scholarly journals Recycled Green PE Composites Reinforced with Woven and Randomly Arranged Sisal Fibres Processed by Hot Compression Moulding

2020 ◽  
Vol 23 (2) ◽  
pp. 81-86 ◽  
Author(s):  
Bruno Dorneles De Castro ◽  
Paulo Eustáquio De Faria ◽  
Luciano Machado Gomes Vieira ◽  
Claudia Victoria Campos Rubio ◽  
Rômulo Maziero ◽  
...  

AbstractGreen plastics are constantly being used to minimize the negative impacts of the polymers made of fossil fuels such as petroleum. Non-renewable petroleum-based products are employed in wide range of human activities, yet plastic waste accumulation represents a serious issue for the environment (Mohd Rafee et al., 2019). On the other hand, the use of natural fibres in composite materials, such as sisal fibres, in substitution for synthetic fibres, has increased considerably. The aim of this study was to develop a low-cost manufacturing process of composites with reuse of polyethylene bags made of sugarcane ethanol (green polyethylene) reinforced with sisal fibres. The hot compression moulding (185 °C) was used to mould composite structural board. Tensile tests were conducted to evaluate the influence of the reinforcement configuration on the mechanical properties of the composites, considering two arrangements: woven fibres in (0°/90°) and randomly arranged. The results indicated that the use of woven sisal fibres in (0°/90°) as reinforcement of the green HDPE showed an increase in the tensile strength (33.30%) in contrast to the pure traditional HDPE. Randomly arranged sisal fibre-reinforced green HDPE composites showed higher modulus of elasticity than pure traditional HDPE (76.83%). Composites with woven sisal fibres showed higher values for tensile strength and ultimate strain, and lower modulus of elasticity than composites with randomly arranged sisal fibres. In addition, failure modes of the composites were observed. The results showed the viability of producing these composites by the developed equipment and the potential use of these materials as structural components.

2021 ◽  
Author(s):  
Budi Arifvianto ◽  
Teguh Nur Iman ◽  
Benidiktus Tulung Prayoga ◽  
Rini Dharmastiti ◽  
Urip Agus Salim ◽  
...  

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.


2020 ◽  
Vol 6 (3) ◽  
pp. 591-601
Author(s):  
Ausamah Al Houri ◽  
Ahed Habib ◽  
Ahmed Elzokra ◽  
Maan Habib

Tensile strength of soil is indeed one of the important parameters to many civil engineering applications. It is related to wide range of cracks specially in places such as slops, embankment dams, retaining walls or landfills. Despite of the fact that tensile strength is usually presumed to be zero or negligible, its effect on the erosion and cracks development in soil is significant. Thus, to study the tensile strength and behavior of soil several techniques and devices were introduced. These testing methods are classified into direct and indirect ways depending on the loading conditions. The direct techniques including c-shaped mold and 8-shaped mold are in general complicated tests and require high accuracy as they are based on applying a uniaxial tension load directly to the specimen. On the other hand, the indirect tensile tests such as the Brazilian, flexure beam, double punch and hollow cylinder tests provide easy ways to assess the tensile strength of soil under controlled conditions. Although there are many studies in this topic the current state of the art lack of a detailed article that reviews these methodologies. Therefore, this paper is intended to summarize and compare available tests for investigating the tensile behavior of soils.


Buildings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Chanachai Thongchom ◽  
Nima Refahati ◽  
Pouyan Roodgar Saffari ◽  
Peyman Roudgar Saffari ◽  
Meysam Nouri Niyaraki ◽  
...  

This study aims to explore the tensile and impact properties (tensile strength, modulus of elasticity, and impact strength) of polypropylene (PP)-based nanocomposites reinforced with graphene nanosheets, nanoclay, and basalt fibers. The response surface methodology (RSM) with Box–Behnken design (BBD) was adopted as the experimental design. An internal mixer was used to prepare compounds consisting of 0, 0.75 and 1.5 wt% graphene nanosheets, 0, 10 and 20 wt% basalt fibers, and 0, 3 and 6 wt% nanoclay. The samples were prepared by a hot press machine for mechanical testing. The tensile tests were run to determine the tensile strength, and modulus of elasticity, and the Charpy impact tests were performed to assess the impact strength. It was found that the addition of basalt increased the tensile strength, modulus of elasticity, and impact strength by 32%, 64% and 18%, respectively. Also, the incorporation of the low-weight graphene nanosheets increased the tensile and impact strength by 15% and 20%, respectively, Adding graphene nanosheets generally improved the modulus of elasticity by 66%. Similarly, the addition of nanoclay improved the tensile strength by 17% and increased the modulus of elasticity by 59%, but further addition of it decreased the impact strength by 19%. The values obtained by this experiment for the mechanical property were roughly close to the data yielded from desirability optimization.


2019 ◽  
Vol 805 ◽  
pp. 59-64
Author(s):  
Achmad Chafidz ◽  
Cholila Tamzysi ◽  
Lilis Kistriyani ◽  
Ratna Dewi Kusumaningtyas ◽  
Dhoni Hartanto

PP/clay nanocomposites samples of 1st and 2nd cycles (recycle) and different nanoclay loadings (i.e. 0, 5, 10, 15 wt%) samples were made by utilizing twin-screw extruder and injection molding machine. The samples were then characterized using a tensile test machine. The tensile tests results showed that modulus of elasticity and tensile strength of the nanocomposites samples for both 1st and 2nd cycles were all higher than the neat PP, and increased with increasing nanoclay loadings. The enhancements of modulus of elasticity (as compared to the neat PP) for 1st cycle of the nanocomposites were about 38.08%, 49.33%, and 78.65% for NC-5-I, NC-10-I, and NC-15-I, respectively. Whereas, for the 2nd cycle of the nanocomposites were about 44.33%, 59.59%, and 84.69% for NC-5-II, NC-10-II, and NC-15-I, respectively. This indicated that the incorporation of nanoclay in the PP matrix significantly increased mechanical properties, especially modulus of elasticity and tensile strength of the nanocomposites. Additionally, values of modulus of elasticity and tensile strength of 1st cycle and 2nd cycle of PP/clay nanocomposites were compared by plotting them in two graphs. The plots revealed that reprocessing of the nanocomposites did not significantly influence the mechanical properties of the nancomposites.


2020 ◽  
Vol 90 (21-22) ◽  
pp. 2428-2440
Author(s):  
A Engelbrecht-Wiggans ◽  
F Burni ◽  
E Guigues ◽  
S Jiang ◽  
TQ Huynh ◽  
...  

To improve the reliability and design of body armor, it is imperative to understand the failure modes and the degradation rates of the materials used in armor. Despite the best efforts of manufacturers, some vulnerability of armor materials to aging due to hydrolytic or oxidative environments is expected and may result in the degradation of material properties such as tensile strength. In this work, p-aramid yarns from two manufacturers were exposed to environmental conditions of various fixed temperature and humidity combinations. The maximum temperature and humidity condition was 70℃ and 76% relative humidity (RH). Tensile tests were performed on specimens extracted at several different times over the course of at least 1 year to determine the change in ultimate tensile strength and failure strain as a function of time, temperature, and humidity. Molecular spectroscopy was used to investigate any chemical changes as a result of the aging. The p-aramid materials were found to be generally resistant to degradation at most conditions, showing changes of less than 10% only at the highest temperature and humidity conditions.


2021 ◽  
Vol 11 (16) ◽  
pp. 7272
Author(s):  
Mohammadreza Lalegani Dezaki ◽  
Mohd Khairol Anuar Mohd Ariffin ◽  
Ahmad Serjouei ◽  
Ali Zolfagharian ◽  
Saghi Hatami ◽  
...  

Fused deposition modeling (FDM) is a capable technology based on a wide range of parameters. The goal of this study is to make a comparison between infill pattern and infill density generated by computer-aided design (CAD) and FDM. Grid, triangle, zigzag, and concentric patterns with various densities following the same structure of the FDM machine were designed by CAD software (CATIA V5®). Polylactic acid (PLA) material was assigned for both procedures. Surface roughness (SR) and tensile strength analysis were conducted to examine their effects on dog-bone samples. Also, a finite element analysis (FEA) was done on CAD specimens to find out the differences between printing and simulation processes. Results illustrated that CAD specimens had a better surface texture compared to the FDM machine while tensile tests showed patterns generated by FDM were stronger in terms of strength and stiffness. In this study, samples with concentric patterns had the lowest average SR (Ra) while zigzag was the worst with the value of 6.27 µm. Also, the highest strength was obtained for concentric and grid samples in both CAD and FDM procedures. These techniques can be useful in producing highly complex sandwich structures, bone scaffolds, and various combined patterns to achieve an optimal condition.


2018 ◽  
Vol 14 (1) ◽  
pp. 61
Author(s):  
Kosim Abdurohman ◽  
Aryandi Marta

Vacuum infusion is a manufacturing method to improve mechanical properties of composite. Before apply this in LSU structure, it should be experimented using tensile test to know mechanical properties of the composite. Tensile test is an experimental to know tensile strength, modulus of elasticity, and failure modes of composite. Experimental process of CFRP composite using unidirectional carbon fiber and polyester matrix was done using vacuum infusion technology, strart from specimens preparation until testing steps. Manufacturing results gave the values of composite density and thickness; mass and volume fraction of fiber and matrix materials. Specimens and testing process are refer to ASTM D3039 tensile test standard for composite matrix polymers. The testing results showed 1011.67 MPa ultimate tensile strength, 59074.96 MPa modulus of elasticity, and SGV (long spliting, gage, various) failure mode . ABSTRAKVacuum infusion merupakan salah satu metode manufaktur yang digunakan untuk meningkatkan sifat mekanik komposit. Untuk mengaplikasikan metode ini dalam pembuatan struktur LAPAN Surveillance UAV (LSU), perlu diketahui terlebih dahulu sifat mekanik dari komposit hasil metode ini secara eksperimen. Salah satu eksperimen yang dilakukan yaitu pengujian tarik untuk mendapatkan tensile strength, modulus elastisitas, dan failure mode yang terjadi pada komposit. Eksperimen dilakukan terhadap komposit CFRP menggunakan material serat karbon searah (UD) 0⁰ dan matriks poliester dibuat dengan metode vacuum infusion mulai dari tahap preparasi sampai tahap pengujian. Dari hasil manufaktur didapat nilai densitas dan ketebalan komposit serta fraksi massa dan fraksi volume material penyusun komposit. Spesimen dan proses pengujian mengikuti standar ASTM D3039 yang merupakan standar pengujian tarik untuk komposit dengan matriks polimer. Hasil pengujian menunjukkan nilai ultimate tensile strength 1011,67 MPa, modulus elastisitas 59074,96 MPa, dan failure mode SGV (Long Spliting, Gage, Various).


Author(s):  
Akarsh Verma ◽  
Kamal Joshi ◽  
Amit Gaur ◽  
V. K. Singh

AbstractIn this article, biocomposites derived from a starch-glycerol biodegradable matrix reinforced with jute fibers were fabricated using the wet hand lay-up and compression moulding techniques. Samples having different weight percentages of jute fiber in the starch matrix were analyzed. The fiber’s surface was chemically treated by alkaline sodium hydroxide to improve the interphase bonding between the fiber and the matrix. Tensile tests for the composites were done and the sample with highest tensile strength was selected for further tests that included water absorption (WA), scanning electron microscopy (SEM) and thermal analysis (TA). It has been concluded that the ultimate tensile strength was found to be maximum for the composition of 15% fiber by weight composite as 7.547 MPa without epoxy coating and 10.43 MPa with epoxy coating. The major disadvantage of the biocomposite is its high WA property, which in this study was inhibited by the epoxy resin layer. Herein, the results of various tests done disclose a noteworthy improvement in the overall properties of bio-composite, in comparison to the neat biodegradable starch matrix.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5138
Author(s):  
Anna Falkowska ◽  
Andrzej Seweryn ◽  
Marcin Skrodzki

This paper presents the results of experimental research on the strength properties of porous structures with different degrees of density manufactured of Ti6Al4V titanium alloy by Laser Power Bed Fusion. In the experiment, samples with diamond structure of porosity: 34%, 50%, 73% and 81% were used, as well as samples with near-zero porosity. Monotonic tensile tests were carried out to determine the effective values of axial modulus of elasticity, ultimate tensile strength, offset yield strength, ultimate elongation and Poisson ratio for titanium alloys with different porosities. The paper also proposes relationships that can be easily used to estimate the strength and rigidity of a porous material manufactured by 3D printing. They were obtained by the approximation of two quotients. The first one refers to the relationship between the tensile strength of a material with a defined porosity to the strength of full-filled material. The second similarly determines the change in the value of the axial modulus of elasticity. The analysis of microscopic observations of fracture surfaces and also microtomography visualization of the material structure are also presented.


2013 ◽  
Vol 750 ◽  
pp. 208-211
Author(s):  
Hang Li ◽  
Wen Xue Wang ◽  
Yoshihiro Takao ◽  
Terutake Matsubara

This study investigates the tensile properties of UACS (unidirectional arrayed chopped strands) laminates with different slit patterns. UACS composite is a kind of short fiber reinforced polymer by introducing slits into prepregs before the fabrication of laminates. Existing UACS composites have superior flowability but relatively low tensile strength compared to conventional CFRP (carbon fiber reinforced polymer). Consequently, many efforts have been made to improve the strength of UACS composites. In this study, two new discontinuous slit patterns, staggered pattern and bi-angled pattern, have been developed. Tensile tests reveal that two new UACS laminates with staggered and bi-angled slit patterns have higher strength and higher stiffness than existing UACS laminates with continuous slits. Discontinuity of slits plays an important role in inhibiting the development of delamination. Different slit patterns show different failure modes.


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