Transcript Basalt Fibers as new material for technical textiles

Sayed Ibrahim
Faculty at Technical University of Liberec,
Department of Textile Technology
 Ph.D from Technical University of Liberec, Czech
Republic
 Research Interest: Textile Technology and Quality
Control
Topic
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Characterization of Basalt Filaments in
Longitudinal Compression
CHARACTERIZATION OF BASALT
FILAMENTS IN LONGITUDINAL COMPRESSION
Jiří Militký, Vladimír Kovačič, Sayed Ibrahim
Textile Faculty, Technical University of Liberec
461 17 Liberec, Czech Republic
Technical University of Liberec
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(approx. 8000 students)
Faculty of Mechanical
Engineering
Textile Faculty
Faculty of Education
Faculty of Economics
Faculty of Mechatronics
Faculty of Architecture
Technical University of Liberec
Textile Faculty
Staff 120 teachers
1.MSc Studies (technology,
material engineering, clothing)
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800
2.BSc Studies (chemistry,
marketing, design, mechanics,
clothing) 600
3.Part time studies (textile
technology) 60
4. Ph.D. (technology, material
engineering, clothing) 60
Basics of textile engineering
• Fibers are the fundamental and the smallest elements constituting
textile materials. The mechanical functional performance of garments
are very much dependent on the fiber mechanical and surface
properties, which are largely determined by the constituting molecules,
internal structural features and surface morphological characteristics
of individual fibers. Scientific understanding and knowledge of the fiber
properties and modeling the mechanical behavior of fibers are essential
for engineering of clothing and textile products.
Molecular
properties
Fiber
Properties
Yarn
Properties
Fabric
properties
Fiber
Structure
Yarn
Structure
Fabric
Structure
Garment
Structure
• Demands of using textiles in industrial application are very high and
risk should be minimum i.e. precise characterization
OUTLINE
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Basalt rocks
Fibers formation
Basic properties
Compressive creep
Strength statistics
Tempering
Textile structures
Fibrous fragments
Basaltic rocks
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Augite
Basalt is generic name for solidified lava
which poured out the volcanoes
Basalt is 1/3 of earth Crust
Basaltic rocks are melted approximately
in the range 1500 – 1700 C.
When this melt is quickly quenched, it
solidificated
to
glass
like
nearly
amorphous solid.
Slow cooling leads to more or less
complete crystallization, to an assembly
of minerals.
Plagioclase
Olivine
Basalt
composition
Chemical composition:
silicon oxide SiO2 (optimal range 43.3 – 47 %)
Al2 O3 (optimal range 11 – 13 %)
CaO (optimal range 10 – 12 %)
MgO (optimal range 8 – 11 %)
Other oxides are almost always below 5 % level
Essential minerals plagiocene and pyroxene
(augite) make up perhaps 80% of basalts
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Fiber Forming Process
Similar to E-glass forming
Except:
 Only one material, crushed
rock
 No “flux” like boric oxide
added for processing
 Higher melting temperature
 1400 C + vs. 1200 C
 Harder to process, but better
properties
(Silane-based sizing agent is added to facilitate post
processing)
Basalt Furnace
1) Crushed stone Silo, 2)Loading
station, 3) Transport system, 4)batch
charging station, 5) Initial melt zone,
6) Secondary contrlled heat zone, 7)
Filament forming, 8) Sizing applicator,
9) Strand formation, 10) Fiber
tensioning, 11) Winding
Filaments formation
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Classical procedure
Heat transfer from walls
to center
High power (4 kWh/kg)
Long pre heating 8 hours
Spinneret materials
(Platinum, rhodium)
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Microwave heating
Heat transfer from center
to walls
Low power (1 kWh/kg)
Short pre heating 3 hours
Spinneret materials
(ceramics)
Melt after
5 min at
1300oC
Properties of
Basalts
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Basalts are more stable in strong alkalis that
glasses.
Stability in strong acids is low
Basalt products can be used from very low
temperatures (about –200 C) up to the
comparative high temperatures
700 – 800 C.
At higher temperatures the
structural changes occur.
Basalt Glass
Comparison
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standard E-glass fibres
from non-alkali glass
(to 1% alkali),
manufactured at 1550 oC
Manufacturing cost is
between E-glass and Sglass
Sio2 Al2O3 CaO MgO
B2O3
Property
Basalt
E-glass
Diameter[m]
8.63
9 - 13
Density[kgm-3]
2733
2540
Softening temp.
[C]
960
840
Typical composition of basalt fiber vs. E-glass fiber
Chemical components
Basalt Weight
%
E-Glass Weight
%
SiO2 (silica)
58
55
Al2O3 (alumina)
17
15
Fe2O3(ferric oxide)
10
0.3
CaO
8
18
MgO
4
3
Na2O
2.5
0.8
TiO2
1.1
-
K2O
0.8
0.2
B 2 O3
-
7
F
-
0.3
Applications
The basalt-reinforced PP composite meets disposal requirements
without incinerator contamination issues
Samples Preparation
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The marbles and filament roving are
prepared.
From marbles the thick rods were prepared
by grinding.
The roving contained 280 single filaments
are used.
Mean fineness of roving was 45 tex.
Fibers Strength
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The cumulative probability of fracture F(V, )
depends on the tensile stress level and fiber
volume V.
F(V, ) = 1 - exp(- R())
The specific risk function R() for Weibull
distribution (conditional failure function)
R() = [( - A)/B]C
A is lower strength limit, B is scale parameter and
C is shape parameter model (WEI 3)
Shape parameter, location parameter, scale parameter.
Strength distributions
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For brittle materials A = 0 (model WEI 2).
Kies more realistic risk function (model KIES)
R() = [(-A)/(A1-) ]C
Here A1 is upper strength limit.
For brittle materials A = 0 (model KIES2).
Phani (model PHA5)
R() = [(-A)/B1]D/ [(A1-)/B ]C).
Gumbell model (GUM)
R() = exp[(-A)/(B)]
Statistical analysis
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Main aim of the statistical analysis is
specification of R() and parameter
estimation based on the experimental
strengths (i) i=1.....N.
Based on the preliminary computation it
has been determined that for basalt fibers
strength the Weibull distribution is suitable
Testing
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The individual basalt fibers removed from roving
were tested.
The loads at break were measured under standard
conditions at sample length 10 mm
. Load data were transformed to the stresses at
break i [GPa]
Sample of 50 stresses at break
Maximum likelihood
estimation
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When i i=1,...N are independent random
variables with the same probability density
function f() = F’(i, a) the logarithm of
likelihood function has the form
ln L =  ln f((i, a)
The a are parameters of corresponding risk
function.
The MLE estimators a* can be obtained by the
maximization of ln L(a).
Parameter estimates
The
Model
A [GPa]
B [GPa]
C [-]
ln L(a*)
WEI3
0.0641
0.230
1.370
33,50
WEI2
-
0.301
1.829
29.164
differences between three and two parameters
Weibull distribution are identified by the values of
maximum likelihood function ln L(a*).
The three-parameter Weibull distribution was
selected as suitable for glass and tempered basalt
samples as well
Failure mode
Modes of fracture - scanning electron microscopy.
Untreated Basalt
Longitudinal view
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Mechanism of fracture
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Surface is very smooth without
flaws or crazes
Fracture occurs due to
nonhomogenities in fiber volume
(probably near the small
crystallites of minerals)
basalt
glass
Thermal exposition I
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Tempering temperature 50, 100, 200, 300oC was used. Time
of exposition 60 min.
Thermal exposition influence on the ultimate mechanical
properties and dynamic acoustical modulus (DMA) has been
evaluated.
tensile strength [N.tex-1]
deformation to break [%]
dynamic acoustic modulus [Pa] (determined from sound wave
spread velocity in the material)
For 300oC tempering only results statistically significant drop
of strength and dynamic acoustical modulus.
The changes of these properties are based on the changes of
crystalline structure of fibers.
Resonance frequency technique (RFT)
Acoustic Pulse Method (APM)
Sample
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Basalt filament roving tempered at
TT = 20, 50, 100, 200, 300,
400 and 500oC in times tT = 15
and 60 min.
The dependence of the roving
strength on the temperature
exhibits two nearly linear regions.
One at low temperature to the
180oC
with
nearly
constant
strength and one up to the 340oC
with very fast strength drop
Strength
Thermal exposition II
Temperature
The prolongation of tempering leads to high drop of G.
Thermal exposition III
1.Tempered basalt fibers from
lo
25
20
shear modulus [GPa]
roving were tested.
2. The apparatus based on the
torsion pendulum principle
was used.
(fiber of length lo hanged with
pendulum period P and amplitude
A, successive oscillations were
measured, the shear modulus of
circular fiber is calculated)
3. The shear modulus G =11-21
GPa is comparatively high.
15
10
5
0
0
0
60
100
temperature[oC]
250
time[min]
Thermal exposition IV
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Fragility - ratio of critical
loop diameter Dc and fiber
diameter d Fr = Dc / d
critical loop diameter - by
deformation of basalt loop
under microscope to failure
temperature 50, 150, 250,
350oC was evaluated
time of exposition 60 min
In
accordance
with
assumption are fragilities
increasing function of
tempering temperature
the quality or state of being easily broken or destroyed
45
40
35
fragility [-]
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30
25
20
15
10
5
0
50
150
250
temperature [oC]
350
Thermo mechanical
analysis (TMA)
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In TMA the dimensional changes
are measured under defined load
and chosen time
Special device TMA CX 03RA/T
has been used
Sample is placed on the movable
holder (in oven) connected with
displacement sensor, which
measures dimensional changes
DMA
Thermal
expansion

1 h(T )
l 0 T
rate of material expansion as a function of temperature
Dependence of basalt rod height on the
temperature was measured.( heating rate 10
deg min-1 , compressive load 10 mN).
 The coefficients of thermal expansions a for
region below and above Tg
L = Lg + a1*(T - Tg) for T below Tg
L = Lg + a2*(T - Tg) for T above Tg
o
 Parameter estimates: Tg = 596.3 C ,
a1 = 4.9 10-6 deg-1, a2 = 19.1 10-6 deg-1.
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Compressive creep
For the basalt rods and linear composites the
dependence of sample height L on the time t
were measured.
L = Lp + L1 exp (-k1* t) + L2 exp(-k2* t)
Parameters Lp, L1, L2, k1 and k2 estimated by LS
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The maximum dilatation D = L1 + L2
Half time of dilatation t1/2 (it is time for which is
dilatation equal to Lp + (L1+ L2)/2.
Compressive creep
parameters
T
[oC]
D[mm]
t1/2 [s]
D [mm]
t1/2 [s]
30
50
100
250
300
0.003
0.028
0.053
0.035
-
145.1
36.90
29.80
41.10
-
0.015
0.008
0.042
16015
21.30
51.7
maximum dilatation D[mm] = L1 + L2
maximum dilatation D[mm] = L1 + L2
Linear composite (C)
0,06
Basalt rod (R)
Linear composite (C)
0,06
0,05
0,05
0,04
0,04
0,03
0,03
0,02
0,02
0,01
0,01
0
Basalt rod (R)
0
30
50
temperature [oC]
100
30
250
300
50
temperature [oC]
100
250
300
Non-isothermal
compressive creep
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The responses of basalt to the compressive loads under
non-isothermal conditions were investigated from creep
type experiments.
The load was 200 mN.
For the basalt rod the dependence of sample height L on
the temperature T (increased linearly with time t )were
measured.
Starting temperature was To = 30 oC and rate of heating
was 10 oC/min. For avoiding the initial
The dilatation di = Lo – L has been recorded
Data Smoothing
The experimental points were smoothed by Reinsch
smoothing spline (parameter s = 1)
deltatation
temperature
Creep model I
From isothermal experiments is deduced that the rate of
creep only is markedly temperature dependent. The rate
of height changes can be expressed by differential
equation
dL
= f(K,L , L ,t)
dt
K is the rate constant
L  is sample height in equilibrium.
Function f(.) is creep rate model.
Creep model II
The classical reaction kinetics the creep rate can be
expressed in the form
dL
=  K* ( L  L )n
dt
where n is constant (order of reaction). For n=1 the simple
exponential model of creep (rate process of first order)
results.
Temperature dependence of the creep rate constant K
E
K = K 0 exp()
RT
Creep model III
In non-isothermal conditions it is assumed that
temperature dependent is rate constant only
d Lt
= K(T) f( L, L )
dt
By the formal integration of this eqn. for exponential type
model (n = 1) the following relation results
L = L  ( Lo  L )* exp( F(t))
Creep model IV
For the case of linear heating during creep is valid
F(t)= G(t)- G( T 0 )
Symbol To denotes initial temperature and G(x) is the
integral
x
K
0
G(x)=
 exp(-E/Rx)dx

0
where  is rate of heating
Approximation of integral
Simple and precise approximation of temperature term
has the form
RT 

)
2  1 - 2(
E
E
RT
E
exp()

 exp(- RT )dT  E 
RT
RT
 1 - 5(
)
E 

The relative error of approximation is for E/RT<7
under 1%.
Parameter estimation
These should be estimated from experimental data. The
nonlinear regression have to be used. More simple is to
use rate equation for first order model combined with
Arrhenius dependence in the linearized form
dL
E
ln( )  ln( L  L)  ln( Ko ) 
dt
R(To   * t )
Application of this equation requires knowledge of L  and
computation of creep rate dL
dt
Creep rate
The rate of creep curve can be derived from
Reinsch smoothing procedure (s=1)
Estimation of activation
parameters
The dependence of
Ko and E are: 0.047727 and -2.2036
dL
ln(
)  ln( L  L )
dt
-3.1
-3.2
-3.3
-3.4
on 1/T (in absolute temperature
scale) was created.
-3.5
-3.6
-3.7
-3.8
-3.9
1
1.5
2
2.5
3
3.5
x 10
-3
From parameters of this fit:
preexponential factor Ko = 0.04772
activation energy of creep E =
2.203 kJ/mol
Creep discussion
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More precisely it will be necessary to use general
order of rate process and investigate n as well
Thermally stimulated creep is successfully used
in the area of polymers.
In non-polymeric solids where compressive creep
is due to rearrangements of molecular clusters and
structural reordering are rate models quite useful.
Longitudinal compressive
modulus
Linear composite (C) from
the phase of Basalt fibers (K)
and epoxy resin matrix (E). a)
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Both phases are deformed
elastically
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The volumetric ratio of Basalt fibers is K.
The simple rule of mixture
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F
b)
E C   K E K  1   K E E
Ec is creep modulus of linear composite E E is creep modulus of
epoxy resin,E K is creep modulus of basalt fibers
M
Modulus estimation
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The K was estimated by the image analysis
value K = 0,9 was obtained.
The modulus EC at individual temperatures
F
EC 
AC  E 30 
F = 200 mN is load, AK = 20.725 mm2 is cross sectional area
K(10) is deformation under compressive creep in time t = 10 s.
By the same way the modulus EE was estimated from the
compressive creep curve of pure epoxy resin
Longitudinal Compressive Modulus E[Gpa]
Estimated
moduli
120
100
80
60
EE (Resin) [GPa]
40
EK (Basalt) [GPa]
20
EC(Composite) [GPa]
0
25
50
100
200
temperature [oC]
T
[oC]
EK
(Basalt)
[GPa]
EC(Composite)
[GPa]
EE (Resin) [GPa]
25
112.27
105.41
40.5129
50
95.256
87.49
17.5076
100
114.084
108.575
58.9869
200
99.76
90.95
11.6239
Textile structures
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The basalt filament yarns were prepared with
fineness 40x2x3.
Knits and sewing thread were created.
Utilization of basalt for preparation of knitted
fabric was without problems
During sewing tests the basalt yarns were
frequently broken due to its brittleness.
The composite basalt thread coated by PET was
prepared.
Sewing threads properties
Property
fineness [tex]
yarn twist 1[m-1]
yarn twist 2[m -1]
yarn twist 3 [m-1]
break strength [N.tex-1]
Break deformation [%]
abrasion resistance[cycle]
Basalt/PET
283.3 ± 1.6
208 ± 7.4
400 ± 9.8
180 ± 5.6
0.34
2.3 ± 0.2
180 ± 49.8
breaks at sewing test
0
Emitted particles
analysis
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Some characteristics of the basalt fibers are
similar to the asbestos.
Since the mechanisms for asbestos
carcinogenicity are not fully known it cannot
be excluded that basalt fibers may also be
hazardous to health.
Thus there is a need for analysis of fibrous
fragment characteristics in production and
handling in order to control their emission.
Fragmentation
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The weave from basalt filaments was used.
The fragmentation was realized by the abrasion
on the propeller type abrader.
Time of abrasion was 60 second.
It was proved by microscopic analysis that basalt
fibers are not split and the fragments have the
cylindrical shape.
Analysis
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Fiber fragments were analyzed by the image
analysis, system LUCIA M.
The fragments shorter that 1000 m were
analyzed.
Results were lengths Li of fiber fragments.
For comparison the diameters Di of fiber
fragments were measured as well.
Fragments length
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Basic statistical characteristics fiber fragments
lengths are
mean value LM = 230.51 m
standard deviation L = 142.46 m
skewness g1 = 0.969
kurtosis g2 = 3.97
These parameters show that the distribution of
fiber fragments is unimodal and positively
skewed.
Fragments diameter
Basic statistical characteristics of fragments
diameters are:
mean value DM = 11.08 m
standard deviation L = 2.12 m
skewness g1= 0.641
kurtosis g2= 2.92
Because the mean value of fiber fragment diameter
is the same as diameter of fibers no splitting of
fibers during fracture occurs.
Fragmentation conclusion
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It is known, that from point of view of cancer
hazard the length/diameter ratio R is very
important.
For basalt fiber fragments is ratio
R = 230.51/11.08 = 20.8.
Despite of fact that basalt particle are too
thick to be respirable the handling of basalt
fibers must be carried out with care.
Thank you
for your attention . . . .