Presented by:

Overview of biocomposites

Properties, production methods and applications

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Benjamin Hornblow, Lyngby, 03-12-2014

Overview

• Natural fibres

– Types

– Production

– Fabrics

• Bio-based resins

• Natural fibre composites

– Manufacturing

– Properties

– Sustainability

• Biocomposites market in the EU

• Applications

• Conclusion 2

What are biocomposites?

• Formed by a matrix (resin) and a reinforcement particle or fibre

• At least one part derived from biological origins

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Types of natural fibres

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Plant stem anatomy and fibre separation

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Plant stem cross section

Fibre structure and dimensions

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Natural fibre structure

Fibre dimensions and aspect ratio

PlantFibre average length

(mm)

Fibre average diameter

(µm)Aspect ratio

Cotton 18 20 900

Flax 33 19 1750

Hemp 25 25 1000

Jute 2 20 100

Kenaf 70 100 700

Fibre physical properties

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Fibre density

From fibres to yarn

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Twisted bundle

Wrapped bundle

From yarn to fabric

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Unidirectional

Biaxial ±45°

2x2 twill weave

Hopsack weave

Bio-based matrix materials

• Made from renewable biomass such as vegetable fats and oils, starches and microbiota

• Can also be blended with petroleum based resins

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Thermoset resin properties

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Epoxy resin comparison

Polyester resin comparison

PropertyStandard epoxy

(Pro-set INF 114)

100% Biobased epoxy

(Super SAP INH)Comparison

E-modulus (GPa) 3.7 3.3

Tensile strength (MPa) 56 59 -

Viscosity at 23°C (mPas) 267 360

PropertyStandard polyester

(Reichhold Polylite 413-575)

25% biobased polyester

(Reichhold Envirolite 31430-50)Comparison

E-modulus (GPa) 3.3 3.2-3.5 -

Tensile strength (MPa) 67 60-75 -

Viscosity at 23°C (mPas) 160-175 180-200

Manufacturing of NFC

• Essentially the same as for synthetic fibre composites

• Drying of fabric before processing is recommended

• Typically fast infusion and good wet-out

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Laminate characteristics

• Brown-gold appearance (flax fibre laminates)

• Low fibre volume fraction (30-35%)

• Typically higher porosity than synthetic fibre composites

• Easy to trim and drill holes

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Prepreg material

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UD - Flaxpreg

44% FVF

Laminate stiffness properties

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UD Laminate stiffness UD Laminate specific stiffness

33% FVF

56% FVF

60% FVF

Laminate damping properties

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Fibre damping

Three orders of magnitude higher damping

High vibrations In carbon layer

Damped vibrations In flax layer

Carbon layer

Carbon layer

Flax layer

Carbon/flax-fibre lamiante Source: Lineo flax fibres reinforcements

Laminate aging and degradation

• Water wicking through exposed fibres (untreated)

• Degradation due to water absorption and UV light

• Influenced by matrix material and surface coating

• Limited information available

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Test series planned at

FORCE Technology

Sustainability of NFC

18 Source: Composites Evolution

Fibre mat production energy

Claim 50% reduction in carbon footprint

Summary of NFC properties

• Advantages

– High specific stiffness (better than glassfibre composites)

– Good vibration damping

– Low embodied energy / carbon foot print

• Disadvantages

– Variability (growth conditions, plant anatomy, etc.)

– Low fibre volume fraction (approx. 30-45%)

– Degradation from moisture and UV light (TBD)

– Limited mechanical properties data

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EU composites market (2012)

20 Source: bioplastics MAGAZINE [03/14] Vol. 9

Industrial applications

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Automobiles Wood Cotton Flax Kenaf Hemp

Industrial applications cont.

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Buhler Versatile hood 100% Flax-fibre 100% Bio-based epoxy

Sport and leisure

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Artengo tenis racket 25% flax fibre – 75% carbon fibre

Schwinn Vestage bicycle 80% flax fibre – 20% carbon fibre

Sports and leisure cont.

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Notox surfboard 100% flax fibre 100% bio-based resin

Swift flax fusion canoe Flax/kevelar fibre Bio-based vinylester

Hemp sunglasses 100% hemp fibre (CSM) 100% bio-based resin

Sports and leisure cont.

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C-Tech fairing 100% Flax-fibre Epoxy pre-preg

Conclusion

• NFC are finding their niche markets:

– Light structural applications (stiffness driven)

– Sound and vibration damping applications

– Low environmental impact consumer products

• Supply chain is growing and maturing:

– Multiple fabric suppliers

– Variety of bio-based resins available

– Some pre-preg fabrics available

• Cost:

– Fabric costs vary substantially – dependent on volume, weaving, supplier etc.

– Natural fibre fabrics will approach the price of glass fabrics (long term forecast)

– Bio-based resins only slightly more expensive (for low volumes)

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Thank you!

Fibre mechanical properties

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Fibre stiffness Fibre strength

Laminate strength properties

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UD Laminate strength UD Laminate specific strength

Forecast production in 2012

30 Source: bioplastics MAGAZINE [03/14] Vol. 9