SFB/TRR 402: Pultrusion of semi-finished products with graded properties using recyclates from plastic waste streams

News

10.12.2025 | events
Launch of KI4KI: Artificial intelligence for the plastics industry

On 25 November 2026, nine companies launched the KI4KI consortium project at the Plastic Innovation Centre 4.0 at the IKV. At the kick-off event, the partners’ key requirements were analysed, initial AI use cases were identified and valuable insights from the

read more

Teilprojekt B05

Sub-project B05 aims to understand the process, modelling and control of a multi-step process chain consisting of waste processing, compounding and pultrusion to produce graded semi-finished products, which are to be further processed. They consist of thermoplastic resins and fibre reinforcements based on short, long and continuous glass- and carbon fibres. Three types of semi-finished products are investigated: spoolable tapes a few tenths of a millimetre thick, stiffer profiles as well as strands with up to several millimetre thickness.

The graded semi-finished products are processed in further projects in tape laying (A02, B01) and tape braiding processes (B03) and used as graded local reinforcement in the injection molding and compression molding processes for manufacturing the demonstrators (A03, A04). In the production of the surface structure demonstrators, the graded strands serve as plasticisable inserts for extrusion (A04). B05 thus supplies materials, process and material models as well as the necessary data for the iEP.

SFB TRR 402 - B05 — The process line including all methods used to produce graded tapes from virgin and recycled materials. It starts with a mechanical waste processing chain to produce recyclates with sensor-based material flow characterisa-tion of the input (SBMC) and sensor-based quality control (SBQC) of the recyclates and continues with the compounding of the recy- clates and the following production

The processes investigated in B05 include the mechanical processing of plastic waste (post-industrial and post-consumer), the production of compounds and a combined pultrusion/extrusion process. Thanks to various additive options (e.g. to promote adhesion) and reinforcement with short fibers during extrusion, as well as the embedding of continuous fiber-reinforced layers with glass and/or carbon fibers, they offer many degrees of freedom in the creation of graded morphologies. To investigate the processing of recycled materials, a range of waste streams are evaluated, analyzed and mechanically processed.

The prepared recyclates are processed into pellets in twin-screw extruders together with virgin thermoplastics, glass/carbon fibers and masterbatches with coated fibers from sub-project B03. The granulates are made available for further sub-projects for the production of molded parts and used in the extrusion/pultrusion process for the impregnation of continuous fibers. By mixing different melt streams, gradations can be adjusted in a targeted manner. At IKV, a modular test setup is being realised that enables the defined and repeatable production of graded semi-finished products and provides in-situ measurement options for process analysis. The long-term aim is to provide data, methods and models that automatically configure production resources, process sequences and material flows on the basis of a target configuration specified by the iEP.