The efficacy of coconut fibers on the sound-absorbing and thermal-insulating nonwoven composite board

The aim of this study is to examine the efficacy of the coconut fiber on the sound absorption and thermal insulation performance towards the composite nonwoven fabrics. The 2D polyester fiber and 12D fire retardant three-dimensional hollow crimp polyester fiber are individually mixed with 4D low-melting point polyester fiber (4DLMf) to produce 2D polyester nonwoven fabric (2D-PETF) and 12D polyester nonwoven fabric (12D-PETF) respectively. Subsequently, the coconut fiber (CF) is then laminated with the 2D-PETF and 12D-PETF to fabricate two types of PET/CF composite boards through the multiple needle-punching techniques. Accordingly, the sound absorption, thermal insulation, Limiting Oxygen Index and relative mechanical properties of the PET/CF composite boards are evaluated properly. The experimental results reveal that both types of PET/CF composite boards possess excellent thermal insulation performance and fire resistance property. Also, for both types of PET/CF composite boards, the average sound absorption coefficient increases with the increased amount of CF.     

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.     

苎麻／黄（红）麻织物服用性能测试分析

本文通过实验测定了苎麻/黄(红)麻混纺交织织物的服用性能，并与苎麻织物的服用性能进行比较，结论表明苎麻/黄(红)麻混纺交织织物具有良好的服用性能。     

Manufacturing technique and acoustic evaluation of sandwich laminates reinforced high-resilience inter/intra-ply hybrid composites

This study focused on the fabrication and acoustic property evaluation of sandwich cover-ply-reinforced highresilience thermal-bonding nonwoven hybrid composites. P-phenyleneterephthalamides and bicomponent high-resilience bonding polyester intra-ply hybrid nonwoven fabrics were compounded with glass plain fabric to produce the high strength sandwich structural cover ply by means of needle punching and thermal bonding to reinforce the whole composites and dissipate energy when being impacted. Then, the acoustic absorption properties of the homogenous intra-ply hybrid meshwork layer were investigated before and after being reinforced with the aforementioned cover ply. The influencing factors, including areal density, fiber blending ratio, needle punching depth, and air cavity thickness between back plate of the impedance tube and composites, were comparatively investigated. Results revealed that hybrid composites exhibited exceedingly high acoustic absorption properties. Acoustic absorption coefficients were promoted with increases in areal densities and fiber blending ratio of 3D crimped hollow polyester, particularly at low-mid frequency range. In addition, needle punching depths and back air cavity thicknesses considerably affected the average absorption coefficients. The meshwork center layer reinforced with sandwich structural cover-ply perform high resilience properties.     

黄麻和红麻纤维磨木木质素的红外光谱特征

从黄麻和红麻纤维中分离出磨木木质素,利用红外光谱分析了两种麻纤维磨木木质素的特征峰及归属,得知磨木木质素中有复杂的官能团,含有羟基、羰基、甲基等基团,木质素结构中含有相当数量的紫丁香基单元。根据黄麻和红麻纤维磨木木质素的红外光谱吸收峰强度,推断其结构属于阔叶木类木质素化学结构GS型木质素。     

Effect of the low and radio frequency oxygen plasma treatment of jute fiber on mechanical properties of jute fiber/polyester composite

We investigated the surface modification of jute fiber by oxygen plasma treatments. Jute fibers were treated in different plasma reactors (radio frequency “RF” and low frequency “LF” plasma reactors) using O₂ for different plasma powers to increase the interface adhesion between jute fiber and polyester matrix. The influence of various plasma reactors on mechanical properties of jute fiber-reinforced polyester composites was reported. Tensile, flexure, short beam shear tests were used to determine the mechanical properties of the composites. The interlaminar shear strength increased from 11.5 MPa for the untreated jute fiber/polyester composite to 19.8 and 26.3 MPa for LF and RF oxygen plasma treated jute fiber/polyester composites, respectively. O₂ plasma treatment also improved the tensile and flexural strengths of jute fiber/ polyester composites for both plasma systems. It is clear that O₂ plasma treatment of jute fibers by using RF plasma system instead of using LF plasma system brings about greater improvement on the mechanical properties of jute/polyester composites.     

黄麻／棉织物服用性能探讨

本文通过试验测定了黄麻／棉织物的服用性能，并与苎麻／棉，涤／棉，纯棉等织物的服用性能进行比较，结论表明黄麻／棉织物作为服用织物是可行的。     

Nonwoven fabric/spacer fabric/polyurethane foam composites: Physical and mechanical evaluations

In the first stage, polyethylene terephthalate (PET) fibers and Kevlar fibers are combined at a blending ratio of 80/ 20 wt% in order to form PET/Kevlar nonwoven fabrics. Two pieces of PET/Kevlar nonwoven fabrics that enclose a carbonfiber (CF) interlayer are then needle punched in order to form PET/Kevlar/CF (PKC) composites. In the second stage, the sandwiches compose PKC composites as the top and the bottom layers, as well as an interlayer that is composed of a spacer fabric and polyurethane (PU) foam. PU foams have different densities of 200, 210, 220, 230, and 240 kg/m³. These resulting nonwoven fabric/spacer fabric/PU foam sandwiches are then tested using a drop-weight impact test, a compression test, a bursting strength test, a sound absorption test, and a horizontal burning test. The test results indicate that the optimal properties of sandwiches occur with their corresponding PU foam density as follows: an optimal residual stress (240 kg/m³), an optimal compressive strength (240 kg/m³), and an optimal bursting strength (220 kg/m³). In addition, the sandwiches reach the HF1 level according to the horizontal burning test results. They also have an average electromagnetic interference shielding effectiveness of -48 dB, as well as a sound absorption coefficient of 0.5 in a frequency between 1500-2500 Hz, which indicates a satisfactory sound absorption effect. The nonwoven fabric/spacer fabric/PU foam sandwiches proposed in this study are mechanically strong, sound absorbent, and fire retardant, and can be used in construction material and electromagnetic shielding composites.     

Evaluating antistatic performance of plasma-treated polyester

Use of low temperature plasma treatment has been attempted in the textile industry and there the has been some success in the dyeing and finishing processes. In this paper, an attempt was made to apply low temperature plasma treatment to improve the antistatic property of polyester fabric. The polyester fabrics were treated under different conditions with low temperature plasma. An orthogonal array testing strategy was employed for obtaining the optimum treatment condition. After low temperature plasma treatment, the polyester fabrics were evaluated with different characterization methods. Under the observation of scanning electron microscope, the surface structure of the polyester fabric treated by low temperature plasma was found to be seriously altered which provided more capacity for polyester to capture moisture and hence increased the static charges dissipation. The relationship between moisture content and half-life decay time for static charges was studied and the results showed that the increase in moisture content would result in shortening of the time for static charges dissipation. Moreover, the antistatic property of the low temperature plasma treated polyester fabric was greatly improved. In addition, the antistatic property of the polyester fabric treated by low temperature plasma was compared with that of the polyester fabric treated with a commercial antistatic finishing agent.     

Effect of the atmospheric plasma treatment parameters on surface and mechanical properties of jute fabric

Plasma treatment is a kind of environmentally friendly surface modification technology, which has been widely used to modify various materials in many industries. Plasma treatment improves the fiber-matrix adhesion largely by roughening the surface of fibers to increase mechanical interlocking between the fiber and the matrix. For this aim, the effect of atmospheric air plasma treatment on jute fabrics has been discussed in this study. The plasma treatment has been employed at different powers and time intervals. The effects of plasma treatment on fiber properties were revealed by wickability, surface roughness, fiber tensile test and pull-out tests. The effect of plasma treatment on functional groups of jute fibers was observed by attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR). Scanning electron microscopy (SEM) images showed the etching effect of plasma treatment on the surface. It can be concluded that plasma treatment is an effective method to improve the surface and mechanical properties of jute fabrics to be used for composite materials.     

Development of moisture transition ability on porous complex structured woven fabric with convergence of pattern,porosity, and plasma technology

A porous complex structured woven fabric was manufactured to maximize the moisture transition ability of the prepared fabric by increasing the absorptive property of the fabric through surface modification using plasma, which is a dry modification method. Porous single and complex structured woven fabrics were produced by applying pattern, porosity, and plasma technology, including fabric patterning based on the sheath/core complex structure, the formation of porosity by removing the weft thread or warp thread, and hydrophilic surface treatment using plasma and the improvement in water absorption of different fabrics by the porous and plasma treatment was investigated. Therefore, two different types of fabrics were prepared. One is the porous single structured FAB-SINGLE fabric which was taken out in the direction of the Polyester (PET) warp thread of a general single structure to form a porous. Another is FAB-COMPLEX fabrics that the water-soluble polylactic acid (PLA) yarns with a 1.7 to 2.0 times longer absorption distance than that of PET yarns were inserted into the weft threads, and the PLA yarns were dissolved in a solvent to form the porous complex fabric. And then the physical properties and water absorption of the two types of fabric were compared after the plasma treatment. The results showed that when the FAB-SINGLE fabric, which has porosity induced by the removal of the warp threads in a certain gap, was plasma treated for 5 min, the contact angle was decreased to the extent that a measurement of the contact angle was impossible, whereas the fabric that had not undergone a plasma treatment had a contact angle of 123.6 o. The contact angle of the FABCOMPLEX with porosity caused by the dissolution of the PLA yarns was reduced from 76.8 o to 0 o after 3 minutes of a lowtemperature plasma treatment, indicating that the hydrophilic property was increased. In addition, the water absorption measurements showed that the absorption height was increased from 2.3 cm of the fabric sample that had not been treated with plasma to the highest absorption height of 8.3 cm, suggesting that the water absorption also increased with the improvements in moisture transition ability by the plasma treatment. The physical tensile strength of the fabrics was not changed by the plasma treatment, despite the changes on the fabric surface, suggesting that the combination of double complex structures and the plasma treatment helped improve the water absorption.     

Surface treatments of jute fabric: The influence of surface characteristics on jute fabrics and mechanical properties of jute/polyester composites

In this study, jute fabrics were modified by alkali, micro-emulsion silicon (MS) and fluorocarbon based agents (FA) in order to enhance the interfacial adhesion between the polyester matrix and the jute fiber. X-ray photoelectron spectroscopy (XPS) and contact angle measurements were used to characterize fiber surfaces. The effects of various surface treatments on the mechanical and morphological of jute/polyester composites were also studied. All surface treatments were shown to improve the tensile, flexural strengths and interlaminar shear strengths of the composites. Moreover, the maximum improvement in the mechanical properties was obtained for the FA treated jute/polyester composites. SEM micrographs of the tensile fracture surface of jute/unsaturated polyester composites also exhibited improvement of interfacial and interlaminar shear strengths by the alkali, MS and FA treatments of jute fibers.     

Sound absorbent,flame retardant warp knitting spacer fabrics: Manufacturing techniques and characterization evaluations

This study proposes a combination for reciprocal reinforcement between warp knitting spacer fabrics and PU foams. PET/Kevlar nonwoven fabrics are made with an 80:20 ratio and an incorporation of various needle-punching speed of 100, 150, 200, 250, and 300 needles/min. Ascribing to having an optimal bursting strength, sound absorption coefficient, and limited oxygen index (LOI), the PET/Kevlar nonwoven fabric that is made by 200 needles/min are selected to be combined with a glass-fiber fabric by applying needle punch in order to form a surface layer. Next, warp knitting spacer fabrics and the nonwoven fabrics are laminated, followed by being combined with polyurethane (PU) foam that are featured with different densities of 200, 210, 220, 230, and 240 kg/m³ in order to form spacer fabric/PU foam composites with multiple functions. The composites are then tested with a drop-weight test, a compression test, a bursting strength test, a sound absorption test, and a horizontal burning test. The test results indicate that all spacer fabric/PU foam composites reach a horizontal burning level of HF1, and their sound absorption coefficients at 2500-4000 Hz also suggest a satisfactory sound absorption. In particular, the optimal residual stress and compressive strength are present when the composites contain 210 kg/m³ PU foam. Similarly, the optimal bursting strength of the composites occurs when they are composed of 230 kg/m³ PU foam. The spacer fabric/PU foam composites are proven to have high strengths, sound absorption, and fire retardant, and thus have promising potentials for use as construction materials and light weight composite planks.     

Effects of structure design on resilience and acoustic absorption properties of porous flexible-foam based perforated composites

In this paper, perforated composite panel was combined with porous and resonance structures to investigate the influence on acoustic absorption and resilient properties. The perforated composite panel was fabricated based on highdensity flexible-foam via perforating and reinforcing with laminated hybrid nonwoven fabric. Effect of aperture size (AS) (ranging from 3 mm to 6 mm), perforation ratio (PR) (5 %, 10 %, 15 % and 20 %) and perforation depth (PD) (25 %, 50 %, 75 % and 100 %) on the compressive hardness, rebound resilience and acoustic absorption properties was explored. Multiply hybrid nonwoven fabric which was fabricated with low-melting point polyester (LMPET), flame-retardant polyester (FRPET) and recycled Kevlar fibers was utilized to reinforce the flexible composites and improve the acoustic property. Nonwoven that was fabricated with entangled LMPET fibers had porous structures which could reinforce the flexible foam and enhance the acoustic absorption properties. The result revealed that the continuity and supporting of porous flexible foam had directly influence the compressive hardness. The maximum hardness of the flexible-foam based perforated composites reached 420 N. The rebound resilience result showed that the sample had high resilient structure and the resilience was up to 48 %. The perforated flexible composites plate (PFP) with 4 mm-AS performed the highest acoustic absorption coefficient at 0.9. The acoustic absorption coefficient was higher than 0.8 in the frequency range from 800 to 1600 Hz and 1600 to 2400 Hz when perforated composites had 4 mm-AS at 5 % and 10 % perforation ratio. With the increase in perforation ratio, absorption peak moved from 3200 Hz to 4000 Hz. Hybrid nonwoven laminated layer help to broaden the frequency range of acoustic absorption of perforated high-density flexible foam based composites panel. Acoustic absorption coefficient was higher than 0.4 when frequency ranging from 900 Hz to 4000 Hz.     

Manufacturing and analyses of wet-laid nonwoven consisting of carboxymethyl cellulose fibers

Carboxymethyl cellulose (CMC) is a cellulose derivative having water-soluble property, biodegradability, and biocompatibility. It has been used in various medical applications as forms of gel, film, membrane, or powder. In this study, composite CMC nonwovens were produced, by a wet-laid nonwoven process, to improve the wet strength of carboxymethyl cellulose nonwovens. Followed by preparing the CMC fibers from cotton fiber, the composite CMC nonwovens composed of CMC fibers and PE/PP bicomponent fibers were manufactured by using 85/15 % v/v of ethanol/water solution as a dispersion medium. Structural analyses of CMC fibers, such as XRD, TGA, FT-IR, and degree of substitution indicated that CMC fibers were successfully produced. The wet strength of CMC nonwoven was dramatically increased by blending with the PE/PP fibers without sacrificing the key properties for wound dressing materials such as liquid absorption, gel blocking and liquid retention. It is expected that the composite CMC nonwovens will be a good candidate for wound dressing materials for mild exudate condition.     

Functional modification of sanitary nonwoven fabric by chitosan/nanosilver colloid solution and evaluation of applicability

For their functional enhancement, sanitary nonwoven fabrics with a relatively smooth surface were treated using chitosan, a natural polymer with excellent biocompatibility, and nanosilver colloid solution, which has strong antibacterial effects even when used in small amounts. The treatment effect was examined at various mixing ratios. When the mixing ratio of the nanosilver solution was higher, antibacterial and deodorization activity was increased. For CH3/NS1 treated fabric, when the mixing ratio of chitosan and nanosilver solution was 3:1, the air permeability was most excellent, and worked as a positive in improving the pleasantness of the sanitary nonwoven fabric. In all samples, the electrostatic propensity was reduced, regardless of the mixing ratio. In terms of the moisture characteristics of chitosan/nanosilver treated nonwoven fabrics, the moisture uptake was found to be superior in the CH3/NS1 treated fabric. When the mixing ratio of the nanosilver solution was higher, moisture permeability decreased, showing a similar tendency to that of air permeability. The vertical water permeability coefficient increased in all treated fabrics. The dynamic water absorption rate was good in CH4 and CH3/NS1 treated fabrics. This means that the absorption of water in the liquid state became easier, thus improving applicability as sanitary nonwoven fabrics.     

Study on heat and moisture vapour transmission characteristics through multilayered fabric ensembles

A detailed study on the heat and moisture vapour transmission characteristics of different types of single and multi-layered fabric ensemble by using sweating guarded hot plate (SGHP) has been reported in the present paper. A comparison has been made on thermal and moisture vapour transmission properties of five different insulative fabrics, namely, knitted-raised fabric, needle punched nonwoven, through air bonded nonwoven, spunbonded-through air bonded sandwich nonwoven and warp knitted spacer fabric and three different coated fabrics, namely, plain woven rubber coated, plain woven polyester polymer coated and plain woven polytetrafluoroethylene (PTFE) coated fabric, used for thermal insulation purpose. ANOVA has been conducted to analyse the significance of type of insulative and coated fabrics used. Sandwich nonwoven fabric which has higher thickness and porosity shows higher thermal resistance followed by through air bonded fabric, raised fabric, needle punched fabric and spacer fabric. Spacer fabric shows lesser evaporative resistance due to its lesser thickness and larger aperture size, which increases the diffusion of moisture vapour. Needle punched fabric shows slightly higher evaporative resistance than spacer fabric, followed by raised fabric, through air bonded fabric and sandwich nonwoven fabric. Permeability index of different multilayered fabric ensembles are also compared.     

A comparative study on performance properties of yarns and knitted fabrics made of biodegradable and conventional fibers

Biodegradable products are parts of a natural cycle. The biopolymers and the fibers that can be produced from them are very attractive on the market because of the positive human perception. Therefore, PLA being a well known biodegradable fiber and some conventional fibers were selected for the current study to examine the differences between them and to emphasize the importance of biodegradability beside fabric performance. 14.8 tex (Ne 40/1) combed ring spun yarns produced from biodegradable fiber PLA, new generation regenerated fibers Modal and Tencel, synthetic and blends 50/ 50 % cotton/polyester and 50/50 % viscose/polyester, polyester were selected as yarn types and by using these yarns, six knitted fabrics were produced and some important yarn and fabric properties were compared. In this context, moisture and the tensile behavior of yarns and pilling, bursting strength, air permeability and moisture management properties of the test fabrics are discussed.     

不同处理对黄麻纤维木质素去除及织物性能的影响

本文研究了草酸铵、漆酶以及木聚糖酶单独或联合处理对黄麻机织布中木质素的去除作用及对织物褶皱、力学性能的影响。结果表明,漆酶单一处理仅能去除少量的木质素,联合处理可提高木质素的去除效率,以草酸铵、木聚糖酶、漆酶联合处理效果最好。在ATR红外谱图中,草酸铵、木聚糖酶、漆酶联合处理后的黄麻机织布较未处理织物在1594 cm-1、1506cm-1和1424 cm-1处的木质素芳香族特征吸收峰,1731 cm-1和1646 cm-1处的木质素羰基特征吸收峰及1242 cm-1-1031 cm-1处的半纤维素醚键特征吸收峰均有减弱,说明经草酸铵、木聚糖酶、漆酶联合处理后黄麻纤维表面木质素和半纤维素含量降低。经处理后黄麻机织布褶皱回复角提高,其中草酸铵、木聚糖酶、漆酶联合处理褶皱回复性最佳。漆酶单独处理后黄麻机织布断裂强力和断裂延伸率均提高,联合处理后断裂强力降低,断裂延伸率提高。     

Study on anisotropic creep behavior of nonwoven geotextiles

The anisotropy in creep behavior of two types of nonwoven fabrics (needle-punched and thermobonded spun laid) has been studied. It has been observed that the amount of time dependent extension depends on the direction, amount of loading and the structure of nonwoven the fabrics. The time dependent extension (creep) for the nonwoven fabric increases with the increase in amount of load. The higher initial extension and creep are observed for needle-punched nonwoven fabric as compared to thermobonded spun-laid nonwoven fabric. The creep behavior of needle-punched nonwoven shows a logarithmic relationship with time, but the thermobonded spun-laid nonwoven fabric does not show such logarithmic relationship. For a particular fabric, the creep is dependent on the fiber arrangement and is minimum in the direction in which the proportion of fiber is maximum and visa versa.