Rotor blade manufacturing
State-of-the-art mixing and dosing systems for resin, adhesive and gelcoat applications
Rotor blades are exposed to extreme loads during operation. They must be able to withstand all types of weather conditions. Wind speeds of up to 400 km/h can occur at the tips of a rotor blade. Hail, impact from birds and even raindrops can cause significant damage to the leading edges. In addition, increasingly large turbines are being produced, and the length of the rotor blades and the rotor diameter are growing steadily.
Even the smallest error in production could have serious consequences. This poses particular challenges for the construction of the systems. The components are still manufactured by hand. Although there is a tendency towards automation for certain process, this has not yet become established. For the production of fibre composite components, DOPAG offers special metering and mixing systems that can handle the large material volumes involved in the production of rotor blades and can meet all the current production requirements.
Our product range includes infusion systems with volume outputs of more than 60 l/min as well as bonding resin systems that process compounds of more than 30 kg/min. This ensures minimal mould cycle times. Due to the high resin consumption during infusion and the quality standards of the fibre composite components, resin degassing systems need to be used. DOPAG has a validated system which can degas more than 40 litres of resin per minute. In addition, there is also a wide range of gel coat systems as well as systems for mixing erosion coatings and putties for finishing the rotor blades.
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We offer metering technology for these applications:
Infusion
Metering infusion resin
Rotor blades must be able to withstand extreme loads and demonstrate high strength and rigidity. The infusion process ensures optimum cohesion of the internal components. This involves impregnating the semi-finished fibre products with infusion resin. Here, dry woven or non-woven (non-crimp fabrics/NCF) fibre materials are placed in an open mould and a vacuum build-up is prepared with infusion tubes and valves. The main infusion tube is then connected directly to a metering system, which dispenses the infusion resin and applies it into the mould. The DOPAG metering systems eldomix or compomix can be used to optimally dispense the material.
Filament Winding
Filament winding with DOPAG metering systems
In the case of the filament winding technique, cylinders, tubes and vessels are wound. The composite components can then withstand high pressure in spite of their low weight. In filament winding, the fibres, such as carbon or glass fibre, are continuously fed from a roll through an impregnating bath and then wound onto a winding mandrel, resulting in a fully wrapped profile. The fibres are first impregnated in the bath. It is filled with materials such as polyurethane or epoxy resin and must be kept at a constant level during the winding process. The DOPAG metering system eldomix can perform this task, for example.
Pultrusion
Manufacture of pultruded composite components
Rotor blades contain composite components produced through a pultrusion process. They are installed inside the rotor blades to ensure a higher rigidity of the rotor blade. Carbon or glass fibres are fed from a roll and passed through an impregnating bath filled with epoxy or polyurethane resin. The impregnating bath is kept at a constant fill level with DOPAG eldomix, for example. The fibre composite is subsequently pulled through a heated moulding tool, which has the negative shape of the generated profile. The endless profiles in T, U or O-form are then individually cut to length.
Adhesive Bonding
Bonding fibre composite components
Adhesive bonding involves bonding smaller composite or metallic components. The application is also used in the manufacture of rotor blades for wind turbines. DOPAG systems dispense the adhesive either manually or fully automatically. For example, the application can be conducted in point and/or bead form. The DOPAG gluemix, for example, is used in the wind power industry. This was specially developed for use in the production of rotor blades and is capable of metering large quantities of epoxy resin precisely and reliably.
LEP + Putty
Protecting edges and smoothing out irregularities
Rotor blades are exposed to extreme loads. It is therefore very important that the leading edges are protected from damage. A two-component polyurethane is applied to the leading edges of the rotor blades. This is known as leading edge protection (LEP). Even in the high-precision manufacturing process, small irregularities may occur on the surface of the blade at the end of the production process. In the putty process, these cavities are filled with a putty based on 2K polyurethane, ensuring that the surface of the rotor blade is smooth throughout. The two-component material can be prepared with eldomix from DOPAG for both applications.
Gelcoat
Surface protection for composite components
As composite components are exposed to extreme weather conditions, corresponding surface protection is necessary. This is either applied to the composite material as a gel coat or applied beforehand as an in-mould gel coat. This means that the surface protection is applied in the mould, e.g. before the infusion or RTM process. DOPAG developed the metering and mixing system gelcomix for gel coat applications in rotor blade production. It is used to prepare the two-component material, an epoxy resin or polyurethane, and then manually applied to the mould surface.
Reference projects
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We ensure that your dispensing system runs reliably - with our DOPAG services. These range from maintenance and repairs to spare parts ordering and online support.
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Bischof+Klein uses the eldomix to bond packaging for the food industry. We were on site.
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Large quantities of adhesive are required in the manufacture of rotor blades. This is achieved with specially developed metering and mixing systems.
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For the secure bonding of paintbrushes we have customised the metering and mixing system economix.
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Precision is crucial when it comes to planning. Which factors are particularly important and how can common design flaws be avoided?
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The vectomix TC metering and mixing system from DOPAG processes thermally conductive materials precisely and cleanly. This application shows the processing of Wacker Semicosil 9672.
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Higher quantities in less time - For bonding housings for LED luminaires, DOPAG has configured an automated metering system that meets precisely these requirements.
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Technology, material and component - these three factors must be optimally coordinated for the automated production of PU foam gaskets. DOPAG and Stassen Industries GmbH advise customers together.
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SAE Schaltanlagenbau Erfurt relies on the dynamicLine from DOPAG for the individual production of control cabinets. We have visited them on site.
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We configured an automated lubricant dispensing system that optimises production processes in the automotive industry.
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The eldomix dispensing system fills an impregnation bath for the production of hydrogen tanks using the filament winding process.
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Particularly strict conditions apply to production in the medical technology and food industries. A special configuration from DOPAG enables the use of the dispensing system in the clean room.
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When is it beneficial to switch from manual dispensing to a metering and mixing machine? - We support you to identify all relevant influencing variables.
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Learn all about Form-In-Place-Foam Gasketing (FIPFG) and how it’s already begun revolutionizing engineering industries and applications around the world.
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PU gaskets and potting compounds protect the sensitive electronics in a wallbox against dust, dirt and moisture. We offer solutions for both applications.
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We offer dispensing systems for a reliable application of adhesives and sealants in the manufacturing of liquefied natural gas (LNG) transport tanks.
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The contactless application of lubricants meets all conditions for complex, automated production processes and is now standard in many industries. We present the options.
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With the dynamicLine, DOPAG provides an automated and clean application of PU foam gaskets on recyclable HEPA filters from the Swiss manufacturer Tecnofil.
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The Swiss start-up dhp technology constructed the world’s first retractable solar roof. The individual modules are manufactured with dispensing technology from DOPAG.
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With the dynamicLine, DOPAG offers a system for both applications and thus enables an efficient, automated series production.
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DOPAG offers special dispensing stations for the manual application of lubricants. With the help of an adapter, components such as O-rings and other seals can be greased or oiled manually.
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Self-adhesive labels and stickers are produced with silicone coating via coating systems. We provide the metering system to ensure material feed.
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DOPAG provided a metering and mixing system for potting electronics boards for e-bike battery packs.
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With the dynamicLine, DOPAG offers an efficient solution for series production of PU foam gaskets in all industries.
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The metering and mixing system volumix provides a smart solution for filling cartridges with adhesives and sealants in aircraft production.
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For the production of plastic filter elements, DOPAG configured and automated metering and mixing system.
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DOPAG provides an individual solution for the application of one-component sealant in the production of cardan shafts for special vehicles.
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With the dynamicLine, DOPAG offers an efficient solution for series production of PU foam gaskets in all industries.
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DOPAG develops a metering and mixing system for adhesive bonding of automotive components to ensure uniform standards worldwide.
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DOPAG offers furniture manufacturers flexible and reliable solutions for the automated application of lubricants.
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For the automated application of PU gaskets to control cabinet doors, DOPAG provides a dynamic mixing system in combination with a linear robot and shuttle sliding tables.
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With the dispensing system coredis, the honeycomb core of sandwich panels, which are used for the interior of aircraft, could be filled homogeneously.
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DOPAG successfully supported a truck manufacturer with a dispensing system for the manual application of a single-component sealant.
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Valves for the spray application of grease and oil. Contactless application of lubricants in areas difficult to access.
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Precise potting of filters and filter elements is necessary for high safety and purity. DOPAG supported a global manufacturer with individually configured metering and mixing systems.
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With the dynamicLine from DOPAG, customers will be able to implement gasketing and bonding applications with just one system.
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The requirements for the type of lubricant dispensing vary and always depend on the application being carried out. Learn here more about the four key factors for successful system design!
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The membrane dispensing valve ensures a clean application and a high reliability in automated dosing processes.
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Using thermal gap fillers leads to more advanced metering technology requirements - learn more about the solutions from DOPAG.
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Compared to manually inserted seals, automatically applied PU gaskets offer many advantages.
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DOPAG presents the shot valve in a new video: It is perfectly suited for contactless material application in highly automated processes.
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The control cabinet manufacturer Fandis applies foam gaskets on various components. DOPAG has designed a FIPFG system for this application.
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DOPAG has developed two special lubricant application systems for the production of ball screws in automotive industry.
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The eldomix dispensing system fills material reservoirs of 3D printers with liquid printing technology.
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DOPAG provides automated potting solutions for variuos applications - two practical examples!
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CTO Daniel Geier talks in the interview about challenges in automated dispensing technology.
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DOPAG presents a production cell, that could be used for greasing and oiling applications. Disocver also valves for contactless material application.
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Metering and mixing systems are necessary in various applications in rotor blade production. DOPAG presents its solutions.
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The household appliance manufacturer Amica uses an invidual glue dosing system from DOPAG for the production of oven doors.
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With dynamicLine, the metering technology manufacturer DOPAG presents a new dynamic mixing system for a wide range of applications.
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DOPAG developed a special dosing system for the automated lubrication of gas springs.
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Individual grease and adhesive dispensing systems from DOPAG guarantee highest quality electric parking brakes.
gluemix: 2K glue dosing system
Expert in wind turbine rotor blade production
Trends in rotor blade production
In recent years, the rotor blades of wind turbines have been getting even larger. Carbon fibre semi-finished products in combination with standard glass fibre materials enable blade lengths of more than 100 metres. Due to the increased need for reinforced fibre layers, mould occupancy times are getting longer. Tonnages for infusion and bonding resins as well as coating materials are increasing. Consequently, the systems for providing mixed materials must meet these growing demands. This also applies to the very high quality standards involved in offshore.
A rotor blade typically consists of glass fibre composites and reinforcement materials such as balsa or foam materials in order to transmit the shear stresses. The production process begins with the manufacture of the upper and lower shells. For the first layer, a gel coat is applied using the gelcomix metering system to give the component a high-quality surface finish. Dry semi-finished fibre products are then placed in the mould, auxiliary materials are added, and then the entire component is sealed vacuum-tight with a film and evacuated. This ensures the maximum freedom from pores.
Further steps include degassing the infusion resin and the actual infusion process. Degassing is necessary because some air bubbles can collect in the material due to contact with the air and due to transportation, which can result in undesired air pockets in the fibre composite during vacuum build-up. Degassing reliably removes even the smallest bubbles from the material. The compomix BL infusion system is connected directly to the vacuum build-up by means of tubes. Alternatively, buffer tanks are also possible, which are supplied with mixed material and also connected using infusion tubes. The mould is set after infusion. The temperature is closely monitored and controlled during this process in order to prevent material damage due to the exothermic reaction of the resin.
Once the component is fully set, all auxiliary materials are removed and the bonding process of the stiffening elements and the two shell halves begins. The adhesive beads are applied with a gluemix binding mix system. Once this process is complete, the two halves of the mould are closed up and a complete rotor blade is created.
DOPAG offers reliable solutions for the manufacture of fibre composite components, for example RTM, Filament Winding, Infusion, Pultrusion, etc.