In order to be able to manufacture large fiber reinforced plastic (FRP) components – such as those used for aircraft and wind turbine construction – which are free of release agents, researchers of Plasma Technology and Surfaces PLATO and experts in the Fraunhofer Project Group Joining and Assembly FFM at Fraunhofer IFAM have developed a deep-drawable FlexPLAS® release film.
Removal of the FlexPLAS® release film developed by Fraunhofer IFAM, Bremen, from a fiber composite component that was in-mold coated with a gel-coat. (© Fraunhofer IFAM)
This is an elastic polymer film with a flexible plasma-polymer release layer that allows easy removal of components from molds, even when stretched by 300 percent. The film can be applied using a special deep-drawing process without alteration of the tool design, and is suitable for both female and male molds.
The FlexPLAS® release film has already been used to manufacture large carbon fiber reinforced plastic (CFRP) components on a 1:1 scale, without using release agents, via a prepreg process at 180 °C in an autoclave. As will be able to be seen at Booth H 64 in Hall 1 at JEC 2012 in Paris, the resulting large components can then be coated without further pre-treatment. This is because the use of the release film allows clean removal from the mold without transfer of any residues.
The innovative FlexPLAS® release film is not only suitable for use with prepreg technology but can also be used for other manufacturing processes such as the (vacuum) infusion process or the wet layup process. The release properties of the flexible release film are not solely limited to carbon fiber and glass fiber matrix resins.
In addition, the new technology allows in-mold coating of fiber composite components, whereby the component is coated by applying a gel-coat to the film (see photo). The matt effect of the coated surface can be adjusted via the roughness of the FlexPLAS® release film that is employed. The risk of coating defects is significantly reduced using this approach.
Besides obviating the need to apply release agent on the surfaces of molds, the productivity of various other steps in the process chain can also be increased by using FlexPLAS® release film. Notably, there is no downtime required to thoroughly cleaning the molds and free them from release agent residues. This means that the service life and availability are considerably increased. Also, the fiber composite component can be coated, without release agent residues having to first be removed. Furthermore, if the film remains on the component to the end of the process or up to delivery to the final customer then it also acts as a protective film.
Release agents are essential for manufacturing fiber composite components. Prior to the start of the layer build up, they are applied to the full surface of the molds in order to ensure easy removal of the cured components. On removing a fiber composite component from a mold, the separation occurs within the release agent layer. This is why some release agents always end up on the component surface. These release agent residues must be removed prior to coating or bonding the fiber composite components. This can be achieved by cleaning or surface abrasion of resin materials via grinding or blasting processes. It is also necessary to regularly remove release agent residues from the surfaces of the molds.
The scientists of Plasma Technology and Surfaces PLATO at Fraunhofer IFAM have already developed an ultra-thin plasma-polymer release layer to replace release agents. This is already being used in, for example, the car manufacturing industry. A prerequisite for this technology is that the mold is coated in a low pressure plasma reactor. This is, however, not viable for the manufacture of large fiber composite structures for reasons of size. This shortcoming is solved by the newly developed FlexPLAS® release film.Contact
Anne-Grete Becker | Fraunhofer-Institut
Modular safety concept increases flexibility in plant conversion
22.03.2018 | Deutsches Forschungszentrum für Künstliche Intelligenz GmbH, DFKI
Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions
21.03.2018 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy