Effects of Processing Parameters on Constant-Rate Puncture
Resistance Behaviors of Compound Fabrics
Ching-Wen Lou1, Ting-Ting Li2, b, Jan-Yi Lin3, Mei-Chen Lin3 and Jia-Horng
Lin3, 4, 5, a
1
Institute of Biomedical Engineering and Material Science, Central Taiwan University of Science
and Technology, Taichung 406, Taiwan.
2
School of Textiles, Tianjin Polytechnic University, Tianjin 300387, China.
3
Laboratory of Fiber Application and Manufacturing, Department of Fiber and Composite Materials,
Feng Chia University, Taichung City 407, Taiwan.
4
School of Chinese Medicine, China Medical University, Taichung 40402, Taiwan.
5
Department of Biotechnology, Asia University, Taichung 41354, Taiwan.
Corresponding email: ajhlin@fcu.edu.tw, blitingting_85@163.com
Keywords: Compound fabric, Kevlar fiber, puncture resistance, thermal bonding.
Abstract. The effect of Kevlar fibers amount, number of layers, thermal bonding and fabric type on
constant-rate puncture resistance of low-cost compound fabrics are discussed. Therein, compound
fabrics were prepared by nonwovens and woven fabric via needle-punching and thermal-bonding
processes. The result shows that, Kevlar fibers amount and number of layers are both positive to
improvement of puncture resistance. And thermal bonding process increases the wearer safety of
puncture-resistance materials. For different kinds of fabrics, compound Kevlar fabric shows the
maximum puncture resistance.
Introduction
As human people become conscious to individual protection, development of puncture-resistance
protective materials are aroused much attention. Nowadays, the armor only to resist
puncture-resistance is rarely used. And in commercial, current puncture-resistance armor has also
bullet resisting function [1]. Thus it is expensive to be used for puncture resistance, and limited in
use of police, army fields. Nevertheless, these materials are also necessary to be applied for
motorcycle racing driver, taxi driver, and instruments packaging [2]. In view of these, the cost of
puncture resistance material needs to be reduced. To reduce cost, some researchers have
impregnated thermoplastic films on aramid fabrics [3, 4, 5]. But puncture-resistance materials made
by this method are inflexible and uncomfortable to wearers. In this paper, we will only use textile
technology to prepare a flexible puncture-resisting material based on nonwoven and
needle-punching technique. Meanwhile, different kinds of fabrics after being compounded with
nonwovens were discussed comparatively in relation with puncture resistance property.
Experimental
Compound Fabric Preparation. Recycled Kevlar fibers (50-60 mm length, provided by
DuPont Company, America), 6D high-strength Nylon 6 staple fibers (supplied by Taiwan
Chemical Fiber Co. Ltd., Taiwan), and 4D low-Tm polyester fibers (supplied by Huvis Corporation,
South Korea) were used to make high-modulus nonwovens through opening, blending, carding,
lapping and needle-punching (at 100 needles/cm2) processes. The Kevlar fiber was varied from 0
wt%, 10 wt%, 15 wt% and 20 wt%, while the proportion of the low-Tm polyester fibers was
constant as 30 wt%. After that, one layer of woven fabric was inserted between double layers of
high-modulus nonwovens via needle-punching density, forming compound glass fabrics. Therein,
woven fabrics were chosen as glass fabric, Kevlar fabric, and carbon fabric, whose specifications
were shown in Table 1. After that, compound fabrics were hot-pressed by Twin-Roller calendaring
at 160℃ in velocity of 0.5 m/min, intended to form thermo-bonded fabric. The distance between
upper and lower roller was constant as 1.5 mm. Comparatively, the compound fabric before thermal
bonding was considered as the control group to discuss thermal-bonding effect influencing on
puncture behavior.
Constant-rate puncture test. The constant-rate puncture test, also called as static puncture test,
was conducted by Instron 5566 (Instron, America) at constant rate of 508 mm/min according to
ASTM 1342-05 [6]. The dimensions of testing probe head has chosen Probe A as specified in
ASTM standard. During testing, puncture displacement-force curve was displayed, and the
maximum puncture force was found. To ignore the thickness and weight on puncture resistance, the
puncture resistance was characterized with maximum puncture force divided by volume density, in
expression of N/(g/cm3).In this test, six specimens were duplicatedly tested in each group.
Table 1. The structural parameters of three fabrics.
Area
Fabric
Fineness
Density
Thickness
Weight
Glass fabric
1100 D
328 g/m2
34 × 26/inch
0.31 mm
Kevlar Fabric
1500D
227 g/m2
17×17/ inch
0.32 mm
Carbon fabric
12 K
390 g/m2
6×6/inch
0.60 mm
Results and Discussions
Influence of recycled Kevlar fibers on static puncture resistance
Figure 1. Static puncture resistance per unit volume density of compound glass fabrics as related to
different weight fractions of recycled Kevlar fibers contained in the surface nonwoven.
Figure 1 shows the static puncture resistance of compound glass fabrics whose surface
nonwovens have different fractions of recycled Kevlar fibers. Apparently, the static puncture
resistance per volume density improves from 0 wt% to 20 wt% of Kevlar fibers. This reflects the
positive effect of cut-resistance Kevlar fibers. When more Kevlar staple fibers contact with the
puncture probe, the more cut-resistance from Kevlar fibers would resist against more puncture
energy. Abnormally, the static puncture resistance mains constant between the 10 wt% and 15 wt%
Kevlar fibers that contained in nonwovens. This is due to the fact the smaller addition of Kevlar
amount compromises to Kevlar fibers non-uniform distribution.
Influence of number of layers on static puncture resistance
It is displayed in Figure 2 that as the number of compound glass fabrics increases, the static
puncture resistance improves steadily. Initially, when adding from one layer to two layers, static
puncture resistance is increased by more than two times. This is because the interfacial shear
strength and friction strength both provide the additional static puncture resistance. Moreover, while
from two layers to five layers, the static puncture resistance per volume density rises proportionally.
This increase is due to adding thickness, thus the friction between probe and compound fabric in the
process of penetrating through the compound fabrics promotes linearly.
Static Puncture Resistamce
(N/(g/cm3))
Figure 2. Static puncture resistance of compound glass fabrics comprised of 20 wt% Kevlar fibers
on surface as related to number of layers.
Influence of heat bonding on static puncture resistance
It is shown from Figure 3 that the heat bonding shows negative effect on puncture resistance.
Clearly, the hot-pressed compound fabric shows lower puncture resistance regardless of fabric type.
We also observed that the compound fabric after being thermo-bonded produce small puncture
damage region after puncture test. That means that thermal bonding effect would minish the trauma
depth to wearer. Furthermore, the hot-pressed compound fabrics have stable resistance to puncture
damage. This results from the smaller interspace contained in compound fabric as compared to
un-hot-pressed specimens, and thus bigger pushing forces occur to resist against the puncture.
1400
1200
1000
800
Hot-press
600
non-hot-press
400
200
0
5G
5K
5C
Figure 3. Comparative static puncture resistance per volume density of 5-layer compound glass
fabric, Kevlar fabric and carbon fabric after being hot-pressed or un-hot-pressed.
Comparative fabric pattern change on static puncture resistance
In Figure 3, we compare the puncture resistances of different kinds of compound fabrics with
five layers. It is clear that the compound Kevlar fabric posses the maximum puncture resistance,
reaching 948.439 N/(g/cm3) after being hot-pressed, and compound carbon fabric shows the
lowest746.871N/(g/cm3). However, for those un-hot-pressed compound fabrics, the compound
fabric consisting of nonwovens and glass fabric owns the optimum puncture resistance, 1159.55
N/(g/cm3), which reflects the fiber density more significantly influence on the static puncture
behavior. For being thermal-bonding fabric, fabric type and cut resistance performance determined
the puncture performance. Relatively, the high impact-resistance and high cut-resistance fabric
compounded with double layers of nonwovens reveals excellent puncture performance after
constant-rate puncture impact.
Conclusions
This paper systematically analyzes the constant-rate puncture resistance of compound fabrics
comprised of double layers of nonwovens and a fabric via both needle-punching and heat bonding
processes. The Kevlar fiber amount in nonwovens and fabrics type both significantly influence on
the puncture resistance of compound fabrics. Puncture resistance improves linearly with Kevlar
fiber amount, and multiply and then proportionally increases as the layers of compound fabrics add.
Thermal bonding effect would decrease the trauma depth even that negative to the puncture
resistance. Finally, comparing with different kinds of fabrics, Kevlar fabric reinforced with
nonwovens have the optimum puncture resistance at per volume density. According to this study,
we are expected to fabricate low-cost and high-performance puncture-resistance compound fabric
for purpose of civil puncture-resistance protection.
Acknowledgements
This work would especially like to thank National Science Council of the Taiwan, for financially
supporting this research under Contract NSC 101-2621-M-166-001.
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