scholarly journals Influences on Textile and Mechanical Properties of Recycled Carbon Fiber Nonwovens Produced by Carding

2021 ◽  
Vol 5 (8) ◽  
pp. 209
Author(s):  
Frank Manis ◽  
Georg Stegschuster ◽  
Jakob Wölling ◽  
Stefan Schlichter

Nonwovens made of recycled carbon fibers (rCF) and thermoplastic (TP) fibers have excellent economic and ecological potential. In contrast to new fibers, recycled carbon fibers are significantly cheaper, and the CO2 footprint is mostly compensated by energy savings in the first product life cycle. The next step for this promising material is its industrial serial use. Therefore, we analyzed the process chain from fiber to composite material. Initially, the rCF length at different positions during the carding process was measured. Thereafter, we evaluated the influence of the TP fibers on the processing, fiber shortening, and mechanical properties. Finally, several nonwovens with different TP fibers and fiber volume contents between 15 vol% and 30 vol% were produced, consolidated by hot-pressing, and tested by four-point bending to determine the mechanical values. The fiber length reduction ranged from 20.6% to 28.4%. TP fibers cushioned the rCF against mechanical stress but held rCF fragments back due to their crimp. The resulting bending strength varied from 301 to 405 MPa, and the stiffness ranged from 16.3 to 30.1 GPa. Design recommendations for reduced fiber shortening are derived as well as material mixtures that offer better homogeneity and higher mechanical properties.

2020 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Nhan Thi Thanh Nguyen ◽  
Obunai Kiyotaka ◽  
Okubo Kazuya ◽  
Fujii Toru ◽  
Shibata Ou ◽  
...  

In this research, three kinds of carbon fiber (CF) with lengths of 1, 3, and 25 mm were prepared for processing composite. The effect of submicron glass fiber addition (sGF) on mechanical properties of composites with different CF lengths was investigated and compared throughout static tests (i.e., bending, tensile, and impact), as well as the tension-tension fatigue test. The strengths of composites increased with the increase of CF length. However, there was a significant improvement when the fiber length changed from 1 to 3 mm. The mechanical performance of 3 and 25 mm was almost the same when having an equal volume fraction, except for the impact resistance. Comparing the static strengths when varying the sGF content, an improvement of bending strength was confirmed when sGF was added into 1 mm composite due to toughened matrix. However, when longer fiber was used and fiber concentration was high, mechanical properties of composite were almost dependent on the CF. Therefore, the modification effect of matrix due to sGF addition disappeared. In contrast to the static strengths, the fatigue durability of composites increased proportionally to the content of glass fiber in the matrix, regardless to CF length.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Zhao Yang ◽  
Kun Wu

To study the tensile mechanical properties of sprayed FRP, 13 groups of specimens were tested through uniaxial tensile experiments, being analyzed about stress-strain curve, tensile strength, elastic modulus, breaking elongation, and other mechanical properties. Influencing factors on tensile mechanical properties of sprayed FRP such as fiber type, resin type, fiber volume ratio, fiber length, and composite thickness were studied in the paper too. The results show that both fiber type and resin type have an obvious influence on tensile mechanical properties of sprayed FRP. There will be a specific fiber volume ratio for sprayed FRP to obtain the best tensile mechanical property. The increase of fiber length can lead to better tensile performance, while that of composite thickness results in property degradation. The study can provide reference to popularization and application of sprayed FRP material used in structure reinforcement.


2021 ◽  
Vol 6 (1) ◽  
pp. 30-37
Author(s):  
Sri Hastuti ◽  
Herru Santosa Budiono ◽  
Diki Ilham Ivadiyanto ◽  
Muhammad Nurdin Nahar

Inovasi baru serat dari sabut kelapa dimanfaatkan untuk meningkatkan nilai ekonomis dari serat sabut kelapa, oleh karena itu dirancanglah pendayagunaan serat dari sabut kelapa untuk penguat komposit dengan material serat alam yang biodegradable. Hal ini untuk mendukung penggunaan komposit yang ramah terhadap lingkungan dan mengurangi penggunaan material komposit serat sintetis yang polutan. Tujuan penelitian adalah menganalisis sifat mekanik pada komposit serat alam bermaterial serat dari sabut kelapa yang ramah lingkungan. Metode penelitian pembuatan komposit berpenguat serat dari sabut kelapa dilakukan treatment NaOH 15% selama 5 jam dan fraksi volume serat 10 %, 15 %, dan 20 %. Komposit  serat dari sabut kelapa dengan matriks UPRs 157 BQTN dengan hardener MEXPO. Pengujian mekanik dilakukan uji bending menggunakan standar ASTM D790 dan uji impak  menggunakan standar ASTM D5941.  Pengujian impak komposit serat alam menunjukkan ketangguhan impak komposit pada fraksi volume serat 20% dengan nilai 0.017588J/mm2. Hasil pengujian menunjukkan peningkatan fraksi volume serta berpengaruh terhadap peningkatan kekuatan bending komposit serat dari sabut kelapa  dengan kekuatan optimum bending pada fraksi volume serat 10% dengan nilai 44,33N/mm2. Hal ini menunjukkan peningkatan fraksi volume serat dengan perendaman NaOH 15% akan meningkatkan sifat mekanik bending dan impak komposit. Perendaman NaOH memberikan pengaruh daya serap sabut kelapa terhadap matrik Unsaturated Polyester yang dapat meningkatkan daya rekat antara penguat serat dengan matrik sehingga meningkatkan sifat mekanik bending dan impak komposit. ABSTRACT The innovation of coco fiber is used to increase the economic value of coconut coir, therefore the utilization of coconut fiber for reinforcing composites with biodegradable natural fiber material is designed. This is to support the use of composites that are friendly to the environment and reduce the use of pollutant synthetic fiber composite materials. The research objective was to analyze the mechanical properties of natural fiber composites with environmentally friendly coconut fiber as material. The research method of making fiber-reinforced composites from coconut coir was carried out by 15% NaOH treatment for 5 hours and a fiber volume fraction of 10%, 15%, and 20%. Composite fiber from coconut coir with UPRs 157 BQTN matrix with MEXPO hardener. Mechanical testing is carried out using the ASTM D790 standard and the impact test using the ASTM D5941 standard. The impact test of natural fiber composites showed the impact toughness of the composite at a fiber volume fraction of 20% with a value of 0.017588 J/ mm2. The test results showed an increase in volume fraction and an effect on the increase in the bending strength of coconut fiber composites with the optimum bending strength at a fiber volume fraction of 10% with a value of 44.33N /mm2. This shows that the increase in fiber volume fraction by immersion in 15% NaOH will increase the bending mechanical properties and the impact of the composite. Soaking NaOH has an effect on the absorption power of coconut coir on the Unsaturated Polyester matrix which can increase the adhesion between the fiber reinforcement and the matrix thereby increasing the bending mechanical properties and impact of the composite.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Gwang-Hee Heo ◽  
Jong-Gun Park ◽  
Ki-Chang Song ◽  
Jong-Ho Park ◽  
Hyung-Min Jun

In the present study, SiO2 particles were coated on the surface of carbon fibers by means of chemical reaction of silane coupling agent (glycidoxypropyl trimethoxysilane, GPTMS) and colloidal SiO2 sol to improve the interfacial bonding force between fibers and matrix in cement matrix. The surface of the modified carbon fibers was confirmed through a scanning electron microscope (SEM). The mechanical properties of SiO2-coated carbon fiber mortar and uncoated carbon fiber mortar with different fiber lengths (6 mm and 12 mm) and fiber volume fractions (0.5%, 1.0%, 1.5%, and 2.0%) were compared and analyzed. The experimental results show that the flow values of the carbon fiber mortar were greatly disadvantageous in terms of fluidity due to the nonhydrophilicity of fibers and fiber balls, and the unit weight decreased significantly as the fiber volume fractions increased. However, the air content increased more or less. In addition, regardless of whether the fibers were coated, the compressive strength of carbon fiber-reinforced mortar (CFRM) composite specimens tended to gradually decrease as the fiber volume fractions increased. On the other hand, in case of the SiO2-coated CFRM composite specimens, the flexural strength was significantly increased compared to uncoated CFRM composite specimens and plain mortar specimens, and the highest flexural strength was obtained at 12 mm and 1.5%, particularly. It can be seen that the new carbon fiber surface modification method employed in this study was very effective in enhancing the flexural strength as cement-reinforcing materials.


2006 ◽  
Vol 7 (5) ◽  
pp. 10-17 ◽  
Author(s):  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu ◽  
Sufyan K. Garoushi

Abstract Aim The aim of this study was to determine the effect of short fiber volume fraction and fiber length on some mechanical properties of short fiber-reinforced composite (FRC). Methods and Materials Test specimens (2 x 2 x 25 mm3) and (9.5 x 5.5 x 3 mm3) were made from short random FRC and prepared with different fiber volumes (0%-22%) and fiber lengths (1-6 mm). Control specimens did not contain fiber reinforcement. The test specimens (n=6) were either dry stored or thermocycled in water (x10.000, 5 – 55°C) before loading (three-point bending test) according to ISO 10477 or statically loaded with a steel ball (Ø 3.0 mm) with a speed of 1.0 mm/min until fracture. A universal testing machine was used to determine the flexural properties and the load-bearing capacity. Data were analyzed using analysis of variance (ANOVA) (p=0.05) and a linear regression model. Results The highest flexural strength and fracture load values were registered for specimens with 22 vol% of fibers (330 MPa and 2308 N) and with 5 mm fiber length (281 MPa and 2222 N) in dry conditions. Mechanical properties of all test specimens decreased after thermocycling. ANOVA analysis revealed all factors were affected significantly on the mechanical properties (p<0.001). Conclusions By increasing the volume fraction and length of short fibers up to 5 mm, which was the optimum length, the mechanical properties of short FRC were improved. Citation Garoushi SK, Lassila LVJ, Vallittu PK. Short Fiber Reinforced Composite: The Effect of Fiber Length and Volume Fraction. J Contemp Dent Pract 2006 November;(7)5:010-017.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5741
Author(s):  
Agnieszka Baziak ◽  
Kinga Pławecka ◽  
Izabela Hager ◽  
Arnaud Castel ◽  
Kinga Korniejenko

The aim of this paper is to analyze the influence of hybrid fiber reinforcement on the properties of a lightweight fly ash-based geopolymer. The matrix includes the ratio of fly ash and microspheres at 1:1. Carbon and steel fibers have been chosen due to their high mechanical properties as reinforcement. Short steel fibers (SFs) and/or carbon fibers (CFs) were used as reinforcement in the following proportions: 2.0% wt. CFs, 1.5% wt. CFs and 0.5% wt. SFs, 1.0% wt. CFs and 1.0% wt. SFs, 0.5% wt. CFs and 1.5% wt. SFs and 2.0% wt. SFs. Hybrid reinforcement of geopolymer composites was used to obtain optimal strength properties, i.e., compressive strength due to steel fiber and bending strength due to carbon fibers. Additionally, reference samples consisting of the geopolymer matrix material itself. After the production of geopolymer composites, their density was examined, and the structure (using scanning electron microscopy) and mechanical properties (i.e., bending and compressive strength) in relation to the type and amount of reinforcement. In addition, to determine the thermal insulation properties of the geopolymer matrix, its thermal conductivity coefficient was determined. The results show that the addition of fiber improved compressive and bending strength. The best compressive strength is obtained for a steel fiber-reinforced composite (2.0% wt.). The best bending strength is obtained for the hybrid reinforced composite: 1.5% wt. CFs and 0.5% wt. SFs. The geopolymer composite is characterized by low thermal conductivity (0.18–0.22 W/m ∙ K) at low density (0.89–0.93 g/cm3).


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
K. B. Prakash ◽  
Yahya Ali Fageehi ◽  
Rajasekaran Saminathan ◽  
P. Manoj Kumar ◽  
S. Saravanakumar ◽  
...  

There is more demand for natural fiber-reinforced composites in the energy sector, and their impact on the environment is almost zero. Natural fiber has plenty of advantages, such as easy recycling and degrading property, low density, and low price. Natural fiber’s thermal properties and flexural properties are less than conventional fiber. This work deals with the changes in the thermal properties and mechanical properties of S-glass reinforced with a sodium hydroxide-treated pineapple leaf (PALF) and banana stem fibers. Banana stem and pineapple leaf fibers (PALF) were used at various volume fractions, i.e., 30%, 40%, and 50%, and various fiber lengths of 20 cm, 30 cm, and 40 cm with S-glass, and their effects on the thermal and mechanical properties were studied, and their optimum values were found. It was evidenced that increasing the fiber volume and fiber length enhanced the flexural and thermal properties up to 40% of the fiber volume, and started to decrease at 50% of the fiber volume. The fiber length provides an affirmative effect on the flexural properties and a pessimistic effect on the thermal properties. The PALF S-glass combination of 40% fiber load and 40 cm fiber length provides maximum flexural strength, flexural modulus, storage modulus, and lowest loss modulus based on hybrid Taguchi grey relational optimization techniques. PALF S-glass hybrid composite has been found to have 7.80%, 3.44%, 1.17% higher flexural strength, flexural modulus, and loss modulus, respectively, and 15.74% lower storage modulus compared to banana S-glass hybrid composite.


2021 ◽  
Vol 113 ◽  
pp. 65-73
Author(s):  
Jakub Kawalerczyk ◽  
Marcin Kuliński ◽  
Dorota Dziurka ◽  
Radosław Mirski

The possibility to use a side-timber in glulam beams manufacturing for structural applications. The aim of presented study was to determine the mechanical properties of three-layered glued structural beams manufactured with the use of side-timber pieces as an outer layers and the fragmented main yield as an inner layer. Four types of beams were pressed and tested in terms of four-point bending strength and modulus of elasticity. Variants differed from each other in the direction of the fibers in the inner layer and in the presence of adhesive layer between the fragmented wood. Studies have shown that the bending strength of the beams depended on the calculation method. Moreover, no significant effect of the inner layer arranging method on the bending strength of the beams was found. The values of modulus of elasticity (MOE) were low. The presented study is a starting point for further investigations concerning the possible way of the rational application of fragmented timber pieces and the side-timber for structural applications.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1448 ◽  
Author(s):  
Yingwu Zhou ◽  
Bin Xi ◽  
Kequan Yu ◽  
Lili Sui ◽  
Feng Xing

This paper presents the authors’ newly developed hybrid ultra-high performance (HUHP) engineered cementitious composite (ECC) with steel (ST) and polyethylene (PE) fibers. From this point on it will be referred to as HUHP-ECC. The volumes of steel and PE fibers were adjusted to obtain different mechanical properties, including compressive strength, tensile, and flexural properties. We found that tensile and flexural properties, including bending strength and ductility indexes, increased with higher PE fiber amounts but reduced with the increased ST fiber volume. Notably, the compressive strength had the opposite tendency and decreased with increases in the PE volume. The ST fiber had a significantly positive effect on the compressive strength. The fluidity of HUHP-ECC improved with the increasing amount of ST fiber. The pseudo strain-hardening (PSH) values for all the HUHP-ECC mixtures were used to create an index indicating the ability of strain capacity; thus, the PSH values were calculated to explain the ductility of HUHP-ECC with different fiber volumes. Finally, the morphology of PE and ST fibers at the fracture surface was observed by an environmental scanning electron microscope (ESEM).


2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Xinzhong Wang ◽  
Jun He ◽  
Ayman S. Mosallam ◽  
Chuanxi Li ◽  
Haohui Xin

Basalt fiber reinforced concrete (BFRC) has been widely utilized in various constructions such as buildings, large industrial floors, and highways, due to its excellent physical and mechanical properties, as well as low production cost. In order to address the influence of basic parameters such as fiber volume fraction (0.05∼0.40%), fiber length (12∼36 mm) of BF, and compressive strength (30, 40, and 50 MPa) of concrete on both physical and mechanical properties of BFRC including compressive strength, tensile and flexural strength, workability, and anti-dry-shrinkage cracking properties, a series of standard material tests were conducted. Experimental results indicated that clumping of fibers may occur at relatively higher fiber volume fraction resulting in mixing and casting problems. Based on experimental values of mechanical properties and anti-dry-shrinkage cracking resistance of BFRC, the reasonable basalt fiber length and fiber volume fractions are identified. The addition of a small amount of short basalt fibers can result in a considerable increase in both compressive strength and modulus of rupture (MoR) of BFRC and that the proposed fiber length and content are 12.0 mm and 0.10%∼0.15%, respectively. As the length of basalt fibers increases, the development of early shrinkage cracks decreases initially and then increases slowly and the optimal fiber length is 18.0 mm. Results of the study also indicated that early shrinkage cracks decrease with the increase of fiber volume fraction, and when the volume fraction of 0.20% is used, no cracks were observed. All the findings of the present study may provide reference for the material proportion design of BFRC.


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