Cincinnati Viper 1200

In the current configuration with 12 individual tapes, 3-dimensional structures can be laid up after their geometry is modeled in CATIA. The geometry is produced to contour with reference to the outer contour and cut-outs. The tapes are cut with twelve individually controlled cutting blades. The NC programs are generated automatically before exporting the geometry from the CATIA workstation to the system control. The tapes are laid up on negative or positive molds with sizes of up to 8 m x 1.6 m.

With the PRTM system, continuous double-T sections with a defined laminate structure can be produced by pultrusion. The prepared woven preform is placed in the creel, which is designed so that the pull process produces the correct laminate structure. The fiber preform is continuously pulled through the entire system via the so-called pullers. In the first step, the system is pulled through a preforming tool. There, the material is formed step by step until the desired cross-section is achieved in order to then be passed through the injection system. The injection system impregnates the dry fiber tow under pressure and at a specific temperature. The resin gels by application of specific temperatures as it passes through the length of the injection system, but it does not fully cure. Then, the section is transported into a press tool, where it is shaped to its final contour and further hardens. To keep tensile stresses low across the entire tow and thus prevent deformation, the press tool briefly moves along while pressure is applied. After opening the press tool, the latter then moves forward a certain distance again. This produces an extremely precise contour and very high laminate quality. Then, the section is pulled through a secondary curing oven to fully cure the composite.

Preforming system

This experimental system disposes of three separate preforming zones located above one another, which can produce continuous preforms with C-, Z-, or L-shaped cross-sections. The curvature of the preforms can be adjusted during operation between 2 m (e.g. for frames) and straight (e.g. for stringers) so that varying sections can be produced. The preforming zones can be combined or operated individually.

Circulating air oven and resin injection systems

The circulating air oven with an output of 108 kW is used in conjunction with the production of CFRP components as a temperature control chamber. This encompasses the injection of resin into dry preforms at specified temperatures or temperature curves and the temperature control of preforms fitted with binders for forming tests. The oven is equipped with penetrations for vacuum and measuring lines, and it is used for component production in combination with the injection system. The temperature curves can be programmed. The actual temperature is measured with two Pt100 resistance thermometers.

Other characteristics of the air circulation oven include: Temperature: max. 300 °C with gradual adjustment, precision +/-5 °C, useful space: 2000 x 2000 x 3500 mm.

Prior to resin injection, the respective downstream resin tank can be vented. This step is, however, not necessary if the typically used resin system is employed, which is delivered in a degassed state. The injection and transfer lines as well as the resin tanks can be heated. The system control loop allows for the monitoring of pressure, temperature, and transported resin volume. The resin injection system can be used in combination with the air circulation oven and the heated press for RTM production.