Person: SANCAK, ERHAN
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SANCAK
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ERHAN
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Publication Open Access Analyses of the mechanical, electrical and electromagnetic shielding properties of thermoplastic composites doped with conductive nanofillers(SAGE PUBLICATIONS LTD, 2018-05) SANCAK, ERHAN; Yilmaz, Ali Can; Ozen, Mustafa Sabri; Sancak, Erhan; Erdem, Ramazan; Erdem, Ozlem; Soin, NavneetThe purpose of this study is to observe effect of incorporating vapor-grown carbon nanofibers with various amounts in polyvinylidene fluoride matrix in terms of mechanical strength and electromagnetic shielding effectiveness. Thermoplastic conductive nanocomposites were prepared by heat-pressed compression molding. Vapor-grown carbon nanofibers were utilized at various weight ratios (1wt.%, 3wt.%, 5wt.%, and 8wt.%) as conductive and reinforcing materials. Polyvinylidene fluoride was used as a thermoplastic polymer matrix. Scanning electron microscopic analysis was conducted in order to characterize the morphology and structural properties of the nanocomposites and results revealed well dispersion of carbon nanofibers within the matrix for all concentrations. Mechanical characteristics were investigated according to standards. Findings proved that overall increments of 16%, 37.5%, and 56% were achieved in terms of tensile strength, elasticity modulus, and impact energy, respectively, where a total reduction of 44.8% was observed in terms of elongation for 8wt.% vapor-grown nanofiber matrix compared to that of 0wt.%. Electromagnetic shielding effectivenesses of the nanocomposites were determined by standard protocol using coaxial transmission line measurement technique in the frequency range of 15-3000 MHz. It was observed that resistance, sheet resistance, and resistivity of nanocomposites depicted substantial reduction with the increment in nanofiber content. Nevertheless, it was observed that nanofiber content, dispersion, and network formation within the composites were highly influent on the electromagnetic shielding effectiveness performance of the structures.Publication Metadata only Investigation of electromagnetic shielding properties of needle-punched nonwoven fabrics with stainless steel and polyester fiber(SAGE PUBLICATIONS LTD, 2013) BEYİT, ALİ; Ozen, Mustafa Sabri; Sancak, Erhan; Beyit, Ali; Usta, Ismail; Akalin, MehmetIn this study, electromagnetic shielding properties of needle-punched nonwoven fabrics were investigated. The paper evaluates and compares the electromagnetic shielding of needle-punched nonwoven fabrics produced from stainless steel/polyester and normal polyester fibers. Stainless steel/polyester fiber and normal polyester fiber were blended at specified ratios in the experimental study. Webs were produced from the fibers with the carding machine and then bonded with the needle-punching machines. The thickness and electromagnetic shielding properties of the needle-punched fabrics were tested. An electromagnetic shielding effectiveness (EMSE) device was used for measuring the electromagnetic shielding. The experimental study indicated that as the conductive stainless steel fiber ratio in nonwoven fabrics increases, the EMSE also increases at low, medium and high frequencies. Satisfactory electromagnetic shielding values were obtained at wide bandwidth, i.e. 1200-3000 MHz. The highest EMSE values of the needle-punched nonwoven fabric with 25% conductive steel fiber were, respectively, 6 dB at 0-300 MHz low frequency, 12 dB at 300-1200 MHz medium frequency and 18 dB at 1200-3000 MHz high frequency. It was found that 90% of electromagnetic waves were shielded by nonwoven fabric at high frequencies, 85% at medium frequencies and 80% at low frequencies.Publication Metadata only The Effects of Fabric and Conductive Wire Properties on Electromagnetic Shielding Effectiveness and Surface Resistivity of Interlock Knitted Fabrics(KOREAN FIBER SOC, 2018) SANCAK, ERHAN; Sancak, E.; Akalin, M.; Usta, I.; Yuksek, M.; Ozen, M. S.Our aim in this study was to investigate the effects of course density, yarn linear density and thickness and type of conductive wire on electromagnetic shielding effectiveness. Metal/cotton conductive composite yarns were produced by the core-spun technique on the ring spinning machine, involving stainless steel, copper and silver coated copper wires with 40 mu m, 50 mu m, 60 mu m thicknesses and Ne10/1 and Ne20/1 count yarns. The interlock fabrics were knitted on a 7G flat knitting machine with the three different machine settings. The EMSE and the surface resistivity of knitted fabrics were measured by the co-axial transmission line method according to the ASTM-D4935-10 standard in the frequency range from 15 to 3000 MHz and by the ASTM D257-07 standard, respectively. It was observed that all fabrics shielded around 95 % of electromagnetic waves at low frequencies, 80 % at medium frequencies and 70 % at high frequencies. Increasing the course density and thickness of conductive wire in interlock knitted fabrics increased the EMSE correspondingly. The knitted fabrics that had been produced with high yarn count showed greater EMSE because there was less isolation. The effect of the metal wire type was highly significant between 15 and 600 MHz.Publication Metadata only Development of bio-composite structures for Interior noise reduction in automobiles(2018-12-07) PARS, ABDULKADİR; SANCAK, ERHAN; BEYİT, ALİ; ÖZEN, MUSTAFA SABRİ; YÜKSEK, METİN; USTA, İSMAİL; PARS A., SANCAK E., BEYİT A., ÖZEN M. S. , YÜKSEK M., USTA İ.Publication Metadata only Investigation of the Electromagnetic Shielding Effectiveness of Needle Punched Nonwoven Fabrics Produced from Stainless Steel and Carbon Fibres(INST CHEMICAL FIBRES, 2018) SANCAK, ERHAN; Ozen, Mustafa Sabri; Usta, Ismail; Yuksek, Metin; Sancak, Erhan; Soin, NavneetThe electromagnetic shielding effectiveness (EMSE) of needle punched, nonwoven fabrics produced using staple stainless steel and carbon fibres was investigated. Utilising carding and large scale industrial type needle punching machines, webs of staple stainless steel and carbon fibres were produced, which were subsequently bonded on the needle punching machine at approximately 132 punches/cm(2) and 13.5 mm needle penetration depth. The effect of varying the carbon fibre content was studied by varying the blend ratio of stainless steel and carbon fibres between 5-20%. EMSE measurements of as-produced needle punched nonwoven fabrics were carried out using the coaxial transmission line method (ASTM D4935-10) in the frequency range of 15-3000 MHz. Within the range, the EMSE values were enhanced from 22.3 dB (95/5, stainless steel/carbon) to 44.7 dB (80/20, stainless steel/carbon), which was attributed to the enhanced conductivity of the fabrics. In fact, the surface resistivity of the samples decreased from 5.80E + 3 Omega to 2.43E + 2 Omega, enhanced for 95: 5 and 80: 20 stainless steel/carbon blends.Publication Metadata only Investigation of electromagnetic shielding effectiveness of needle punched nonwoven fabrics with staple polypropylene and carbon fibres(TAYLOR & FRANCIS LTD, 2016) SANCAK, ERHAN; Ozen, Mustafa Sabri; Sancak, ErhanConductive needle punched nonwoven fabrics are developed from staple polypropylene (PP) and varying weight fractions (10, 20 and 30 wt.%) of staple carbon fibres. A fibrous webs of staple PP and carbon fibres were formed at a wool-type carding machine, and these webs subsequently bonded on needle punching machine with 132 punches/cm(2) and 13.5 mm needle penetration depth. The electromagnetic shielding effectiveness (EMSE), absorption and reflection characteristics of as-produced needle punched nonwoven fabrics were determined using a network analyser as specified in ASTM D4935-10 in the frequency range 15-3000 MHz. The surface resistivity measurements were carried out in accordance with ASTM D 257-07 standard. These results indicate that the EMSE values increase incrementally with frequency in the 15-3000 MHz range. The nonwoven sample with 30 wt.% carbon fibre showed the lowest surface resistivity of 3.348 k Omega and corresponding highest EMSE of similar to 42.1 dB in the 3000 MHz frequency range. In comparison, the highest EMSE values from 10 to 20 wt.% staple carbon fibre were found to be 15.6 and 32.2 dB in the 3000 MHz frequency, respectively. It was observed that the absorbance and reflectance curves of each nonwoven fabric move at opposite directions to each other. It was found that as the amount of carbon fibre in the nonwoven fabric increases, absorbance values decrease, but reflectance values increase. The resultant nonwoven fabric samples are expected to be used as garment interlining after thermal bonding and wall interlayer in the future.Publication Open Access Unprecedented Electromagnetic Shielding Effectiveness of Lightweight Nonwoven Ag/PA66 Fabrics(KOREAN FIBER SOC, 2018-02) SANCAK, ERHAN; Ozen, M. S.; Sancak, E.; Soin, N.; Shah, T. H.; Zarei, A.; Siores, E.Novel, high-performance silver coated polyamide, Ag/PA66, nonwoven fabrics with a density of only 0.04 g/cm(3) have been developed using staple fibres of 19 (3.3 dtex) and 27 (6.7 dtex) mu m diameter. The obtained nonwoven fabrics with an Ag loading of 12-18 wt% exhibited excellent weight-normalised specific electromagnetic shielding effectiveness of over 1200 dB/(g/cm(3)) in the 0.015-3 GHz range, which is among the highest reported till date. Moreover, the applied microwave was verified to be absorbed rather than being reflected back making the fabrics highly suitable for shielding applications. It was also observed that nonwoven fabrics made from finer 3.3 dtex Ag/PA66 fibres have higher reflection and lower absorption values than their thicker (6.7 dtex) counterparts. Additionally, we have also explored the use of these nonwoven Ag/PA66 fabrics for personal thermal management via Joule heating with samples showing rapid heating response (up to 0.2 degrees C/sec) and long-term stability measured over 10,000 seconds. The needle-punched Ag/PA66 nonwoven fabrics, in spite of their low density of the order of 0.04 g/cm(2), exhibited high EMSE values of nearly 69-80 dB, leading to excellent weight-normalised specific electromagnetic shielding effectiveness of over 1200 dB/(g/cm(3)) in the 0.015-3 GHz range. The production of Ag/PA66 needle punched nonwoven fabrics thus offers a facile route to develop multifunctional fabrics for EMI shielding as well as personal thermal management applications.Publication Metadata only Investigation of electromagnetic shielding effectiveness of needle punched nonwoven fabric produced from conductive silver coated staple polyamide fibre(TAYLOR & FRANCIS LTD, 2016) SANCAK, ERHAN; Ozen, Mustafa Sabri; Sancak, Erhan; Soin, Navneet; Shah, Tahir H.; Siores, EliasIn this paper, electromagnetic shielding effectiveness (EMSE) of needle-punched nonwoven fabric produced from silver-coated staple polyamide fibre having a fineness of 1.7dtex was investigated. This production was carried out at Automatex needle punching line, which consists of carding, cross lapper and needle punching machine. After production, the surface resistivity measurements of needle-punched nonwoven fabric was carried out in accordance with ASTM D 257-07 standard. The EMSE of the as-produced needle-punched nonwoven fabric was determined using a network analyzer as specified in ASTM D4935-10 in the frequency range of 15-3000MHz. Electromagnetic shielding test shows that needle-punched nonwoven fabric produced from 1.7-dtex silver-coated polyamide fibre has the highest shielding value of 36.53dB in the frequency range of 15-3000MHz. The EMSE of needle-punched nonwoven fabric with fibre fineness of 1.7dtex increased from 11.00dB maximum to 36.53dB in the 15-3000 MHz frequency range. It was seen that as the frequency increases, reflection values of the needle-punched nonwoven fabric decrease at floating mode, while absorption values of the nonwoven fabric increase at floating mode in the frequency range of 15-3000MHz. EMSE results of the needle-punched nonwoven fabric produced from 1.7-dtex silver-coated staple polyamide fibres were compared to carbon fabric and needle-punched nonwoven fabric made from stainless steel fibres.Publication Metadata only The Effect of Laser Radiation in Different Mordant and Ratios on Silk Fabrics Dyed with Weld (Reseda luteola L.)(TAYLOR & FRANCIS INC) PARS, ABDULKADİR; Pars, Abdulkadir; Karadag, Recep; Ozen, Mustafa Sabri; Sancak, ErhanIn this study, the silk fabrics mordanted at the ratio of 1%, 5%, 10%, 20% of aluminum potassium sulfate (KAl(SO4)(2)center dot 12H(2)O) and 0.1%, 0.5%, 1%, 3%, of iron sulfate (FeSO4) were separately dyed 50% weld (Reseda luteola L.). Then firstly, laser radiation was used on un-mordanted silk fabrics and as a second step, silk samples with different ratios mordanted and dyed with weld were irradiated to investigate the laser radiation effects on color using several combinations of the two main laser parameters namely energy density and number of pulses. Nd:YAG laser device was used two different wavelengths of 1064 nm and 532 nm, and it was found that the laser wavelength of 532 nm is most appropriate to all dyed fabrics, while 1064 nm wavelength causes damages such as discoloration and burning in the iron sulfate mordanted fabrics. Colorimetric analysis was performed to examine surface alterations of silk samples. The CIEL*a*b* color values of the silk fabrics were measured and compared with each other. In general, the use of iron sulfate (FeSO4) as a mordant increased the color difference (Delta E*) of dyed fabrics at 1064 nm. The color coordinates and fastness values of rubbing and light were investigated. Morphological analysis was performed using optical and scanning electron microscopy. Elemental analysis was performed using SEM-EDX (scanning electron microscopy-energy-dispersive X-ray spectroscopy) to identify mordants. A reserved phase high-performance liquid chromatography (RP-HPLC) with the diode-array detection (DAD) method was utilized for the identification of the components of dyes present in the silk samples.Publication Metadata only The effect of needle-punched nonwoven fabric thickness on electromagnetic shielding effectiveness(SAGE PUBLICATIONS LTD, 2015) SANCAK, ERHAN; Ozen, Mustafa Sabri; Sancak, Erhan; Akalin, MehmetIn this study, the effect of nonwoven fabric thickness on electromagnetic shielding effectiveness (EMSE) was investigated and there was found to be a correlation between the thickness of needle-punched nonwoven fabric and EMSE. The production of needle-punched nonwoven fabrics from stainless steel staple fiber in the experimental study was carried out. Stainless steel staple fibers provided by Bekaert were used as a raw material. The webs were formed using a wool-type carding machine. The webs were bonded using needling punching machines. The pre-needled, twice-needled and thrice-needled nonwoven fabrics at three different thicknesses were produced. The experimental studies were carried out using large-scale production machines instead of small-scale laboratory-type machines. EMSE measurements of produced needle-punched nonwoven fabrics, in addition to physical properties such as strength, elongation and thickness, were performed. The coaxial transmission line method specified in ASTM D4935-10 was utilized to test the nonwoven fabrics and the needle-punched nonwoven fabrics were tested in the frequency range from 15 to 3000 MHz. It was understood that needle-punched nonwoven fabric thickness was a very important parameter for EMSE. It was found that as the frequency increases, EMSE values of needle-punched nonwoven fabrics showed continuously increasing tendency by starting from a specific frequency in the frequency range of 15-3000MHz. There were no significant differences between absorption and reflection values of needle-punched nonwoven fabrics produced at different thicknesses. It was found that pre-needle-punched, twice-needled and thrice-needle-punched nonwoven fabrics produced from the conductive stainless steel staple fibers in our study have, respectively, highest EMSE values of 22, 25 and 27 dB between 2100 and 2400 high frequency ranges.