ANALYSIS OF MECHANICAL PROPERTIES OF COM
ANALYSIS OF MECHANICAL PROPERTIES OF COMPOSITES FOR
BALISTIC SCREENS AS A FUNCTION OF PROPERTIES OF FIBROUS
MATERIAL
Sylwia Tarkowska1, Marek Snycerski2, Maria Cybulska2
1
ITWW MORATEX, Lodz, Poland
2
Department of Architecture of Textiles, Faculty of Textile Engineering and Marketing, Technical
University of Lodz, Poland
Abstract
Paper presents analysis of yarns, woven fabrics, prepregs and composites made form aramide fibres. It
has been found that initial very high tenacity of aramide yarns significantly decreases on the successive
stages of technological processing - during weaving, finishing, coating (prepreg) and pressing
(composite). Properties of anti-ballistic screens have been studied in terms of some parameters of the
fibrous material of composite.
Key Words: textiles, mechanical properties, ballistic packets, ballistic screens
1. INTRODUCTION
Aramide yarns, depending on the yarn linear density, are used to produce the woven fabrics
designated for, among others, soft packets of bulletproof jackets, or as a fibrous reinforcement for
preimpregnates used for fibrous composites (laminates) applied for bulletproof shields or screens for
mobile and stable objects. Their usability in this area results from very high strength of aramide fibres,
especially their tensile and compression strength effecting from their specific chemical structure.
When designing the packets or composites for stiff anti-ballistic shields, one needs to take into
account the changes of mechanical properties of fibrous material on particular stages of the processing,
form woven fabric to composite.
Paper presents some basic mechanical properties, as a breaking load and elongation in the
weft and warp direction of woven fabrics, prepregs and composites made from or on the basis of
aramide fibres. Analysed fabrics were woven from yarns of linear density 93, 110, 330 and 350 tex. The
influence of properties of fibrous components on the other mechanical parameters of composites, as
energy to break, bending strength and deflection in the weft and warp direction has been also analysed.
2. MATERIAL AND METHODS
Testing material includes 9 soft packets of woven fabric (number of layers of fabric sewed) and
10 stiff composites with fibrous reinforcement () number of layers of aramide based prepreg composed
by thermal pressing in high temperature under high pressure).
To prepare the fabric packets and the reinforcement of composites three kinds of woven fabrics
have been chosen diversified by thickness, density and crimp of weft and warp. As a matrix the
derivative of benzophenol resin and two gum mixtures were used.
Structure of analysed anti-ballistic products is shown in Table 1.
Table 1. Analysed material
Material
1
2
3
4
5
Fabric packet CT 716
Fabric packet CT 716
Fabric packet CT 716
Fabric packet TXM-300
Fabric packet TXM-300
number of reinforcement/ matrix
layers
20
25
40
20
24
Aramide
Aramide
Aramide
Aramide
Aramide
Aerial mass
of
reinforcement
(g/m2)
construction
5600
7000
11200
6120
7344
sewing
sewing
sewing
sewing
sewing
6
7
8
9
10
11
12
13
14
15
16
17
18
Fabric packet TXM-300
Fabric packet Styl 770S
Fabric packet Styl 770S
Fabric packet Styl 770S
Composite MILAGRO 2001*
Composite INDUTEX 2001*
Composite INDUTEX 2002
Composite INDUTEX 2003
Composite INDUTEX 2003
Composite INDUTEX 2004
Composite INDUTEX2004
Composite INDUTEX2004
Composite AKZO 2001*
40
17
24
40
25
24
24
24
25
20
25
40
17
Aramide
Aramide
Aramide
Aramide
Aramide/rubber 1
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/
benzophenol resin
19 Composite AKZO 2002
18
Aramide/
benzophenol resin
*)reinforcement of composite MILAGRO 2001 - woven fabric CT 716,
fabric TXM-300, composite AKZO- woven fabric Styl 770S.
12240
7905
11160
18600
7000
7344
7344
7344
7650
6120
7650
12240
7950
sewing
sewing
sewing
sewing
gluing 5x5 layers
pressing
pressing
pressing
gluing 5x5 layers
gluing 5x5 layers
gluing 5x5 layers
gluing 5x5 layers
pressing
8370
pressing
composite INDUTEX - woven
3. RESULTS OF ANALYSIS
Relationship between some properties of fibrous component of the composite and the
properties of composite can be easily perceptible. However in some cases it is not that obvious.
Increasing number of layers of fibrous reinforcement not always results in proportional increase of its
strength and stiffness. On the other hand increasing content of fibrous material always effects in
increase of mechanical parameters of the composite.
Tenacity of the packet of woven fabric depends on the fabric aerial mass, which increases with
linear density of the yarn used, warp and weft density and crimp.
For each packet the ballistic efficiency has been determined as a boundary velocity of punchthrough
V50, defined as a velocity for which the probability of piercing has the same value as a probability of not
piercing, equal to 0,5.
Results of shooting with bullet 9 mm PARA FMJ for analysed packets of woven fabric are
shown in Fig.1.
Fig.1. The effect of the aerial mass on the ballistic performance.
When analysing the results presented in Fig.1. one can see that the efficiency of aramide fabric
packet is the linear function of it aerial mass.
For analysed packets the number of layers not penetrated (rear layers) increases linearly with
aerial mass of the screen - see Fig.2.
Fig.2 Number of layer not pierced in the textile packet.
Analysis shows that initial very high tenacity of aramide yarns significantly decreases on the
successive stages of the yarn processing - during weaving, finishing, coating (prepreg) and pressing
(composite). Fig.3. presents the changes of tenacity of the aramide yarn. Comparison concerns the
yarn on the bobbin, in the woven fabric, in prepreg and in the composite.
Fig. 3. The effect of consecutive processing on the strength of aramide composites.
Analysis of the slope of lines in Fig.3. shows the effect of weaving and pressing processes on
the utilised yarn strength. Analysis has shown that after weaving process the yarn tenacity drops about
20 percents, whole after pressing - above 50% and depends on the pressing degree.
Fig.4. The comparison of the tensile strength of textile packets and aramide composites.
In Fig 4 one can see the change of tenacity of fabric packets and aramide composites. When
compare with the composite of the same aerial mass, the tenacity of the fabric packet can be
characterised by much higher tensile strength.
Application of aramide yarns in forming anti-ballistic product effects form their high tensile
strength. That why some decrease of this parameter results in negative reduction of protective efficiency
of the final product. When processing the aramide yarn the attention should be put on minimisation of
the loss in yarn tenacity.
In last few years a progress can be noticed in development of antiballistic composites with
fibrous reinforcement [3]. Fabric packets are often replaced by composite materials, even if the cost of
production of the last ones is much higher.
During pressing under the high pressure further decrease of tenacity of aramide yarn takes
place, what should effect in the reduction of composite ballistic efficiency. However, analysis of the
results presented in Fig.5. shows opposite effect. One can see that when compare with the fabric
packets, most of composites shows much better efficiency determined by boundary punchthrough
velocity V50.
Fig.5. The comparison of ballistic performance of the textile packets and aramide composites of the
same aerial mass.
On the basis of the results obtained the conclusion can be drawn that the decrease of the yarn
tensile strength is compensated by some other factors, what results in higher value of the boundary
velocity V50 for composites. When compare to this for fabric packets. Further analysis has shown that
the density and hardness of surface of composite (defined as the load necessary to ram the steel pin of
8 mm diameter into the tested material for 3 mm depth) is much higher for composites than for
multilayer packets of aramide fabric. (Fig.6).
Fig. 6. The effect of the composite’s density on its ballistic performance.
Rubber mixture and benzophenol resin significantly increase the stiffness and hardness of the
material surface. For this reason in the moment the bullet hits the surface of the material the energy
used for bullet deformation also increases significantly. It means that the most of the bullet energy is
utilised for its deformation.
The effect of surface hardness of ballistic screen on maximum punchthrough velocity V 50 is
shown in Fig. 7.
.
Fig.7. The effect of the composite’s surface hardness on its ballistic performance.
Results obtained can be used when designing the ballistic materials designated personal
safeguard (bulletproof jackets, shields and helmets), vehicle and stable objects armour.
Acknowledgement: Research has been subsidised by KBN grant T00C02522 "Designing the structure
of fibrous composite materials for ballistic screens".
REFERENCES
1. W. Jabłoński, J. Wnuk „Włókna aramidowe bazą produktów innowacyjnych", Bielsko Biała 2000;
2. J. Szosland „Podstawy budowy i technologii tkanin", WN-T Warszawa, 1972;
3. W. Królikowski "Tworzywa wzmocnione i włókna wzmacniające", Politechnika Szczecińska, 1984.
ADITIONAL DATA ABOUT AUTHORS
1. Sylwia Tarkowska Ph.D., assistant professor, Institute of Technical Textiles MORATEX, CurieSkłodowskiej 3/5, 90-547 Łódź POLAND, E-mail: Tarkowska@wp.pl, Phone: +48 42 ; Fax: +4842 .
2. Maria Cybulska Ph.D., assistant professor, Technical University of Lodz, Faculty of Engineering and
Marketing of Textiles, Department of Architecture of Textiles, Żeromskiego 116, PL90-543 Łódź
POLAND, E-mail: Cybulska@wipos.p.lodz.pl, Phone: +4842 631-33-37, Fax: +48 42 631-33-43
3. Marek Snycerski,. Ph.D, D.Sc. assoc. professor, Technical University of Lodz, Faculty of Engineering
and Marketing of Textiles, Department of Architecture of Textiles, Żeromskiego 116, PL90-543 Łódź
POLAND, E-mail: marek121@mail.p.lodz.pl, Phone: +4842 631-33-33, Fax: +48 42 636-32-74.
BALISTIC SCREENS AS A FUNCTION OF PROPERTIES OF FIBROUS
MATERIAL
Sylwia Tarkowska1, Marek Snycerski2, Maria Cybulska2
1
ITWW MORATEX, Lodz, Poland
2
Department of Architecture of Textiles, Faculty of Textile Engineering and Marketing, Technical
University of Lodz, Poland
Abstract
Paper presents analysis of yarns, woven fabrics, prepregs and composites made form aramide fibres. It
has been found that initial very high tenacity of aramide yarns significantly decreases on the successive
stages of technological processing - during weaving, finishing, coating (prepreg) and pressing
(composite). Properties of anti-ballistic screens have been studied in terms of some parameters of the
fibrous material of composite.
Key Words: textiles, mechanical properties, ballistic packets, ballistic screens
1. INTRODUCTION
Aramide yarns, depending on the yarn linear density, are used to produce the woven fabrics
designated for, among others, soft packets of bulletproof jackets, or as a fibrous reinforcement for
preimpregnates used for fibrous composites (laminates) applied for bulletproof shields or screens for
mobile and stable objects. Their usability in this area results from very high strength of aramide fibres,
especially their tensile and compression strength effecting from their specific chemical structure.
When designing the packets or composites for stiff anti-ballistic shields, one needs to take into
account the changes of mechanical properties of fibrous material on particular stages of the processing,
form woven fabric to composite.
Paper presents some basic mechanical properties, as a breaking load and elongation in the
weft and warp direction of woven fabrics, prepregs and composites made from or on the basis of
aramide fibres. Analysed fabrics were woven from yarns of linear density 93, 110, 330 and 350 tex. The
influence of properties of fibrous components on the other mechanical parameters of composites, as
energy to break, bending strength and deflection in the weft and warp direction has been also analysed.
2. MATERIAL AND METHODS
Testing material includes 9 soft packets of woven fabric (number of layers of fabric sewed) and
10 stiff composites with fibrous reinforcement () number of layers of aramide based prepreg composed
by thermal pressing in high temperature under high pressure).
To prepare the fabric packets and the reinforcement of composites three kinds of woven fabrics
have been chosen diversified by thickness, density and crimp of weft and warp. As a matrix the
derivative of benzophenol resin and two gum mixtures were used.
Structure of analysed anti-ballistic products is shown in Table 1.
Table 1. Analysed material
Material
1
2
3
4
5
Fabric packet CT 716
Fabric packet CT 716
Fabric packet CT 716
Fabric packet TXM-300
Fabric packet TXM-300
number of reinforcement/ matrix
layers
20
25
40
20
24
Aramide
Aramide
Aramide
Aramide
Aramide
Aerial mass
of
reinforcement
(g/m2)
construction
5600
7000
11200
6120
7344
sewing
sewing
sewing
sewing
sewing
6
7
8
9
10
11
12
13
14
15
16
17
18
Fabric packet TXM-300
Fabric packet Styl 770S
Fabric packet Styl 770S
Fabric packet Styl 770S
Composite MILAGRO 2001*
Composite INDUTEX 2001*
Composite INDUTEX 2002
Composite INDUTEX 2003
Composite INDUTEX 2003
Composite INDUTEX 2004
Composite INDUTEX2004
Composite INDUTEX2004
Composite AKZO 2001*
40
17
24
40
25
24
24
24
25
20
25
40
17
Aramide
Aramide
Aramide
Aramide
Aramide/rubber 1
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/rubber 2
Aramide/
benzophenol resin
19 Composite AKZO 2002
18
Aramide/
benzophenol resin
*)reinforcement of composite MILAGRO 2001 - woven fabric CT 716,
fabric TXM-300, composite AKZO- woven fabric Styl 770S.
12240
7905
11160
18600
7000
7344
7344
7344
7650
6120
7650
12240
7950
sewing
sewing
sewing
sewing
gluing 5x5 layers
pressing
pressing
pressing
gluing 5x5 layers
gluing 5x5 layers
gluing 5x5 layers
gluing 5x5 layers
pressing
8370
pressing
composite INDUTEX - woven
3. RESULTS OF ANALYSIS
Relationship between some properties of fibrous component of the composite and the
properties of composite can be easily perceptible. However in some cases it is not that obvious.
Increasing number of layers of fibrous reinforcement not always results in proportional increase of its
strength and stiffness. On the other hand increasing content of fibrous material always effects in
increase of mechanical parameters of the composite.
Tenacity of the packet of woven fabric depends on the fabric aerial mass, which increases with
linear density of the yarn used, warp and weft density and crimp.
For each packet the ballistic efficiency has been determined as a boundary velocity of punchthrough
V50, defined as a velocity for which the probability of piercing has the same value as a probability of not
piercing, equal to 0,5.
Results of shooting with bullet 9 mm PARA FMJ for analysed packets of woven fabric are
shown in Fig.1.
Fig.1. The effect of the aerial mass on the ballistic performance.
When analysing the results presented in Fig.1. one can see that the efficiency of aramide fabric
packet is the linear function of it aerial mass.
For analysed packets the number of layers not penetrated (rear layers) increases linearly with
aerial mass of the screen - see Fig.2.
Fig.2 Number of layer not pierced in the textile packet.
Analysis shows that initial very high tenacity of aramide yarns significantly decreases on the
successive stages of the yarn processing - during weaving, finishing, coating (prepreg) and pressing
(composite). Fig.3. presents the changes of tenacity of the aramide yarn. Comparison concerns the
yarn on the bobbin, in the woven fabric, in prepreg and in the composite.
Fig. 3. The effect of consecutive processing on the strength of aramide composites.
Analysis of the slope of lines in Fig.3. shows the effect of weaving and pressing processes on
the utilised yarn strength. Analysis has shown that after weaving process the yarn tenacity drops about
20 percents, whole after pressing - above 50% and depends on the pressing degree.
Fig.4. The comparison of the tensile strength of textile packets and aramide composites.
In Fig 4 one can see the change of tenacity of fabric packets and aramide composites. When
compare with the composite of the same aerial mass, the tenacity of the fabric packet can be
characterised by much higher tensile strength.
Application of aramide yarns in forming anti-ballistic product effects form their high tensile
strength. That why some decrease of this parameter results in negative reduction of protective efficiency
of the final product. When processing the aramide yarn the attention should be put on minimisation of
the loss in yarn tenacity.
In last few years a progress can be noticed in development of antiballistic composites with
fibrous reinforcement [3]. Fabric packets are often replaced by composite materials, even if the cost of
production of the last ones is much higher.
During pressing under the high pressure further decrease of tenacity of aramide yarn takes
place, what should effect in the reduction of composite ballistic efficiency. However, analysis of the
results presented in Fig.5. shows opposite effect. One can see that when compare with the fabric
packets, most of composites shows much better efficiency determined by boundary punchthrough
velocity V50.
Fig.5. The comparison of ballistic performance of the textile packets and aramide composites of the
same aerial mass.
On the basis of the results obtained the conclusion can be drawn that the decrease of the yarn
tensile strength is compensated by some other factors, what results in higher value of the boundary
velocity V50 for composites. When compare to this for fabric packets. Further analysis has shown that
the density and hardness of surface of composite (defined as the load necessary to ram the steel pin of
8 mm diameter into the tested material for 3 mm depth) is much higher for composites than for
multilayer packets of aramide fabric. (Fig.6).
Fig. 6. The effect of the composite’s density on its ballistic performance.
Rubber mixture and benzophenol resin significantly increase the stiffness and hardness of the
material surface. For this reason in the moment the bullet hits the surface of the material the energy
used for bullet deformation also increases significantly. It means that the most of the bullet energy is
utilised for its deformation.
The effect of surface hardness of ballistic screen on maximum punchthrough velocity V 50 is
shown in Fig. 7.
.
Fig.7. The effect of the composite’s surface hardness on its ballistic performance.
Results obtained can be used when designing the ballistic materials designated personal
safeguard (bulletproof jackets, shields and helmets), vehicle and stable objects armour.
Acknowledgement: Research has been subsidised by KBN grant T00C02522 "Designing the structure
of fibrous composite materials for ballistic screens".
REFERENCES
1. W. Jabłoński, J. Wnuk „Włókna aramidowe bazą produktów innowacyjnych", Bielsko Biała 2000;
2. J. Szosland „Podstawy budowy i technologii tkanin", WN-T Warszawa, 1972;
3. W. Królikowski "Tworzywa wzmocnione i włókna wzmacniające", Politechnika Szczecińska, 1984.
ADITIONAL DATA ABOUT AUTHORS
1. Sylwia Tarkowska Ph.D., assistant professor, Institute of Technical Textiles MORATEX, CurieSkłodowskiej 3/5, 90-547 Łódź POLAND, E-mail: Tarkowska@wp.pl, Phone: +48 42 ; Fax: +4842 .
2. Maria Cybulska Ph.D., assistant professor, Technical University of Lodz, Faculty of Engineering and
Marketing of Textiles, Department of Architecture of Textiles, Żeromskiego 116, PL90-543 Łódź
POLAND, E-mail: Cybulska@wipos.p.lodz.pl, Phone: +4842 631-33-37, Fax: +48 42 631-33-43
3. Marek Snycerski,. Ph.D, D.Sc. assoc. professor, Technical University of Lodz, Faculty of Engineering
and Marketing of Textiles, Department of Architecture of Textiles, Żeromskiego 116, PL90-543 Łódź
POLAND, E-mail: marek121@mail.p.lodz.pl, Phone: +4842 631-33-33, Fax: +48 42 636-32-74.