JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 60

3D printing
Focus
Texilis is a team of R&D engineers and
researchers whose aim is to develop
new flax-based materials and applications. As innovation and engineering consultants, their job is to help
companies develop new materials
and products, from providing research
material and feasibility studies to
helping with prototypes. Texilis works
closely with flax producers and composite processors to offer customers
comprehensive solutions.
The range of target applications and
sectors is broad, including transportation, building, medical, leisure and
many more.

chopped fibres designed for easy metering and mixing with polymer matrices
by extrusion. The fibre length, diameter
and aspect ratio were carefully monitored
to control the metering and the filament
fibre volume content throughout the
extrusion process. This is a crucial step
to ensure efficient 3D printing and part
quality. ComposiTIC first formulated
the chopped fibres recommended by
Texilis with a specific compound based
on PLA. Because the raw polymer gets
stiffer and brittle when loaded with
this type of fibres, it was necessary to
find a formulation that would ensure
good filament handling and processing
through the printer. A brittle material can
compromise the 3D printing process by
inducing filament breakage. A compromise between a softened material and
a mechanically improved material was
finally reached. Once the optimized filament was defined, the printability and
process parameters were determined on
open-source 3D printers (Prusa I3).

Product characteristics
The filament was made of biodegradable
materials, including flax fibres grown
in France. As far as end of life is concerned, the parts are fully compostable
in industrial composting conditions. Flax
fibre-reinforced parts can be printed with
regular 3D machines, and the formulation
of the materials makes the filament flexible

Tab. 1: Printing parameters, mechanical and physical properties of Starflax®3d
Printing parameters
Nozzle temperature (°C)

235

Bed temperature (°C)

Printing speed (mm/s)

Recommended nozzle diameter (mm)

0,5

Tensile properties of printed specimens
Young's modulus (GPa)

3,4

Stress at break (MPa)

39,4

Strain at break (%)

2,0

Hardness (Shore D)

Physical, thermal and rheological properties
Density

1,26

Linear mass (g/m)
Ø 1.75 mm
Ø 3mm

3,2
6,9

Glass transition temperature (°C)

Melt flow rate (MFR, g/10min)
230°C, 2.16kg

Fig. 2: 3D model of the lamp base frame

enough to prevent breakage during the
loading process and printing.
The mechanical properties of the 5%
flax-reinforced material were measured by
tensile tests on printed strips. These first
tests showed that parts printed from the
filament can reach a good level of mechanical performance (Table 1).

Towards customized
and unique functional parts
Metylos is a design studio that designs
and produces objects in close collaboration with young designers. Focusing on
local, sustainable manufacture of the
designs, the studio chose to work with

60 jec composites magazine / No99 September 2015

16,75

Fig. 3: Printed lamp base frame

biocomposites. Metylos made use of the
flax/PLA filament to create the base of
the "Flore" wall lamp prototype, designed
by Arnaud de Palange. Hexacorde helped
with the 3D modelling and printing of the
lamp base. This new flax/PLA material
processed by 3D printing offers new potential for creations that would not be possible with other materials, such as wood,
glass or felt. The material's properties also
enable the design of thin, very stiff parts
with a sophisticated look.

Future prospects
Tests are in process to evaluate other
thermoplastic matrices and to integrate

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #99 - September 2015