Partially Oriented Yarn Research Articles

Design Of the Tension Mechanism Of a Knotter And Optimization Of the Motion Parameters

Abstract Currently, the knotting of chemical fiber filament packages in factories primarily comprises manual operations. It also has a high labor intensity and is subject to artificial subjective factors, due to which it is difficult to guarantee the quality of the finished fiber products. Furthermore, it also significantly restricts the intelligent construction of chemical fiber production. This work employs partially oriented yarn (POY) and full draw yarn (FDY) to develop an automatic knotting device. The catenary theory was used to confirm the state of the yarn and to determine the relevant parameters of the tension mechanism. The results showed that the developed automatic knotting device satisfactorily meets the conditions required for manual knotting. The curve equation that was calculated using the catenary conformations of the yarn state verified that the actual yarn state was consistent with the theory. Moreover, the work provides a theoretical foundation for subsequent mechanism optimizations.

Polyester Yarns Reinforced by Nanoclays

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.

Partially Oriented Yarn (POY) produced from semi-dull via melting spun using an extruder: Effect of die extruder temperature on elongation of the POY

Semi-Dull is a white and slightly opaque polyester type with 0.35 wt% of titanium dioxide (TiO2) content. Whereas, Partially Oriented Yarn (POY) is a type of yarn produced from polyester fibers derived from continuous filament using molten spinning. The used filament fibers have low strength with a very high percentage of elongation. This study aims to analyze the elongation properties of the yarn produced during molten spinning process of raw materials. The yarn produced has 165 denier 96 filaments Semi-Dull POY (i.e. POY 165/96 SDC). In this study, the used raw material is Semi-Dull, which then melted in the extruder machine and spun into Partially Oriented Yarn (POY). The temperatures of the extruder die was varied (i.e. 275, 280, 285°C) and controlled by using a commercial thermal fluid, i.e. DOWTHERM™. The POY samples prepared from the molten spinning process using extruder were then analyzed for their elongation at different extruder die temperatures. The elongation analysis results showed that the elongations of the POY were about 127.17; 137.85; 137.97 % at die temperatures of 275, 280, 285°C, respectively. From the results, it can be concluded that the die temperature has affected the elongation properties of the POY 165/96 SDC yarn.

An investigation on the properties of polyester textured yarns produced with different fiber cross-sectional shapes

In this study, the effects of different fiber cross-sectional shapes and yarn linear density values on Partially Oriented Yarn (POY) and textured yarn characteristics have been examined. In experiment, five different cross-sectional shapes, namely round, trilobal, tetra, hexsa and octolobal and two different linear densities have been used and tenacityelongation, crimp and shrinkage tests have been applied to the yarns. As a result, the round and octolobal crosssectional shapes lead to yarn formation with high tenacity and breaking elongation, on the other hand trilobal and hexsa cause low tenacity and breaking elongation. The round cross-section has provided yarn formation with high crimp and low shrinkage, the hexsa and tetra cross-sectional shapes have caused lower crimp and high shrinkage. It was also observed that the increase in the linear density has caused a decrease in yarn tenacity, however this has increased the crimp and shrinkage behaviours of the yarns.

볼륨감과 신축성이 우수한 신질감 소모조 이수축 혼섬사의 특성분석

c2016 The Korean Fiber Society Abstract: The aim of this study is to develop a mixed polyester latent crimped yarn with excellent bulkiness and stretchability. In order to achieve this goal, the thermal and physical behaviors of yarn obtained from two filaments with different shrinkabilities were investigated under various manufacturing conditions. The partially oriented yarn (POY) exhibited various thermal shrinkages under wet and dry conditions. The fabric hand value is affected by the properties of the POY and by the physical properties of the latent crimped yarns, such as linear density, tenacity, breaking strain, and shrinkage. First, the POY should be spun at speeds in the range of 3,000−3,200 m/min so as to produce a wool-like mixed PET yarn with excellent bulkiness and stretching properties. Second, the manufacturing conditions for the latent crimped yarn should be set as follows: 1) intrinsic viscosity difference between 0.15 and 0.2; 2) setting at 120 C; and 3) a low winding speed and high draw ratio during the spinning process. Finally, the heat roller temperature of the drawing machine should be set between 105−120 C together under overfeeding conditions in order to obtain the desired wool-like mixed latent crimped yarn that exhibits excellent bulkiness and high stretchability, in accordance with the aim of this procedure.

Effect of nature of gas in plasma treatment on thermomechanical properties of polyester fibres

The effect of oxygen (PO), nitrogen (PN) and nitrogen/hydrogen gas mixture (PM) low temperature plasma (LTP) treatment on thermomechanical properties of fully oriented yarn (FOY) and partially oriented yarn (POY) of polyester was studied. The POY was drawn with six different combinations of draw ratios (1.5, 1.8 and 2.0) and draw temperatures (150 °C and 180 °C). Crystallinity, glass transition temperature (Tg) and maximum shrinkage were studied by thermomechanical analyzer (TMA) and differential scanning calorimetry (DSC) in order to identify the effect of LTP on thermomechanical properties of polyester yarns. Crystallinity percentage, Tg and maximum shrinkage were altered differently with LTP treatment.

Effect of drawing temperature on the structure and free volume of semicrystalline polyester yarns

Supercritical carbon dioxide (scCO2), an environmentally friendly solvent, can change the fine structure of fibers depending on treatment temperature and pressure. This article presents the results of an investigation into the effects of drawing temperature, scCO2 exposure and tension on structural changes, and mesomorphic transitions in partially oriented yarn (POY) and oriented poly(ethylene terephthalate) (PET) yarns. Samples of POY and PET yarns were uniaxially drawn at different temperatures to obtain filaments with different structures for subsequent exposure to scCO2 in the presence and absence of tension at a temperature of 80oC and under a pressure of 220 bar. Structural investigation of the samples was performed by combining the results obtained from differential scanning calorimetry, Fourier transform infrared, mechanical deformation, and density and birefringence measurements, all of which exhibited a good correlation. The fractional free volume in the PET samples was considered for interpreting structure–property relations. Results showed that the development of a transient structure strongly depends on process temperature and that for an identical draw ratio, PET yarns drawn at 23oC are significantly more oriented than those drawn at 68oC. Two crystallization mechanisms, that is strain-induced and thermal-induced crystallization, are involved that are frequently used to explain the structural changes during yarn deformation at different temperatures. The degree of crystallinity and orientation factors for PET yarns does not proportionally increase with increasing temperature of the drawing process; indeed, the highest value is obtained at a temperature of 100oC, whereas the lowest is observed at a temperature of 68oC, which is near the glass transition temperature. Tension under scCO2 exposure also produces significant effects in term of causing structural changes. POLYM. ENG. SCI., 55:2030–2041, 2015. © 2014 Society of Plastics Engineers

Study of microstructure of oriented PET fibres exposed to supercritical carbon dioxide

Samples of partially oriented yarn (POY) PET fibers were uniaxially drawn at temperatures below, near, and above the glass transition temperature at a constant draw ratio before exposure to supercritical carbon dioxide (scCO2) in the presence of tension at a temperature of 80 °C and a pressure of 220 bar. The effects of drawing temperature and scCO2 exposure on structural changes and on mesomorphic transitions, in particular, were investigated using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and birefringence and density measurements. A good correlation was obtained among the results obtained from various techniques. Results indicated that the development of a transient mesophase structure depended strongly on process temperature. By drawing PET fibers in the samples at temperatures below the glass transition (cold-drawing), a mesophase structure developed in which the highly extended chains played a key role in structural changes incurred. Meanwhile, exposure to scCO2 led to the plasticization of the samples accompanied by their reduced glass transition and cold crystallization temperatures. This process also gave rise to the appearance of a second melting peak at about 135 °C that is related to the melting of imperfect and thin crystals, thereby inducing structural changes in the treated fibers. In the case of samples subjected to cold drawing and to scCO2 exposure, the transformation of the mesophase structure into the crystalline phase was found to be strongly affected by scCO2 exposure, while this same effect was negligible in the case of hot drawn samples.

Punta Sayısının Örme Kumaşlarda Eğilme Dayanımı Üzerindeki Etkilerinin Araştırılması

In this study, it is aimed to investigate the effects of filament yarn’s number of nips on bending rigidity of knitted fabric which is made of that yarn. For this purpose, polyester POY (Partially Oriented Yarn) filaments with 283 dtex linear density and 68 filaments in cross section were used as raw material. POY bobbins were intermingled at different speed and pressure levels thus yarns having five different numbers of nips were produced. Single jersey knitted fabrics were produced using these yarns on the circular knitting sample machine. According to ASTM circular bending test method, bending rigidity of knitted fabrics was determined by using the digital pneumatic stiffness tester. The effects of the change in the number of nips on the bending rigidity of knitted fabrics were examined and the test results were analyzed statistically.

Preparation and characterization of porous polyester fibres by salt leaching method

Porous polyester fibres with cotton-like dull characteristics were produced by salt leaching method. Polyester was synthesized in the presence of common salt. Fibres containing submicron size salt particles (0.5–1%) were prepared by melt spinning. The fibres were washed in hot water to remove the salt particles creating small craters of size 50–1000 nm. Partially oriented yarn (POY) and fully drawn yarn (FDY) were produced. POY samples were textured to produce polyester textured yarn containing salt particles. The influence of salt particles on polymer crystallization was investigated and found that the presence of salt significantly influences the rate of crystallization. The gloss values of porous FDYs were compared with standard semi-dull polyester yarns of same denier. The light scattering behaviour of the yarn has been enhanced due to porosity. This resulted in a fibre with better dullness characteristics. The light reflectance of porous yarn is lower in the 400–700 nm region compared to control FDY samples. The dyeability of the porous fibre was better than non-porous counterpart.

Puntalama İşleminde Üretim Parametrelerinin ve Filament Özelliklerinin Punta Kalıcılığına Etkisi

The aim of this study is to evaluate many parameters on the intermingling process and to determine statistically the effects of these parameters on the stability of yarn nips. For this purpose, POY (Partially Oriented Yarn) filaments, which have two different linear densities (122, 283 dtex) and two different filament numbers (68, 100) in cross section, were used as raw material. POY bobbins were intermingled by selecting three different speed levels (150, 300, 450 m/min) and three different pressure levels (3, 5, 6 bar). Stability of the nips of intermingled yarns has been tested and this feature was evaluated as response (dependent) variable. Linear densities of POY, number of filaments in crosssection, intermingling speed and intermingling pressure were taken as independent variables. General Factorial Design was applied by using Design Expert 6.0.1 software package and the effects of selected independent variables on the response variables were evaluated statistically and results were interpreted.

Study of structural changes and mesomorphic transitions of oriented poly(ethylene therephthalate) fibers in supercritical CO2

Supercritical carbon dioxide (scCO2), an environmentally friendly solvent, can change the fine structure of fibers depending on treatment temperature and pressure. Samples of partially oriented yarn (POY) PET fibers were uniaxially drawn below the glass transition temperature (Tg) and then exposed to scCO2 under tension to induce morphological changes in them. The effects of draw ratio and scCO2 exposure on the structural changes and mesomorphic transitions were evaluated. For this purpose, thermal characteristics of the structure, especially the rearrangement of polymer chains in the amorphous phase induced by cold-drawing and exposure to scCO2, were evaluated by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR). The orientation factor of the fibers was measured using a polarizing microscope. The paracrystalline portion and the crystallite sizes of exposed samples were estimated by wide-angle X-ray diffraction. To evaluate the solubility of CO2 molecules in the samples, density and fractional free volumes were also measured. A good correlation was obtained between the results obtained from various measurement techniques. Results showed that cold-drawing of PET fibers leads to a strain-induced crystallization and that exposure to scCO2 changes the structure of the oriented PET samples. To investigate mesophase transitions, percentage of extended chains in the amorphous regions was calculated by analyzing the results of DSC and FTIR. Results showed that the amount of extended chains developing during cold-drawing in the amorphous regions decreased when exposed to scCO2.

Effect of drawing temperature on mesomorphic transitions of oriented poly(ethylene terephthalate) fibers exposed to supercritical CO2

Samples of partially oriented yarn (POY) PET fibers were uniaxially drawn at 23, 68 °C (cold drawing) and 100 °C (hot drawing) and then exposed to the supercritical carbon dioxide (scCO2) without tension at a temperature of 80 °C and a pressure of 220 bar. The effect of drawing temperature on the evolution of mesomorphic phases and the structural changes under exposure to scCO2 were investigated by differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and wide-angle X-ray diffraction. The orientation factor of the samples was measured using a polarizing microscope. A good correlation was obtained between the results of various analyses. The results illustrate that evolution of structure strongly depends on both process temperature and post-treatment by scCO2 exposure. The latter process leads to plasticization and reduced glass transition temperature of the samples, thus inducing structural changes in the fibers.

Simulation of polyester melt spinning with axial quench for increasing productivity

AbstractProduction of polyester filament involves melt spinning into partially oriented yarn (POY), followed by drawing to enhance the bulk and mechanical properties. The industrial demand of increasing productivity is generally met by increasing POY melt spinning speeds, which is limited by increasing polymer chain orientation (and reducing residual drawability) in the POY produced at higher spinning speeds. Modification of the quench geometry during melt spinning is claimed to allow reduction of air drag and polymer chain orientation, permitting an increase in productivity during melt spinning into POY. We present a simple way for modeling the quenching of molten filaments under the modified (axial) air flow. Numerical simulations of the melt spinning are developed to demonstrate the influence of the quench geometry modification as we compare the process with the conventional cross‐flow quench and the modified axial quench. We find that increasing quench air flow reduces the polymer chain orientation, in contrast to the well known effect in cross‐flow quench. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Effect of orientation and crystallinity on the photodegradation of poly(ethylene terephthalate) fibers

AbstractIn this research, photodegradation of poly(ethylene terephthalate) (PET) fibers was investigated with emphasis on the morphological state of yarns. Two kinds of yarns, FDY (Fully Drawn Yarn) and POY (Partially Oriented Yarn), with different molecular orientation and crystallinity were applied in this research. FDY is spun in the same way as POY and subsequently drawn at high speed and then entangled before winding up. This sample has higher molecular orientation and crystallinity than the POY sample. Several analytical methods were applied in this study: viscometry, X‐ray diffraction, FTIR spectroscopy, UV–Visible spectrophotometry, and mechanical testing. Viscometry was used to determine molecular weight as a monitoring factor for degradation. X‐ray diagrams showed higher crystallinity for FDY samples during weathering process by irradiation. Results of mechanical testing indicated that the tenacity of the FDY fibers had less deterioration in comparison with the POY ones. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers

The Effects of Operating Conditions on the Product Quality of Partially Oriented Yarn

Fiber spinning is a complex manufacturing process in which the final properties of the spun fiber depend upon the polymer and the process conditions. Due to the great economical and technical importance of the Poly(ethylene terephthalate) (PET) fiber in terms of end use in variety of textile and technical applications, special attention is shown to the relevant processing conditions of the fiber manufacturing. In this study, the effects of polymer residence time, viscosity values, moisture, spinneret throughput, spinneret hole diameter, quench air velocity, friction, and winding speed upon the product quality were examined in a commercial partially oriented yarn (POY) Spinning Plant with a capacity of 70 ton/day.

Application of Box–Wilson Optimization Technique to the Partially Oriented Yarn Properties

A static model for partially oriented yarn (POY) production was examined in a commercial POY spinning plant. A two-level factorial, industrial experimental design was used to identify a statistical model. Three independent variables effecting the elongation at break (a POY property of interest) were selected. Namely, yarn winding speed, spinneret flow rate, and spinneret hole diameter. Elongation at break was chosen as the dependent variable. A first-order statistical model was considered to show the dependence of the elongation at break on the operating parameters: 145%; for elongation at break, the optimum values of yarn winding speed, spinneret flow rate, and spinneret hole diameter were found to be as 2938 m/min, 49.74 g/min, and 205 μm, respectively. The statistical model and Box–Wilson steepest ascent method were used.

連続式高速熱処理／仮撚装置の試作及びそれを利用した常圧可染ＰＥＴ繊維の作成

An attempt was made (1) to design and construct a continuous heat-treatment/false-twisting machine operating at high wind-up speed of up to 600 m/min, and (2) to obtain poly (ethylene terephthalate) (PET) textured yarn dyeable under atmospheric pressure from partially oriented yarn (POY) spun at 3500 m/min by utilizing this machine. In the preliminary experiments, polyurethane rubber disks for a friction media was chosen as adequate, at high speed operation, to give a PET textured yarn without any fault, while much fault was observed on a textured yarn twisted by ceramics disks. The minimum length of the heater necessary when used tublar heater only, for the heat-treatment to obtain PET textured yarn dyeable under atmospheric pressure, was 6 m, too long to use commercially. Then, it was recognized the necessity of making the heat-treatment zone more compact. In the final version of prototype machine, 2 heating rollers were employed on a heat-treatment apparatus coupled with the friction style fales twister. By utilizing this machine, PET-POY was heat-treated at 95°C for 0.43 s with 1st heating roller and at 195°C for 0.43 s with 2nd heating roller followed by false-twisting. After false-twisting, the PET textured yarn was proved dyeable under atmospheric pressure and had good physical properties enabling us to use for textiles practically.