Motivation
Circular economy and resource efficiency are, along with costs, the main drivers for the competitiveness of new products. To reduce environmentally harmful emissions, new materials and processes are needed to save component weight and enable closed-loop recycling. High-performance, continuously fiber-reinforced plastics with a thermoplastic matrix of polyamide 6 have great potential for solving these challenges. A novel process for producing such high-performance composites is "in-situ pultrusion" (pultrusion = strand drawing process) with the monomer ε-caprolactam. The low-viscosity monomer ε-caprolactam offers decisive advantages over comparable matrix systems and polymerizes into polyamide 6 during processing. This continuous process thus enables high-performance profiles based on a recyclable thermoplastic material to be manufactured cost-effectively and with high productivity.
Overall objective of the project
CaproPULL aims to develop a suitable sensor-supported equipment and mold technology with process data analysis for the in-situ pultrusion process for reliable processing of the monomer ε-caprolactam. This enables thermoplastic continuous fiber-reinforced profiles to be produced robustly and reliably that are at least equal in quality and properties to the thermoset profiles that currently constitute the state of the art. The added recyclability of these profiles and the expected cost-effectiveness of the new material and process are likely to give them a clear competitive edge over the state of the art. Pultruded profiles have a wide range of applications, e.g. in the automotive industry, as support systems for renewable energies, in the construction sector and in the chemical industry. With the support of associated partners, the project results are also to be transferred to these industries.
Innovation
The innovation in the project consists primarily of the reliable processing and the related requirements. Due to the low, water-like viscosity of ε-caprolactam and the mandatory avoidance of moisture contact during processing, challenges arise with regard to the processing equipment and the mold technology. The major innovation of the project is therefore a stable process that is suitable for large-scale production. In addition, the pultrusion process will be enhanced in terms of data acquisition, management and use, which will facilitate integration into the digitalized production of the future and ensure improved tracking of the quality of the profiles produced.
Use Cases
CaproPULL focuses primarily on the use of thermoplastic profiles in the automotive and construction industries. In the automotive industry, profiles produced by in-situ pultrusion can be thermoformed and used as crash structures in bumpers, side skirts or as stiffeners in the roof structure, thereby reducing the mass of the vehicle. This reduces the energy required for locomotion and thus emissions during the product's service life. In addition, these components can be fed into appropriate material recycling cycles. In the construction sector, the material properties, e.g. insulation properties and corrosion resistance, of these profiles come into their own. They also meet the new regulations and specifications for thermal insulation and fulfill the high demands made on the materials to be used.
Support from associated partners
The success of the project is to be ensured through cooperation with the associated partners. They support the project with regard to the definition of equipment and mold specifications, necessary interfaces, required sensor technology and relevant machine data, decisive quality parameters and profile geometries. Our thanks go to:
L. Brüggemann GmbH & Co. KG
Johns Manville Europe GmbH
AFBW – Allianz Faserbasierte Werkstoffe Baden-Württemberg e.V.
Röchling Engineering Plastics SE & Co. KG
Mercedes-AMG GmbH
KAUTEX TEXTRON GmbH & Co. KG
Schöck Bauteile GmbH
BMW AG
REHAU Industries SE & Co. KG
Fraunhofer Institute for Chemical Technology ICT
