Issue 05/2015

Fibers & Textiles
By:
Amparo Verdú Solís
Extrusion Department Researcher
AIMPLAS (Technological Institute of Plastics)
Paterna, Spain
PLA has good characteristics, many
of them comparable or even better than
those of conventional plastics derived from
petroleum, which it makes suitable for a
variety of uses. In comparison to PET and
PP, which are the fibres mostly used at the
moment in car interiors, PLA fibre meets
almost all performance specifications of
this application.
The main limitation of conventional PLA
is its thermal resistance; PLA softens at a
temperature of around 52 °C, which limits its
use in applications that require temperature
resistance under pressure and conditions
of environmental and chemical stress. The
interior temperature in modern cars can
easily exceed 80 °C on hot summer days.
Melting temperature (°C)
Modulus (GPa)
260
250
220
200
180
160
140
120
100
80
60
40
20
8
7
6
5
4
3
2
1
0
PCL
PCL
Biopolyester
Biopolyester
PHF
PHF
PLA
PLA
PLA blends
PLA blends
Starch blends
Starch blends
Cellulose
derivatives
Cellulose
derivatives
PE-HD
PE-HD
PP
PP
ABS
ABS
PET
PET
PS
PS
PA 6
PA 6
Project development and results
Throughout the project, different
approaches were followed in the quest to
achieve a material with the desired properties.
Aimplas, with Addcomp and Avanzare
contribution, developed a compound
that is able to fulfill the requirements for
automotive interior applications, including
such aspects as thermal resistance, fogging,
odour emissions, VOCs and antimicrobial
resistance.
The PLA blend formulation and the
processing conditions were key factors
that determined the performance of the
materials, since it has been proven that
crystallization of PLA plays a very important
role in the thermal resistance of this
material. It proved possible to increase the
softening temperature from 57 °C to 102 °C,
without compromising the viscosity of the
material, which could then be processed by
extrusion melt spinning in order to obtain
the fibers.
These fibers were succesfuly converted
into fabrics and non-woven samples in order
to obtain a final prototype of a moulded door
panel. Two non-woven layers and a woven
fabric were combined into a composite
consisting of 100% bio-based material.
www.biofibrocar.aitex.es
www.aimplas.es
Tensile strength (MPa)
Vicat (°C)
90
80
70
60
50
40
30
20
10
0
200
180
160
140
120
100
80
60
40
PCL
PCL
Biopolyester
Biopolyester
PHF
PHF
PLA
PLA
PLA blends
PLA blends
Starch blends
Starch blends
Cellulose
derivatives
Cellulose
derivatives
PE-HD
PE-HD
PP
PP
ABS
ABS
PET
PET
PS
PS
PA 6
PA 6
bioplastics MAGAZINE [05/15] Vol. 10 17