Depth Of Needle Penetration Research Articles

Study on the effect of structural parameters of a thermal liner on its thermal protective performance under radiant heat exposure

To comprehend the impact of elementary construction parameters of nonwoven thermal liners on their thermal protective performance, the current research primarily emphasizes on studying the effect of needle penetration depth and needle punch density of the thermal liner. Nonwoven fabrics with three different punch densities and three needling depths were prepared. The air permeability and thermal resistance of the thermal liner were investigated through regression analysis to determine the influence of needle penetration depth and needle punch density. It was observed that both factors had a notable impact on the air permeability and thermal resistance of the thermal liner. An increase in needle penetration depth and needle punch density resulted in a decrease in the air permeability and thermal resistance of the thermal liner. An experiment was carried out utilizing the 33 Box-Behnken designing approach; the factors employed were the radiant heat flux intensity, needle punch density, and needle penetration depth of the thermal liner. The thermal protective performance of thermal liners was measured at three discrete intensities of radiant heat exposures. To investigate the effect of the test and construction parameters and their interaction, an analysis of variance study was carried out. It was observed that protection time rises with the decrease in needling depth and needle punch density at every level of heat flux. With the rise in incident radiant heat flux, protection time declines, irrespective of needle penetration depth and punch density levels.

CT-guided microcoil versus hook-wire localization of pulmonary nodule prior to video-assisted thoracoscopic surgery without fluoroscopic guidance

BackgroundBoth microcoils and hook-wires are commonly utilized for preoperative pulmonary nodule localization due to their convenience, but it remains unclear which one should be prioritized for recommendation.AimsTo compare the safety and efficacy of microcoils and hook-wires for pulmonary nodule localization.MethodsFrom January 2021 to December 2021, 310 consecutive patients (113 males and 197 females) with 341 pulmonary nodules who underwent CT-guided microcoil or hook-wire localization prior to video-assisted thoracoscopic surgery (VATS) at our center were retrospectively included in this study. There were 161 patients in the microcoil group and 149 patients in the hook-wire group. The successful localization rate, complication rate, radiation exposure, and medical costs were compared between the two groups.ResultsA total of 341 pulmonary nodules were localized, with a success rate of 99% (180/184) in the microcoil group and 93% (146/157) in the hook-wire group, respectively. All patients successfully underwent VATS. Multivariate analysis revealed that hook-wire localization, shorter needle depth into the lung tissue and the longer waiting time from localization to VATS were the risk factors for the localization failure. The incidences of pneumothorax in the microcoil group and hook-wire group were 34.8% (56/161) and 34.9% (52/149), respectively (P = 0.983). The incidences of pneumorrhagia were 13% (24/184) and 46.5% (73/157), respectively (P = 0.000). Multivariate analysis revealed that hook-wire localization and greater depth of needle penetration into lung tissue were risk factors for pneumorrhagia.ConclusionMicrocoil localization of pulmonary nodules is superior to hook-wire localization in terms of efficacy and safety. This finding provides insight into priority and broader promotion of microcoil localization.

Coccygeal Nerve Blockade vs. Impar Ganglion Blockade in Coccydynia: A Randomised Clinical Trial.

Background and objective Coccydynia is a condition that causes pain around the coccyx, severely limiting functionality. Interventional treatment options are available for cases that do not respond to conservative treatment. Coccygeal nerve block (CnB) is a novel method for treating coccydynia. This study compared the efficacy of CnB and ganglion impar block (GiB) and aimed to evaluate the efficacy of CnB in treating coccydynia. Methods The 12-week results of 56 patients were analysed. One group underwent ultrasound (US)-guided CnB, while the other group underwent fluoroscopy (FL)-guided GiB. Pain intensity was assessed using the numerical rating scale (NRS), and functionality was assessed using the PARIS Coccydynia Functionality Questionnaire. Evaluations were conducted before treatment, as well as four and 12 weeks after treatment. Results The baseline median NRS score was eight in both groups, while at week 12, it was three in the CnB group and 2.5 in the GiB group. The median PARIS score at baseline was seven in the CnB group and 6.5 in the GiB group, while at week 12, it was four and three, respectively.At week 12, compared to baseline, both the CNB and GiB groups showed statistically significant improvements in NRS and PARIS scores (p<0.001). When comparing the two groups, no significant difference was observed in the NRS and PARIS scores before and four and 12 weeks after treatment. No serious adverse events were observed in any patient. Conclusions Coccydynia is sometimes refractory to treatment. In our study, we found that CnB, a method recently used in the treatment of coccydynia, was as effective as GiB, which has been used for a long time, and we found no evidence of superiority. The lack of radiation exposure due to its US-guided application, the superficial course of the coccygeal nerves and the low depth of needle penetration make it easier to perform. These advantages suggest that it will be a preferable method in the treatment of coccydynia.

Appropriate needle penetration depth for intramuscular injections depends on the injection site, recipient arm position, and injection technique: A randomized crossover study

Appropriate needle penetration depth for intramuscular injections depends on the injection site, recipient arm position, and injection technique: A randomized crossover study

Factors influencing the accuracy and safety of preoperative computed tomography (CT)-guided soft hook-wire localization for pulmonary nodules: a comprehensive analysis.

The necessity of localization of pulmonary nodules lies in ensuring the ability to locate the nodule quickly and accurately during surgery, thereby improving the success rate of the operation. The accuracy and risk of preoperative localization of pulmonary nodules need further exploration. Therefore, the purpose of this study was to investigate the factors of accuracy and safety of computed tomography (CT)-guided localization of pulmonary nodules using a flexible wire hook positioner. In this retrospective cross-sectional analysis, 281 patients with a single pulmonary nodule underwent video-assisted thoracoscopic surgery (VATS) following localization with a soft hook-wire guided by CT scan from January 2021 to July 2022 at Nanjing Drum Tower Hospital. The patients underwent VATS to remove pulmonary nodules within 24 hours after localization. The demographic, pulmonary nodule, and technical factors were analyzed retrospectively. Univariate and multivariate analysis were used to analyze the identified factors that influence pulmonary nodule localization accuracy and complications. Localization was successfully performed in 280 patients, with only 1 patient being excluded due to a displaced positioner and the hook wire failing to enter the lung parenchyma as a result of pneumothorax. Out of the total cases, 191 (68.2%) were accurately positioned in group G0, whereas 89 cases (31.7%) were inaccurately positioned in group G1. Hemorrhage and self-limited hemoptysis were observed in 64 patients (22.8%), whereas pneumothorax was observed in 84 patients (29.9%). There were no serious complications such as air embolism or death. The accuracy of localization was found to be influenced by both the depth of pulmonary nodules [odds ratio (OR) =22.610, 95% confidence interval (CI): 10.351-49.391, P=0.001] and the depth of the needle used (OR =0.322, 95% CI: 0.136-0.765, P=0.010). Additionally, postoperative hemorrhage was found to be affected by several important factors, including the diameter (P=0.036) and depth of the nodule (P=0.011), as well as the thickness of the chest wall (P=0.043) and the depth of the needle used (P=0.005). The CT-guided flexible wire hook positioner has been found to be a safe and effective device for locating pulmonary nodules. The depth of pulmonary nodules and needle penetration are key factors affecting the accuracy of lung nodule localization under CT guidance and are important factors affecting postoperative bleeding.

A comparative study of physical properties of nonwoven fabrics produced by uni- and bi-directional needles using response surface methodology

In the production of needle-punched nonwoven fabrics, the direction of needle barbs is towards the tip of the needle. When the needle penetrates into the fabric, the barbs carry some fibres into the fabric and when it returns the barbs are empty. This means that, the needle works when it penetrates into the fabric and doesn’t work when it returns. Using a bi-directional barb needle in the needle-punch process was proposed as an idea with the theory that, the needle also works when returning (leaving the layer). This study investigates the physical properties of needle-punched nonwoven fabrics produced with unidirectional and bi-directional needle types. Effects of needle penetration depth (NPD), strokes per minute (SPM), and needle type (N1, N2) on properties such as gram per square meter (GSM), thickness, fabric density (FD), and static puncture resistance (SPR) are examined. An experiment with 19 runs was designed using response surface methodology and optimal design with two quantitative factors, including NPD and SPM, and one qualitative factor containing needle types. In addition, four responses were measured and reported, including GSM, thickness, FD, and SPR. Test results show that needle N2 produces a fabric with lower FD, higher GSM, thickness, and SPR in comparison to needle N1, and was selected in optimization process with a desirability value of 0.872 against 0.688 for needle N1. The improved fabric properties of needle N2 may be exploited for the economic benefits of the nonwoven fabric producers or textile industry.

Assessment of retention of training in improving the accuracy of needle penetration depth.

[Purpose] This study aimed to assess whether the effects of training in fine motor skills, such as improving the accuracy of acupuncture depth, persisted after the training was completed. [Participants and Methods] Fifteen students (age, 28.0 ± 8.4 years) participated in the study. A 0.2 × 50 mm needle was inserted, as precisely as possible, against an acupuncture training gel at a depth of 15 mm. After explaining how to check the distance using their fingers as indicators and how to use a guide piece to check for depth, the students were instructed to train independently for two weeks. Error distance of the acupuncture depth was evaluated before the training (beginning of the training) and at training 1 (training for 7 days), training 2 (training for 14 days/end of training), and post-training (28 days after training 2). [Results] The error distance (absolute value) from 15 mm in training 1, training 2, and post-training decreased significantly compared with those before the training. The error distance was not significantly different between post-training and training 2. [Conclusion] After two weeks of acupuncture training, the error distance decreased significantly, suggesting that this technique was retained after 28 days of completing the training.

Optimisation of punching parameters for enhanced filtration performance of non-woven by response surface methodology

This work highlights the relevance of punch density, needle penetration depth and basis weight on the nonwoven fabric’s properties. Fibre fineness-specific optimised carding parameters, that is feeder, cylinder and doffer speeds were used for the preparation of carded web to produce considered basis weight of carded batts. Fabric thickness, bursting strength, mean flow pore size, air permeability, air filtration efficiency and pressure drop were extensively investigated, and a relationship was developed using the Box–Behnken design. The punch density and needle penetration depth were optimised to achieve the required levels of mean flow pore size at constant basis weight for enhancing the air filtration behaviour of non-woven fabrics.

Appropriate intradeltoid muscle needle penetration depth in vaccine administration: an MRI study in Thailand.

The objective of this study was to evaluate the appropriate vaccination needle penetration depth into the deltoid muscle to avoid injection-site complications from an inappropriate injection depth and/or injection site in the Thai population. This was a retrospective study using axial proton density-weighted images of MRI shoulders at the level of 2 fingerbreadths below the acromion process to measure the combined thickness of the skin, subcutaneous fat pad and deltoid muscle to evaluate the percentage of injections into the deltoid muscle with various needle penetration depths. There were 509 MRI shoulder images of 222 males and 287 females (265 right shoulders and 244 left shoulders). The average body mass index and age were 24.54 ± 3.54 kg/m2 and 64.81 ± 10.20 years, respectively. Using a needle penetration depth of 12.7 mm (0.5 inches) achieved 100% of injections into the deltoid muscle. We recommend advancing the entire length of a 0.5-inch needle perpendicular to the skin at 2 fingerbreadths below the acromion process for adult intradeltoid vaccinations. This approach ensures optimal vaccine delivery and minimizes the risk of injection-related injuries.

Improvement of road infrastructure on the example of the Center-South transport corridor of the Akchatau-Akzhal section

The study investigates the enhancement of road infrastructure in the Center-South transport corridor of the Akchatau-Akzhal section, addressing the challenges posed by rapid road pavement deterioration due to increased traffic flow. By analyzing the natural and climatic conditions of the area, optimal concentrations of additives were determined to improve the properties of bitumen and asphalt concrete, with a focus on increasing strength and durability. Specifically, the addition of monoethanolamine to bitumen at a concentration of 0.08% led to notable improvements in key properties. The needle penetration depth at 25°C decreased from 80 to 71, indicating enhanced consistency. Moreover, the ring and ball softening point increased from 52 to 56, demonstrating increased resistance to temperature variations. Stretchability at 40 improved from 65 to 70, highlighting enhanced flexibility and durability. The study emphasizes the critical importance of quality construction and regular maintenance to ensure the durability and resilience of road networks to various factors. By utilizing innovative technologies and materials, such as modified binders with additives, the study showcases the potential to significantly enhance the performance, safety, and efficiency of road networks while reducing costs and environmental impact. The findings underscore the need for continued research and implementation of optimized solutions to improve road infrastructure sustainability and longevity.

Synthesis, Characterization, and Investigation of Coating Properties of Carboxymethyl Acorn Starch (CMAS)

AbstractKyrgyzstan is a landlocked country in Central Asia, famous for its crystal‐clear lakes, majestic Tien Shan Mountains that bisect the territory of Turkistan, and magnificent natural beauty. This study aims to evaluate the fruit (acorns) of the oak trees (Quercus robur L.) grown in Bishkek, the capital city of Kyrgyzstan. For this purpose, carboxymethyl acorn starch (CMAS), which is not synthesized in literature, is first synthesized by isolating acorn starch (AS) from the acorns. The structures of CMASs are characterized by 1H(13C)‐NMR, FT‐IR, XRD, and SEM techniques. The viscosities of the samples with different degrees of substitution (DS), such as 0.62, 0.95, and 1.01, determined by the titrimetric method, are measured as 247, 600, and 388 mPa s, respectively. In addition, considering the film‐forming properties of CMASs, tomatoes are coated, and their shelf lives are investigated. Weight loss (WL) is 38.36% in control and 25.52% in coated tomato after 4 weeks. The needle penetration depth is measured as 388 mm in the control and 249 mm in the coated tomato. Total soluble solids (TSS) content showed approximate results in both samples. Control tomatoes containing 78.8 mg 100 g−1 ascorbic acid lost significantly during storage, reducing to 13.90 mg 100 g−1.

Modelling using fuzzy logic: study of needle-punched filters

The tensile behaviour dependency on the process parameters of blended nonwoven fabric is highly non-linear. This paper explores the potentiality of fuzzy logic inference in such a nonlinear environment as predictive process modelling with minimal experimental data. A model based on fuzzy inference engine has been attempted using recycled polyester fibre blend percentage, needling density and depth of needle penetration as the input variables and tensile strength in both machine direction (MD) and cross direction (CD) as the output variables. Proposed model was built in MAT LAB/Simulink and has been verified by experimental sample data set. Mean relative error percentage and correlation coefficient between the fuzzy model predicted and actual experimental sample values were found to be around ±2.5% and up to 0.97 respectively. These results validate that the model may be applied with high accuracies for the prediction of tensile behaviour of the blended nonwoven fabric in the textile industries.

Partial infraspinatus tear with bursitis following an mRNA vaccination: a case report.

A 52-year-old Thai female without preexisting shoulder pathology and symptom had developed left shoulder pain for 3 days. Two weeks prior to shoulder pain, she received an mRNA COVID-19 vaccination. She positioned her arm in combined internal rotation with 60° of arm abduction. Her symptoms were pain in all directions of shoulder motion and tenderness at the bicipital groove and over the deltoid area. The testing of the rotator cuff power of the infraspinatus tendon showed pain. An MRI showed infraspinatus tendinosis with a low-grade (almost 50%) bursal-surface tear at the footprint of the superior fiber with associated overlying subacromial-subdeltoid bursitis. She was treated with both intraarticular and subacromial corticosteroid injections (triamcinolone acetate (40mg/ml) 1ml+1% lidocaine with adrenaline 9ml). She did not respond to oral naproxen but responded well to intraarticular and subacromial corticosteroid injections. The best way to deal with SIRVA is to prevent this condition by using the correct injection technique. First, the injection site should be two or three fingerbreadths below the mid-acromion process. Second, the needle's direction should be perpendicular to the skin. Third, using the correct needle penetration depth.

Statistical analysis of the effect of processing machine parameters on acoustical absorptive properties of needle-punched nonwovens

The object of this paper is to investigate the acoustic insulation properties of needle-punched nonwovens produced from recycled polyester waste blended with virgin polyester serving as supportive material. The research work also studies the effect of different processing parameters of needle punching nonwoven machines through the investigation of different needle speeds, lattice speeds, and penetration depths. Throughout the research work, several needles punched nonwoven fabrics were produced under different conditions as follows: Three needle speeds were applied: 280, 245, and 227 rpm. Three lattice speeds were applied: 0.72, 1.47, and 2.35 m/min. Three depths of penetration for the needles were applied: 26, 10, and 5 mm. Finally, different blends of waste/virgin polyester fibers were produced and tested: 40/60%, 20/80%, and 100% virgin polyester. The four parameters investigated had a statistically significant effect on the sound transmission losses obtained. It was proved that as the frequency increases, the needle speed gains importance while the needle penetration depth loses importance. The results of testing the different samples indicated that the highest sound transmission loss is attained using non-woven fabrics produced from virgin polyester fibers and prepared at high stitch density.

STUDY OF PHYSICO-CHEMICAL PROPERTIES OF ROAD BITUMEN ORB 70/100

The practice of the motor roads operation in the Republic of Kazakhstan shows that the durability of asphalt concrete pavements on them is much lower than the standard terms. Therefore, maintaining roads in a condition, whichmeets the requirements of traffic flows is impossible without the use of new, progressive materials and technologies. The main factor influencing a sharp decrease in the service life of the road surfaces is the use of low-quality bitumen as a binder in asphalt concrete mixtures, since microcracks develop mainly in its film.The goal of the work. In this paper, the physical and mechanical properties of bitumen of the grade ORB(oil road bitumen) 70/110 of the Aktau bitumen plant have beenstudied. Methods.To improve the operational characteristics of bitumen, modification with polyethylene and polystyrene waste has beencarried out.Results and discussion.It has beenshown that after the addition of the modifying additives, the main indicators of bitumen have improved. For polyethylene: the depth of needle penetration has decreased from 70 down to 61 mm, the extensibilityof bitumenhas decreased by 52 cm, which indicates an improvement in the plasticity and elasticity, the softening temperature along the ring and ball has increased from 49 up to 59 °C, which leads to reducingthe tendency of bitumen deformation, and the brittleness temperature has beenwithin the normal range -not less than -20 °C. In case of using polystyrene, the penetration characterizing the bitumen hardness decreases from 70 mm down to 61 mm; the extensibilityof bitumen increases by 10 cm, which indicates an improvement in the elasticity and strength, due to the presence of the resulting structural network. Conclusion. The softening temperature of bitumen increases, which leads to an improvement in the heat resistance and viscosity.

PRODUCTION OF THERMOSTABLE ROAD BITUMENS BY THE METHOD OF "OXIDATION-COMPOUNDING"

The paper proposes a technology for producing petroleum road bitumen by compounding deeply oxidized bitumen with tar, pre-oxidized to various temperatures, in order to produce binders stable to the processes of thermo-oxidative aging. The rate of technological and chemical aging of tar and bitumen has been studied. It was found that tar is most susceptible to technological, and bitumen to chemical aging. It is shown that the use of tar pre-oxidation technology is a promising direction in bitumen production in the production of standard grades of bitumen binders. The obtained compounded bitumens have high extensibility values at 250C and maximum tensile force, which characterizes their high cohesive properties, as well as high values of the needle penetration depth at 00C and low brittleness temperatures, which indicate good low-temperature properties of bitumen. It has been revealed that the use of oxidized tar with a softening point of 360C during compounding with deeply oxidized bitumen can achieve the minimum values of softening temperature change after aging and obtain standard bitumen grades BND 70/100 and BND 100/130 according to GOST 33133-2014. The resulting compounded bitumen is less susceptible to destructive and thermo-oxidative aging processes and can be effectively used for paving

Effect of Structure on Vertical and Horizontal Wicking Performance Concerning Jute (Chorchorus Olitorius) and Water

ABSTRACT Vertical and horizontal wickings were studied for jute, a lingo-cellulosic natural fiber, as fiber, yarn, woven fabric, and nonwoven. The effect of yarn parameters (linear density, twist density, and tension), fabric type (plain woven, twill woven, and nonwoven) and nonwoven parameters (parallel laid, cross laid, areal density, punch density, and depth of needle penetration) were observed and analyzed using a fabricated setup for wicking testing. Wetting of jute with water was studied by measuring contact angle using Sissili-drop method. The rate of wicking shows two distinct parts: instantaneous and time dependant. The horizontal wicking is always higher than the vertical wicking. The weft shows better wicking than warp yarn followed by two-ply yarn. Yarn twist level and linear density play a significant role. Twill fabric shows better wicking than plain-woven fabric. Wicking effect of needle-punched nonwoven shows lower than woven fabric. It is negatively correlated with areal density and positively correlated with punch density. It will help to design a textile from jute, where wicking plays a significant role.

A study on resistance of asphalt concrete exposed to the effect of mycelial fungi

Introduction. In recent years, the issue of improving the quality and service life of road surfaces has been relevant in Russian and worldwide. The main reasons for the early destruction of road surfaces is the quality of individual components and the imperfect composition of asphalt concrete that has pre-set durability. The results of studies, characterizing changes in the roadway surface properties, are of practical value. In this case, we consider the surface hardness of asphalt concrete specimens of various types, subjected to microbiological destruction, which is the property to be studied. The purpose of the work is to study the microbiological resistance of various asphalt concretes, to select and substantiate methods for assessing the biological stability of asphalt concrete subjected to mycelial fungi.&#x0D; &#x0D; Materials and methods. Asphalt concrete specimens contain BND 60/90 bitumen that has the following characteristics: needle penetration depth 0.1 mm at 25 °С – 85; needle penetration depth 0.1 mm at 0 °С — 35; ring and ball softening point 0 °С — 48; extensibility — 83 cm; penetration index — 0.6. Mineral powder, glass cullet powder, and food flour are used as fillers. MP-1 inactivated mineral filler, made of carbonate rock, having the true and average density of 2.71 and 1.71 g/cm3, respectively, was also used. Glass powder was obtained by grinding the waste glass of JSC “Lisma”, Saransk. The chemical composition of glass waste is (in percent for weight): SiO2 — 68.75–72.90; Na2O — 11.9–16.7; K2O — 1.2–3.8; CaO — 5.0–6.0; BaO — 2.2–5.5; MgO — 3.2–3.8; Fe2SO4 — 0.1–0.12; Al2O3 — 1.0–1.5. Food flour was considered as an additive that serves as the nutritional medium for mycelial fungi. Some other components, added to the studied specimens of asphalt concrete, are discussed in the work. The studied property, or hardness, was identified using the Hoppler consistometer. Testing results are provided in the paper. Linear interpolation of experimental data was conducted to identify hardness at the intermediate points to rank the tested asphalt concrete, the standard error between the hardness curve during the exposure and the straight line for the same exposure points. The results of the proposed method are explained graphically using the experimental data. It is assumed that the smaller the root-mean-square error, the more resistant the corresponding composition of asphalt concrete to the effect of mycelial fungi.&#x0D; &#x0D; Results. As a result of the studies and the application of the proposed hardness control methods, the best compositions were identified in terms of resistance to the effects of mycelial fungi. Each group of specimens and compositions of asphalt concrete under study was broken down by their resistance to the effects of the external environment, or mycelial fungi.&#x0D; &#x0D; Conclusions. The results of this research project enable the authors to evaluate the quality of asphalt concrete compositions exposed to the biological environment. The proposed approach to assessing the quality of asphalt concrete compositions can be applied to other building materials and products subjected to certain aggressive media.

Intelligent monitoring and assessment on early-age hydration and setting of cement mortar through an EMI-integrated neural network

In this study, the authors presented a smart sensing method for monitoring and evaluating the early-age hydration and hardening process of cement mortar through the integration of the EMI technique with deep learning (DL) models. The main research works and contributions of this research are given as follows: The development of the penetration resistance was acquired by measuring the Vicat needle penetration depth. Meanwhile, the EMI spectra within two scanning frequency ranges, 1000 kHz and 3000 kHz, were continuously captured. The key innovation of this research is that a DL-based framework named EMI-integrated neural network (EMI-IntNet) was proposed, which could facilitate the achievement of intelligent monitoring and assessment. The EMI-IntNet, which combines a one-dimensional convolutional neural network (1D-CNN), a long short-term memory neural network (LSTM) and an attention mechanism, can accurately predict the dynamic penetration impedance from raw EMI data without any pre-processing or subjective judgment. Two datasets collected in two separate vibration modes (d31 and d33) were used to validate the effectiveness of the proposed method. The results show that the EMI-IntNet can quantitatively evaluate the dynamic penetration impedance of cement mortar with an error of less than 2 % and a coefficient of determination (R2) value over 0.99 for both datasets. The EMI-IntNet’s forecasting accuracy, noise immunity and adaptability were thoroughly investigated, which outperform that of the machine learning-based approaches, 1D-CNN and 1D-CNN-LSTM. In conclusion, the proposed method enables automatic data acquisition, feature extraction and identification of EMI signals, contributing to the intelligent monitoring and accurate assessment of the mechanical impedance change throughout the early-age hydration and setting of cement mortar.

Comparison of tensile properties of needle punched nonwoven fabric produced by bi-directional and unidirectional barb needles employing response surface methodology

In production of needle punched nonwoven fabrics, direction of needle barbs is towards the tip of the needle. When the needle penetrates into the fabric, the barbs carry some fibres into the fabric and when it returns the barbs are empty. This means that the needle works when it penetrates into the fabric and doesn’t work when it returns. Using a bi-directional barb needle in the needle-punch process was proposed as an idea with the theory that the needle also works when returning (leaving the fabric). In this study, the test specimens were prepared by two type of needles in an industrial needle machine. Fibre displacement at fabric cross-section was examined by optic and scanning electron microscopy for two types of needles. An experiment with 190 samples was produced using the response surface methodology and optimal design with two quantitative factors, including the number of strokes per minute and needle penetration depth, and one qualitative factor containing needle types. In addition, six responses were measured and reported in the machine direction and cross direction, including breaking load, extension, and tenacity. According to the findings, the tensile characteristics of non-woven (NW) fabrics generated produced by bi-directional barbed needles were higher than those produced by unidirectional barbed needles.