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Thermal optimization of autoclave molds is essential to increase part quality, reduce manufacturing costs and increase autoclave capacity. Previous experience-based tooling designs allowed an optimization only after the mold was manufactured and tested. Manufacturing process simulation provides the capability for virtual tooling optimization within the design phase. Thereby, the range of possible optimizations increases and the tooling cost decreases. In order to use manufacturing process simulation efficiently, fast but accurate simulation methods must be available. The so-called shift factor approach was previously presented by the authors. This paper takes up the given approach and explains different influences on mold heat-up and how they can be covered in a thermal tooling simulation on an industrial scale. Proof of the simulation accuracy under realistic manufacturing conditions is provided together with an example of its application.

The preparation of nanofibrillar composite (NFC) materials using single‐polymer nanofibrils as starting materials is described. Such a possibility is offered by (i) the concept of polymer/polymer NFCs, which have recently been manufactured and represent a further development in the field of microfibril‐reinforced composites, and (ii) the opportunity to isolate neat nanofibrils through selective dissolving of the second blend component. The resulting nanofibrillar single‐polymer composites are characterized by superior mechanical properties (the tensile modulus and strength are improved up to 350%), competing with glass‐fiber‐reinforced PET.magnified image

Fully impregnated fiber-reinforced thermoplastic sheets, or the so-called organic sheets, allow the thermoforming of parts within very short cycle times. This article describes the development of the next generation of organic sheet materials based on recycled carbon fibers and polyamide 6 staple fiber yarns. Regardless of the recycled nature of the fibers and an average fiber length of 25 mm, the organic sheets still reach a comparable level of the tensile strength and modulus of continuous fiber-reinforced organic sheets made of virgin CF with the same reinforcement structure. Due to the staple fiber yarn architecture, the organic sheets feature a deep-drawing ability of a total plastic deformation up to 50% in the fiber direction. The effect is enabled via an interfiber sliding when the organic sheet is processed in the molten condition. The creation of a finite element model for the thermoforming process simulation of the material is also presented. Predictions of the plastic strain distribution and its magnitude are shown to agree well with forming experiments where a curved geometry is formed to different depths.

Exploring the polymorphism phenomenon of polyamide 66 (PA 66) a single polymer composite (SPC) was prepared. The matrix was obtained via compression molding and quenching in ice water expecting to comprise the modification with lower melting temperature (T m ). The reinforcement was commercial textile yarn of PA 66, characterized by a higher T m . Layers of the yarn were sandwiched between matrix films and compression molded at 250 °C, i.e. 10 °C below T m of the reinforcement. SEM observations revealed the layered structure of SPC as well as a good adhesion between the composite components due to surface premelting. The tensile testing showed, as compared with the matrix, an increase of the initial modulus by 28% and of the tensile strength by 160% when the reinforcing component of the SPC amounted to only 20 wt%. Optimization of the preparation conditions, including variation of the matrix/reinforcement ratio as well as trialing of other polyamides, is in progress.

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