Comparative Study on the Effect that Coir Fibers Have on the Dynamic or Quasi-Static Elastic Moduli of Glass Fiber Laminates Obtained by the Vacuum Bag Technique

2015 ◽  
Vol 668 ◽  
pp. 137-144
Author(s):  
Mario Villalón ◽  
Hugo Vega ◽  
Nahary Montoya ◽  
Byron Rubio ◽  
Julio Hernandez ◽  
...  

The use of natural fibers has a great interest due to their damping properties, low density and moderate strength. The effect of incorporating chopped natural fibers, as disperse reinforced phase, on the dynamic or quasi-static elastic modulus of glass fiber laminates is presented. Squares of 32 cm2 plain wave glass fiber prepreg with epoxy resin were used in a stacking sequence [0]4. Short length chopped (1-3 mm) natural coir fiber was placed in between of each glass fiber prepreg sheet (4) and laminates were prepared by the vacuum bag technique. The volume fraction of natural fiber was 30% (mass fraction of 10%) and samples of 254 mm length and 25.4 mm width were cut and tested at vibration conditions in a cantilever beam arrangement. The vibration frequency was measured by an accelerometer ADXL335 at z-axis, perpendicular to the sample test plane and the elastic modulus was estimated with the cantilever model. The results showed that the samples with coir fiber showed an increase in the dynamic elastic modulus value of 150 to 171% with regard to that one of glass fiber samples without fiber. Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials (ASTM D3039) was also used to further characterize the thin samples (≈0.75 mm) with an Instron machine 8800, 25kN. The tensile properties obtained are lower for coir fiber samples than the ones without.

2014 ◽  
Vol 592-594 ◽  
pp. 202-205
Author(s):  
V. Santhanam ◽  
M. Chandrasekaran ◽  
N. Venkateshwaran

Composite materials are widely used for their superior properties such as high strength to weight ratio, high tensile strength, low thermal expansion, low density etc. Due to environmental issues the eco-friendly composites are being explored. Natural fibers as reinforcement for polymer composites are widely studied. But natural fibers lack better mechanical properties when compared with synthetic fibers. Hence mixing the natural fiber with a synthetic fiber such as glass fiber will improve mechanical properties of the composites. In this study banana fiber is mixed with glass fiber, and the mixture is used as reinforcement in epoxy matrix. The composite specimens were prepared using hand layup technique, the fibers were randomly oriented. Further the fiber length was varied as 10, 15, 20 and 25mm and volume fraction as 10%, 15%, 20% and 25%. Experiments were conducted to find the effect of fiber length and volume fraction on tensile strength, flexural strength, water absorption properties of the composites. It is observed that a fiber length of 20mm and 20% fiber volume fraction gave better mechanical properties.


2011 ◽  
Vol 471-472 ◽  
pp. 291-296 ◽  
Author(s):  
Piyush P. Gohil ◽  
A.A. Shaikh

Composites are becoming essential part of today’s material because they offer advantages such as low weight, corrosion resistance, high fatigue strength; faster assembly etc. composites are generating curiosity and interest all over the worlds. The attempts can be found in literature for composite materials high strength fiber and also natural fiber like jute, flax and sisal natural fibers provides data but there is need of experimental data availability for unidirectional natural fiber composite with seldom natural fiber like cotton, palm leaf etc., it can provide a feasible range of alternative materials to suitable conventional material. It was decided to carry out the systematic experimental study for the effect of volume fraction of reinforcement on longitudinal strength as well as Modulus of Elasticity (MOE) using developed mould-punch set up and testing aids. The testing is carried out as per ASTM D3039/3039M-08. The comparative assessment of obtained experimental results with literature is also carried out, which forms an important constituent of present work. It is also observed through SEM images and theoretical investigations that interface/interphase plays and important role in natural fiber composite.


2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Alfan Ekajati Latief ◽  
Nuha Desi Anggraeni ◽  
Dedy Hernady

ABSTRAK Serat alam yang berfungsi sebagai penguat memiliki sifat yang lebih ringan, mudah dibentuk, tahan korosi, harga murah dan memiliki kekuatan yang sama dengan material logam. Serat bahan alami yang memiliki kekuatan tarik, tekan dan impak yang baik diantaranya serat rami dan daun nanas. Untuk matriks Polipropilena high impact (PPHI) yang banyak digunakan dalam industri otomotif.. Pada penelitian ini dipelajari pengaruh fraksi volume serat alami terhadap sifat mekanik komposit PPHI berpenguat serat alami. Komposit PPHI dibuat dengan menggunakan metode Hand Lay Up pada temperatur 2500C dengan fraksi volume serat alami sebesar 10%, dimana serat dibuat digunting halus hingga memiliki ukuran mesh 120/170, 170/200 dan dibawah 200 mesh, Kekuatan tarik komposit diukur dengan mengacu pada standar ASTM 3039, kekuatan tekan diukur mengacu pada ASTM D 695. Harga Impak dari komposit diukur dengan mengacu pada ASTM D 6110-04. Pada penelitian ini dapat disimpulkan, fraksi volume 10 % serat alami yang baik ketika dicampur dengan matriks polipropilena high impact adalah serat nanas dengan meshing 170/200 dapat meningkatkan kekuatan tarik PPHI sebesar 40 % dan meningkatkan harga impak PPHI sebesar 50,8 % jika dilihat penelitan sebelumnya yakni menggunakan serat rami dibawah mesh 1200 dengan matriks PPHI. Kata Kunci: Rami, Daun Nanas, Polipropilena High Impact, Hand Lay Up. ABSTRACT Natural fibers that function as reinforcement have lighter properties, are easily formed, are corrosion resistant, are cheap and have the same strength as metal materials. Natural fiber which has good tensile, compressive and impact strength including Ramie and pineapple leaves. For high impact polypropylene matrix (PPHI) which is widely used in the automotive industry. In this study the effect of volume fraction of natural fibers on the mechanical properties of PPHI composites with natural fiber reinforced properties was studied. PPHI composites are made using the Hand Lay Up method at a temperature of 2500C with a volume fraction of natural fibers of 10%, where fibers are made finely shaved to have a mesh size of 120/170, 170/200 and below 200 mesh, the tensile strength of the composite is measured by reference to the standard ASTM 3039, compressive strength measured refers to ASTM D 695. The impact price of the composite is measured with reference to ASTM D 6110-04. In this study it can be concluded, a good volume fraction of 10% natural fiber when mixed with high impact polypropylene matrix is pineapple fiber with meshing 170/200 can increase the tensile strength of PPHI by 40% and increase the impact price of PPHI by 50.8% if seen by research previously that used hemp fiber under mesh 1200 with PPHI matrix. Keywords: Ramie Pineapple, High Impact Polypropylene, Hand Lay Up.


2014 ◽  
Vol 69 (6) ◽  
Author(s):  
A. Mataram

Polypropylene (PP) including a type of plastic which ranks second on the most number of types of plastic waste after the type of High Density Polyethylene (HDPE). Glass fibers have superior mechanical properties of natural fibers. Because it has good mechanical properties, glass fibers currently plays an important role in the use of composite reinforcement. Mechanical properties of glass fiber owned and PP waste in environmental conditions that more conditions, it can be utilized as a composite reinforcement and matrix materials. This research was conducted by of injection molding method. The comparison between the volume fraction of the glass fiber matrix of type PP plastic waste with variation 0% fibers 100% matrixs, 10% fibers 90% matrixs, 20% fibers 80% matrixs, 30% fibers 70% matrixs, 40% fibers 60% matrixs, and 50 % fibers 50% matrixs. The optimum conditions obtained in this study was the comparison of variation occurs in 50% fibers volume fractions of 50% matrixs were: tensile stress was 24.30 N/mm2, tensile strain was 13.60%.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Gul Bali Shah

AbstractThe effect of bimodality i.e. blending short and long chain (0 to 80 % w/w) silicone prepolymers, and that of concentration of the crosslinker on the tensile properties such as percent elongation at break (%Eb), ultimate tensile strength (UTS), 100 % modulus and elastic modulus (E) has been investigated. It was found out that the greater amount of crosslinker used for crosslinking provide an additional reinforcement to the silicone network whereas bimodality further significantly accentuates this effect. Remarkably, the %Eb of the silicone networks was found to increase to an average of 2.4 times than that of the monomodal network, cured in each of the three series of bimodal networks cured with 3.9, 9.1 and 12.3% of crosslinker. The optimum property in each case was observed at about 70 mol % of P100. The over all order of sensitivity of these properties up to about 70 mol % of short chain prepolymer has been observed to be as: %Eb > UTS > 100% modulus > elastic modulus. It has been shown that in addition to the previously published reports the tensile properties are acutely dependent not only upon the degree of crosslinking and primary molecular weight; but also on bimodality and crosslinker concentration for preparation of the unfilled silicone polymer networks. The concept of phase inversion (or phase transition) associated with the optimum properties in polymer blends has for the first time been applied to the bimodal polymer networks. It has been observed that the maxima in tensile properties generally corresponds to phase inversion which takes place at 0.5 volume fraction (70 mol %) of short chain (P100) prepolymer which is in accordance with the literature for other systems.


Polímeros ◽  
2006 ◽  
Vol 16 (3) ◽  
pp. 252-256 ◽  
Author(s):  
Alessandra E. F. S. Almeida ◽  
Osny P. Ferreira

Foram obtidas as propriedades mecânicas e viscoelásticas da poliuretana derivada do óleo de mamona após sua exposição ao intemperismo artificial, a fim de avaliar a aplicabilidade deste material como revestimento polimérico para substratos de concreto na Construção Civil. Os procedimentos experimentais foram realizados em conformidade com a ASTM G 53 for "Operating Light and Water Exposure Apparatus (Fluorescent UV - Condensation Type) for Exposure of Nonmetallic Materials"[1]. O ensaio para a caracterização mecânica dos corpos-de-prova após exposição ao intemperismo artificial foi realizado conforme a norma ASTM D 638M-96 "Standard Test Method for Tensile Properties of Plastics (Metric)"[2]. Foi empregado o método de análise dinâmico-mecânica para a obtenção das propriedades viscoelásticas da poliuretana vegetal. Os resultados mostraram que a exposição ao intemperismo artificial não ocasionou mudanças significativas nas propriedades do revestimento polimérico para o tempo de exposição estudado.


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