Needle Punching Research Articles

Comfort Characteristics of Nettle Nonwoven Fabrics

ABSTRACT In this work, an attempt has been made to develop nonwoven fabrics by needle punching technology and comfort characteristics of needle punched nonwoven fabrics are analyzed with respect to thermal conductivity, water absorbency, and air permeability. Box-Behnken experimental design was used to study the influence of parameters such as needle punch density, needle penetration depth and fabric areal weight on thermal conductivity, water absorbency, and air permeability. From the responses, it was noted that the maximum water absorbency of 494% and air permeability of 79 cm3/cm2/s and minimum thermal conductivity of 0.0251 W/mK was achieved at needle punch density 75 punches/cm2, 8 mm needle penetration depth and fabric areal weight 150 g/m2.

Impact resistance of fiber reinforced sandwich-structured nonwoven composites: Reinforcing effect of different fiber length

Apart from the main function of stab resistance, personal protective equipment is required to be comfortable, flexible, and light weighted and as such to prevent soldiers and police officers from the danger caused by a long-term use and accidents. The stab resistance is dependent on the structure formed of different materials and processes majorly, and therefore this study proposes sandwich-structured composites using high-strength polyester staple fibers (S-type) and high strength polyester filaments (F-type) that have differing characteristics by means of the nonwoven process. First, recycled Kevlar® fibers, nylon fibers, and low-melting-point polyester fibers are processed, thereby forming the surface and bottom layers. In addition, the needle punching process and heat treatment are performed with the aim of combining high strength polyester filaments or staple fibers as the interlayer. Next, the differences in the fiber structure and damage modes of sandwich composites are examined in terms of the interlayer type (i.e. S- and F-type) by conducting the quasi-static stab resistance testing and SEM/FE-SEM observations, respectively. The test results indicate that the S-type sandwich composites outperform the F-type sandwich composites in terms of absorbing the puncture, and the stab resistance is 415 N for S 30013 group. However, the S-type sandwich composites have the potential to develop personal protective equipment by virtue of a light weight and being comfortable provided by filaments.

Investigating the integral-structure of HRBP/CHP/CF consisting of non-woven flexible inter/intra-ply hybrid composites: Compression, puncture-resistance, electromagnetic interference shielding effectiveness

This study fabricated the integral-structure flexible inter/intra-ply hybrid composites, composed of HRBP cushioning layer and inter/intra-ply hybrid laminates surface-reinforcements through needle-punching and thermal-treating. Effects of the factors, including HRBP/CHP blending ratio, needle punching frequency and laminating sequence, on the compression, puncture resistance and electromagnetic interference shielding effectiveness (EMI SE) of flexible inter/intra-ply hybrid composites were investigated. An integral memory model on the compressive loading of non-woven structure was designed based on Poisson distribution, on which the numerical analysis was based to predict the compressive resistance and hysteresis loss. The support factor was greater than 8.2, and the highest value was recorded at a fiber blending ratio of 7H/3C and needle-punching frequency of 100 S/minute. The predicted compression energy loss was in good agreement with the actual value. The puncture resistance was enhanced with an increase in HRBP fiber blending ratio and a decrease in needle-punching frequency. With an electromagnetic wave frequency ranging from 2.0 to 2.5 GHz, the hybrid composites had excellent electromagnetic shielding effect. The EMI SE of the hybrid composites exhibited similar curve in different wave band when needle-punching frequency was enhanced. The hybrid composites with a cushioning center-ply and double hybrid-laminates cover-plies exhibited the highest EMI SE.

Effect of the Carding Process and Reinforcement Method of Carbon Fiber/Polypropylene Fiber Nonwoven Fabrics on the Anisotropic Mechanical Properties of Hot-Pressed Composites

In this work, nonwoven fabrics made from carbon fibers (CFs) and polypropylene (PP) fibers were manufactured through a carding process and a cross-laying process and reinforced by either a needle punching method or a thermobonding method. The effects of the carding parameters (adding oil, increasing the gauge and decelerating the speed) and reinforcement method (needle punching method or thermobonding method) on the anisotropic mechanical properties of hot-pressed CF/PP composites were investigated. Additionally, the length, distribution and orientation of carbon fibers in the hot-pressed composites were studied. The carbon fibers were oriented by the carding method, and the composites exhibited anisotropic properties. Moreover, the fiber distribution results indicated that increasing the gauge and decelerating the speed had a slightly negative influence on the distribution of carbon fibers and that the cross-laying process led to a uniform distribution of fibers. Furthermore, adjusting the carding parameters and reinforcement method could reduce the damage sustained by carbon fibers during manufacturing and subsequently improve the mechanical properties of the CF/PP composites in the transverse direction (TD).

Damage evaluation of quartz woven fabrics during needle punching process

This paper reports an experimental study on the damage evaluation of quartz woven fabrics during needle punching process under different needle punching densities. The straight fiber bundles begin appearing in Z direction at 50 punches · cm−2 and the “U-shaped” fiber bundles begin being observed at 210 punches · cm−2. The retention ratio of mean breaking force (RRMF) of the needle-punched quarts woven fabrics in warp direction decreases from 100% to 49.4% with an increase in needle punching density from 0 to 10 punches · cm−2, and that in weft direction decreases from 100% to 50.21% with the same increments in needle punching density, but the RRMF in warp direction decreases from 49.4% to 0.35% when the needle punching density increases from 10 to 245 punches · cm−2 and that in weft direction decreases from 50.21% to 0.19% with the same increments in needle punching density; obviously, the initial needle punching density increments (0 to 10 punches · cm−2) seem to have weakened tensile property more significantly compared with needle punching density increments from 10 to 245 punches · cm−2. The retention ratios in warp and weft directions are 0.61% and 0.34%, respectively, at 210 punches · cm−2, which are roughly equal with those at 245 punches · cm−2. Therefore, it could be concluded that the tensile property has reached the minimized at 245 punches · cm−2. In addition, there is an obvious paired similarity existing in the macro damage morphologies, the load–displacement curve trend at the adjacent needle punching density from 70 to 245 punches · cm−2 in 35 punches · cm−2 increments, also such similarity exists when the needle punching density is at 10 to 60 punches · cm−2.

Mechanical properties of needle-punched/thermally treated non-woven fabrics produced from recycled materials

The textile industry is indispensable to our lives, and the ongoing development of related products also results in an increasing amount of textile waste, especially selvages that account for the majority of textile waste. This study proposes making nonwoven composites with recycled high-strength polyester (HPET) fibers and polypropylene (PP) fibers using needle punching and thermal treatment. One-way ANOVA and multiple regression analysis are employed to analyze the correlation between mechanical properties of nonwoven composites and influencing parameters of fiber blending ratios, needle punching depths, and temperature of thermal treatment. In particular, the HPET/PP nonwoven composites have optimal mechanical properties when the fiber blending ratio is 60/40 (wt%) and the needle punching depth is 19 mm. Moreover, the statistical analyses indicate that the factors that affect the properties are ranked as the intrinsic properties of materials, followed by manufacturing parameters.

Three Dimensional Nylon Cushioning Composite Fabrics: Manufacturing Technique and Property Evaluations

It is trendy to use polymers with different forms in a diversity of fields. This study uses nylon fibers and low-melting-point polyester (LMPET) fibers or low melting point polylactic acid (LMPLA) fibers to fabricate three-dimensional nylon/LMPET and nylon/LMPLA cushioning composite fabrics employing the nonwoven manufacturing. The employment of needle punching process and thermal treatment reinforce the cushioning composite fabrics, and the subsequent thermal bonding points strengthen the mechanical properties effectively. In comparison to pure nylon nonwoven fabrics, the nylon cushioning composite fabrics exhibit higher tensile strength by 2.3 times regardless of whether it is a nylon/LMPET or nylon/LMPLA cushioning composite fabric. Similarly, based on the hammer rebound rate measurement, when the 3D cushioning composite fabrics are composed of 20 wt% of LMPLA fibers or 80 wt% of LMPET fibers, the hammer rebound rate reaches 20 %, which is 1.4 times greater than that of the control group. Additionally, the composite fabrics that are composed of 80 wt% of LMPLA fibers or 40 wt% of LMPET fibers also demonstrate higher compression recovery than the control group.

Mechanical performance of hybrid bast and basalt fibers reinforced polymer composites

With increasing limitation of petrochemical resources, there is a growing demand for the replacement of nonrenewable fiber-reinforced polymer composites by renewable polymer composites. Therefore, the aim of this research work was to improve the mechanical properties of bast (plant) fibers reinforced polymer composites without reducing their renewable material content. To achieve this goal, basalt fibers (natural mineral fibers) were used to partially substitute the amount of bast fibers in the polymer composites. The applied fibers were processed to semi-finished materials by carding and needle punching and processed further by afterwards press-molding. An intense optimization of the carding process led to the production of homogeneous fabrics based on various types of fibers (bast, basalt and PP). The homogeneity of the fabrics was confirmed by scanning electron microscopy (SEM) analysis of the composites. Several composites based on polypropylene and acrylate thermoset resin, reinforced with merely bast fibers, were prepared as reference. In the next steps, the bast fiber content of the reference compositions was partially replaced by basalt fibers. The compression-molded samples were tested for their flexural, tensile, and impact energy properties. The very positive finding was that the addition of basalt fibers not just improved significantly the strength and stiffness of the composites, but simultaneously increased the properties of the composites regarding energy absorption, a key requirement in the automotive industry. The fracture surface analysis confirmed a better fiber matrix adhesion in thermoset composites compared to thermoplastic composites. The tested renewable hybrid polymer composites have great potential to replace nonrenewable fiber-reinforced polymer composites.

A Robotic Biopsy Endoscope with Magnetic 5-DOF Locomotion and a Retractable Biopsy Punch.

Capsule endoscopes (CEs) have emerged as an advanced diagnostic technology for gastrointestinal diseases in recent decades. However, with regard to robotic motions, they require active movability and multi-functionalities for extensive, untethered, and precise clinical utilization. Herein, we present a novel wireless biopsy CE employing active five degree-of-freedom locomotion and a biopsy needle punching mechanism for the histological analysis of the intestinal tract. A medical biopsy punch is attached to a screw mechanism, which can be magnetically actuated to extrude and retract the biopsy tool, for tissue extraction. The external magnetic field from an electromagnetic actuation (EMA) system is utilized to actuate the screw mechanism and harvest biopsy tissue; therefore, the proposed system consumes no onboard energy of the CE. This design enables observation of the biopsy process through the capsule’s camera. A prototype with a diameter of 12 mm and length of 30 mm was fabricated with a medical biopsy punch having a diameter of 1.5 mm. Its performance was verified through numerical analysis, as well as in-vitro and ex-vivo experiments on porcine intestine. The CE could be moved to target lesions and obtain sufficient tissue samples for histological examination. The proposed biopsy CE mechanism utilizing punch biopsy and its wireless extraction–retraction technique can advance untethered intestinal endoscopic capsule technology at clinical sites.

Research on Thermal Insulation Characteristic of Multilayer Clothing

Winter outdoor clothing is aimed at protecting human being against harsh environmental conditions, especially against cold. Thermal insulating properties of a textile material plays significant role in protective clothing. Thermal protective clothing usually is a multilayer construction composed of three layers -Base layer, Insulating material, Outer layer. The previously available jacket insulating layer is always filled with down feather which cause harm to the wearer. This study concentrates on replacing the middle layer with ecofriendly natural Fiber-Kapok. Thickness, thermal conductivity, Air permeability, and wickability properties of fiber and fabric is determined. The layers are been bonded with Needle punching and thermal bonding technique. The effect of Multilayer clothing in cold weather is been tested and analyzed using different proportions of natural ecofriendly-kapok fiber.

Mechanical properties evaluation of nonwoven industrial cotton waste produced by needle punching method

This paper describes the fabrication method and mechanical characterization of nonwoven fabrics from industrial fabric wastes by different machine variables. Cotton waste fibres underwent the mechanical recycling methods, needle punching process and worked into a continuous web of nonwoven fabrics. The measurement method of full factorial design of experiment was implemented in this study as a systematic and efficient way to distinguish between the interaction of more than one factor which are the fibre feeder speed and the number of stacking layers, respectively. Three different fibre feeder speed of 1.8 m/s, 2.2 m/s and 2.8 m/s and three levels of stacking layer (4, 5 and 6 layers) were examined. Analysis of variance (ANOVA) was used to determine the significant factors that influenced the mechanical properties of the web nonwoven fabrics. The mechanical properties of nonwoven web were measured by bursting strength test and puncture resistance test. The results displayed that the difference in fibre feeder speed and number of stacking layer significantly affect the puncture resistance performance. S26L web resisted the highest load during puncture resistance test which is 70.5 N while S14L resisted the lowest load of 25.5 N. Whereas, bursting strength performance was only affected by the fibre feeder speed. Lower fibre feeder speed produced stronger nonwoven fabric. Hence, the faster the fibre feeder speed and the higher number of stacking layer give good puncture resistance properties of nonwoven fabrics while the bursting properties of nonwoven fabrics shows the opposites results.

Thermo-mechanical and morphological characterization of needle punched non-woven banana fiber reinforced polymer composites

The purpose of this study is to employ a novel technique for the fabrication of natural fiber reinforced polymer composites that could stand toe to toe with glass fiber composites in terms of thermo-mechanical properties without any chemical treatment. The reinforcement fibers were extracted from the pseudostem of the nendran banana plant. Later a non-woven fabric composite consisting of banana fibers reinforced with unsaturated polyester (UPE) matrix was fabricated using the needle punching technique. Composite specimens were subjected to tensile, flexural, hardness, quasi-static indentation (QSI) and dynamic mechanical analysis (DMA) test for evaluating mechanical properties. However, the optimal properties was achieved at 40 wt% fiber content with an increase in tensile and flexural strength of 36% and 33% for needle-punched banana fiber composites (NPBFC) compared with random banana fiber composites (RBFC) respectively. It was also evidenced from the load bearing capacity and hardness of NPBFC having 2420 N and 87 HRRW, proves its superiority over RBFC and comparable with RGFC. Further, the viscoelastic properties of UPE and NPBFC were analyzed. Subsequently, the characteristic bonds of cellulose were represented through infra-red spectroscopy and the crystallinity index was exposed through X-ray diffraction analysis. In addition, thermal analysis was done and the stability of the optimized NPBFC witnessed was up to 260 °C. Also, morphology-properties correlation was established. Finally, the experimental results were validated using theoretical models. This study concludes that the synthesized novel NPBFC endorses its potentiality as a probable reinforcement in industrial safety helmet, automotive door panel and light weight structural applications.

Acoustic Properties of Kapok Fibre

Noise pollution has become an important burning issue in today’s modern industrial era after Air and Water pollution. Noise adversely affects human health and decrease productivity in various environments. The present study tries to study the acoustic properties of natural hollow fiber-kapok to develop a cost-effective and eco-friendly sound absorbing material as an alternative of conventional sound absorbing material which is harmful to the environment. Therefore, sound absorbing material consist of a blend of Natural hollow fibres Kapok and Modal were used to produced needle-punched nonwoven fabrics. A nonwoven needle punch method to produce fabrics was selected due to its technical merits and low production cost. Different nonwoven needle punched samples were produced by varying blend ratio, web mass per unit area, needle stroke and needle depth. After conducting several pre-trial, designs of the experiment was plan using Response surface methodology - Central composite design (RSM-CCD) method. Sound absorption coefficients of the sample were measured at a different frequency of incident sound using impedance tube test method ISO 10534-2. It was observed that sample with a higher percentage of kapok fiber showed higher sound absorbency at higher Frequency of 2000 to 6000 HZ. It was also found sound absorption coefficient increased with the increased in mass per unit area, needle stocks and needle depth.

Optimisation of Process Parameters in Kenaf/Polypropylene Composites in Connection Moulding

Renewable natural fibres like kenaf can be used to produce composites as replacement to plastic boards in household and industrial applications. The objective of this study is to optimise the process parameters for compression moulding of kenaf polypropylene composite to get maximum tensile, flexural and impact strength values for three different blend ratios. Three levels of temperature (160oC, 180oC and 200 oC), compression pressure (7, 9 and 11 Mpa) and time of application (10,20 and 30 min ) for producing kenaf/ polypropylene blend ratios of 50:50, 65:35 and 80:20 have been used. The samples were produced through carding for web formation, needle punching for non woven making and finally in compression moulding machine for boards making. All the composite boards were analysed for tensile, flexural and impact strength. The tensile and flexural strengths have positive correlations with time and temperature and contact pressure in all the blend ratios kenaf / polypropylene. The impact strength has positive correlation with time, temperature whereas it has negative correlation with contact pressure in all the blend ratios. The highest tensile strength and flexural strength is achieved with 65:35 kenaf / polypropylene blend at 200 o C temperature, 11Mpa pressure and 10 minutes duration in compression moulding machine. The highest Impact strength is achieved with 80:20 blends at 180 o C, 7 Mpa pressure and 30 minutes duration. The tensile and flexural strength is the highest at the blend ratio of 65:35 whereas the Impact strength increases with the increase kenaf content up to 80%

Analysis of the effect of fiber cross section and different bonding methods on sound absorption performance of PET fiber based nonwovens using Taguchi method

In this study, sound absorption coefficients (SACs) of needle-punched and thermal-bonded nonwovens produced from polyester (PET) fibers with various cross sections, i.e., hollow, round and hexaflower, blended with a low melt PET, was reported. The acoustic performance of a hexaflower PET fiber was studied for the first time. Fibers were carded and then one set of samples was bonded by needle punching while the other set was air-through thermal bonded. A third set of samples was needled at various punch densities. Design of experiments was planned according to Taguchi method. Relationship between production parameters and SAC was analyzed using Minitab software. The most important independent variables affecting the sound absorption were areal density and web bonding method. The sample produced according to optimum production levels reached to a SAC value of 0.57 at 2000 Hz which could be a suitable choice for acoustic applications in the automotive industry.

Simulation Analysis of the Bed of Needling Machine Producing High Gram Weight Nonwovens

The needle punctures non-woven fabrics up and down reciprocating when the needling machine producing high gram weight nonwovens is working. The bending deformation of the supporting bed, an important part, will be caused by impact loads such as penetration force. Based on the basic principle of mechanical vibration, the vibration bending and mode shapes of the supporting were analyzed by field measurement and finite element simulation. The results showed that the deflection of the bed was affected by the penetration force under certain working conditions. But the influence value was small and the downward bending deflection was within the allowable range. The needling process would not cause resonance of the machine since its first four natural frequencies in Z direction were much larger than the working frequencies. The engineering significance of the study is to ensure that the needle punching machine meets the requirements of strength and stiffness, and realizes the function of producing high gram weight nonwovens.

Electrostatic Filtration Performance of Conductive Fibrous Filters

Experiments were performed to improve the filtration efficiency of conductive fibrous filters by applying electrostatic charges. Ordinary polyester staple fiber and organic conductive fiber were blended in 90/10, 80/20, 70/30, and 60/40 ratios. Quantitative conductive needle felts were prepared by needle punching. The conductive fibrous filters were applied to a dc voltage supply (from 0 to 6 kV), and the relationship between filtration efficiency and the high voltage applied was studied. The results suggested that there was an approximately linear relationship between the filtration efficiency and the applied voltage value. The conductivity of filter material increased with increased blending ratio of the conductive fibers, basis weight, and thickness.

PROCESSING AND STRUCTURE OF PAPERBOARD WITH A NEEDLED MIDDLE LAYER

The possibility to change the fibre network structure of paperboard by using the needle punching method was studied. Needling was performed on the middle layer made from unbleached softwood kraft pulp at a dry content of 20%. The needled structure was studied by several microscopy methods, which showed that the fibres were redistributed mainly in-plane. Denser regions of the fibre network structure were observed close to the needle penetration sites. The local density was estimated to be 25% higher than that of the surrounding unaffected structure.

Fabric Composites Reinforced with Thermally Bonded and Irregularly Aligned Filaments: Preparation and Puncture Resistant Performance.

This study proposes fabric composites with improved static and dynamic puncture via increasing a friction force to restrain the slide of filaments as well as the compression and abrasion between the fibers and the puncture probe. The the bi-layered shell layers of composite fabrics are composed of aramid staple fibers and nylon staple fibers and a layer of low-melting-point polyester (LPET). The nonwoven layer consisting of recycled aramid and nylon staple fibers provides a shear effect to dissipate part of the puncture energy. Reinforcing interlayers include a woven fabric and PET filaments that are circularly aggregated between the surface layers, providing isotropic filament reinforcement and strengthening the resistance against the tip of the puncture probe. The reinforcing filaments may slide after the employment of needle punching, and to compensate for this disadvantage, the LPET layers are used to thermal bond the composite fabrics and the total thickness is controlled at 2 mm. The thermally bonded fabric composites are evaluated in terms of puncture resistance, thereby examining the effects of fabric structure and thermal bonding. According to the test results, the optimal composite structure is the sample N/L/W/F/L/N, which was reinforced by the LPET adhesive layer and irregularly aligned filaments. The sample which used the LPET adhesive layer had a positive influence on static puncture resistance and dynamic puncture resistance, preventing the slide of filaments, but the poor interfacial combination only contributed to limited reinforcement.

Optimizing the processing parameters of mechanical and hydraulic conductivity of geotextile liner

ABSTRACTGlass geotextile reinforcement and needle-punch bonding are applied to compensate for the low mechanical strength of a geotextile clay liner (GCL) and reduce damage under complicated service conditions. Moreover, the effects of glass fibers embedded in the bentonite on hydraulic conductivity are investigated. A hybrid-structure glass geogrid-reinforced GCL (GGCL) is constructed by needle punching the bentonite laminated by a glass geogrid layer and separated by a 0.3 mm thick meltblown nonwoven layer. The central composite design (CCD) is proposed to discuss the effects of needle punch density (ND) and depth of punch (DP) on the tensile properties, quasi-static and dynamic puncture resistances, and hydraulic conductivity of the GGCL, and an empirical regression model of these properties is established. Results show that ND and DP significantly affect tensile the properties and puncture resistances while DP insignificantly affects the hydraulic conductivity of the GGCL. Glass fibers embedded into the bentonite improve the hydraulic conductivity of the material. At the 95% confidence interval, the process parameters can be optimized by the empirical regression model. The proposed regression model is consistent with experimental results and can thus be used to predict the mechanical properties and hydraulic conductivity of GGCL.