Pre-2-K - Development of (semi-)automatic processes for preform manufacturing and 2K injection for highly complex 3D components

The aim of this project is to develop a semi- automatic RTM process for preform manufacturing and 2K
injection designed for complex 3D-components in the aviation industry. This project focuses on the forming
process technology, for spars with complex geometries such as curvatures (Figure 1.1.1), joggles
(Figure1.1.2), and high thickness. The expected outcome is to have a semi-automated process to produce
parts with curvatures, joggles and high thickness to conform to the aviation structural requirements.
Currently, the preforming of dry fibers or prepregs is a tedious process that requires hand lay-up leading to
high workforce requirement, inefficient draping, high energy consumption, fiber sliding and distortions. This
project delves into a semi-automated process with the cutting of materials such as woven, unidirectional
(UD) or non-crimp fabrics (NCF) with handheld ultrasound to semi-automated cutting devices. In the
preforming process, the cutting speed, angle, length, fiber orientation and the cutting of long plies play a big
role in the quality of the final products, making semi-automated cutting a crucial step. Moreover, the 2K
system in the aviation is limited and currently has no flying part made with technology. Due to the upcoming
high production rates and speed, the mixing system for 2K resin has recently been developed, allowing
isothermal processes and homogenous mixing. This allows for reduction of energy through multiple heating
cycles and better mechanical requirements on the final parts.

The cutting process will lead to the lay-up of stacks with adequate fixation and manipulation. The
repeatability of accurate positioning of various ply sizes with grippers and binder fixation is pivotal to meet
the design and structural requirements of spars within the aviation industries. An important aspect within this
project is to determine the fixation behavior for different thicknesses, to reduce the multi-step process
currently required to produce thicker spars as shown in Figure 1.1.3. This would lead to a more efficient
production cycle, energy reduction and cost consumption. Within the RTM process, the accurate drapability
allows for near-net shaping, as well as stress continuity at curvatures, joints, or seams. The process
development within this project is accompanied by draping simulations of different ply thicknesses of NCFs
including a comparison of topology, boundary contours and fiber angles from laser scanning with the
simulations.