Hollow Polyester Fibers Research Articles

Sound absorption characteristics of agro-sourced kapok fibrous materials

In this work, a new band yarn woven (BYW) fabric has been developed to improve the sound absorption of kapok fibrous materials. BYW fabric materials were prepared by the interweaving of the normal hollow polyester yarn with new band yarn produced by wrapping the super thin nonwoven around a twisted fiber web. This soft, thin, lightweight fabric is promising to get the door of a wide variety of agro-sourced kapok fiber for sound absorption applications. The sound absorption of BYW fabric and the normal woven fabric have been compared, and the effects of fiber type, kapok fiber content, and airflow resistivity on sound absorption of BYW fabric materials have also been investigated. The results show that BYW fabric exhibited better sound absorption than the normal fabric, and it can be further enhanced when the band yarn was prepared from kapok fiber instead of hollow polyester or cotton fiber. The sound absorption can be improved with the increasing content of kapok fiber. Furthermore, a new sound absorption empirical model based on the Delany-Bazley model was developed. Calculated sound absorption coefficients obtained from the new model agreed well with measured results. Kapok fiber, exhibits higher hollowness and smaller fiber diameter than common natural fibers, and it presents promising prospect to reduce environmental noise pollution.

The normal incidence sound absorption of the thin band yarn woven fabric with kapok fiber

In order to increase kapok fiber content to improve the sound absorption of woven fabric materials with kapok fiber, the kapok fiber woven fabric materials with a new band yarn structure have been fabricated in this paper. The mass percent of kapok fiber in the band yarn woven fabric (BYW) materials can reach to 80%. Comparisons of sound absorption coefficients of BYW with different fiber, the normal plain woven fabrics and nonwoven have been made. The effects of kapok fiber content, woven weave, warp density and band yarn diameter on sound absorption of BYW materials have been studied. It is shown that BYW with kapok fiber have the better sound absorption in the frequency range of 125–1600 Hz than BYW with cotton or hollow polyester fiber. The higher kapok fiber content, the better sound absorption of BYW owing to the large lumen structure filled with air of kapok fiber. The smaller warp density or the larger band yarn diameter, the higher the kapok fiber content as a result of the more number of band yarn per unit length of fabric, yields the better sound absorption of BYW. In addition, BYW with plain weave has the better sound absorption than BYW with twill or honeycomb weave in the frequency range of 1250–1600 Hz, and the phenomenon is opposite in the frequency range of 400–1250 Hz owing to the thinner thickness of material.

The effect of hollow polyester fiber additive on expansive clay soil

Controlling the swelling of expansive clay soils is always challenging for geotechnicians. In this study, the effect of hollow polyester fiber as an additive on the free swelling percentage and pressure reduction of bentonite clay is investigated experimentally. The fibers are employed in two forms of spread and concentrated. Fiber dosages of 0.2, 0.5, 1, and 1.5 are employed for the spread form and fiber columns with diameters of 1.2, 2 and 3.2 cm, are considered for the concentrated form with fiber column densities of 30 and 60 kg/m3. The obtained results show a significant improvement in the swelling behaviour of bentonite for both the spread and concentrated forms, with better performance for the later form. In which, higher densities and larger diameters of the fiber columns generally decreases the swelling percentage and pressure. The best improvement was observed in the concentrated form sample, with 60 kg/cm3 density and 3.2 cm diameter, with 19 and 57 percent reduction in swelling percentage and pressure, respectively.

Assessment of the effect of body pressure on the warmth retention in sleeping bags

Sleeping bags are a common type of personal protective equipment that maintains the individual’s comfort during rest in an open environment. One of the main purposes of utilizing sleeping bags is protection against cold weather in order to prevent body heat loss. However, during use, the exertion of body pressure on the sleeping bag may impact its protective performance. In this study, the influence of body pressure on the thermal insulation of two sleeping bags containing solid and hollow polyester fibers was investigated with consideration of body pressure in the head, shoulder, hips, and feet regions. Moreover, the sleeping bag layer’s thickness and compressibility variations were analyzed. The results revealed that both sleeping bag layers suffer from the thickness and thermal insulation reduction under body pressure, especially in the hip area. However, due to the entrapped air inside the fiber structure, hollow fibers presented enhanced thermal resistance.

Reduced Graphene Oxide Coated Hollow Polyester Fibers for Efficient Solar Steam Generation

Solar steam generation based on photothermal materials has emerged as a green and efficient technology for a broad variety of applications, such as solar energy harvesting, desalination, power generation, wastewater treatment, and so on. Herein, the fabrication of a kind of a novel photothermal material that is prepared by simple coating of reduced graphene oxide (rGO) onto commercial hollow polyester fibers (HPFs) for efficient solar steam generation is reported. The as‐resulted rGO‐wrapped HPFs possess a porous structure, low thermal conductivity (0.042 W m−1 k−1), and broad light absorption (85%), which satisfies the criterion for construction of ideal photothermal materials. As expected, a high solar‐thermal efficiency of ≈81% is obtained at 1 kW m−2 irradiation, showing great potential for practical applications based on high solar energy conversion efficiency and a simple and, in particular, scalable manufacturing process.

Investigation on the structure and mechanical properties of acoustic-absorbing composite laminates

This study designed a novel porous acoustic-absorbing composite laminates structure with reinforced mechanical properties. Three-dimensional crimped hollow polyester (3D CHPET) fiber and high resilience polyester (HRPET) fibers with various blending ratio were fabricated into porous base fabric. Kevlar woven plain fabric was embedded between HRPET/CHPET porous base fabrics to reinforce strength, which were combined through needle punching and thermal bonding process. Air permeability and tear strength of the acoustic-absorbing composite laminates were tested to evaluate the mechanical properties of the acoustic-absorbing composite laminates. The results showed that the acoustic-absorbing composite laminates exhibited a little higher air permeability after being thermal-treated. Tear strength of the thermal-treated composite laminates was also better than that without thermal treating.

Sound Absorption Properties Of Single-Hole Hollow Polyester Fiber Reinforced Hydrogenated Carboxyl Nitrile Rubber Composites

Abstract A series of single-hole hollow polyester fiber (SHHPF) reinforced hydrogenated carboxyl nitrile rubber (HXNBR) composites were fabricated. In this study, the sound absorption property of the HXNBR/SHHPF composite was tested in an impedance tube, the composite morphology was characterized by scanning electron microscope (SEM), and the tensile mechanical property was measured by strength tester. The results demonstrated that a remarkable change in sound absorption can be observed by increasing the SHHPF content from 0% to 40%. In the composite with 40% SHHPF in 1 mm thickness, the sound absorption coefficient reached 0.671 at 2,500 Hz; the effective bandwidth was 1,800-2,500 Hz for sound absorption coefficient larger than 0.2. But the sound absorption property of the composite deteriorated when the SHHPF content increased to 50% in 1 mm thickness. While with 20% SHHPF proportion, the sound absorption property was improved by increasing the thickness of composites from 1 to 5 mm. Compared with the pure HXNBR of the same thickness, the tensile mechanical property of the composite improved significantly by increasing the SHHPF proportion. As a lightweight composite with excellent sound absorption property, the HXNBR/SHHPF composite has potential practical application value in the fields of engineering.

Experimental and theoretical investigation of hollow polyester fibers effect on impact behavior of composites

In this paper, the effect of utilizing hollow polyester fibers as reinforcement in composite material in comparison with solids is investigated. The three-point bending impact test is carried out to study the impact behavior and mode of failure of composites. After that, the finite element method is used for theoretical investigation and modeling the behavior of two different reinforced composites during impact tests. It was found that the fiber–matrix interface failure is the most dominant mode of failure and the crack was initiated at the middle of the bottom surface of composites. It was also found that the impact resistance of the hollow fiber composite is more than the others. Theoretical results showed good correlation with experimental results as well. The stress distribution and the maximum value of strain energy density was found as two factors which lead to improvement in the impact behavior of hollow fiber composites.

The influence of cork on the thermal insulation properties of home textiles

Novel strategies and technologies to obtain home textiles with thermal insulation properties are increasingly being researched as a strategic approach in the textile industry. The fabric conductivity and heat resistance are two important parameters to take into consideration in order to obtain a structure with improved performance. It is widely accepted that thermal insulation fabrics that resist heat flow possess still air in their structure. The higher is the thickness of the fabric, the bigger is the air entrapped in the structure and thus better is their thermal insulation properties. Nevertheless, these types of textiles face a critical challenge that is obtaining a structure with decreased thickness, without losing the thermal insulation properties required to provide comfort to users. The main objective of this work was to develop different low thickness fibrous structures with improved thermal insulation properties by incorporating cork particles within nonwoven structures. The nonwoven fabrics were produced with wool and hollow polyester fibers and the cork particles were incorporated within the structure in the process of nonwoven fabrication. Nonwoven structures have been prepared in different compositions including 75 % of wool and 25 % of hollow polyester blended with cork granules with sizes ranging from 1-2 and 2-5 mm using as a control an agglomerated cork of 0.8 mm. After production, samples were tested for their thermal behaviour using Alambeta equipment. Results have shown that nonwoven composition comprising cork particles greatly influences the thermal performance, and enables for obtaining a low weight material with improved thermal insulation properties.

A study on heat insulation of composites made of recycled far-infrared fibers and three-dimensional crimped hollow polyester fibers

Far-infrared polyethylene terephthalate (FPET) fibers have been commonly used in clothing in order to attain heat retention, and the combination of three-dimensional crimped hollow polyethylene terephthalate (TPET) fibers makes the clothing to be fluffy and air permeable, and thereby improves the wearing comfort. This study aims to make thermally insulating nonwoven composites by using recycled far infrared fibers. The composites are used to cover the heat transfer lines and prevent the heat emissivity. A specified amount of low-melting-point polyethylene terephthalate (LPET) fibers and FPET and TPET fibers at different ratios are blended, followed by being needle punched at 100-300 needles/min, and then hot pressed at 120 °C, in order to form thirty nonwoven composite types. These nonwoven composites are measured for their porosity, thickness, and air permeability, and are tested for thermal insulation and temperature-rise slope under a constant ambient temperature.

Sound-Absorption Properties of Kapok Fiber Nonwoven Fabrics at Low Frequency

In this study, the sound-absorption properties of kapok fiber nonwoven fabrics were investigated in the frequency region of 100–2500 Hz using the impedance tube method. The effects of physical parameters including fiber mixing ratio, bulk density, and thickness on sound-absorption properties of composites were studied. The comparisons of kapok fiber with polypropylene fiber and hollow polyester fiber indicated that as a natural fiber, kapok fiber had superior acoustical properties at low frequency. A new simple model had been developed to predict the sound absorption coefficient of kapok fiber nonwoven composites at low frequency.

The Influence of Hot Pressing Temperatures in Needle Punching Nonwoven

Non-woven textile industry in an emerging field, with the process short, high yield, low cost and wide source of raw materials, but also has excellent performance of many functions on, making non-woven over the past half century gained textiles attention and consumers of all ages. The proportion of the world of non-woven fiber material used in the product, 85% in rayon ,and the other 15% in natural fibers, polyester fibers which accounted for the largest proportion of use. The experiment uses a low melting point polyester fiber (LPET) 20%, three-dimensional hollow curly polyester fiber (TPET) and recycled far infrared fiber (REPET) 40% each as the basic conditions change pressing temperature 100 °C-140 °C, in order to observe and compare the effects of temperature on the non-woven fabric, this experiment tests including air permeability, tensile strength testing, infrared testing and SEM, respectively in different hot pressing temperature, each of the non-woven hot pressing temperatures sample go through microscopic to analysis for non-woven with the hot temperatures strong reason to improve or decline with hot temperature of air permeability.

Effect of Thermal Finishing on the Mechanical Properties of Hollow Polyester Fiber

The effect of thermal setting parameters namely tensile stress, temperature and time on the breaking strength and breaking elongation of hollow polyester (PET) fiber (PorelTM fiber) were investigated, and their synergistic effect was studied via orthogonal experiment. The results show that protection of fiber wall is an important task during thermal finishing process of hollow fiber. There are direct relationships between micro-molecular structure and mechanical properties. Orthogonal experiment analysis shows that the most significant effect factor for breaking strength and breaking elongation are temperature and tensile stress, respectively. The suggested thermal finishing conditions for PorelTM fiber are summarized as following: elongation (viz. tensile stress) 4%, temperature 165°C, and time 60s.

Damping acoustic properties of reclaimed rubber/seven-hole hollow polyester fibers composite materials

A series of thin, low-cost and environment-friendly elastomeric composites consisting of reclaimed rubber, which is a waste product of roller processing of textile mill and seven-hole hollow polyester fibers, were fabricated. In this study, the damping property of the reclaimed rubber composites was tested in the dynamic mechanical thermal analyzer, the sound absorption property was investigated using the impedance tube method, the morphology was characterized by scanning electron micrographs and the mechanical property was measured by strength tester. The study concluded that reclaimed rubber/seven-hole hollow polyester fibers elastomeric composites exhibited an exceptional damping performance with a broad temperature range, and that acoustical absorption of materials increased significantly with increasing seven-hole hollow polyester fibers content. Meanwhile, reclaimed rubber/seven-hole hollow polyester fibers demonstrated an acoustic property of 1 mm thickness and a mass ratio of 100/25, giving a sound absorption coefficient peak, 0.407 at 2500 Hz. The analysis also revealed that the mechanical properties of the composites improved significantly with the increase of fibers. As an acoustical absorption material with high damping performance and a broad temperature range, reclaimed rubber/seven-hole hollow polyester fibers composites have potential applications in fields of engineering.

An investigation in structural parameters of needle-punched nonwoven fabrics on their thermal insulation property

The thermal characteristics of hollow polyester fibers were compared with solid polyester fibers in order to study their processing behavior and performance characteristics. The effects of different processing and structural properties including fiber diameter, bulk density of layer, and surface pressure on layers of needle-punched nonwoven fabrics with hollow fibers on thermal resistance properties were also investigated. The results show that hollow fibers have a higher thermal resistance in comparison with solid ones. This is a consequence of air trapping inside the fibers, higher bulkiness, and higher surface area of hollow fibers. Furthermore, thermal resistance of microfibers is better than those of macrofibers in both hollow and solid fibers. The thermal resistance of nonwoven subjected to this study, have an inverted-U-shaped pattern versus the bulk density of the fabric. The results also showed that thermal resistance of needle-punched nonwoven fabrics can be affected by the range of heater temperature during the test, however considerably can be affected by fabric thickness as a main structural property of nonwoven fabrics.

Sound-Absorbing Properties of Kapok Fiber Nonwoven Composite at Low-Frequency

More and more concern for environmental problems has led public to use natural and environmentally benign sound-absorbing materials. In this study, the sound-absorbing nonwoven composites based on kapok fiber and hollow polyester fiber were developed and sound absorption properties of kapok fiber nonwoven composites were investigated in the low frequency region of 100-500 Hz using the impedance tube method. The poor sound-absorbing at low-frequency is one of the difficult problems that urgently need to be solved in fibrous sound-absorbing materials. The effects of physical parameters, including bulk density and thickness, and depth of back cavity on sound absorption properties of composites were studied. Increasing of the bulk density, thickness and depth of back cavity is contribute to improve sound absorption properties of composites at low frequency. The comparisons of kapok fiber with polypropylene (PP) fiber and hollow polyester fiber indicated that as a natural fiber, kapok fiber had a superior acoustical properties at low frequency.

Multi-functional Polyester Hollow Fiber Nonwoven Fabric with Using Nano Clay/Nano TiO2/Polysiloxane Composites

Surface modification and property improvement of hollow polyester fiber nonwoven fabric is very important due to the application of substrate in the various fields. Here, nano clay, nano TiO2 and polysiloxane softener as been applied on the hollow polyester fiber nonwoven fabric through conventional impregnation-dry-cure method in order to enhance the fabric properties. The alkaline hydrolysis of polyester was performed on the nonwoven surface to functionalize the fabric and increase the nanoparticles uptake. The nano clay was first dispersed by using nonionic dispersing agent, and then nano titanium dioxide dispersion was added dropwise to the prepared nano clay dispersion. Also, other dispersions were prepared with adding polysiloxane softener and polyurethane resin under sonication. The SEM images and EDX/XRD patterns indicated the presence of various applied particles on the surface of the fabric. Thermal gravimetric analysis was employed to investigate the thermal decomposition behavior of the treated samples. Self-cleaning properties of polyester nonwoven treated by TiO2/nano clay/polysiloxane composite was followed by degradation of methylene blue under daylight irradiation at ambient temperature. It was found that nano clay/TiO2/polysiloxane composite on the fabric surfaces improved self-cleaning property, thermal stability above 400 °C, and water absorption properties of the fabric.

Estimating material properties of solid and hollow fibers in suspension using ultrasonic attenuation.

Estimates of the material properties of hollow fibers suspended in a fluid using ultrasound measurements and a simple, computationally efficient analytical model are made. The industrial application is to evaluate the properties of wood fibers in paper pulp. The necessity of using a layered cylindrical model (LCM) as opposed to a solid cylindrical model (SCM) for modeling ultrasound attenuation in a suspension of hollow fibers is evaluated. The two models are described and used to solve the inverse problem of estimating material properties from attenuation in suspensions of solid and hollow polyester fibers. The results show that the measured attenuation of hollow fibers differs from that of solid fibers. Elastic properties estimates using LCM with hollow-fiber suspension measurements are similar to those using SCM with solid-fiber suspension measurements and compare well to block polyester values for elastic moduli. However, using the SCM with the hollow-fiber suspension did not produce realistic estimations. In conclusion, the LCM gives reasonable estimations of hollow fiber properties and the SCM is not sufficiently complex to model hollow fibers. The results also indicate that the use of a distributed radius in the model is important in estimating material properties from fiber suspensions.

Evaluating the Acoustic Properties of Estabragh (Milkweed)/Hollow- Polyester Nonwovens vfor Automotive Applications

Reduction in noise pollution in general and particularly in automotive industry has become an important issue that has gained the interest of numerous researchers. The present research is aimed to introduce a new product which could serve as an alternative for other commonly used sound absorbing materials. It is expected that hollow fibers due to their structure can significantly influence noise insulation performance of materials in which these fibers are incorporated. Therefore sound absorbing material compose of blend of natural hollow fibers Milkweed or as it known Estabragh and hollow polyester fibers were used to produce needle-punched nonwoven samples. Eighteen different samples were produced by varying blend ratio, mass per unit area, punching density, and frequency of the incident sound. Noise Absorption Coefficient (NAC) of the samples was evaluated using impedance test method. The evaluation procedures were designed using Taguchi method. Results showed samples solely comprise of Estabragh fibers have attained the ability to absorb noise. It was observed that NAC decreases as the amount of Estabragh in the blend is reduced. Although the results showed an increase in punching density improves NAC of the samples, however statistical analysis dismissed the effectiveness of this parameter on sound absorption characteristics of the samples. It was found that NAC increases in direct relation to increase in mass per unit area (g/m2) of the samples. This was attributed to the increase in tortuosity of the samples and the energy losses due to frictional resistance. Finally it was observed that NAC peaks at frequency of 4000 Hz.

Using Nonwoven Hollow Fibers to Improve Cars Interior Acoustic Properties

This research aims to produce nonwoven fabrics that can be used in car interior components (head liners, doors, side panels and trunk liners) to prevent noise from reaching the passenger compartment and therefore achieving comfort in the car interior. Two kinds of fibers were used, polyester and hollow polyester fibers, both of 6 denier, to produce three different fabrics of 100% polyester fibers, 75% polyester/25% hollow polyester fibers, and 55% polyester45% hollow polyester fibers. Four fabric weights were produced: 300, 400, 500 and 600 g/m2. All samples were bonded using thermal bonding technique. More results were reached and most samples have achieved the expected results for example, samples produced with high percentage of hollow fibers have recorded the highest rates of sound absorption whereas samples produced with 100% polyester fibers have recorded the lowest rates. It was also found that there is a direct relationship between weight per m2 and sound absorption efficiency. Samples produced with 55% polyester/45% hollow polyester fibers and 600 g/m2 have achieved the best results.