#Nonwovens / Technical Textiles
BASF at “JEC Composites Show 2012”
+Automotive lightweight activities expanded
+Innovative coating systems for wind turbine rotor blades
+Epoxy systems: innovative solutions for next-generation rotor blades
BASF moves forward as a globally recognized supplier of innovative epoxy and coating systems designed specifically for manufacturing and coating rotor blades of modern wind turbines. An additional focus this year will be on novel composites based on polyurethane (PUR) and stepped-up automotive lightweight activities.
Automotive lightweight activities expanded
Opel Astra OPC seat pan: first serial application for continuous-fiber-reinforced thermoplastic composite containing Ultramid from BASF The new Opel Astra OPC, a sports coupé that premiers in March 2012 at the Geneva Motor Show, features a seat pan made from continuous-fiber-reinforced thermoplastic laminate (known as “organo sheet”). The plastics used here are polyamide specialties from BASF’s Ultramid® range. This is the world’s first auto seat pan in a mass-produced vehicle that uses this technology.
BASF developed two Ultramid specialties for the Opel Astra OPC seat pan: a non-reinforced grade serves as impregnating material for the glass-fiber fabric, while an impact-modified short-fiber-reinforced Ultramid grade is used for overmolding the preform, creating the required ribs and edges by a classic injection molding process. The high strength of the fiber-reinforced laminate allows significantly lower wall thicknesses, reducing the weight of the seat pan by 45 percent.
Body and structural parts for RTM mass production: roof module concept study
In mid-2011, BASF took another step forward on the road to plastic applications on automobile bodies and chassis by establishing its cross-divisional, multi-material Lightweight Composite Team. This team is simultaneously investigating the potential that three plastic matrix systems, epoxy resin, PUR and polyamide, hold for continuous-fiber reinforcement in resin injection processes suitable for mass production, including in particular resin transfer molding (RTM).
Under the Baxxodur® and Elastolit® R brands, BASF offers solutions based on epoxy resin and PUR systems, respectively, already at this stage. Both of these thermoset materials feature novel curing mechanisms that make them cross-link in a matter of minutes. They can be processed by means of common high- and low-pressure equipment. The new polyamide systems being developed start from very low-viscosity Caprolactam, a precursor of PA 6, and advanced activator and catalyst systems. These thermoplastic composites can accordingly be formed, recycled and welded. Apart from add-on parts like doors, tailgates and roof modules, potential applications also include highly loaded structural automotive parts.
A first demonstrator component based on BASF’s multi-faceted materials for RTM processing is the conceptual study of a multi-segmented convertible roof module in which a polyurethane foam core is sandwiched between carbon-fiber reinforced cover layers. The layer in the core of the demonstrator sandwich plate is a closed-cell structural PUR foam branded Elastolit® D. With its low bulk density it acts as a spacer between the skins of the laminate, ensuring extremely high component stiffness. It also provides the roof module with good insulating properties. At a total weight of 2.6 kilograms, the roof segment based on a fiber-reinforced composite sandwich concept reduces weight by more than 40 % compared to an aluminum, and by more than 60 % compared to a steel structure.
New coating materials
The BASF Coatings division is the expert for the coating of rotor blades and will present two new technologies in one sweep at JEC.
RELEST Wind Leading Edge
The new coating system RELEST® Wind Leading Edge improves the economic efficiency of wind turbines. It provides excellent protection of the front and leading edge of the rotor blade from erosion. Thanks to its extremely high erosion resistance against rain, sand and hail and its outstanding properties RELEST Wind Leading Edge is therefore particularly useful for offshore turbines as it extends their life span significantly and increases the service intervals. Moreover, the material offers major advantages in the application process: flexible film thicknesses are possible during the coating process, and the short drying time ensures high production efficiency.
Repair system for rotor blades
BASF’s answer to the enormous stresses and strains rotor blades are exposed to is the intelligent repair system RELEST® Wind RepKit. Wind and water, UV radiation, erosion and bending loads place highest demands on the rotor blade. At this immense height and rotation speeds, raindrops turn into real bullets when hitting the material. These stresses and strains may cause severe damage during a wind turbine’s life cycle that needs to be repaired in order to safeguard the turbine’s economic efficiency. In addition to all the materials and tools required for the repair, the new RELEST Wind RepKit also includes extensive application training. The kit is characterized by its simple and fast handling. After being trained by BASF specialists, the employees of wind turbine operators will be able to implement professional repairs. The new RELEST Wind RepKit is designed for stationary use both on the ground and on the turbine.
Solutions for next-generation rotor blades
Two new applications by BASF are on display at JEC for the production of rotor blades of advanced wind turbines, which keep growing in size:
More efficient production of larger components
With rotor blades increasing in size, you need new cost-efficient manufacturing technologies and carefully adapted epoxy systems. The process of manufacturing a blade root, which is exposed to great mechanical strain, becomes much simpler if you use a Baxxodur® system by BASF. Rather than being built up step by step in several layers, the component can be manufactured much more efficiently by a single-step process known as “one-shot infusion.” Due to its very low initial viscosity the Baxxodur system features excellent impregnation properties. In addition, it allows the release of heat to be controlled in the curing phase.
Epoxy system for spar caps made from carbon fiber
Taking account of the growing importance of carbon-fiber-reinforced components for certain rotor-blade areas, BASF has the appropriate Baxxodur system available: it is particularly suitable for spar caps made from carbon fiber, which are increasingly being used for large rotor blades because of their strength and stiffness. In spar cap production, the Baxxodur system ensures unparalleled speed and thoroughness in carbon-fiber mat impregnation.
Under its Baxxodur brand, BASF offers epoxy systems that allow rotor blades of wind turbines to be produced more efficiently. The offering comprises a number of systems composed of epoxy resins and curing agents. The use of curing agents known as latent hardeners offers users a significantly longer pot life while it reduces cycle times at the same time by up to 30 %. BASF has a range of patented systems that it is currently developing for use in structural molded parts meant to reduce weight in automobiles.
