Browsing by Author "ULCAY, YUSUF"

Now showing 1 - 8 of 8

An experimental study for chemical characterization of artificial anterior cruciate ligament with coated chitosan as biomaterial
(De Gruyter Poland Sp Z O O, 2023-06-16) ULCAY, YUSUF; Tursuçular, Ömer Fırat; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Tekstil Mühendisliği Bölümü.
The importance and aim of this experimental study is that raw artificial anterior cruciate ligament samples were produced with various 3-D braiding constructions with various technical yarns using the 3-D braiding method. Later, it is aimed to determine the chemical bond changes between raw samples with ethylene oxide (EtO) sterilization and bio-chemical finishing samples by applying padding process and EtO sterilization processes for all samples with 3-D braiding structures, due to the cross-linking of biocompatible chitosan (CHI) with biological cross-linker glutaraldehyde (GA). The importance of this experimental study is that it is the first experimental chemical analysis in this field in the world scientific study. Padding and EtO sterilization processes were applied on all samples and compared to various technical yarns with 3-D braiding structures thanks to biocompatible CHI. Chemical analysis was interpreted for all samples. It was determined that the applied temperature, concentration, pH, yarn types, characteristic bonds in the chemical structure of the technical yarns, applied bio-chemical finishing process and EtO sterilization had effect on the formation, shifting and breaking of chemical bonds. It was determined that the yarn number, braiding geometry, braiding angle (& DEG;) and braid construction had no effect on the formation or shifting of chemical bonds. New bonds were formed thanks to CHI and GA due to their extremely reactive between 5 and 5.5 pH. They reacted quickly with Schiff base bond in all samples. CHI was ionized in all samples. It was determined that new bonds were formed in UHMWPE, PPD-T and HT PET structures. The most common bond formations were HT PET > PPD-T > UHMWPE. The reasons for these chemical structure changes in all samples depended on their chemical structures, bond types, molecular weights, reactivities, ease and speed of diffusions, crystallinities of technical yarns and all chemicals used. In order to increase the formation of new chemical bonds the pH should be between 5 and 5.5. GA concentration should be a minimum of 25% or higher. The dissolution time of CHI should be minimum 3 h or more. The dissolution process temperature of CHI should be minimum of 70 & DEG;C or higher. The absorption, adsorption and chelation properties of CHI on all samples will also be evident successfully as in this experimental chemical study.
An investigation on the thermal and solar properties of graphene-coated polyester fabrics
(MDPİ, 2021-02-01) Manasoglu, Gizem; MANASOĞLU, GİZEM; Celen, Rumeysa; ÇELEN, RUMEYSA; Kanik, Mehmet; KANIK, MEHMET; Ulcay, Yusuf; ULCAY, YUSUF; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Tekstil Mühendisliği Bölümü.; 0000-0002-1504-8694; 0000-0002-2972-8295; JTS-3559-2023; AAI-8441-2021; AAI-8087-2021; IZE-4329-2023
In this study, coatings were made with graphene nanopowder in two different thicknesses (0.1 and 0.5 mm) at three different concentrations (50, 100 and 150 g/kg) on polyester woven fabrics. The effects of the coating thickness and graphene concentration were examined with optical and scanning electron microscopy (SEM) images. The thermal stability properties of the samples were also evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Thermal conductivity was evaluated with two different principles: contact and radiant heat transfer, according to JIS R 2618 and EN ISO 6942, respectively. Solar measurements were performed with a Shimadzu UV-3600 Plus spectrophotometer. The graphene coating improved the thermal stability of the polyester fabrics. The solar absorbance value increased by 80% compared to reference fabrics, and reached approximately 90%. One of the important results was that the thermal conductivity coefficient increased by 87% and 262% for the two coating thicknesses, respectively.
Investigating electromagnetic shielding effectiveness of knitted fabrics made by barium titanate/polyester bicomponent yarn
(Sage Publications, 2019-04-02) Çelen, Rumeysa; Ulcay, Yusuf; ÇELEN, RUMEYSA; ULCAY, YUSUF; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Tekstil Mühendisliği Bölümü.; 0000-0002-2972-8295; AAI-8087-2021; GHA-2068-2022
Electromagnetic pollution is a problem that damages all creatures and electronic devices. Most of the electronic devices we use at homes emit electromagnetic radiation. Conductive textile surfaces are used for electromagnetic shielding applications. However, to provide electromagnetic shielding, there has not been any study on the bicomponent fiber production with barium titanate. For this purpose, in this study, bicomponent yarns were produced using three different adding ratios of barium titanate. The mechanical and electrical properties of the yarns were investigated. Knitted fabrics were produced from bicomponent yarns with two different fabric densities using a circular knitting machine. The effects of the additive ratio and the fabric density on the effectiveness of the electromagnetic shielding were also investigated. The fabric with the highest content of the barium titanate and greater fabric density showed the highest shielding effectiveness, reaching 25.95 dB at 0.02 GHz.
Investigation of electromagnetic shielding and solar properties of woven fabrics made by barium titanate/polyester bicomponent yarns
(Ege Üniversitesi, 2020-10-14) Çelen, Rumeysa; Ulcay, Yusuf; ÇELEN, RUMEYSA; ULCAY, YUSUF; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Tekstil Mühendisliği Bölümü.; 0000-0002-2972-8295; 0000-0001-6685-8278; AAI-8087-2021; GHA-2068-2022
In this study, electromagnetic shielding and solar properties of woven fabrics which were produced barium titanate/polyester bicomponent yarns were investigated. 1, 2 and 3% additive ratios of barium titanate and three different fabric structures (1/1 plain, sateen and special weave) were used in the experiments. The effect of additive ratio and the fabric structure on sheet resistance and electromagnetic shielding properties were evaluated. Electromagnetic Shielding Effectiveness (EMSE) of the woven fabrics was determined according to the ASTM D4935-10 standard by using coaxial transmission line measurement technique in the frequency range of 15-3000 MHz. The fabric with the highest content of the barium titanate (3%) and special weave showed the highest shielding effectiveness, reaching 13.96 dB at 15 MHz. The solar properties were measured according to EN14500 using a UV/VIS/NIR spectrophotometer and results were calculated according to EN 410 standard. The reflectance values of barium titanate added polyester fabrics increased and the transmittance values decreased.
Polyester yarns reinforced by nanoclays
(Maik Nauka/interperiodica/springer, 2021-05-01) Ulcay, Yusuf; ULCAY, YUSUF; Hojiyev, Rustam; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Tekstil Mühendisliği Bölümü.; AFP-6442-2022
In the present study, poly(ethylene terephthalate)-clay nanocomposite multifilament yarns were prepared using two commercial and four nanoclays synthesized from Resadiye Na-montmorillonite (Na-MMT). Two type multifilament yarns, i.e., fully drawn yarn (FDY) and partially oriented yarn (POY), were melt spun. The FDY yarns were prepared using pilot type Buschaert SpinBoy II CC melt spinning machine with a masterbatch feeding ratio of 4-5% in order to meet industrial machine requirements. The POY spinning was made on the Barmag industrial machine, and the POY yarn was subsequently texturized. All multifilament yarns were prepared via the masterbatch approach, similarly used for the preparation of colored dope dyed yarns. The mechanical properties, flame retardancy, thermal stability, and morphology of produced yarns on melt spinning experiments were analyzed and discussed along with the effect of nanoclay properties such as thermal stability, polymer-clay compatibility, and particle size distribution.
Production of bi-component polyester fibres for emr (Electromagnetic radiation) protection and examining emr shielding characteristics
(Ege Universitesi, 2015-04-01) Eren, Semiha; Ulcay, Yusuf; EREN, SEMİHA; ULCAY, YUSUF; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Tekstil Mühendisliği Bölümü; AEQ-0877-2022; AFL-4209-2022
In this study, multifilament polyester yarns consist of bicomponent S/C (sheath/ core) fibres were produced in order to create electromagnetic shielding properties. Yarns were produced in 260 dtex linear density with 72 bicomponent filaments. The conductive additive material was nano iron oxide 20% (w/w) in PBT (polybutylene terephthalate) masterbatch.1, 2 and 3% masterbatch (20% nano iron oxide in PBT) were fed into the sample yam production device, however; acceptable yarn production could only be achieved by 1% masterbatch due to the high number of machine stops at higher amounts of additive material. Shrinkage at the boil and tenacity tests were performed on the produced yarns. Also, the produced yams were knit to form fabrics and test the EMSE (electromagnetic shielding efficiency) values by these knitted surfaces. The EMSE tests on the knitted fabric samples were performed basically according to ASTM D 4935 Coaxial Holder Method but the method used was a modified method that uses a smaller sample holder. The EMSE values at 30 MHz of the fabric samples knitted by the produced bicomponent yarns were measured as 18,78 dB and 13,59 dB for tight and loose stitch densities, respectively.
Production of bi-component polyester fibres for emr (electromagnetic radiation) protection and examining emr shielding characteristics
(Ege Univ, 2015-04-01) Eren, Semiha; EREN, SEMİHA; Ulcay, Yusuf; ULCAY, YUSUF; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Tekstil Mühendisliği Bölümü.; AEQ-0877-2022; AFL-4209-2022
In this study, multifilament polyester yarns consist of bicomponent S/C (sheath/ core) fibres were produced in order to create electromagnetic shielding properties. Yarns were produced in 260 dtex linear density with 72 bicomponent filaments. The conductive additive material was nano iron oxide 20% (w/w) in PBT (polybutylene terephthalate) masterbatch.1, 2 and 3% masterbatch (20% nano iron oxide in PBT) were fed into the sample yam production device, however; acceptable yarn production could only be achieved by 1% masterbatch due to the high number of machine stops at higher amounts of additive material. Shrinkage at the boil and tenacity tests were performed on the produced yarns. Also, the produced yams were knit to form fabrics and test the EMSE (electromagnetic shielding efficiency) values by these knitted surfaces. The EMSE tests on the knitted fabric samples were performed basically according to ASTM D 4935 Coaxial Holder Method but the method used was a modified method that uses a smaller sample holder. The EMSE values at 30 MHz of the fabric samples knitted by the produced bicomponent yarns were measured as 18,78 dB and 13,59 dB for tight and loose stitch densities, respectively.
Usage of barium titanate in fabric coating and investigation of some properties
(Korean Fiber Soc, 2021-03-03) Celen, Rumeysa; Manasoğlu, Gizem; Ulcay, Yusuf; Kanık, Mehmet; ÇELEN, RUMEYSA; MANASOĞLU, GİZEM; ULCAY, YUSUF; KANIK, MEHMET; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Tekstil Mühendisliği Bölümü; 0000-0002-2972-8295; 0000-0002-1504-8694; JTS-3559-2023; HRC-4302-2023; KGU-5587-2024; GHA-2068-2022
In this study, nano-sized barium titanate powder was applied for the first time to polyester woven fabrics by knife coating at three different concentration rates. Some physical (thickness, mass per unit area, bending rigidity, air permeability and tear strength) properties, electromagnetic shielding efficiency and solar (transmittance, reflectance) properties of samples were presented. The samples were also characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Electromagnetic shielding effectiveness of the fabrics was determined according to the ASTM D4935-10 standard by using a coaxial transmission line measurement technique in the frequency range of 15-3000 MHz. The solar properties were measured according to EN14500 standard using a UV/VIS/NIR spectrophotometer and results were calculated according to EN 410 standard. Results revealed that the electromagnetic shielding effectiveness and solar reflectance property of samples improved with increasing barium titanate concentration.