MECHANICAL PROPERTIES OF UHMWPE WOVEN FABRIC/EPOXY COMPOSITES

Transcription

1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 12, December 18, pp , Article ID: IJMET_9_12_17 Available online at aeme.com/ijmet/issues.asp?jtype=ijmet&vtype= =9&IType=12 ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed MECHANICAL PROPERTIES OF UHMWPE WOVEN FABRIC/EPOXY COMPOSITES P.RajendraPrasad Research Scholar, School of Mechanical Engineering, Reva University, Bangalore, INDIA; Assistant Professor, Department of Mechanical Engineering, G.Pulla Reddy Engineering College, Kurnool, INDIA J.N.Prakash Research Supervisor, School of Mechanical Engineering, Reva University, Bangalore, INDIA L.H.Manjunath School of Mechanical Engineering, Reva University, Bangalore, INDIA ABSTRACT Woven fabric reinforced composites or textile composites are more progressively used in wide variety of industries such as aerospace, marine construction, automotive, and sports due to their unique advantages over conventional materials such as metals and ceramics. Predominantly the Ultra high molecular weight polyethylene (UHMWPE) fiber/woven fabric composites comprise highest strength to weight ratio, and outstanding features like environmental resistance and long life. In this article mechanical properties like Tensile, Flexural and Impact Strengths of Ultra-high molecular weight polyethylene plane woven fabric/epoxy composites were investigated as per ASTM standards. For synthesis of these composites Hand lay-up technique was adopted and commercially available plain woven fabric/ /mat of different areal densities like gsm and 2 gsm were used. To probe the bonding between the reinforcement and matrix, Scanning Electron Microscopy (SEM) analysis is also carried out. Areal density of 2 gsm woven fabric composite laminates possessed high mechanical properties when compared to gsm woven fabric composite laminates. Keywords: Woven fabric, Textile Composites, UHMWPE, ASTM, and Hand lay-up. Cite this Article: P.RajendraPrasad, J.N.Prakash and L.H.Manjunath, Mechanical Properties of UHMWPE Woven Fabric/Epoxy Composites, International Journal of Mechanical Engineering and Technology, 9(12), 18, pp et/issues.asp?jtype=ijmet&vtype=9&itype e=12 IJMET/index.asp 17 editor@iaeme.com

2 P.RajendraPrasad, J.N.Prakash and L.H.Manjunath 1. INTRODUCTION From decades the traditional metals or materials have been replaced with Polymer matrix composites (PMC) because of ease of processing, productivity, and cost reduction. Due to their magnificent formability, low specific mass, high stiffness to weight and high strength to weight ratios the fiber-reinforced polymer (FRP) [1, 2] composites are utilized in numerous fields of engineering structures, ship superstructures, marine, auto mobile, machine parts, and the modern aerospace industries. Fiber-reinforced polymer (FRP) composites are made of thermosetting or thermoplastic resins [11], with fiber or fabric reinforcement [2]. The fiber or fabric provides a load-bearing effect while the resin contributes to transfer of loads to the fiber. Resins also protect the fibers from environmental factors such as humidity, high temperature, and chemical attack [2]. The FRP composites possess desired Mechanical properties like Tensile, Flexural, and Impact strengths, these Mechanical properties of a FRP composites depend on the properties of the fiber and matrix constituents, as well as the interface between the fiber and matrix [3]. The Thermosets (epoxies & phenolics) and Thermoplastics are used as matrix, and Fiber glasses, Carbon fiber, Kevlar (Aramid) fiber, and Ultra-high molecular weight polyethylene (UHMWPE) fiber are used as reinforcement. The UHMWPE fiber or high modulus fiber considered as third generation high-performance fiber [4-8] after Kevlar and carbon fiber. Ultra-high molecular weight polyethylene (UHMWPE) fibers hold remarkable Physical and Mechanical properties such as low weight density, high modulus, high stiffness and strength [12], high cut and abrasion proof, good UV resistance, and non-chemical reactive [9]. Due to these exceptional properties the UHMWPE fiber reinforced composites are extensively used in aerospace, automobile [1], and sports utilities industries [12]. Krishnudu et al. [13, 14] investigated on the mechanical properties of natural fiber hybrid composites and mentioned its applicability based on their obtained strengths. Ultra high molecular weight polyethylene (UHMWPE) woven fabric reinforced composite laminates or textile composites are more progressively used in defense industries and marine construction. These woven fabric reinforced polymer (WFRP) composites would be better replacement of conventional materials such as metals and ceramics. Predominantly the Ultra high molecular weight polyethylene (UHMWPE) fiber/woven fabric composites comprise highest strength to weight ratio, and outstanding features like environmental resistance and long life. In this paper, commercially available Ultra-high molecular weight polyethylene (UHMWPE) or high-performance polyethylene (HPPE) plain woven fabric of gsm and 2 gsm areal densities are used as a reinforcement as it supplied, and epoxy resin (L-12) as a matrix material. The UHMWPE woven fabric composites were produced by adopting hand lay-up technique at room temperature. The failure behavior of mechanical properties like Tensile strength, Flexural strength, and Impact strength were investigated and comparisons made between two different areal density composites. The Scanning electron microscopy test conducted for spotting the intimacy between fabric and matrix material. IJMET/index.asp 171 editor@iaeme.com

3 Mechanical Properties of UHMWPE Woven Fabric/Epoxy Composites 2. EXPERIMENTAL 2.2. Materials Ultra-high molecular weight polyethylene (UHMWPE) plain woven 2D fabric of gsm and 2 gsm areal densities are used as reinforcement material supplied by Huaheng High Performance Fiber Textile Co. Ltd (China), the details of fabrics given in table 1. The reinforcement is strengthened by epoxy resin (LAPOX L-12) of medium viscosity and a room temperature curing polyamine hardener (K-6) both are supplied by ATUL Limited, Gujarat, India. The properties of epoxy resin are given in table 2. Table 1 Details of Fiber Table 2 Properties of Epoxy resin and Hardener Parameter UHMWPE Fabric Areal density (gsm) 2 Weave Plain Plain Fiber count (cm) 15.5X12 1X9 Yarn denier D 1D Thickness (mm) Description Appearance Density at 25 ºC (g/cm3) Viscosity (mpa.s at 25ºC) Epoxy Equi. Wt (g/eq) Epoxy (L-12) Clear viscous liquid Typical values Hardener (K-6) Pale yellow liquid Fabrication of composites The Ultra-high molecular weight polyethylene (UHMWPE) woven fabric/epoxy laminates were prepared in Hand lay-up technique, because Epoxy resin can be processed in hand layup for best results. The UHMWPE fabric/epoxy composite laminates were made-up in three different modules by varying number of layers of woven fabric from 1 to 3. The epoxy resin and hardener were mixed in the ratio of 1:12 by weight. After 24 hours of curing at normal temperature and pressure, the composite panels removed from mould. The laminate so prepared has a size 1 mm X 1 mm X 3mm Mechanical Testing Tensile Test According to ASTM International standard ASTMD [12] tensile test specimens prepared from the cured UHMWPE fabric/epoxy laminates. The tensile tests were conducted on INSTRON 3369 Universal testing machine at constant cross head speed of 1mm/min. The Tensile tests were conducted on three specimens each of different fabric layer composites and the average values were considered Flexural Test The three-point bending flexural tests were conducted to determine the flexural strength of the composites. The test specimens were prepared according to ASTM International standard ASTMD [12]. On INSTRON 3369 Universal Testing Machine specimens were tested at a constant cross head speed of 1mm/min. The flexural tests were conducted on three IJMET/index.asp 172 editor@iaeme.com

4 P.RajendraPrasad, J.N.Prakash and L.H.Manjunath specimens each of UHMWPE fabric/epoxy composite laminate and an average values ware considered Impact Test Impact test specimens were prepared as per ASTM International standard ASTMD [12]. The strength of the composite was recorded on Impact tester supplied by M/s PSI sales (P) Ltd., New Delhi. In each case three samples are tested and the average value is recorded. 3. RESULTS AND DISCUSSIONS 3.1. Tensile properties The UHMWPE fabric/epoxy composite laminate tensile test specimens of gsm and 2gsm with 1, 2, and 3-layer fabric reinforcement were performed. Table 3 shows the results maximum tensile load and maximum tensile strength of gsm and 2gsm of 1, 2, and 3-layer composite laminates. 11% and 34% of tensile strength were increased in 2 gsm of 1-layer and 3-layer composite laminates, but there is no such drastic increase observed in 2 gsm 2-layer composite laminate over gsm 2-layer composite laminate, because tensile strength in 2 gsm 2-layer composite laminate nearly equal to gsm 2-layer composite laminate. The tensile stress-strain curves were collected using Instron 3369 Universal testing machine, to assist the research analysis the data converted into stress-strain curves. Figure 1 to 3 shows the stress-strain curves of two different areal densities 1, 2, 3- layer composite laminates Flexural properties The Flexural rest results are shown in Table 4, the flexural strength of the plain woven UHMWPE fabric/epoxy composite laminates of gsm and 2 gsm. The three-point bending flexural testing were carried out for all the specimens of 1, 2, 3-layer composite laminates of two different areal density composite laminates. The 1-layer and 2-layer composite laminates of 2 gsm shows better flexural strength by 26% and 56% over gsm composite laminates. But the single layer 2 gsm composite laminate shows increment of 24% as compared to gsm composite laminate. The flexural strength results of gsm and 2 gsm were plotted and compared, clearly shown in figure 4. Flexural strength (MPa) gsm 2 gsm 1-layer 2-layers 3-layers Number of layers Figure 4 Flexural strength of composite laminates Impact Strength (KJ/m 2 ) gsm 2 gsm 1-layer 2-layers 3-layers Number of layers Figure 5 Impact strength of composite laminates IJMET/index.asp 173 editor@iaeme.com

5 Mechanical Properties of UHMWPE Woven Fabric/Epoxy Composites 3.3. Impact strength The variation of Impact strength of different layer woven fabrics of areal densities gsm and 2 gsm are shown in figure 5. The clear progressive enhancement of Impact strengths in both 1, 2, 3-layer gsm and 2 gsm areal density fabrics reinforced composites from the results shown in Table 4. Comparisons made between gsm and 2 gsm composite laminates, the 1-layer, 2-layer, and 3-layer fabric reinforced 2 gsm composites Impact strength 5%, 54%, and 53% more than gsm areal density woven fabric composite laminates. Table 3 Tensile properties Specimen label Maximum Tensile load (N) gsm 1-layer gsm 2-layer gsm 3-layer gsm 1-layer gsm 2-layer gsm 3-layer Maximum Tensile Strength (MPa) Tensile stress (MPa) gsm_1-layer 2 gsm_1-layer Tensile strain (mm/mm) Figure 1 Stress-Strain curve of 1-layer composite 7 gsm_2-layer 2gsm_2-layer 1 gsm_3-layer 2gsm_3-layer Tensile stress (MPa) Tensile stress (Mpa) Tensile strain (mm/mm) Tensile strain (mm/mm) Figure 2 Stress-Strain curve of 2-layer composite Figure 3 Stress-Strain curve of 3-layer composite IJMET/index.asp 174 editor@iaeme.com

6 P.RajendraPrasad, J.N.Prakash and L.H.Manjunath Table 4 Flexural and Impact test results Flexural test Impact test Specimen label Max. Load (KN) Maximum Stress (MPa) Flex. Modulus (MPa) Impact Energy(J) Impact Strength(KJ/m 2 ) gsm 1-layer gsm 2-layer gsm 3-layer gsm 1-layer gsm 2-layer gsm 3-layer SCANNING ELECTRON MICROSCOPY The Scanning electron microscopy images of plain woven gsm and 2 gsm areal density UHMWPE fabric/ Epoxy resin composite laminates reveals the bonding between the epoxy resin and the ultra high-molecular weight polyethylene fabric reinforced epoxy composites. Figures 6 to 8 SEM images of composite laminates show clearly the effective bonding between epoxy resin and plain woven fabric along weft and warp. The SEM image figure 7 clearly shows the even distribution of epoxy resin over the plain woven UHMWPE fabric. Figure 6 fabric weft and warp in composite laminate Figure 7 epoxy resin distribution over UHMWPE fabric IJMET/index.asp 175 editor@iaeme.com

7 Mechanical Properties of UHMWPE Woven Fabric/Epoxy Composites Figure 8 Intimacy between matrix and reinforcement 5. CONCLUSIONS The following conclusions can be drawn from this study. There is a gradual increase in Tensile strength by increasing fabric layers of gsm and 2 gsm areal densities in UHMWPE woven fabric/epoxy composite laminates. The UHMWPE plain woven fabric of 2 gsm areal density 3-layer composite laminate accepted maximum tensile load of 3.4 KN and MPa maximum tensile strength produced. From the results assessment between the two areal densities of woven fabric reinforced composite laminates was made, 1, 2, 3-layer composite laminates of 2 gsm execute better load bearing capacity and Tensile strengths. So for greater loads the 2 gsm woven fabric composite laminate is comfortable as compared to gsm woven fabric composite laminates. The progressive increment of flexural strength in both gsm and 2 gsm areal densities UHMWPE plain woven fabric reinforced polymer matrix composites were noticed. The maximum Flexural strength of MPa at maximum load.33 KN produced in 3-layer 2 gsm composite laminate. From the results reason behind variation of strengths between 1-layer gsm and 2 gsm, 2-layer gsm and 2 gsm, and 3-layer gsm and 2 gsm is the intimacy between reinforcement of fabric and matrix material epoxy resin. 2 gsm fabric has greater potential to hold matrix material due to surface roughness of fabric and the gaps between weft and warp fibers. Similar to Tensile and Flexural test results the Impact strength of 2 gsm fabric is more than gsm fabric. The maximum Impact strength of KJ/m 2 produced in 3-layer 2 gsm composite laminate. Scanning electron microscopy reveals remarkable bonding between fiber and epoxy resin in both gsm and 2 gsm composite laminates. Exceptionally epoxy resin distribution over 2 gsm composite laminates is more and made it to produce better mechanical properties. IJMET/index.asp 176 editor@iaeme.com

8 P.RajendraPrasad, J.N.Prakash and L.H.Manjunath REFERENCE [1] Lin, S. P., Han, J. L., Yeh, J. T., Chang, F. C., & Hsieh, K. H. (7). Surface modification and physical properties of various UHMWPE-fiber-reinforced modified epoxy composites. Journal of Applied Polymer Science, 14(1), doi:1.12/app [2] Kang, Y., Oh, S., & Park, J. S. (15). Properties of UHMWPE fabric reinforced epoxy composite prepared by vacuum-assisted resin transfer molding. Fibers and Polymers, 16(6), Doi: 1.17/s [3] Jana, S., Hinderliter, B. R., & Zhong, W. H. (8). Analytical study of tensile behaviors of UHMWPE/nano-epoxy bundle composites. Journal of Materials Science, 43(12), doi:1.17/s [4] Li, C., Jia, J., Wang, G., Zhang, R., & Li, X. (16). A study on the tensile properties of UHMWPE fiber weft-knitted structural composites. Journal of Reinforced Plastics and Composites, 36(6), doi:1.1177/ [5] Amanda L, Aaron M, Joannie W, et al. Long-term stability of UHMWPE fibers. Polym Degrad Stab 15; 114: [6] Xia L, Xi P and Cheng B. A comparative study of UHMWPE fibers prepared by flashspinning and gel-spinning. Mater Lett 15; 147: [7] You X and Hu P. Structure of high strength organic synthetic fibers. J Textile Res 1; 65: [8] Zhang Y, Wang Y, Huang Y, et al. Preparation and properties of three-dimensional braided UHMWPE fiber reinforced PMMA composites. J Reinf Plastics Compos 6; 25: 11 1 [9] Jian, Y., & Ming, L. (18). Improving the interfacial strength of PMMA resin composites by chemically grafting graphene oxide on UHMWPE fiber. Composite Interfaces, 25(11), doi:1.18/ [1] Mohammadalipour, M., Masoomi, M., Ahmadi, M., & Kazemi, Z. (18). The effect of simultaneous fiber surface treatment and matrix modification on mechanical properties of unidirectional ultra-high molecular weight polyethylene fiber/epoxy/nanoclay nanocomposites. Journal of Composite Materials, 52(21), doi:1.1177/ [11] Ku, H., Wang, H., Pattarachaiyakoop, N., & Trada, M. (11). A review on the tensile properties of natural fiber reinforced polymer composites. Composites Part B: Engineering, 42(4), [12] P.Rajendra Prasad, J.N.Prakash, & L.H.Manjunath.(18). MECHANICAL CHARACTERIZATION OF EPOXY/POLYETHYLENE FIBER-REINFORCED COMPOSITES. International Journal of Mechanical and Production Engineering Research and Development (IJMPERD), 8(8), [13] Krishnudu, D. M., Sreeramulu, D., & Reddy, P. V. (18, April). Optimization the mechanical properties of coir-luffa cylindrica filled hybrid composites by using Taguchi method. In AIP Conference Proceedings (Vol. 1952, No. 1, p. 58). AIP Publishing. [14] Krishnudu, D. M., Sreeramulu, D., Reddy, P. V., & Rao, H. R. (18). Effect of Alkali Treatment on Mechanical Properties of Prosopis Juliflora Hybrid Composites. International Journal of Applied Engineering Research, 13(5), IJMET/index.asp 177 editor@iaeme.com