Issue 05/2023

Cellulose nano fibres –
a smooth additive
The next big event, the FAKUMA (Friedrichshafen,
Germany) is just around the corner and Asahi Kasei
(Tokyo, Japan) will present, among other things, their
cellulose nano fibre (CNF). Renewable Carbon Plastics talked
to Tomofumi Maekawa, General Manager XRP Development
Project at Asahi Kasei’s Sustainable Polymers Laboratory,
about the material. “The material is derived from cotton linter,
a by-product of the cotton yield, which is usually considered
as a waste material. We only use cotton linter which is already
GRS-certified or in the process of acquiring the certification”,
said Maekawa. “CNF is generated from fibrillated pulp.
Going down to the nanoscopic scale makes our fibre boast
high strength and elasticity, in addition to its lightweight”.
One field of application is to replace glass fibre, as the
material shows a reinforcing effect when used in small
amounts while being lighter than glass fibre. “Naturally,
we aim for glass fibre replacement in plastic compounds.
Since our CNF is a very soft material, it is suitable for sliding
part applications as a filler that does not damage the mating
material. It also shows less material degradation in the
recycling process than glass fibres, which is another added
value”, comments Maekawa. “There is a broad range of
possible applications. One is, for example, in gears and other
moving parts, which can benefit from CNF’s outstanding
sliding properties. Due to its thixotropic behaviour, it also
features a unique viscosity, making it suitable for 3D printing
applications. Compared to other additives, CNF contributes
to a smoother surface appearance after the printing process”.
In Table 1 you can see some of the technical data for
CNF when used with PA6. The table shows reinforced PA6
with 10 % CNF content, as well as reinforced PA6 with
15 % GF content. PA6/CNF10 % shows a high stiffness and
low specific gravity. Compared to PA6/GF15 % the specific
flexural modulus is 7 % higher.
Tensile modulus retention rate / %
Another potentially added value is its biodegradability,
which makes it a great additive for biodegradable applications.
The biodegradability is not certified yet, but Asahi Kasei is
currently considering the certification of their CNF material.
“CNF is a great material, not only does it offer a broader
range of outstanding properties, compared to standard filler
materials, but it also shows a superior recyclability with less
material degradation”, Maekawa concludes.
You can find Asahi Kasei at booth 5319, in Hall B5 during
the Fakuma 2023 (from 17 to 21 October). AT
120
100
www.asahi-kasei.com
80
60
40
20
0
Properties of 100% recycled material
★Tensile modulus retention rate of PA6/CNF10%
materials after 5 times 100% recycle is 92%.
PA/GF15%
Tensile modulus retention after using
100 % regrind (5 cycles).
PA/CNF10%
0 1 2 3 4 5
Times of using 100% regrind
Fibres / Textiles
Items Method Condition unit PA6_CNF10% PA6_GF15%
Specific gravity (ρ) ISO 1183 23°C ― g/cm 3 1.16 1.25
Equilibrium water
absorption
ISO 1110
similar
Table 1: PA/CNF10 % Datasheet. Current development data may change without
notification. The data stated are measured values, not guaranteed values.
23°C / 50%RH % 2.6 2.4
Tensile Strength (TS) ISO 527 23°C
DRY
95 110
MPa
WET 63
70
Tensile Modulus (TM) ISO 527 23°C DRY MPa 5,800 5,300
Tensile Elongation (TE) ISO 527 23°C
DRY
3 3
%
WET 15 15
Flexural Strength (FS) ISO 178 23°C
DRY
135 190
MPa
WET 60 100
Flexural Modulus (FM)
ISO 178 23°C DRY
5,000 5,000
MPa
ISO 178 23°C WET 2,500 2,800
ISO 178 80°C DRY MPa 1,700 1,950
Specific Flexural Modulus ( 3 √FM/ρ) 23°C DRY MPa 14.7 13.7
Molding Condition: Compliant with ISO 294
Test piece: ISO 20753 type A1
Mold temp.=80
WET condition : 23°C, 50%RH
bioplastics MAGAZINE | Renewable Carbon Plastics [05/23] Vol. 18
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