Development and Characterization of Glass Fibre/Wheat Straw Reinforced Epoxy Hybrid Composites

Transcription

1 Development and Characterization of Glass Fibre/Wheat Straw Reinforced Epoxy Hybrid Composites Vishal Rathore Department of Mechanical engineering, Gautam Buddha University, Greater Noida (U.P.) Ruchi Yadav Assistant Professor, Department of Mechanical engineering, ITS Engineering College, Greater Noida (U.P.) Abstract- Burning of crop residue is an old traditonal method done by farmers so as to prepare their fields for sowing which produces harmful gases in atmosphere and also states soil loses. Worldwide, over 5 million tonnes of wheat straw are produced which can be used as an energy source because it posses a great mechanical properties. The objective of this work is to evaluate the mechanical properties of wheat straw reinforced epoxy composite by making this composite hybrid by using glass fibre as another reinforcemnt material. The mechanical properties like tensile strength, impact strength, flexural strength and hardness of composites will be evaluated and examined by varying different weight ratios of fibre (4% wheat straw with % glass fibre, 3% wheat straw with 1% glass fibre, 2% wheat straw with 2% glass fibre and 1% wheat straw with 3% glass) in 6% epoxy resin. Keywords: epoxy resin, hybrid composites, wheat straw, and glass fibre. I. INTRODUCTION Natural fibre polymers have a lot of applications in construction, transportation and packaging sectors. Despite of their relative low cost, light weight, recyclability and environmentally friendliness of composites, they also have some well-known limitations, including poorer mechanical properties when compared to their synthetic, poor water and fire resistance and etc. [1]. Its shows that natural fibres have the potential to replace synthetic fibres in some light construction area. Several bio-based fibres such as agricultural waste have attracted considerable interest. Wheat straw is one of such derived materials with applications in polymer composites [3]. In general, the term natural fibre is used to designate materials (used as fibre or filler in composites) that are derived from plant tissue containing cellulose fibres on the cell wall. Wheat is the most primarily food in India. So, a large quantity of wheat straw is produced, which is relatively modest agricultural by-product and is used for animal bedding and animal food. According to Combine Culinary technologies, India produces a huge amount of straw as a waste which ultimately is burned. It has been observed that, the burning of straw harm the atmosphere which produces harmful gases in the atmosphere such as N 2O, CO 2, NO x, CH 4, NMHCs and aerosols. India in the year 2, burning of wheat straw from rice produces CH 4, CO, N 2O and NO x to be about 11, 236, 2 and 84 Gg respectively. Residue burning also affects the soil which ultimately leads to loss in nutrients from soil, thus needs to be take care according to RWS (rice wheat system) management [4]. As part of inventorying of emission from open crop residue burning, it was estimated during this work that in the year 2 about 78 and 85 million tons dry rice and wheat straw were generated in India alone, of which about 17 and 19 million tons may end up in field-burning respectively. So, in this research work attempts have been made to take the best use of this richfull resource by using wheat straw as a reinforcement material into the composite and also making this composite a hybrid composite by adding another reinforcement material i.e. glass fibre to increase the strength of the hybrid composite significantly. Due to their high strength, high performance capabilities, glass fibres are used as strength giving material in structural composites. A. Materials II. EXPERIMENTAL STUDIES Epoxy is used because it has low density; low thermal conductivity and they also have good corrosion resistance. Due to its numerous advantages epoxy resin was chosen as the matrix material. The Epoxy resin LY556 and Hardener HY951 was purchased from AMTECHESTERS (P) LTD. Karol Bagh, New Delhi. Woven Rowing Glass fibre fabric is purchased from Chandni Chowk, New Delhi and short wheat straw fibres (2-2.5 cm) are used as reinforcement materials. B. Composite Fabrication Glass fiber fabric woven roving and wheat straw fibers were reinforced in Epoxy resin by hand lay-up method to prepare the composites. The length of wheat straw were about cm. washing of wheat straw has been done to remove the dust and impurities. The glass fibre fabric is cut accordingly to the weight and wheat straw is measured as required.

2 Epoxy resin matrix with density g/cm3 was prepared by taking the required weight in a glass beaker and by mixing hardener HY951 with 1.5% by weight and stirred for 2 minutes. Then we start the fabrication of composite by Hand-layup method. First step is to clean the mould to remove the chips or blemishes from the mould surface. Apply wax over the mould and then apply the first layer of epoxy resin with help of brush. Then apply the layers of glass fibre fabric carefully over the area where epoxy resin was applied. Careful attention is required when we distribute the wheat straw fibers over the glass fiber fabric so that it should uniformly distribute. Air bubbles were removed by applying roller with some force. Repeat the procedure on layer by layer on every sample. Keep the mould at rest for 24 hours to cure at room temperature. After fabrication of composite the post curing is done in hot air circulating oven for 3 hours at 8 o C to make the composites plates stiffer. Four samples with different weight ratios were taken as shown in Table 2.1 with designations. Cutting of specimens for mechanical testing have been prepared according to the given dimensions. Fig. 3.1 Tensile test specimen (mm) of Wheat straw/glass fibre reinforced hybrid epoxy composite b). Flexural Test The three-point bending or flexural test was carried out on Universal testing Machine [UTM] as per the ASTM D79-21 test standards. The flexural test measures the force required to bend a beam under 3-point loading. The size of the specimen was 1mm x 4mm x 8mm. Fig. 2.1 Wheat straw/glass fibre reinforced hybrid epoxy composite Table 2.1 Weight ratios and designations of samples Composite Sample Wheat straw (% by weight) Glass Fibre (% by weight) Epoxy resin (% by weight III. TESTING OF COMPOSITES A. EQUIPMENT FOR TESTING a). Tensile Testing Tensile test of composite samples were carried out in ASTM D test standard. Tests were conduct under ambient conditions in an environmentally controlled room. Specimens were cut in dumbbell shape type IV as shown in figure 3.1. Figure 3.2 (a) Experimental setup and (b) loading arrangement of specimen in tensile test. Fig. 3.2 (a) Experimental setup and (b) loading arrangement of specimen in tensile test c). Impact test The charpy impact test was carried out as per ISO: The specimens were cut according to the test standards. Impact strength of composites is low as compared with metals and this is the main reason for performing this test. Figure 3.3 shows the experimental setup of charpy impact test. This test performed to investigate the behavior of specimens under impact conditions and for estimating the toughness of specimens.

3 composites all the samples. The maximum tensile modulus is obtained at G3W1. Table 4.1 Tensile properties of composite materials Samples W4GO W3G1 W2G2 W1G3 Tensile Strength Tensile Modulus Tensile Elongation (%) Break Load (N) Extension (mm) Fig. 3.3 Experimental setup for Charpy Impact Test d). Shore D Hardness test Shore D Hardness test was carried out with ASTM D In this method, hardened steel indenter with specific force and geometry is indented on the specimen. The indenter tip displacement is measured for calculating the specimen hardness. VI. RESULTS AND DISCUSSION A. Discussion on Tensile properties a). Tensile test analysis Tensile Strength, N/mm 2 Tensile strength of 4 samples with different weight ratios shown in figure 4.1. It is observed from the tensile test results that there is an increment in the tensile strength with the additional reinforcement by specific weight percentage of glass fibre W4Gcontains 4% wheat straw. With no reinforcement of glass fibre (% glass fibre) have 8.3 N/mm 2 tensile strength. Tensile strength of W3G1 (3% wheat straw and 1% glass fibre) is 19.1 N/mm 2. Tensile strength of W2G2 (2% wheat straw and 2% glass fibre) is 23.6 N/mm 2. This shows that as we decrease the weight % of wheat straw from 3% to 2%. This shows as we increase the glass fibre content and decrease the wheat straw the tensile strength is increasing. The tensile test results show that the maximum load applied was 61 N at W1G3 after which specimen fractured. From the results of all the different tests, the best results among all the samples is of W1G3 which contains 3% glass fibre and 1% wheat straw. Tensile properties of all specimens are shown in tabulated form in Table 4.1. Table 4.1 Shows the tensile modulus of Glass fibre/wheat straw hybrid GW4 G1W3 G2W2 G3W1 Fig. 4.1 Tensile strength graph of composite materials b). Flexural test analysis Flexural test of the glass fibre/wheat straw reinforced epoxy hybrid composites at various percentage shows the flexural strength of W4G, W3G1, W2G2 and W1G3 are 2.3 N/mm2, 44.2 N/mm2, 62.2 N/mm2 and N/mm2 respectively as shown in figure 4.2.

4 Flexural Strength, N/mm Fig. 4.2 Flexural strength graph of composite materials c). Impact test analysis Impact energy of the glass fibre/wheat straw reinforced epoxy hybrid composites at various percentage shows the impact energy of W4G, W3G1, W2G2 and W1G3 are 7.3 KJ/m2, 11.7 KJ/m2, 12.9 KJ/m2 and 23.1 KJ/m2 respectively as shown in figure 4.3, W4G hows poor impact strength whereas W1G3 shows the highest impact strength comparatively. As we are decreasing the wheat straw and increasing the glass fibre, the impact strength is increasing. The reason of low impact strength depends on the cellulose content which is higher in natural fibre. Impact strength also depends upon the matrix toughness and the orientation of fibres which defends the crack propagation. Fig. 4.3 Impact strength graph of composite materials d). Shore D Hardness of composites Hardness test was performed in Shore Durometer. Figure 4.4 shows the comparative results of hardness which shows the almost similar results of W4Gand W3G1 and of W2G2, and W1G3. Hardness of composite depends upon the matrix material and the reinforcement which holds the matrix. The hardness of W3G1, W2H2 AND W1G3 is comparable because of the synthetic fibre content in the composite. All results have been given in Table Hardness, Shore D Fig. 4.4 Hardness graph of composite materials Table 4.2 Mechanical properties of wheat straw/glass fibre hybrid epoxy composite Charpy Impact Strength, Kj/m Samples strength Tensile Young s modulus Flexur al V. CONCLUSION Charpy impact (Kj/m 2 ) Shore D Hardne ss W4G W1G W2G W1G In this research work, it has been noticed that the various properties such as tensile, flexural, impact and hardness are comparatively good but greatly influenced with the additional reinforcement of glass fibre into wheat straw reinforced epoxy composite. The maximum tensile strength, flexural strength, impact strength and hardness are 3.8 MPa, MPa, 23.1 Kj/m2 and 78-8 respecyively is

5 obtained at W1G3 with 3% glass fibre and 1% wheat straw. Hence, we can conclude that addition of particular weight percentage of glass fibre reinforcement into wheat straw reinforced epoxy composite increases the overall mechanical properties which can replace the wheat straw reinforced epoxy composite in various strength based applications. References [1] Thwe M M and Liao K. Tensile behavior of modified bamboo glass fibre reinforced hybrid composites Plast. Rubber Compos , 22. [2] Saheb D.N. and JOG J.P. Natural fiber polymer composites: A review. Advances in Polymer Technology, 18(4), pp , [3] Hornsby P.R., Hinrichsen E. and Tarverdi, K. Preparation and properties of polypropylene composites reinforced with wheat and flax straw fibres. Part II: analysis of composite microstructure and mechanical properties. Journal of Materials Science, 32, pp , 1997b. [4] Corbie T. Life cycle assessment of biofibres replacing glass fibres as reinforce plastics. Resources, Conservation & Recycling, vol. 33, p , 21. [5] Gupta P.K., Sahai S., Singh N., Dixit C. K., Singh D.P., Sharma C., Tiwari M.K.,Gupta R.K. and Garg S.C. Residue burning in rice wheat cropping system: Causes and implications. Current Science, Vol. 87, NO. 12, 24. [6] Alamri H and Low IM. Effect of water absorption on themechanical properties of Nano-filler reinforced epoxy nanocomposites. Mater Des; 42: , 212. [7] Comas-Cardona S, Groenenboom P, Binetruy C. A. Generic mixed FE-SPH method to address hydromechanical coupling in liquid composite moulding processes. Compos Part A: Appl Sci Manuf; 36:14 11, 25. [8] Sun D and Yao Y. Synthesis of three novel phosphorus containing flame retardants and their application in epoxy resins. Polym Degrad Stab; 96: , 211. [9] Mishra V and Biswas S. Physical and mechanical properties of bi-directional jute fiber epoxy composites. Procedia Eng; 51: , 213. [1] Guadagno L, Vertuccio L, Sorrentino A. Mechanical and barrier properties of epoxy resin filled with multiwalled carbon nanotubes.carbon; 47: , 2

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