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1

Influence of Acoustic Emission Signals and Damage Analysis During the Tensile Test on Al8011 Hybrid Composites by Stir Casting Method

Kannan C. R., Suresh S., Navaneetha Krishnan M.

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

223--235

EN

Metal network compounds have primary properties. The use of lightweight and low vitality is a testament to the growing interest in the automotive industry. Aluminum alloys, due to their advanced physical, mechanical and tribological properties, have become a highly emerging material for a variety of industrial applications and the importance of efficient material selection is explained. In this paper, an Al8011 hybrid metal matrix composite is developed through the stir casting process. The different weight proportions of B4C (3%, 6%, 9% & 12%) and fixed proportions of 2% MoS2 have been used. Composite developed are subjected to mechanical properties evaluation and seawater corrosion studies following standard procedures. To study the porosity of the composite samples, theoretical density and actual density are calculated. An acoustic emission system-assisted tensile test is carried out to report the strength of the composite. From this experimental method, adding reinforcement can increase the tensile strength and hardness of the composites. Under sea water, the increase in reinforcement found an increase in corrosion resistance. Fractured surfaces were perused using SEM and EDS analysis.

2

Designing a Three-Dimensional Woven Fabric Structure as an Element of a Baby Stroller

Bethalihem Samuel T., Barburski Marcin, Lemmi Tsegaye Sh.

Autex Research Journal

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2022

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Vol. 22, no. 2

148--154

EN

A baby stroller allows the transportation of a child over long or short distances. The materials used to produce the stroller make it heavy for users, which creates difficulties when lifting the stroller. The goal of this project was to design and fabricate a three-dimensional (3D) fabric structure that can be used as part of a stroller seat to improve its mechanical and physical properties. The idea of implementing a woven 3D system allows the development of an egg-shaped or shell-like structure as part of a stroller seat. The combination of double-woven material and honeycomb polypropylene (as the reinforcing material) was used to create a 3D composite structure. Single and double layers of polypropylene honeycomb sandwiched within layers of linen flax fabric were used to prepare the composite samples. Subsequently, tests on mechanical and physical properties, such as density, flexural strength, and tensile strength, were carried out. Analysis of the results showed that the composite with one layer of honeycomb has half the density of polyvinyl chloride.

3

Mechanical Effects on Different Solid to Liquid Ratio of Geopolymer Filler in Epoxy Resin

Abu Hashim Mohammad Firdaus, Ghazali Che Mohd Ruzaidi, Daud Yusrina Mat, Faris Meor Ahmad, Al Bakri Abdullah Mohd Mustafa, Zainal Farah Farhana, Hasyim Saloma, Lokman Muhammad Taqiyuddin

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 1

215--220

EN

Geopolymer is formed from the alkali activation of materials rich in Si and Al content with the addition of a silicate solution to enhance the properties of the materials. This paper presents research on the mechanical properties of fly ash-based geopolymer filler in epoxy resin by varying different solid to liquid ratios using sodium hydroxide and sodium silicate as the alkaline activator. However, the common problem observed from the solid to liquid ratio is the influence of curing time and compressive strength of geopolymer to have the best mechanical property. The mix design for geopolymers of solid to liquid ratio is essential in developing the geopolymer’s mechanical strength. A series of epoxy filled with fly ash-based geopolymer materials with different solid to liquid ratio, which is prepared from 0.5 to 2.5 solid to liquid ratio of alkaline activator. The tensile strength and flexural strength of the epoxy filled with fly ash-based geopolymer materials is determined using Universal Testing Machine under tensile and flexural mode. It was found that the optimum solid to liquid ratio is 2.0, with the optimum tensile and flexural strength value. However, both the tensile and flexural properties of epoxy filled with fly ash-based geopolymer suddenly decrease at a 2.5 solid to liquid ratio. The strength is increasing with the increasing solid to liquid ratio sample of geopolymer filler content.

4

Investigation of Thermal and Mechanical Properties of Three-Dimensional Braided Composite Materials

Arbaoui Jamal, Aucher Jérémie, Gomina Moussa, Breard Joel

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 4

1325--1332

EN

This paper investigates the thermal and mechanical properties of a composite made from a combination of 2063-epoxy resin and three different braided carbon-fiber fabric reinforcements. These fibres consist of HTS carbon, HTS carbon braided with nickel coated carbon and HTS carbon braided with nickel coated copper, respectively. The composites were manufactured through resin transfer molding (RTM) route. The thermal diffusivity of carbon fibers composites was measured at different temperature by using a flash method. The transverse and planar thermal conductivities were determined by measuring the specific heat, density and thermal diffusivities, respectively. The current research highlights the influence of adding nickel coated carbon and nickel-plated copper wires on the braided composites. The evaluation shows that the HTS carbon braided manufactured with nickel-plated copper wires presents higher in-plane thermal conductivity (in direction parallel of the fibres) when comparing to HTS carbon and HTS carbon braided manufactured with nickel coated carbon. The thermal conductivity benefits of those composite were achieved at the expenses of lower mechanical properties of braided composites investigated.

5

Natural filler based composite materials

Nayeeif A.A., Hamdan Z.K., Metteb Z.W., Abdulla F.A., Jebur N.A.

Archives of Materials Science and Engineering

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2022

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Vol. 116, nr 1

5--13

EN

Purpose: The first goal is to get rid of waste and reduce environmental pollution, and the other goal is to investigate the effect of these fibres on properties (resistance of composite materials for bending and tensile testing) of polyester and use them in applications. Also, The moisture environment effect on the properties of composite materials was studied. Design/methodology/approach: It uses natural fibres, which are considered waste, namely eggshell and sawdust with polyester. Several samples were prepared with different weight percentages (30% and 40%), and their mechanical properties were studied and immersed in water for 15 days. And studying the effect of water on these properties. It was found that it is possible to use these fibres (waste) with polyester and benefit from them. It was found that when adding fibres to polyester, the tensile strength decreases, but the bending increases the strength. Finally, it was found that when the samples are immersed in water, the material weakens, and its mechanical properties decrease. Findings: It can be noticed that adding natural fibres by 40% and 30% improved the mechanical properties of polyester in the bending test, where the bending test increased with increased volume fraction of fibre. It can be noticed that adding natural fibres by 40% and 30% decreased the mechanical properties (tensile strength) of polyester in a tensile test. When the natural composite materials were treated with water for 15 days, water decreased the mechanical properties in bending and tensile test. Research limitations/implications: One of the limitations of this research that was found through the work is that when increasing the weight ratios of the fibres added to polyester leads to the failure of polyester, so we recommend using lower weight ratios of fibre. Practical implications: One of the limitations of this research that was found through the work is that when increasing the weight ratios of the fibres added to polyester leads to the failure of polyester, so we recommend using lower weight ratios of fibre. Originality/value: The original value of this research is the use of fibres that are considered waste, their reuse, and utilization in some applications that do not require composite materials with high mechanical properties.

6

Processing of Boron Nitride Nanotubes Reinforced Aluminum Matrix Composite

Nemutlu B., Kahraman O., Demirel K. B., Erkul I., Cicek M., Sahin H., Dizdar K. C., Dispinar D.

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 2

5--10

EN

Aluminum and its alloys are one of the most favored metal-based materials for engineering applications that require lightweight materials. On the other hand, composites are getting more preferable for different kinds of applications recently. Boron nitride nanotubes (BNNTs) are one of the excellent reinforcement materials for aluminum and its alloys. To enhance mechanical properties of aluminum, BNNTs can be added with different processes. BNNT reinforced aluminum matrix composites also demonstrate extraordinary radiation shielding properties. This study consists of BNNT reinforced aluminum matrix composite production performed by casting method. Since wetting of BNNT in liquid aluminum is an obstacle for casting, various casting techniques were performed to distribute homogeneously in liquid aluminum. Different methods were investigated in an aim to incorporate BNNT into liquid method as reinforcement. It was found that UTS was increased by 20% and elongation at fracture was increased by 170% when BNNT was preheated at 800°C for 30 minutes.

7

Influence of untreated abaca fibre on mechanical properties of lightweight foamed concrete

Othuman Mydin Md Azree

Architecture Civil Engineering Environment

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2022

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Vol. 15, no. 3

51--61

EN

Presently, the expenditure on construction materials grows dramatically along with the enduring effect on the ecosystem, and it has led the academics to the recognition of natural plant fibres such as abaca fibre (AF) for enhancing the mechanical properties of concrete. AF is plentifully obtainable making it fairly relevant to be employed as a strengthening material in lightweight foamed concrete (LFC). Moreover, natural plant fibre-reinforced concrete has been progressively utilized in construction for several decades to decrease crack growth under the static load. This paper anticipates examining the effectiveness of the addition of AF in LFC to enhance its mechanical properties. LFC specimens of 550 kg/m3 density were reinforced with AF at weight fractions of 0.00%, 0.15%, 0.30%, 0.45% and 0.60%. Three parameters have been assessed which were flexural strength, compressive strength and tensile strength. The results revealed that adding 0.45% AF into LFC enables optimal compressive, flexural and splitting tensile strengths. The presence of AF augments material strength by filling spaces, micro-cracks, and gaps inside the LFC structure. Additionally, AF helped reduce crack spreading when the plastic state of the LFC cementitious matrix was loaded. Though, further, than the optimum level of AF addition, accumulation and the non-uniform distribution of AF were identified, which triggers the lowering of the LFC strength properties substantially. The output of this preliminary investigation would give a better understanding of the potential utilization of plant fibre in LFC. It is of great importance to drive the sustainable development and application of LFC material and infrastructures.

8

Utilization of wrightia tinctoria nano seed fibers as a reinforcement in the preparation of epoxy-based composites

Syed Habibunnisa, Nerella Ruben, Madduru Sri Rama Chand, Reddy S Raja Gopal

Acta Innovations

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2022

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no. 45

5--17

EN

Natural seed fiber reinforced composite materials are replacing many conventional ones because of their excellent properties, less weight, easy availability, etc. Composite materials are used in many areas because of their superior features. Mechanical property is one of the vital parameters for choosing the material. The current investigation has revealed an importance of recently well-known Wrightia tinctoria nano seed fibers (WTNSFs), which are extracted physically. Wrightia tinctoria nano seed fiber reinforced composite was prepared with the epoxy resin by hand layup method. Epoxy resin is easy to handle and available at low cost. Mechanical tests are conducted reinforced composites of plain epoxy and WTNSFs to obtain strength properties like tensile, flexural, impact. Water absorption tests also performed on composites. Here, the developed composites are easy to handle, offered economically, and used primarily in marine applications due to less water absorption and good wax content. A comprehensive description of different tests and the properties of WTNSFs are studied and compared with the other existing natural fibers. This work showed that 35% combination of WTNSFs reinforced epoxy matrix offers enhanced mechanical properties with minimum water absorption compared with plain epoxy composites.

9

An analysis of innovative and maintenance free active pre-stressed soil nail with reinforced grout hybrid anchor in the region of Rawang, Malaysia

Jamain Mohd Fadhil, Muda Mohammad Ashari, Beddu Salmia, Noor Mohamad Jamaludin Md, Manan Teh Sabariah Binti Abd, Ahmad Mushtaq

Acta Geophysica

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2022

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Vol. 70, no 6

2965--2978

EN

Steep cut slops along the highways and hillsides closer development projects are generally stabilize using soil nailing method in Malaysia. Soil nail system (i.e., passive and active soil nail systems integrated with tendons pre-stressed) is widely applied to strengthened slopes. However, slope failures occurred observing flaws on the fundamental design. The loss of the pre stressed tension on the creep behaviour of the nail tendon affects the functionality of the soil nail system. This research has introduced a cylindrical shape reinforced grout hybrid anchor and the objectives is to assess its efficiency at refraining the creep behaviour of the soil. Therefore, laboratory evaluation of the pull-out creep behaviour of the anchor was assessed in a large pull-out box (length: 2 m, σ: 1 m×1 m). An effective stress of 100 and 200 kPa were applied to the soil in the pull-out box. The creep behaviour was tested at the pull-out tensions of 100 and 200 kN, respectively. Results show that the prestressing force is the main factor affecting the stress and deformation in the soil. The anchor was able to mobilise the tensions of 100 and 200 kN. The load was maintained, and the creep behaviour was monitored. A minimal amount of creep (approximately 1 mm) was observed. This finding presents a good justification showing that, the anchor could resist creep and thus can function as a maintenance free active soil nail system.

10

Influence of the Soaking Time on the Mechanical Properties of Coir as a Natural Composite Reinforcement

Arsyad Muhammad, Soenoko Rudy, Arman Arman

Fibres & Textiles in Eastern Europe

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2020

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Vol. 28, no. 6 (144)

98--103

EN

This study aimed to determine the effect of the long soaking of coir in sodium hydroxide solution on its mechanical properties. The materials used, namely coir, sodium hydroxide solution, polyester matrix, catalyst, and aquades. The coir was soaked in a sodium hydroxide solution for 1, 5, 7, 9, and 11 hours. After that, coconut fibre was washed using distilled water, and then dried in an oven at 90 °C for 5 hours. Next, a single fibre tensile and pull out test was performed. Based on the results and discussion, it was concluded that immersing coconut fibre in sodium hydroxide solution for 7-hours gave the maximum tensile strength and interfacial shear strength of 223.91 N/mm2, and 9.8 N/mm2, respectively Coir as a composite reinforcement has the potential to be used for engineering material such as ceiling boards and fishing boat walls.

PL

Celem pracy było określenie wpływu długotrwałego moczenia włókna kokosowego w roztworze wodorotlenku sodu na jego właściwości mechaniczne. Zastosowane materiały, a mianowicie: kokos, roztwór wodorotlenku sodu, matryca poliestrowa i katalizator. Włókno kokosowe moczono w roztworze wodorotlenku sodu przez: 1, 5, 7, 9 i 11 godzin. Następnie włókno kokosowe przemyto wodą destylowaną i suszono w piecu w temperaturze 90 °C przez 5 godzin. Następnie przeprowadzono pojedynczą próbę rozciągania włókna. Na podstawie wyników i dyskusji stwierdzono, że zanurzenie włókna kokosowego w roztworze wodorotlenku sodu na 7 godzin dało efekt w postaci maksymalnej wytrzymałości na rozciąganie i międzyfazowej wytrzymałości na ścinanie wynoszących odpowiednio 223,91 N/mm2 i 9,8 N/mm2. Tak wzmocnione włókno kokosowe ma szansę na użycie jako zbrojenie kompozytowe i potencjał do wykorzystania w materiałach inżynieryjnych, takich jak płyty sufitowe i ściany łodzi rybackich.

11

Effect of Rhenium Addition on Microstructures and Mechanical Properties of Oxide Dispersion Strengthened Ferrtic Steels

Noh Sanghoon, Kang Suk Hoon, Kim Tae Kyu

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 4

1261--1264

EN

In this study, to investigate effects of rhenium addition on the microstructures and mechanical properties, 15Cr-1Mo ODS ferritic steels with rhenium additions were fabricated by the mechanical alloying, hot isostatic pressing, and hot rolling processes. Unremarkable differences on grain morphologies and nano-oxide distributions were estimated in the microstructure observations. However, the ODS ferritic steels with 0.5 wt.% rhenium showed higher tensile and creep strengths at elevated temperature than that without rhenium. It was found that rhenium is very effective to improve the mechanical properties.

12

Effect of Al/Cu Weight Fraction on the Mechanical and Electrical Properties of Al-Cu Conductors for Overhead Transmission Lines

Han Deokhyun, Kim Geon-Hong, Kim Jaesung, Ahn Byungmin

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 3

1019--1022

EN

In the past few years, overhead copper transmission lines have been replaced by lightweight aluminum transmission lines to minimize the cost and prevent the sagging of heavier copper transmission lines. High strength aluminum alloys are used as the core of the overhead transmission lines because of the low strength of the conductor line. However, alloying copper with aluminum causes a reduction in electrical conductivity due to the solid solution of each component. Therefore, in this study, the authors attempt to study the effect of various Al/Cu ratios (9:1, 7:3, 5:5) to obtain a high strength Al-Cu alloy without a significant loss in its conductivity through powder metallurgy. Low-temperature extrusion of Al/Cu powder was done at 350ºC to minimize the alloying reactions. The as-extruded microstructure was analyzed and various phases (Cu9Al4, CuAl2) were determined. The tensile strength and electrical conductivity of different mixing ratios of Al and Cu powders were studied. The results suggest that the tensile strength of samples is improved considerably while the conductivity falls slightly but lies within the limits of applications.

13

Effect of sago starch and plasticizer content on the properties of thermoplastic films: mechanical testing and cyclic soaking-drying

Halimatul M. J., Sapuan S. M., Jawaid M., Ishak M. R., Ilyas R. A.

Polimery

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2019

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T. 64, nr 6

422--431

EN

Studies on the effect of sago starch and plasticizer concentrations on the tensile and tearing properties of the produced starch films were carried out using universal testing machine. The results showed that both sago starch and plasticizer contents significantly affected the mechanical properties of starch films. With increasing the starch concentration, an increase in tensile strength was observed. This was accompanied by radically reduced tensile strain and increased tearing strength. On the contrary, when increasing the plasticizer concentration, a reduction in tensile and tearing strength was observed, as well as an increment in tensile strain. The results of repeated soaking and drying tests made on sago starch films showed that the films with high plasticizer and low starch content exhibited lower mass loss compared to those containing lower plasticizer and higher starch concentration. Increasing the number of soaking and drying cycles reduced starch dissolution and it was probably related to retrogradation process inside the film. In a nutshell, the study provided preliminary information to assess the possible application fields of sago starch films.

PL

Z zastosowaniem uniwersalnej maszyny testującej zbadano zależność wytrzymałości na rozciąganie i rozdarcie wytworzonych błon skrobiowych od zawartości w nich skrobi sago i plastyfikatora. Stwierdzono, że udział zarówno skrobi, jak i plastyfikatora (mieszanina sorbitolu i glicerolu 1 : 1) wpływają wyraźnie na właściwości mechaniczne otrzymanych błon. Zwiększenie zawartości skrobi powodowało wzrost wytrzymałości na rozciąganie połączone z drastycznym zmniejszeniem wartości naprężenia. Ponadto zwiększyła się wytrzymałość na rozerwanie. Większa zawartość plastyfikatora w błonie skrobiowej, w przeciwieństwie do udziału skrobi sago, prowadziła do zmniejszenia wytrzymałości na rozciąganie przy zwiększeniu wartości naprężenia, a także do zmniejszenia wytrzymałości na rozerwanie. Wyniki testu cyklicznego moczenia i suszenia błon skrobiowych sago wykazały, że błony z dużą zawartością plastyfikatora i małym udziałem skrobi charakteryzowały się małym ubytkiem masy, w przeciwieństwie do błon z dużą zawartością skrobi i małym udziałem plastyfikatora. Zwiększanie liczby cykli moczenia i suszenia wpływało na ograniczenie procesu rozpuszczania skrobi wwodzie, co można tłumaczyć przebiegającą retrogradacją cząsteczek skrobiowych sago. Przeprowadzone badania mogą być przydatne do określenia obszarów potencjalnych zastosowań błon wytworzonych ze skrobi sago.

14

Comparative Study on Carded Cotton Yarn Properties Produced by the Conventional Ring and New Modified Ring Spinning System

Buharali Gozde, Omeroglu Sunay

Fibres & Textiles in Eastern Europe

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2019

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Vol. 27, no. 2 (134)

45--51

EN

In this paper, the properties of yarns which were produced by using a modified ring spinning system (ProSPIN®) and conventional ring spinning system were comparatively investigated. The modified spinning system which was used in yarn production has basically the characteristic of compact spinning system and is at present used especially in the production of mid-count yarns. In this study, conventional ring yarns and equivalent modifiedring spun yarns were produced with different yarn counts and twists using 100% carded cotton raw material. Tests were conducted to determine the tensile, unevenness, imperfection and hairiness properties of the yarns. It was found that the modified ring spun yarns showed considerable positive differences in some yarn properties compared with conventional ring yarns. The differences in tenacity values were more evident especially in yarns with lower twist coefficients, while differences in hairiness values were more so in finer yarns. Also the unification of two separate and compacted fibre strands during yarn formation ensures better values for both mass irregularity and IPI because of the doubling effect.

PL

W niniejszym artykule porównano właściwości przędz, które zostały wytworzone przy użyciu zmodyfikowanego systemu przędzenia obrączkowego (ProSPIN®) i konwencjonalnego systemu przędzenia obrączkowego. Zmodyfikowany system przędzenia, który był stosowany w produkcji przędzy, ma zasadniczo charakterystykę kompaktowego systemu przędzenia i jest obecnie wykorzystywany w szczególności do produkcji przędzy o średnim numerze. Wytworzono konwencjonalne przędze obrączkowe i zmodyfikowane przędze obrączkowe z różnymi skrętami z użyciem 100% zgrzebnego surowca bawełnianego. Przeprowadzono testy w celu określenia właściwości rozciągania, nierówności, niedoskonałości i włochatości przędz. Stwierdzono, że przędze obrączkowe wytworzone nowym sposobem wykazują znaczne różnice w niektórych właściwościach przędz w porównaniu z konwencjonalnymi przędzami obrączkowymi. Różnice w wartościach wytrzymałości na rozciąganie były bardziej widoczne, zwłaszcza w przędzach o niższych współczynnikach skrętu, podczas gdy różnice we włochatości były bardziej widoczne w cieńszych przędzach. Również ujednolicenie dwóch oddzielnych i sprasowanych pasm włókien podczas tworzenia przędzy zapewnia lepsze wartości zarówno dla nieregularności masy jak i IPI z powodu efektu podwojenia.

15

Mechanical properties of kenaf fiber thermoplastic polyurethane-natural rubber composites

Noor Azammi A. M., Sapuan S. M., Ishak M. R., Sultan M. T. H.

Polimery

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2018

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T. 63, nr 7-8

524--530

EN

Thermoplastic polyurethane-natural rubber TPUR-NR composites filled with treated and untreated kenaf fiber as filler were prepared at different TPUR and NR contents. The content of kenaf fiber was maintained at 12.5 wt % and the fiber was treated with 6 % solution of sodium hydroxide (NaOH), then dried for 24 hours in 100 °C, hot blended with polymer components, pulverized and pressed. The mechanical properties of the composites such as tensile, flexural and impact strength were determined, and their dependence on NaOH treatment of kenaf fibers was investigated. The analysis using scanning electron microscope (SEM) was implemented to identify the effect of alkali treatment on the microstructure of kenaf fiber and TPUR-NR composites. An improvement of fiber surface roughness and bonding between the fiber and polymer as well as an increase in impact energy and elongation at break of the composites was observed.

PL

Otrzymano kompozyty na osnowie termoplastycznego poliuretanu (TPUR) i naturalnego kauczuku (NR) (o różnej zawartości TPUR i NR), napełnionej włóknami kenafu KF (12,5% mas.). Włókna poddawano wstępnej obróbce przy użyciu 6% roztworu wodorotlenku sodu, suszono w temp. 100 °C przez 24 h, mieszano na gorąco z komponentami polimerowymi, pulweryzowano i prasowano. Zbadano właściwości mechaniczne przy ściskaniu i rozciąganiu oraz odporność na uderzenie kompozytów zawierających modyfikowane lub niemodyfikowane włókna kenafu, a także wpływ alkalicznej obróbki włókien na właściwości kompozytu. Obserwacje mikrostruktury kompozytów prowadzono metodą skaningowej mikroskopii elektronowej. Stwierdzono, że obróbka włókien KF roztworem NaOH wpłynęła na zwiększenie chropowatości ich powierzchni i zdolności wiązania z osnową polimerową, a także na poprawę odporności na uderzenie i zwiększenie wydłużenia przy zerwaniu kompozytów zawierających modyfikowane włókna.

16

Effects of the Vacuum Moulding Process on the Mechanical Properties of Cotton/Epoxy Composite

Tafur C. L., Mora E. E., Baracaldo R. R.

Fibres & Textiles in Eastern Europe

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2018

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Vol. 26, no. 3 (129)

93--97

EN

A study on the effect of the vacuum assisted resin transfer moulding (VARTM) manufacturing process on the mechanical properties of cotton/epoxy composite is presented in this investigation. Woven cotton was used as reinforcing material embedded in epoxy resin. The woven cotton was treated with sodium hydroxide for one hour at concentrations of 0% to 20%. The tensile test showed that the untreated material had the highest ultimate strength and Young’s modulus. Observation of the fracture surface by scan electronic microscopy (SEM) was compared to the hand lay-up process as well as the results of the tensile test. The comparison showed that the VARTM process presents better mechanical properties than the hand lay-up process due to the reduction in discontinuities observed by means ofoptical microscopy.

PL

W pracy przedstawiono badanie wpływu procesu wytwarzania kompozytów metodą VARTM (vacuum assisted resin transfer moulding) na właściwości mechaniczne kompozytów bawełniano-epoksydowych. Jako materiał wzmacniający osadzony w żywicy epoksydowej zastosowano tkaninę bawełnianą. Tkaninę bawełnianą poddano obróbce wodorotlenkiem sodu przez godzinę w stężeniach od 0% do 20%. Próba rozciągania wykazała, że materiał nie poddany obróbce miał najwyższą wytrzymałość końcową i moduł Younga. Dokonano obserwacji powierzchni pęknięcia metodą mikroskopii skaningowej (SEM), a wyniki porównano z procesem ręcznego układania. Porównanie wykazało, że proces przy zastosowaniu procesu VARTM otrzymano lepsze właściwości mechaniczne kompozytów, niż przy uzyciu procesu ręcznego układania.

17

Chemical treatment of recycled pulp fibers for property development: Part 2. Effects on old newspapers

Sutcu A., Sahin H. T., Tutus A.

Drewno : prace naukowe, doniesienia, komunikaty

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2018

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vol. 61, nr 201

177--192

EN

The recycling of paper is an important issue and requires a systematic and investigative approach. However, it is necessary to scrutinize alternative methods on the strength of the development of recycled fibres to explore the impact of recycling on properties of recycled fibres. In this study, it was found that repeated treatments of recovered fibres with all three chemicals usually enhance their ability to re-swell and improve bonding potential in fibre networks. This is evidenced by higher water retention values (WRV) and improved strength properties. The highest WRV value of 2.65 g/g was observed with a 10.0% ethyl acetate treatment in the third recycling stage, which indicates approximately 660% higher WRV compared with control samples (0.34 g/g). Measurements also showed that the optical properties of lightness and the brightness properties of the sheets show variations. However, the highest brightness improvement of 3.8% was observed at 5.0% ethyl acetate treatment at the second recycling stage. This level of treatment has also given the highest lightness value of 73.97, which indicates only 0.54% improvement. The maximum tensile strength value of 23.89 N·m/g was observed at the third recycling stage with 10.0% formamide charge. However, this level of treatment also gave the highest burst at 1.50 kPa·m2/g and tear value of 2.88 N·m2/g, which indicates a 128.2% higher burst and 176.9% higher tear strengths, compared with control samples, respectively.

18

Wytrzymałość na rozciąganie i rozciągliwość papierów przeznaczonych do drukowania

Jakucewicz S.

Przegląd Papierniczy

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2017

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R. 73, nr 11

753--755

19

Wzmocnienie kompozytowe PBO-FRCM. Cz.2

Urbańska D., Musiał M.

Builder

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2017

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R.21, nr 9

64--66

PL

Kompozyty PBO-FRCM (Fibre Reinforced Cementitious Matrix) składają się z włókien PBO (p-Phenylene Benzobis Oxazole) i zaprawy mineralnej, która pełni rolę matrycy. Dzięki temu, w przeciwieństwie do kompozytów FRP, mogą być one stosowane w obiektach narażonych na oddziaływanie wysokiej temperatury. Zastosowanie zaprawy jako matrycy wiąże się jednak ze specyficzną mechaniką pracy tego systemu, która znacznie odróżnia go od systemów FRP. W badaniach przeprowadzonych na kompozytach PBO-FRCM wykazano, że w tym systemie dochodzi do poślizgu między włóknami a warstwą matrycy. Wiąże się z niedokładnym pokryciem wszystkich włókien zaprawą i występowaniem tzw. efektu teleskopowego. W artykule opisano mechanizm pracy wzmocnienia kompozytowego PBO-FRCM poddanego rozciąganiu oraz naprężeniom ścinającym. Omówiono trójfazowy mechanizm pracy kompozytów FRCM oraz główne problemy związane z zastosowaniem tego typu systemu, czyli przedwczesne odspajanie się włókien od matrycy.

EN

PBO-FRCM (Fibre Reinforced Cementitious Matrix) composites cosist of PBO fobers and mineral mortar used as a matrix. It can therefore be used in places exposed to high temperatures, contrary to the systems FRP. The use of mortar, however, is associated, however, with the specific mechanics of work of this system, which significantly differentiates it from FRP systems. The performed studies have shown that in the FRCM system slippage occurs between the fibers and the matrix layer, which is associated with inaccurate coverage of all fibers by mortar and the occurrence of "telescopic effect". The article describes the work mechanism of PBO-FRCM composites subjected to tensile and shear stresses. Three-phase work of FRCM composites and main problems associated with the use of this type of system, which is among other things premature debonding of the fibers from the matrix, were discussed.

20

Development of Knitted Materials Selection for Compression Underwear

Cheng Z., Kuzmichev V. E., Adolphe D. C.

Autex Research Journal

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2017

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Vol. 17, no. 2

177--187

EN

The presented research deals with the development of comfortable male underwear taking into account the development of pattern block methods and the analysis of the relationships existing between the compression pressure, the knitted materials properties, and some push-up effects. The main aim of this study is to achieve the technical selection of the materials based on KES-FB evaluations. The ease value has been used as the main index to connect the structural design of underwear, on one hand, and the body sizes, on other hand. A “bodyshell” system for testing the soft tissue of male bodies by FlexiForce sensor has been implemented. The pressures under the shells at six different places on the male body with ease changing have been tested. The collected results including maximum-possible pressure and material tensile indexes measured thanks to KES-FB have been analyzed in order to find the most relevant indexes of the material properties. A mathematical equations based on relationships combining theoretical model with practical application have been established. These equations will be helpful for the consumers and designers to select “the suitable knitting materials for male underwear” and they can be used too in the perspective of parameterization in CAD, in order to improve product developments efficiency.