JEC COMPOSITES MAGAZINE - Issue #94 - January/February 2015 - 44

LCM

Fig. 1: Different approaches for automated profile preforming through ADFP
(sources: (a) Airbus Group Innovations, (b) and (c) Electroimpact)

Continuous profile preforming
The basic idea of continuous profile preforming is to use
several non-crimp or woven fabrics "from the roll", which are
continuously stacked, draped to the desired cross-sectional
geometry, fixed through thermal binder activation or stitching, and cut to the required length. Two solutions could be
found that follow this approach: the Continuous Composite
Preforming System (CCPS, see Figure 2a), jointly developed
by Broetje Automation, Faserinstitut Bremen and CTC Stade,
and the Continuous Profile Preforming System (CPPS, see
Figure 2b), developed at the Institut für Verbundwerkstoffe
GmbH [5,6].
These processes allow the fully automated fabrication of nearnet-shape preforms with production speeds of up to 6 m/min.
Their modular setup enables flexibility in material, layup and
profile geometry, which, however, cannot be changed during
manufacturing. While rather simple cross-sectional geometries can be fabricated directly, more complex geometries
require separate processing and assembly of sub-preforms,
therefore increasing the handling effort.

Profile roll forming and placement
This concept combines the principles of ADFP and continuous profile preforming and was developed by Premium Aerotec, while ATK introduced a similar concept for prepreg layup
(Automated Stiffener Forming Machine). Basically, it uses a

Fig. 3: Roll forming onto a curved, C-shaped profile tooling
(source: Premium Aerotec)

processing head mounted on an automated positioning system
(e.g. six-axis robot) to batch-wisely drape a fabric from the roll
onto a stationary profile tool through roll forming and cutting,
and to fix it using a binder technology, as depicted in Figure 3
[7]. Hence, no subsequent assembly of preform and infusion
tooling is needed. Although production speed is lower compared to continuous preforming methods, this process comes
with more flexibility in terms of layup changes and curvature
along the major profile axis. A drawback of this approach is
that the number of different fabrics and the complexity of the
folding unit are limited by the processing head, making this
technique suitable for rather simple profile shapes.

BraF braiding process
Automated manufacturing of profile preforms can also be
addressed by means of braiding [8]. A highly sophisticated
modification of this technique is the BraF (Braided Frames)
process (see Figure 4) developed by Airbus Group Innovations and SGL Kümpers, where braiding is combined with
winding and UD tape placement in a circular setup to continuously manufacture curved frame preforms (up to 1 m/

Fig. 2: Existing solutions for continuous profile preforming (sources: (a) Broetje Automation, (b) Institut für Verbundwerkstoffe)

44 jec composites magazine / No94 January - February 2015

JEC COMPOSITES MAGAZINE - Issue #94 - January/February 2015

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #94 - January/February 2015