Characterization and properties of recycled materials · PDF fileASTM 3379-75: Method for...
Transcript of Characterization and properties of recycled materials · PDF fileASTM 3379-75: Method for...
Fraunhofer Research Institution for
Casting, Composite and Processing Technology IGCV
Correlation between micro- and macroscopic characterization of recycled carbon fibre materials
Frank Manis, Ananda Schindler, Michael Sauer and Jakob Wölling
Fraunhofer IGCVLocated in Augsburg
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Processing technology
Fraunhofer IGCVWe use synergies in these fields of research and development:
Composite technologyCasting technology
Resource efficiency in factories
Intelligent networked production
Flexible production
Networked modeling and simulation
Additive manufacturing
Hybrid composite constructions
Online process monitoring
Materials and test engineering
CFRP manufacturing engineering
Recycling
Efficiency and balancing
Molding materials
Sand and gravity die casting processes
Simulation and design of mold and cast components
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Possibilities for cooperationThe Fraunhofer-Model
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Carbon fibers are a high energy and cost intensive raw material:
Generally: recycling can be rewarding – ecological and economical
MotivationEnergy and resource intense manufacturing
Why do we need characterization technics?
Pyrolysed (550 °C, 30 minutes dwelltime) CFRP-Woven out of epoxy resin
Tensile Bending Shear
Price Optical Chemical
Sustainability Impact Electrical
Durability Mechanical Etc.
Virgin vs. Recycled carbon fibresWhat is the difference?
Fibreorientation
Fibrelength
Fibrevolumecontent
Filament Interphase
Why do we need characterization technics?
[CES Selector by Granta Design]
Why do we need characterization technics?Influences on properties by recycling
Microscopic characterizationSingle filament testing
ASTM 3379-75: Method for Tensile Strength and Young Modulus forHigh-Modulus Single-Filament Materials
Carbon fibre
Resin / Glue
Paper
Diameter
𝜎𝑥𝑥 =𝐹𝑥𝑥
𝐴=
𝐹𝑥𝑥
𝜋 𝑅²
Favimat-Single fibretensile test
Microscopic characterizationSingle filament testing
Statistic Diameter
Fibre-manufacturer Testing Parameters
Microscopic characterizationInterface – Surface Groups and Adhesion
https://en.wikipedia.org/wiki/Epoxy
Fibre Interphase Matrix
https://www.weizmann.ac.il/materials/Wagner/research
Microscopic characterizationInterface – Defects and roughness
Macroscopic characterizationStructural and textural homogeneity
Explanation of measurement:
Transmitted Light calcuation
Calculation Ø,
Calculation of average value over
e.g. 10x10 Pixel
Increasing of pixel size
fence
Macroscopic characterizationStructural and textural homogeneity
Homogeneity in MD is good. Steady production direction
Longer fibres result in worse homogeneities
4,61 6,15 7,0210,3411,59
7,12
16,14
34,2
Sigrafil12mm 0.1
vCF SGL12mm 1.1
vCF SGL18mm 1.2
vCF SGL36mm 1.3
Stabw MD Stabw CD
(g
rey-v
alu
e)
H
om
og
en
eit
yin
MD (Grey Value)
Homogeneityin CD
CDMD
Macroscopic characterizationStructural and textural homogeneity
Proof of Technology mit CT Untersuchungen und zerstörenden Zugfestigkeitsmessungen in >= 10 Studien
Fibre-orientation
Fibre-volume content
Homogeneity and defects
Microscopic and Macroscopic
Macroscopic characterizationStructural and textural homogeneity
Project „Izi-Direct“ starts in 2018
Development of in- and online measurement of fibre orientation in recycled fibre production via eddy current measurement
Application in textile processes (Wet- and Dry laid nonwovens)
Macroscopic characterizationStructural and textural homogeneity
Micro and Macroscopic viewClean doesn‘t mean clean
Pyrolysed (550 °C, 30 minutes dwell time) CFRP-Woven out of epoxy resin
Micro and Macroscopic viewClean doesn‘t mean clean
600 °C 30 minutes oxidised20,9 % O2
600 °C 30 minutes pyrolysed100 % N2
Virgin Fibers
rCFRP-CharacterizationCorrelations of fibres and couponds
rCFRP-CharacterizationCorrelations of fibres and couponds
rCFRP-CharacterizationCorrelations of fibres and couponds
Results and discuss ion
Enhanced material failure effects
Strength of composites as a function of single fibre degradation
Char, voids, matrix rich regions, intra tow voidslead to increase failure
Maximum rCFRP degradation -27,78 % onwoven and -41,37 % on unidirectional material
-15% e.g. additional missorientation due handling
-2%-12% e.g. Char, voids, matrix rich regions, intra tow voids
-18% e.g. Char, voids, matrix rich regions, intra tow voids
U (V) U/500/30 U/500/60 W (V) W/500/60 W/475/30
0
20
40
60
80
100
120
140
rCF
/vC
F s
trength
[%
]
Materials
rCF/vCF strength (SF)
rCF/vCF strength (rCFRP)
SUMMARY AND OUTLOOKWHY DO WE NEED CHARACTERIZATION TECHNICS?
Recycling of composites leads to new questions that are not answered at the moment
Macroscopic properties are depending on microscopic effects like fibreproperties, char content, voids, fibre defects
New testing methologies has to be implmeneted for prodcuts out of rCF
Online measurment of rCF properties necessary for future application
Recycling of CompositesContact us
Fraunhofer IGCVAm Technologiezentrum 286159 Augsburg, Germany
Dipl.-Ing. Frank Manis
Phone +49 821 / [email protected]