings that could be used for a broader range of outdoor products. The new thin film made of special thermoplastic polyurethane that is transparent, waterproof and abrasion resistant, would bring immense benefits to appliances which are under constant tear and wear. It could typically be used for wind turbine rotors, which require transparent coating. The new polyurethane film is also perfect for textiles such as awnings, life vests and clothes with reflective stripes.

From protecting fire-fighters to extending the lifetime of wind turbines; the latest PU coating innovations are another example of how polyurethanes contribute to improving lives and protecting the planet in new ways every day.

 

Polyurethane foam in rail tracks: reducing noise and increasing comfort [21 September 2010]

Have you ever wondered why, when riding a train, you hear that cluttering and pervasive sound? Well, just like a lot of things in our lives, railroads are not perfect. They have irregularities, which occur due to a set of factors, like wheel and track geometry, distance between joints, and material resistance. Situation can be exaggerated by heavy tear and wear, which is intensified by increased carriages over the years. Especially distressing is when rail track is crossing densely populated urban areas, which are becoming more common train routes. Noise pollution, caused by passing trains, increase annoyance, aggression, hypertension and stress levels.

There are several ways of reducing noise pollution caused by rail track irregularities. The best way is to “smoother” irregularities of the track with the help of flexible mats and pads. These pads are laid between rails and baseplates which connect rail to the sleeper. Good example of this type of system is Edilon TRACKELAST® created by edilon)(sedra. Fifty years ago, edilon)(sedra started producing special resilient pads, which became a standard feature of urban transport tracks over time.

Increased usage and weight of carriage has put more pressure on railroads and smothering pads. The solution was found in the polyurethane foam, which is commonly used in automotive and construction sectors. edilon)(sedra and Huntsman, one of the leading producers of polyurethanes, started a collaboration which resulted in creating ACOUSTIFLEX®V. New PU foam proved to be a perfect complement for Edilon TRACKELAST®. Their joint usage virtually eliminates noise pollution. In addition, it increases the lifetime of railways which leads to reduced maintenance costs for both tracks, and trains.

Originally, ACOUSTIFLEX®V has been used in cars as a light and environmentally friendly sound absorber. Its usage in railroad tracks has been another confirmation of polyurethanes’ versatility and commitment to comfort. ACOUSTIFLEX®V has already proven itself as a highly practical, environmentally friendly and effective material in a range of rail projects from Madrid to Warsaw and from Helsinki to Kumamoto.

Just another example of how polyurethanes contribute to improving lives and protecting the planet in new ways every day.

Polyurethanes to stand storm tides [ 5 November 2009]

A new exciting and innovative contribution to tackle adverse climate change effects comes from the polyurethanes industry.

Polyurethanes have recently been used to protect exposed coastlines. The largest project to date featuring this new coastal protection system was completed recently at Bathpolder, at the southern tip of the Dutch North Sea coast.

Elastogran Holland, with technical support from Elastogran Germany used approximately 250 tons of crushed stones mixed with 60 tons of Elastocoast® (polyurethane) to cover an enormous bank revetment over a total area of 12,000 square metres and a length of one kilometre. The old bank revetment of concrete, stones and plates was removed.

This is the first coastal fortification project using polyurethanes. The polyurethanes crushed stone mixture absorbs more water, thus reducing wave accumulation, weakening the breaking waves and resulting in a much smaller load for the entire bank system.

During the punishing tests carried out by the local authorities, no ruptures or tears were caused to the polyurethanes revetment. This is essential as the use of heavy equipment is sometimes unavoidable during storm tides, and other conventional bank revetments had been unable to stand up to such harsh treatment. They had suffered damage which entailed lengthy repairs and completely unnecessary costs.

Such a successful application of polyurethanes could be crucial for the other endangered coastal regions that are increasingly affected by climate change. Protecting exposed coastline with polyurethanes provides a solution that is stronger, safer and, in the long run, much more economical than all other conventional methods.

View Elastocoast Video – Long Term Coastal Protection

Polyurethane set for big successes at swimming World championships [26 August 2009]

Polyurethane swim suits are set to take the swimming world by storm. The swim suits, which were officially approved on 22 June by the International Swimming Federation (FINA), are set to play a central role at the upcoming World Championships in Rome (17 July – 2 August)

FINA published a list of authorised swimsuits, including adidas’ Hydrofoil and Arena’s X-Glide, two all-polyurethane suits used by world class swimmers such as Alain Bernard and Frédéric Bousquet. Whereas Bousquet’s recent record over 50 metres using one of the suits was confirmed, Bernard’s 100 meter success was rejected because it happened before approval had been given to the suits.

Another recent success was that of German swimmer Britta Steffens who recently broke the women's 100m freestyle world record in Berlin, with a time of 52.85 seconds. Britta was helped to her world-beating time thanks to her polyurethane swim suit – the adidas Hydrofoil.

Polyurethane high-technology swimsuits are renowned for valuable compression and buoyancy thanks to their ability to trap air. They are extremely light, resistant, and flexible. Furthermore, they can improve performance thanks to minimum water drag and they do not lose their shape over time. These remarkable and adaptable qualities give the swimmer maximum fluid-dynamics in the water and additionally lead to a level of muscle compression which reduces resistance in the water.

This key application of polyurethane is yet another example of the versatility of this unique product.

4 Wrinkle-free Polyurethane Skin for Service Robots [12 December 2008]

Bayer MaterialScience AG (BMS) has been awarded the "Polyurethanes 2008" prize for innovation for its work on the "Care-O-bot 3" service robot.

"Care-O-bot 3" is a service robot for the home, conceived by the Fraunhofer Institute. BMS developed an elastic polyurethane skin for the external moving parts, which hardly wrinkles at all when the robot is in motion. "The skin is an intelligent combination of flexible polyurethane foam and polyurethane dispersion frothed foam. It is a completely novel, innovative class of material which, above all else, has great potential for use in the future robotics market", explains Manfred Naujoks, an expert in flexible polyurethane foams who accepted the award on behalf of BMS.

"The result has an extremely attractive look and a pleasantly soft feel. The thickness, density, color and surface texture of the material can be varied to meet the requirements of the respective application", says Dr. Andrea Maier-Richter. Although extremely flexible, the composite material patented by BMS is also very strong and highly resistant to standard cleaning agents and everyday chemicals.

This shows another area in which Polyurethane has been used to improve the efficiency and aesthetics of a product, with the potential for future use in robotics.

Flexible cable bushings with polyurethane gel [26 August 2008]

The new, intelligent cable sealing system from Hauff-Technik GmbH & Co. KG, Herbrechtingen, seals cables quickly, easily, and reliably.

Within the segments, the highly-flexible polyurethane gel Technogel® envelops the cables and lines, thereby providing excellent sealing properties. This high-performance material, which is based on polyurethane, moulds itself to each cable contour for a lasting perfect fit – and this holds true for even the smallest cable diameters. Moreover, it also boasts outstanding low-temperature flexibility and a high degree of compensation for movement.

This process involves a minimum of effort and eliminates the need to open up the entire system. The different coloured segments can be assigned separately, and spare places can be kept available for retrofit installations. The principle of coloured segments also allows cables to be sorted by function, e.g. data cables.

This area is just one example of the close collaboration between Bayer Material Science and its customers in the development of tailor-made system solutions with polyurethanes.

Polyurethane in this application has increased its performance and functionality.

A material that is very much on track [19 August 2008]

Better dimensional and weather stability than wood, lighter than concrete Railroad builders are turning increasingly to polyurethane composite marketed under the name Eslon Neo Lumber FFU from SEKISUI CHEMICAL CO. LTD., Tokyo as the material of choice for manufacturing the ties or sleepers that are used to support railroad tracks. The material is noted for the far greater durability of the ties and the correspondingly lower lifecycle costs. In Tokyo, plastic ties have been in service for more than a quarter of a century. They have been laid, for example, under the track for the Shinkansen high-speed train, and the FFU (Fiber reinforced Foamed Urethane) polyurethane ties have now been premiered in Germany.

Railroad ties must be able to withstand high mechanical loads and must also be dimensionally stable and weather-resistant over a long period to comply with the conditions for safe rail operation and low maintenance costs. Frequent temperature changes, radiation and moisture start to affect wooden ties after a relatively short time, and repairing the wooden track involves a considerable amount of material, time, organization and cost. In comparison polyurethane ties have an estimated service life of at least 50 years. With considerably longer maintenance cycles and associated cost benefits for the railroad operator, individual ties can be replaced quickly and accurately, helping to lower construction costs even further.

The flexural strength of the polyurethane ties is also very much higher than that of wood, even after 15 years, the material is also suitable for the construction of high-speed tracks.

The polyurethane material looks like wood and combines all the positive properties of the natural product with those of a modern composite product. The polyurethane ties can be processed in the same way as timber, and compared with concrete, the polyurethane material weighs much less and boasts the reproducible evenness that is important with turnouts. The polyurethane ties are also very suitable for bridges due to their lightweight and they can be manufactured in virtually any desired length and cross-section up to a current maximum of 9.60 meters.

The ecological compatibility of the polyurethane ties is also an advantage. As a rule, ties that have already been in service can be reused, or can be recycled in the same way as the production scrap.

The polyurethane system based on long-fiber reinforced Baydur® 60 integral skin foam comes from Sumika Bayer Urethane Co., Ltd., the Japanese polyurethane systems house in Bayer MaterialScience's global BaySystems® network.

Polyurethane in railroad ties, increases durability, safety and decreases cost.

1 - 0 for polyurethane foams [18 July 2008]

One-thousand new miniature playing fields in Germany fenced in with metal-faced sandwich panels the German Football Association (DFB) is investing EUR 25 million in the construction of 1,000 miniature playing fields. To ensure the safety of the players and reduce noise for neighbours, the fencing around the fields is made of metal-faced sandwich panels incorporating a polyurethane foam system from Bayer MaterialScience.

Sandwich panels manufactured for this application by Fischer Profil GmbH of Netphen-Deuz, Germany, offer high mechanical strength and good sound absorption. The fencing around the field comprises panels with integrated goals, on which high demands are imposed. They must withstand impacts with players. To suit the needs of neighbours, the material must also function as a sound-absorber. Metal-faced sandwich panels have proven to be the material of choice, made from steel facings and a polyurethane rigid foam core.

Self-supporting polyurethane/metal sandwich panels were originally developed for insulating large facades and roofs in industrial buildings. They have been put to effective use in many segments of the building industry for more than four decades now. When used as a facade, they simultaneously function as a design element and, together with a coloured surface treatment, give designers great creative freedom. The sandwich panels are used in industrial and commercial construction, as well as in cold stores, warehouses, exhibition halls, sports halls, office buildings and transportation buildings (e.g. airports).

This is just another example of the almost unlimited potential for developing new polyurethane applications made possible by the material's versatility.

Wheelchairs and wheelbarrows run smoothly on tires made of polyurethane foam [ 8 April 2008]

No more flat tires

The British company Greentyre, has developed and designed tires that aren't affected by sharp objects or long periods of inactivity. The tires are made of micro-cellular polyurethane foam based on a Bayflex® system from Bayer MaterialScience. Products made of this innovative material are longer-lasting and much lighter than solid rubber tires.

To manufacture the tires, the mould is filled with a liquid reaction mix before being rotated during the foaming process. This ensures that the material is distributed very evenly across the whole tire circumference, which means that the tires will run very smoothly.

The material is virtually solid at the tire's outer circumference, and its even surface makes for excellent rolling properties. Thanks to the tire's good aging and weathering resistance, it retains its true-running properties in the long term, even when it remains in one position under a heavy load for an extended period of time and becomes compressed on one side. And the high elasticity of the micro-cellular material ensures that the tire’s rolling resistance is almost as good as that of an air-filled tire.

However, this tire technology is not just useful for leisure activities and gardening – it is also ideal for wheelchairs. The Greentyre Company has designed a very special wheelchair for disabled people. One key feature of the sophisticated design concept is its modular structure, which enables users to choose from an array options to meet individual clinical need and the type of use. If required, the wheels can also be removed at the touch of a button. Additionally, the wheels are equipped with ergonomic hand rims also made of polyurethane. The special feature of these hand rims is that they do not get sharp edges through wear and are pleasantly warm to the touch. The wheelchairs’ adjustable arm rests are also padded with this polyurethane foam. It seems that the versatility of this elastomeric cellular material knows no bounds.

This is just another example of the ever increasing versatility of polyurethane.

Lightweight stage sections thanks to polyurethane sandwich composite [26 August 2006]

Back complaints resulting from heavy lifting could soon be a thing of the past as the Dutch company Triple-E Lichtgewicht Meubilair B.V. in Winsum is now offering lightweight stage sections under the name “Flax-Deck” with external dimensions of 0.75 by 1.50 meters and a weight of only 16.5 kilograms. The low weight of the stackable and compact sections is due to a sandwich structure based on the Baypreg® polyurethane spray system from Bayer MaterialScience.

Generally lightweight and extremely stiff

Composite sandwich materials are generally lightweight and extremely stiff. The highly versatile stage sections consist of a light rigid foam core reinforced top and bottom with flax mats to absorb tensile forces, thereby increasing the strength of the composite. The sandwich structure can withstand a concentrated load of up to 150 kilograms. Its surface is protected by a highly abrasion-resistant and robust plastic layer.

Excellent adhesion

During production, the fiber mats made out of natural flax are first impregnated on both sides with the dual-component polyurethane system using a spray process. The mats and the expanded polystyrene (EPS) core are then put together to form a sandwich and inserted into a preheated mold. This highly economical, one-step production process creates a permanently stable, extremely robust and rigid structure capable of withstanding high mechanical loads. This is due in no small measure to the polyurethane system’s excellent adhesion to various materials.