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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Prof. Dr.-Ing. Christian Hopmann

Dipl.-Ing. Marc Linus Fecher

6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, STADE

12th of June 2012

Resin Transfer Prepregging – Process chain for large

scale production of structural composite parts

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Institut für Kunststoffverarbeitung (IKV) an der

RWTH Aachen

Founded in 1950, supported by a Sponsors'

Society (actually ~240 members)

Associated with RWTH Aachen University

4 scientific departments

Composites

Extrusion

Injection Molding /PU

Part Design / Materials Technology

Staff

80 scientific employees

50 employees in laboratories,

workshops and administration

~220 student workers

Location Pontstr. 49

Location Seffenter Weg 201

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Outline

Introduction and motivation

Functional principle of the Resin Transfer Prepregging (RTP)

Fully automated RTP manufacturing center

Determination of the laminate quality

Conclusion and outlook

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Introduction and motivation

An economic high volume production of functional integrated structural

composite parts with endless fibre reinforcement is not realisable with currently

available processes.

Example of a structural composite part:

[EADS]

stringer

hull

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Structure of the DFG Research Unit 860

New process chains for production of continuous fibre reinforced plastic parts:

Integration of preforming, impregnation, forming and curing

Testbild

1

2

3

process-

chain

TP 4 (IKV)

Resin Spray

Prepregging

TP 5 (IKV)

Resin Transfer

Prepregging

TP 8 (IKV)

Forming and

curing

TP 3 (IPT) Handling

ITA: Institute for Textile Technology

IPT: Fraunhofer Institute for Production Technology

IKV: Institute of Plastics Processing

TP 1 (ITA)

One-step

Preforming

TP 2 (ITA)

Multiple-step

Preforming

TP 6 (IKV)

Gap-Impregnation

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Approach: Process chain Resin Transfer Prepregging

Resin Transfer Moulding (RTM)

+ parts with a high complexity

+ high fibre volume contents

Resin Transfer Prepregging (RTP)

Separation of the RTM-process in two isothermal sub processes „impregnation“

and „forming and curing“

No heating and cooling cycles necessary

Reduction of cleaning expenses

- long heating and cooling rates

- high cleaning expenses

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

sub process „impregnation“

Process chain Resin Transfer Prepregging

sub process: „forming and curing“

structural composite part

series production of

near-net-shape preforms

storage subsequent processing

resin feeding

cooled RTP-mould

injection unit

vent

F

heated compression mould

adjacent

mould cavity

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Steps of the sub process „impregnation“

closing of the mould and

evacuation of the cavity

injection of preheated resin

into the cooled mould

impregnation of the fibres

and freezing of the resin

F

injection unit resin feeding

vent preform cooled mould

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

RTP manufacturing center

mould carrier

RTP-mould

cooling system

metering unit

control panel

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Materials and process parameters

materials:

epoxy resin: Huntsman XB 3585

curing agent: Huntsman Aradur 22962

preforms built up with quadraxial glass

fibre non-crimp fabrics: Saertex 984 g/m²

process parameters for impregnation:

resin temperature: 50 °C

mould temperature: 0 °C

injection pressure: 4 bar

vacuum: 100 mbar

fibre volume content: 50 %

0 1 2 3 4 5

cycle time

time [min]

preform insertion / mould closing

evacuation

resin injection

freezing / demoulding

∆tcycle= -40 %

initial RTP-

process

optimised

RTP-process

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

500 mm

Structural composite parts manufactured in the

RTP-process

cut out element Ø 75 mm cut out element 40 x 80 mm² insert

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Determination of the laminate quality

480 mm

480 m

m

500 mm

500 m

m

ultrasonic imaging technique RTP-part

-20 0 -10 [dB]

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Flexural properties of the RTP-parts

(DIN EN ISO 14125)

0

100

200

300

400

500

600

initial RTP-process

optimisedRTP-process

flexura

l str

ess

[M

Pa]

0

5

10

15

20

25

initial RTP-process

optimised RTP-process

flexura

l m

odulu

s

[G

Pa

]

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Conclusion und Outlook

Structural composite parts with fibre volume contents of 50 % can be

manufactured in the Resin Transfer Prepregging process in less than 10 min.

The RTP-parts exhibit low porosity and high mechanical properties.

Functional elements can be integrated into the parts during the process.

Manufacturing of parts with integrated stiffening profiles and combinations of the

three investigated functional elements.

Implementation of an online quality control system

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6th INTERNATIONAL CFK-VALLEY STADE CONVENTION, Resin Transfer Prepregging - Process chain for large scale production of structural

composite parts, Marc Linus Fecher, IKV Aachen

Thank you for your attention!

The presented investigations have been funded by the Deutsche

Forschungsgemeinschaft (German Research Foundation, DFG) within the research

unit Forschergruppe 860 “New process chains for production of continuous fibre

reinforced plastic parts: integration of preforming, impregnation, forming and curing”.

This support is gratefully acknowledged by the authors.

Contact:

Dipl.-Ing. Marc Linus Fecher

Seffenter Weg 201

D - 52074 Aachen

Tel: +49 241 80 28330

Email: fecher@ikv.rwth-aachen.de