Manufacturing Technique and Property Evaluations of Protective
Textiles
Ching-Wen Lou
1, b, Ting-Ting Li
2, Mei-Chen Lin
3, Jan-Yi Lin
3and
Jia-Horng Lin
3, 4, 5, a1Institute of Biomedical Engineering and Material Science, Central Taiwan University of Science and Technology, Taichung 40601, Taiwan.
2School of Textiles, Tianjin Polytechnic University, Tianjin 300387, China.
3Laboratory of Fiber Application and Manufacturing, Department of Fiber and Composite Materials, Feng Chia University, Taichung City 40724, Taiwan.
4School of Chinese Medicine, China Medical University, Taichung 40402, Taiwan. 5Department of Fashion Design, Asia University, Taichung 241354, Taiwan.
*Corresponding author email: a[email protected], b[email protected]
Keyword: puncture-resistant composites; recycled polyethylene terephthalate (PET) fibers;
thermoplastic polyurethane.
Abstract: Global warming increases each day and causes people to pay more attention to the
reduction of carbon dioxide emission in order to mitigate the increase in temperature. Reducing, reusing, and recycling can effectively reduce the emission of carbon dioxide, to attain goals of energy conservation and carbon reduction. This study aims to explore the difference in the punch resistance and impact strength between the polyethylene terephthalate (PET) nonwoven fabrics and PET/TPU honeycomb grid/PET (P/T/P) composites. Recycle PET, high strength PET, and low melting PET are made into PET nonwoven fabrics, two layers of which are laminated with a TPU honeycomb grid, the interlayer, to form P/T/P composites. The constant rate puncture resistance, dynamic puncture resistance, and impact strength of PET nonwoven fabrics and P/T/P composites are evaluated. The experiment results show that both the constant rate and dynamic puncture resistances of P/T/P composites are lower than those of PET nonwoven fabrics.
Introduction
Protective textiles aim to protect human’s health and safety, and their protection can be divided into chemical, radiation, and physical protection. Radiation protect is for X-ray, UV light, and electromagnetic waves [1-4]; chemical protection is for bacteria, blood, and organic solvent ; and physical protection is for flame, bullets, knives, and pointed objects [1, 5-6]. Polyethylene terephthalate (PET) fiber is one common synthetic fiber, a result of the condensation reaction and polymerization of terephthalic acid and ethylene glycol. PET has good strength and weathering resistance, and thus is commonly made into geotextile and compound nonwoven. This study aims to explore the constant rate puncture resistance, dynamic puncture resistance, and impact strength of
PET nonwoven fabrics and P/T/P composites as well as the influence of the lamination layer numbers of the PET nonwoven fabrics on the mechanical of the P/T/P composites.
Experimental Material
HPET fiber (Far Eastern New Century Corporation, Taiwan, R.O.C.) has a fineness of 6 denier (D) and length of 77 mm. LPET fiber (Far Eastern New Century Corporation, Taiwan, R.O.C.) has a 4 D fineness and 51 mm length. RPET woven selvages (Chien Chen Textile Co. Ltd., Taiwan, R.O.C.) have a fineness of 1000 D/192 f and a length of 60-66 mm. Honeycomb grids (Art & Giant Tech. Corp., Taiwan, R.O.C.) have an open-cell structure with a thickness of 10 mm.
Preparation of P/T/P Composites
RPET fibers are obtained after the removal of hank yarn of the PET selvages. RPET fibers, HPET fibers, and LPET fibers are blended with a ratio of 50:20:30, an optimal ratio yielded from a previous study [12]. The mixture then undergoes opening, mixing, carding, laying and needle-punching series to form PET nonwoven fabrics. With a sandwich structure, a TPU honeycomb grid (the interlayer) is laminated with 1 layer or 3 layers of PET nonwoven fabrics as the top and bottom layers, and then needle punched to form PET/TPU honeycomb grid/PET (hereafter P/T/P) composites. A total of 1 layer or 3 layers of PET nonwoven fabrics are needle punched to serve as the control group.
Tests
Constant Rate Puncture Resistance
Ten samples of each specification have a size of 100 mm×100 mm. An Instron 5566 (US) at a specified speed of 508 mm/min measures the punch resistance of the samples
Dynamic Puncture Resistance
PET nonwoven fabrics and P/T/P composites have a size of 100 mm × 100 mm. Samples are placed between the fixtures with a 60-mm diameter hole in the center. The back end of the drop weight is attached to a load cell, which detects the puncture strength. The distance between the drop weight and samples is 28 cm and the probe drops for the test. The number of samples of each specification is 10.
Impact Strength
PET nonwoven fabrics and P/T/P composites have a size of 100 mm×100 mm. Samples are placed between fixtures with a 60 mm hole in the center. A conical drop weights of 10-mm diameter drops from the height that is 24 cm above the sample at strength of 18000 N. Beneath the samples is a load cell, which detects the strength that through the samples, and the strength the samples absorb is calculated. The number of the samples is 10.
Results and Discussion
Constant Rate Puncture Resistance
ascribed to a high crystallinity of the honeycomb grid and orientation of fibers to resist the puncture of the probe, thus augmenting the puncture resistance of the composites. In addition, with increasing lamination layer number, the puncture resistance of both sample types increases. The increasing lamination layer number increases the constant rate puncture resistance of both sample types. The higher the lamination layer number, the greater the fabric’s density, and the higher the puncture resistance.
Figure 1. Constant rate puncture resistance of the PET nonwovens fabrics and P/T/P composites as related to various lamination layer numbers of the constituent PET nonwoven fabrics.
Dynamic Puncture Resistance
Figure 2 shows that the dynamic puncture resistance of the PET nonwovens fabrics and P/T/P composite fabrics has a similar trend to that of their constant rate puncture resistance, and the explanation of this trend is the same as that for constant rate puncture resistance. The dynamic puncture resistance is lower than constant puncture resistance, which is ascribed to the free fall of the dynamic drop weight. The speed is so high that the friction force between the fibers and drop weight decreases. A lower friction force thus causes a dynamic puncture resistance that is lower than constant rate puncture resistance.
Figure 2. Dynamic puncture resistance of PET nonwoven fabrics and P/T/P composites as related to various lamination layer numbers of the constituent PET nonwoven fabrics.
Impact Strength
Figure 3 shows the impact strength that is collected from dynamic puncture resistance test, and the impact strength of P/T/P composites is greater than that of PET nonwoven fabrics. This is due to the interlayer of P/T/P composites, the TPU honeycomb grid has a high crystallinity and elasticity; thereby increasing the impact strength of the composites.
An increasing lamination layer number provides both PET nonwoven fabrics and P/T/P composites with higher impact strength. The density, weight, and needle-punching density of the nonwoven fabrics increase as a result of an increasing lamination layer number, which can help
both sample types effectively absorb and distribute the impact strength, with a subsequent increase in their impact strength.
Figure 3. Impact strength of PET nonwoven fabrics and P/T/P composites as related to various lamination layer numbers of the constituent PET nonwoven fabrics.
Conclusion
This study successfully creates PET nonwoven fabrics and P/T/P composites. The experiment results shows that the constant rate puncture resistance, dynamic puncture resistance, and impact strength of P/T/P composites are greater than those of PET nonwoven fabrics.
Acknowledgements
This work would especially like to thank National Science Council of the Taiwan, for financially supporting this research under Contract NSC 102-2621-M-166-001.
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