Needle Punching Density Research Articles

An Ivestigation on Abrasion Resistance And Bending Rigidity of Recycled Nonwovens Including Blanket Trimmings

In this study blanket trimmings and mechanically recycled fibers were blended and softly pre-needlepunched to be used as innerlayers of conventional needle-punched nonwovens. The outer layers from three types of raw materials (polypropylene, recycled polyester and mechanically recycled fibers) and the control groups were produced by classical needle-punching at two different needle-punch densities. Abrasion resistance and bending properties of the end products were investigated considering recycled layer ratio, raw material type and needle-punching density through standard test methods. Among all types, the highest abrasion cycles and bending rigidity values were observed for the PP outer layered products. Increase in needling density increased the abrasion cycles between 10%-20% and increased bending rigidity 3%-8% among the overall. Comparing the fabrics with recycled layer of 20% to control groups, abrasion resistance was preserved between 67% -75% and bending rigidity was preserved between 86%-93% at overall.

Oil sorption properties of cotton comber noil/recycled polyester blended needle punched nonwoven fabrics- An optimization study

Oil spill pollution is a constant threat to the environment nowadays. The treatment of an oil spill remains a challenge to environmental scientists. Among the various cleanup methods available, the use of sorbents for oil spill cleanups is a popular approach. In this work, an attempt has been made to produce cotton comber noil /recycled polyester needle punched nonwoven fabrics for the oil spill clean-up process. Box–Behnken experimental design is used to optimise the parameters such as cotton comber noil /recycled polyester blend proportion, needle punching density and areal density for maximum oil sorption capacity. At 70:30 cotton comber noil /recycled polyester blend proportion, 64.94 needle punching density and 100 GSM, maximum oil sorption was achieved. The maximum oil sorption achieved in the case of crude oil and vegetable oil is 45.90 g/g and 32.30 g/g respectively. The cotton comber noil/recycled polyester needle punched nonwoven fabric showed a stable water bead morphology with a static contact angle of 133.6. The present work indicates that the cotton comber noil/recycled polyester needle punched nonwoven fabric (70/30) is a potential sustainable product for oil spill removal applications.

Development of Ceramic and Glass Fiber Needle-Punched Nonwoven Fabrics Part I: An Optimization

Abstract The study on the performance of areal density of web, needle punching density, and needle depth of penetration, particularly, the combination of glass and ceramic fiber nonwoven fabrics over the mechanical, thermal, and filtration properties were studied with the Box-Behnken experimental design. For the requirement of filtration behavior, three sets of samples with varying glass fiber areal densities of 250, 300, and 350g/m2 were taken and added with ceramic fibers to achieve sandwich-blend nonwoven materials of 60/40, 50/50, and 40/60 ratios. Then, the processing variables were taken as needle punch density and needle depth of penetration, and three optimized samples were predicted using the Box-Behnken experimental design based on the filtration efficiency of the exhaust along with their mechanical and thermal properties. It is also found that there was significant influence on the properties by the variables taken for the product development for the filters. It was found that there was a significant increase in the tensile properties in the optimized samples, and it was found that the results taken for the optimization process were unaltered.

Influence of Needle-punching Parameters for the Preparation of Polypyrrole-coated Non-woven Composites for Heat Generation

This work deals with the preparation and characterization of electrically conductive needle-punched non-woven composites for heat generation. Electro-conductive non-woven composites were prepared through the in situ chemical polymerization of pyrrole with FeCl3 (oxidant) and p-toluene sulfonic acid (dopant). A two-stage double-bath process was adopted for the in situ chemical polymerization of pyrrole. The effect of parameters such as fibre fineness, needle-punching density and depth of needle punching on a polypyrrole add-on, and surface resistivity were studied by employing the Box-Behnken response surface design. It was observed that fibre fineness was the most influential parameter of the polypyrrole add-on. The lowest surface resistivity of the polypyrrole coated sample (200 g/m2, prepared with a punch density of 200 punch/cm2, a punching depth of 6 mm and fibre fineness of 2.78 dtex) was found to be 9.32 kΩ/□ with a polypyrrole add-on of 47.93%. This non-woven composite demonstrated good electrical conductivity and exhibited Joule’s effect of heat generation. Due to the application of a 30 V DC power supply, the surface temperature of the non-woven composite rose to 55 ºC from a room temperature of 37 ºC. Optical and electron microscopy images of the non-woven composites showed that PPy molecules formed a uniform coating on the non-woven surface. FTIR studies evidenced the coating of PPy on a polyester surface. These coated non-woven composites were highly electrically conductive and practically useful for the fabrication of heating pads for therapeutic use.

An Investigation on Recycling of Blanket Trimmings Through Needle-punched Nonwovens

Utilization of recycled fibers in nonwovens has been an attractive issue for researchers considering environmental and economic benefits. In this study blanket trimmings and mechanically recycled fibers were blended and softly needle-punched to be used as interlayers of traditional needle-punched nonwovens. The outer layers from polypropylene (at four different mass per unit areas), from recycled polyester (at four different mass per unit areas), from mechanically recycled fibers (at three mass per unit areas) and the control groups were produced by classical needle-punching at two needle-punch densities. The recycled interlayers consisting of blanket trimmings and mechanically recycled fibers and are then fixed by needle-punching again, between the two twin layers of needle-punched nonwovens of those three types of raw materials. Control groups did not include the recycled interlayers. Hence, three layered end products were obtained. Tensile characteristics of the end products were evaluated in terms inter layer ratio of the end products, raw material type of outer layers and needle-punching density through standard test methods. The results were statistically analyzed in SPSS 23.0-One way ANOVA. In the conclusion, blanket trimmings were successfully entangled to the end products as interlayers and it was observed that the strength of the nonwovens decrease with the higher recycled interlayer ratio and increase with needle-punch density.

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.

Investigation about the Effect of Manufacturing Parameters on the Mechanical Behaviour of Natural Fibre Nonwovens Reinforced Thermoplastic Composites.

To date, nonwoven fabrics made with natural fibres and thermoplastic commingled fibres have been extensively used in the composite industry for a wide variety of applications. This paper presents an innovative study about the effect of the manufacturing parameters on the mechanical behaviour of flax/PP nonwoven reinforced composites. The mechanical properties of nonwoven fabric reinforced composites are related directly to the ones of dry nonwoven reinforcements, which depend strongly on the nonwoven manufacturing parameters, such as the needle-punching and areal densities. Consequently, the influence of these manufacturing parameters will be analysed through the tensile and flexural properties. The results demonstrated that the more areal density the nonwoven fabric has, the more the mechanical behaviour can be tested for composites. By contrast, it has a complex influence on needle-punching density on the load-strain and bending behaviours at the composite scale.

Effect of needle punching on flexural behavior of carbon fiber-reinforced thermoplastic sandwich panel with spring-backed core

Sandwich structures were manufactured using ultra-thin chopped carbon fiber tape-reinforced thermoplastics as the facing and thermally post-processed carbon fiber paper-reinforced thermoplastics (CPT) as the core. To improve the properties of the structure along the thickness direction to prevent delamination, preformed sheets were subjected to needle punching. We investigated the effects of using a polyamide-6-based CPT sheet as an adhesive layer, and the cores being subjected to different levels of thermal deconsolidation. The sandwich panels were compared using four-point bending tests; while the flexural rigidity was calculated based on beam theory and compared with experimental results. X-ray micro-computed tomography analysis was performed to evaluate the fiber orientations after punching. The needle-punching process increased the adhesion between the facing and core without sacrificing the flexural properties of the composite structure. A higher needle punching density enhanced inter-laminar shear behavior of the core and reduced delamination failure.

Polyethylene terephthalate/basalt stab-resistant sandwich composites based on the Box–Behnken design: Parameter optimization and empirical regression model

In this study, the thicknesswise fibers of the low-melting polyethylene terephthalate (LPET) nonwoven fabrics are needle punched and intertwined with the intra-laminar basalt fibers (BF) of basalt plain woven fabric in order to strengthen the stab-resistant property of LPET/BF sandwich composites as well as to fabricate armor that is composed of less lamination layers. Two LPET nonwoven fabrics and a BF plain woven fabric as an interlayer are laminated and combined using a needle-punch reinforcing method. The response surface analysis based on the Box–Behnken design is used to examine the influences of structure parameters of low-melting PET nonwoven fabrics including areal density (AD) and manufacture parameters including needle punching density (ND), and depth of needle punch (DP) on the spike stab resistance, knife stab resistance, bursting resistance, and tensile property. An empirical regression model of AD, ND, and DP is thereby established. The test results show that the bursting strength and quasi-static stab resistance of sandwich composites are highly dependent on AD and ND. Likewise, DP has a significant influence on the knife stab resistance and bursting strength, while the tensile strength is solely dependent on ND. According to the empirical regress model, the acquired optimal needle punching parameters of sandwich composites are an AD of 400 g/m2, ND of 143.77 needles/cm2, and DP of 6.41 mm. The 95% confidence interval yielded by the empirical regression model is in conformity with the test results. The empirical regression model of the stab resistance is proven to provide effective prediction of the number of lamination layers required by armor in the future.

Geosynthetic clay liners: effect of structural properties and additives on hydraulic performance and durability

In this study, the effects of some structural parameters and also two kinds of additives on hydraulic performance, self-healing ability and wet/dry durability of GCL are experimentally studied. Structural parameters include bentonite mass per unit area of GCL and needle-punching density. Nano-clay particles and sodium poly-acrylate which is a kind of superabsorbent polymers (SAPs) are used as additives. The results show that bentonite mass can affect the permeability of GCL, but it does not impress the healing time and wet/dry durability. Needle-punching density in needle-punched GCLs positively affects both hydraulic performance in case of hydraulic conductivity, self-healing capacity and wet/dry durability. The test results also show that nano-clay particles considerably improve the permeability and self-healing capacity, while they have negative effects on durability of GCL. On the other hand, the wet/dry durability of GCL dramatically enhances by using SAP, while hydraulic performance of GCL is not much affected by SAP inclusion. Experimental results show that using both nano-clay and SAP in GCL can improve its permeability, self-healing capacity and wet/dry durability simultaneously.

Mechanical behavior of flax/polypropylene commingled nonwoven at dry scale: Influence of process parameters

Currently, nonwoven fabrics made with natural and thermoplastic commingled fibers have been extensively used in the composite industry due to their light weight and low processing and material costs. As two key parameters in the manufacturing of nonwoven fabrics, the needle-punching and material surface densities influence strongly the mechanical properties of nonwoven fabrics and their reinforced composite parts. Compared to most studies focused on the composite stage, the present experimental investigation is performed at the dry fabric stage, and the influence of the needle-punching and material surface densities on the mechanical behavior of nonwoven fabrics will be analyzed through tensile and bending tests. The results show that increasing the material surface of the nonwoven fabric leads to a better mechanical behavior, but that such variations do not modify the phenomenon of anisotropy of nonwoven fabrics. By contrast, increasing the needle-punching density can strengthen generally the homogeneity of nonwoven fabrics.

Effect of Needle Punching Process on a Chopped Strand Mat Composite with an Open Hole

The easiest and most reliable joining method is the mechanical joint with a bolt and nut or rivet. However, in the case of composite laminates, mechanical joint properties decrease because of lower interlaminar properties compared to in-plane properties around hole. This study investigated needle punching process with the aim of improving the mechanical properties in the thickness direction of fiber-reinforced plastic composite laminates with an open hole. Needle punching process was applied to glass fiber chopped strand matused as the reinforcement for the composite laminates. Open-hole tensile tests and observations of end cross-sections after the tests were performed. The tensile properties and fracture mechanism of the specimens subjected to needle punching process were investigated. In addition, characteristic distance (a parameter for evaluating resistance to fracture in open-hole tensile test specimens) was also calculated to examine the effects of needle punching process conditions on fracture toughness. Tensile strength was improved by more than 15% by needle punching process. However, when a certain needle punching density was exceeded, the mechanical properties worsened. In addition, characteristic distance increased with increasing needle punching density. Thus, these results suggest that there is an optimal needle punching density with respect to strength and characteristic distance.

A parametric study on hydraulic conductivity and self-healing properties of geotextile clay liners used in landfills

Nowadays, the raise of excessive generation of solid wastes is considered as a major environmental concern due to the fast global population growth. The contamination of groundwater from landfill leachate compromises every living creature. Geotextile clay liner (GCL) that has a sandwich structure with two fibrous sheets and a clay core can be considered as an engineered solution to prevent hazardous pollutants from entering into groundwater.The main objective of the present study is therefore to enhance the performance of GCL structures. By changing some structural factors such as clay type (sodium vs. calcium bentonite), areal density of clay, density of geotextile, geotextile thickness, texture type (woven vs. nonwoven), and needle punching density a series of GCL samples were fabricated. Water pressure, type of cover soil and overburden pressure were the environmental variables, while the response variables were hydraulic conductivity and self-healing rate of GCL. Rigid wall constant head permeability test was conducted on all the samples. The outlet water flow was measured and evaluated at a defined time period and the hydraulic conductivity was determined for each sample. In the final stage, self-healing properties of samples were investigated and an analytical model was used to explain the results. It was found that higher Montmorillonite content of clay, overburden pressure, needle punching density and areal density of clay poses better self-healing properties and less hydraulic conductivity, meanwhile, an increase in water pressure increases the hydraulic conductivity. Moreover, the observations were aligned with the analytical model and indicated that higher fiber inclusion as a result of higher needle-punching density produces closer contact between bentonite and fibers, reduces hydraulic conductivity and increases self-healing properties.

Geo-textiles for Side Slope Protection: Preparation and Characteristics

The vegetation blanket is the most common choice for soil and water preservation. This is a feasible method that protects the land and environment according to basic agriculture and engineering theories. This study manufactured eco-friendly nonwoven vegetation blankets by using cotton fibers, far-infrared fibers, PLA fibers, and low melting-point fibers at a 1:1:7:1 ratio. This ratio yielded from the pilot study provides the resulting vegetation blankets’ optimum air permeability and water absorption. This study further finds that a needle-punching density of 30 needles/cm[sup]2[/sup] allows fibers to lie in a loose structure, and therefore yielding the optimum air permeability and water absorption. In plant growth evaluation, for nonwoven vegetation blankets that contain 50 wt% far-infrared fibers, the plant growth length is 1.3 times greater than that of blankets with 10 wt% far-infrared fibers. This result proves that far-infrared fibers have usually been applied to plant growth.

Evaluation of high-modulus, puncture-resistance composite nonwoven fabrics by response surface methodology

Recycled high-modulus Kevlar fibers were blended with Nylon 6 staple fibers and biocomponent low- Tm/high- Tm polyester fibers to form high-modulus puncture-resistance nonwoven fabrics via opening, mixing, carding, lapping, needle-punching, as well as hot-pressing processes. In this paper, biocomponent low- Tm/high- Tm polyester fiber content, needle-punching density, and hot-pressing temperature were changed to evaluate the tensile strength, bursting strength and static puncture resistance of resulting nonwoven fabrics as related to aforementioned three parameters based on response surface methodology. The result shows that the tensile strength is highly related to needle-punching density and hot-pressing temperature; but the bursting strength and static puncture resistance are significantly involved with the aforementioned three parameters. The tensile strength, bursting strength, and static puncture resistance all present increasing and then decreasing trend with increase of its respective concerning parameters. Moreover, the static puncture resistance strength has linear dependence on bursting strength.

Processing Method and Property Studies of Composite Geotextiles

The relations between properties and processing parameters of needle-punched composite geotextiles are tentatively discussed in the paper. In the meantime, a new kind of adhesive bonded composite geotextiles are developed in the laboratory. Then the hydrokenetic properties of the two composite geotextiles are analyzed and compared. The results were got that with the increment of needle-punching density, breaking strength, vertical permeate coefficient and O95 of needle-punched composite geotextiles are all increase, whereas peeling strength decreases. With the rise of needle-punching depth, the breaking strength decreases, but both peeling strength and O95 are increase. Meanwhile, with the rise of bonded area, adhesive bonded composite geotextiles have good permeate property. On the other hand, adhesive bonded composite geotextiles have similar peeling strength compared with needle-punched composite geotextiles, but manifested with better permeability.

Manufacturing Technique and Mechanical Properties of Environment-Protective Composite Nonwoven Fabrics

Ecological environment deteriorates drastically and rapidly, which can be ascribed to the fast advancement of international economy and technique. Hence, people become green consumers, using green products. The series of lyocell fiber, called as recycled fiber, has been pervasively used. This study used Tencel® fiber, Polylactic Acid (PLA) fiber and high absorbent fiber as well as nonwoven manufacturing, creating Tencel®/PLA/HAF composite nonwoven fabrics. Among the manufacturing parameters, an increase in Tencel® fiber ratio, needle-punching density and basis weight all contributed to heighten the mechanical properties of nonwoven fabrics. In particular, the Tencel®/PLA/HAF composite nonwoven fabric exhibited an optimum tensile strength of 68.8 N and bursting strength of 193.7 N when Tencel® fiber ratio was over 80 wt%, basis weight was 200 g/m2 and needle-punching density was 300 needle/cm2.

Manufacturing Technique and Physical Properties of Environment-Protective Composite Nonwoven Fabrics

Rapid technical advancement threatens the earth ecology, driving people by degrees to develop green energy and green products. Tencel® fiber uses natural fibers. Products made of Tencel® fiber could be biodegraded, which solves the problems for the increasing consumptions of disposable nonwoven product. In this research, Tencel® fiber, polylactic acid (PLA) fiber, and high absorbent fiber (HAF) were used to produce Tencel®/PLA/HAF composite nonwoven fabrics. Among the nonwoven processing parameters, to increase the Tencel® fiber content helped heighten the water absorbency. When there were 80 wt% Tencel® fibers, the basis weight was 100 g/m2 and the needle-punching density was 300 needle/cm2, the Tencel®/PLA/HAF composite nonwoven fabric exhibited the optimum water absorbency in cross machine direction (CD), which was 5.0 cm. The air permeability of the Tencel®/PLA/HAF composite nonwoven fabrics reached 164.4 cm3/cm2/s when the basis weight was 100 g/m2 and the needle-punching density was 300 needle/cm2

Evaluation of the mechanical characteristics of needle-punch materials

Stress indexes on breaking and on attaining less than 20% elongation can be used to satisfactorily describe the effect of the needle-punching density on the mechanical properties of materials of different structure. Varying the needle-punching density is an effective method of increasing the strength of materials but does not affect their resistance to initial deformation.

Effect of needle-punching density on the deformation resistance of materials

The development of deformation of needle-punch materials is a stepwise process related to overcoming the friction between fibres and subsequent redistribution of the load on the active fibres. The development of tensile strain of less than 10% is determined by the fibre packing density attained during needle-punching. In stretching by more than 10%, the dependences of the deformation and strength characteristics of the material on the needle-punching density coincide and have maximum values at the critical value of the needle-punching density.