Structural investigation of spunlace nonwoven

2018 ◽  
Vol 22 (3) ◽  
pp. 158-179 ◽  
Author(s):  
Ravi Kumar Jain ◽  
Sujit Kumar Sinha ◽  
Apurba Das
Keyword(s):  
High Speed ◽  
Structural Changes ◽  
Structural Integrity ◽  
Pore Diameter ◽  
Structural Parameters ◽  
Water Pressure ◽  
Air Permeability ◽  
Strong Positive Correlation ◽  
Content Type ◽  
Significance Level

Purpose Spunlacing is a promising nonwoven technology for the production of fabric with good handle and better structural integrity. Structural parameters such as pore size, thickness and number of binding point/entanglement between fibres are decisive for good mechanical and comfort properties of nonwoven fabrics. This study aims to focus on the effect of different process parameters on the structural change in spunlace fabrics. Design/methodology/approach Spunlacing is purely a mechanical bonding technology where high-speed jets of water strike a web to entangle the fibres. Different spunlace nonwoven structures were produced by varying processing parameters such as waterjet pressure, delivery speed, web mass and web composition as per four-factor, three-level Box–Behnken design. The effect of these parameters on the structural arrangement was studied using scanning electron microscopy. An attempt has also been made to study the changes in pore geometry and thickness of the fabrics by using response surface methodology with backward elimination. Findings Significant structural changes were observed with variation in water pressure, web mass and web composition. The test results showed that fabric produced at higher waterjet pressure has lower mean pore diameter and lower thickness. The variation in mean pore diameter and mean thickness due to waterjet pressure is around 26 and 34 per cent, respectively, at 95 per cent significance level. The web composition and web mass also significantly influence the mean pore diameter and thickness at 95 per cent significance level. There is a strong positive correlation (r = 0.523) between mean air permeability and mean pore diameter of fabric, and this correlation is significantly linear. A strong negative correlation (r = −0.627) is found between weight and air permeability of fabric. Research limitations/implications The delivery speed failed to show any significant effect; this is in contrary to the general expectation. Originality/value The effect of concurrent variation in waterjet pressure, web mass, delivery speed and web composition on the structure of spunlace nonwoven is studied, which was not reported in the literature. The effect of web composition on pore diameter of spunlace nonwoven is interesting finding. This study is expected to help in designing the spunlace nonwoven as per end uses and specifically for apparel application.

Prediction of structural parameters and air permeability of cotton woven fabric

2017 ◽  
Vol 88 (14) ◽  
pp. 1650-1659 ◽  
Author(s):  
Guocheng Zhu ◽  
Yuan Fang ◽  
Lianying Zhao ◽  
Jinfeng Wang ◽  
Weilai Chen
Keyword(s):  
Pressure Drop ◽  
Pore Diameter ◽  
Structural Parameters ◽  
Air Permeability ◽  
Experimental Results ◽  
Woven Fabric ◽  
Analytical Models ◽  
Yarn Diameter ◽  
Poiseuille Equation ◽  
Good Agreement

Air permeability is a very important property influencing the performance of clothing comfort and technical textiles particularly in applications for protective products, including airbags, parachutes, and tents. Several analytical models for predicting air permeability have been made by considering porosity and pore diameter or porous area. However, the connection between fabric structure and air permeability with analytical models has not been well reported as yet. In this work, the diameter of cotton yarn was predicted by considering yarn count, twist, and packing density. Subsequently, the pore area and equivalent pore diameter of fabric were predicted after finding the warp and the weft densities of fabric. The predicted values had very good agreement with the experimental results in yarn diameter and other structural parameters of fabric. The air permeability of fabrics was measured and several well-known analytical models for predicting air permeability were compared. The results revealed that the Hagen–Poiseuille equation had much better prediction than other models and also had good agreement with the experimental results, especially when it was applied for tight fabrics at low pressure drop (≤60 Pa). The Hagen–Poiseuille equation could be improved by considering the Reynolds number, interfiber interstices, and the deformation of pores under higher pressure drop.

scholarly journals Durable Wash-Resistant Antimicrobial Treatment of Knitted Fabrics

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jolita Krisciunaite ◽  
Brigita Kalendraite ◽  
Lina Ragelienė ◽  
Evelina Merkelyte ◽  
Daiva Mikucioniene
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Structural Changes ◽  
Structural Parameters ◽  
Antimicrobial Properties ◽  
Air Permeability ◽  
Antimicrobial Treatment ◽  
Knitted Fabrics ◽  
Textile Products

Abstract Antimicrobial finishing is increasingly used in textile products to increase their functionality. Antimicrobial properties became extremely important during the COVID-19 situation. The main problems faced by antimicrobial finishing are nontoxicity and durability (wash-resistance) of antibacterial activity. Also, it is important to determine whether the antimicrobial finishing changes comfort properties, such as air permeability. This paper deals with the durability of antimicrobial treatment, that is, resistance to washing, and effect on the structural changes that may have influence on the comfort properties, such as permeability to air. Knits of various raw compositions were antimicrobial-treated with the new commercial antimicrobial product, Si Bactericidal (Smart Inovation, Portugal). After the antimicrobial treatment, knitted specimens were washed 50 times and changes in their structural parameters, air permeability, and antimicrobial activity were measured. It was found that the mentioned antimicrobial treatment gives very good antimicrobial activity to the treated fabric and is wash-resistant and long-lasting. Also, it does not change dimensions and permeability to air of the treated fabrics with some exceptions of cotton-based knitted structures.

scholarly journals Characterization of a Conjugate between Rose Bengal and Chitosan for Targeted Antibiofilm and Tissue Stabilization Effects as a Potential Treatment of Infected Dentin

2012 ◽  
Vol 56 (9) ◽  
pp. 4876-4884 ◽  
Author(s):  
Annie Shrestha ◽  
Michael R. Hamblin ◽  
Anil Kishen
Keyword(s):  
Mechanical Properties ◽  
Rose Bengal ◽  
Structural Changes ◽  
Structural Integrity ◽  
Green Light ◽  
Cross Linking ◽  
Antibiofilm Activity ◽  
Content Type ◽  
Dentin Collagen

ABSTRACTBacterial biofilms and dentin structural changes are some of the major challenges in the management of infected dentin tissue. This study characterized a photosensitizer-conjugated chitosan with enhanced photodynamic efficacy against dental biofilms, as well as the ability to reinforce the postinfected dentin matrix in order to improve its mechanical and chemical stability. Rose Bengal-conjugated chitosan (CSRB) was synthesized using a chemical cross-linking method and characterized for photophysical, photobiological, and cytotoxicity properties. Its potential as an antibacterial and matrix-reinforcing agent on dentin collagen was also evaluated.Enterococcus faecalisas planktonic andin vitrobiofilms was treated with CSRB and photodynamically activated with 5 to 60 J/cm2green light. Dentin collagen was used for the CSRB cross-linking experiments and evaluated for chemical changes, resistance to enzymatic degradation, and mechanical properties. CSRB was a photosensitizer with efficient singlet oxygen yield.In vitrophotoactivation gave higher fibroblast cell survival than did RB alone. CSRB showed significant antibiofilm photoinactivation (P< 0.01). The CSRB-cross-linked dentin collagen showed higher resistance to collagenase degradation and superior mechanical properties (P< 0.05). In summary, the photoactivated CSRB particles synthesized in this study may be a synergistic multifunctional treatment approach with lower cytotoxicity and effective antibiofilm activity as well as the ability to reinforce the dentin collagen to enhance resistance to degradation and improve mechanical properties. This may be a targeted treatment strategy to deal with infected dentin hard tissues in a clinical scenario, where both disinfection and structural integrity need to be addressed concomitantly.

High-speed data provision by mobile networks in the Asia-Pacific region

2018 ◽  
Vol 20 (3) ◽  
pp. 225-243
Author(s):  
Peter Curwen ◽  
Jason Whalley
Keyword(s):  
Mobile Networks ◽  
High Speed ◽  
Structural Changes ◽  
Initial Step ◽  
Asia Pacific ◽  
Large Individual ◽  
Content Type ◽  
The Status ◽  
Data Provision ◽  
High Speed Data

Purpose The purpose of this paper is to examine in a fully up-to-date manner the position in respect to the licensing and launch of long-term evolution (LTE) in a region that attracts relatively little attention when treated as a whole because the emphasis is usually upon the very large individual markets (China, India and Japan) contained within it. The purpose is also to examine the role of international groups and the extent to which the licensing of LTE can make a difference to the structure of mobile markets in the region. Design/methodology/approach The initial step was to compile extensive databases with respect to the licensing and launch of high-speed networks in the region – defined both narrowly and also to encompass countries that are often treated as part of the Middle East – arranged so as to emphasise the status of dominant incumbents. There is a discussion of new entry and its potential to disrupt incumbents. Findings For historical reasons, the region contains countries that have strong differences whether defined in terms of economic, social or cultural characteristics, and hence it has not been easy for a network with international aspirations to expand outside its home market nor for, say, European-based operators to gain a foothold. Attempts to introduce competition via new licences has also been problematic because of the strong, and sometimes very large, incumbents already present. Research limitations/implications This is necessarily an overview that uses selected data to describe the overall picture because of the substantial number of quite different markets surveyed. Practical implications It is possible to forecast how certain structural changes will occur – primarily the withdrawal of international groups such as Millicom that prefer to concentrate upon other regions. Originality/value The databases that underpin the analysis are author-compiled and entirely original.

scholarly journals Investigation of Moisture Management and Air Permeability Properties of Fabrics with Linen and Linen-Polyester Blend Yarns

2018 ◽  
Vol 26 (4(130)) ◽  
pp. 39-47 ◽  
Author(s):  
Erhan Kenan Çeven ◽  
Gizem Karakan Günaydin
Keyword(s):  
Experimental Study ◽  
Absorption Rate ◽  
Structural Parameters ◽  
Air Permeability ◽  
Test Results ◽  
Warp Yarn ◽  
Significance Level ◽  
Moisture Management ◽  
Different Types ◽  
Wetting Time

This paper has focused on moisture management (MMT) and air permeability properties of fabrics produced from linen (100%) and linen-polyester yarns (80% polyester and 20% linen) at different weft densities. In the experimental study, eighteen different types of fabrics composed of six different weft yarns with three levels of weft density (weft density of 8,10 &12 pick/cm for 100% linen fabrics and 14,16,18 pick/cm for polyester-linen fabrics) were selected in order to determine the influence of weft density and yarn structural parameters (number of yarn folds) on moisture management as well as air permeability properties. The following weft yarns were selected: 104/1 tex, 104/2 tex & 104/3 tex for 100% linen and 41/1 tex, 41/2 tex & 41/3 tex for 80% Polyester – 20% linen fabrics, whereas the warp yarn was constant – 50/1 tex 100% linen for all fabric types. Satin type fabrics were subjected to moisture management tests and air permeability tests as well. According to test results, it was determined that some of the moisture management (wetting time, absorption rate (%/s) and one-way accumulative transport index of the fabrics’ top surfaces and bottom surfaces) and air permeability properties were significantly affected by the number of yarn folds and the weft density at a 0.05 significance level.

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

Individual differences in white and grey matter structure associated with verbal habits of thought

2019 ◽  
Author(s):  
Justin C. Hayes ◽  
Katherine L Alfred ◽  
Rachel Pizzie ◽  
Joshua S. Cetron ◽  
David J. M. Kraemer
Keyword(s):  
Individual Differences ◽  
White Matter ◽  
Cognitive Processing ◽  
Grey Matter ◽  
Structural Changes ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Self Report ◽  
White Matter Tracts

Modality specific encoding habits account for a significant portion of individual differences reflected in functional activation during cognitive processing. Yet, little is known about how these habits of thought influence long-term structural changes in the brain. Traditionally, habits of thought have been assessed using self-report questionnaires such as the visualizer-verbalizer questionnaire. Here, rather than relying on subjective reports, we measured habits of thought using a novel behavioral task assessing attentional biases toward picture and word stimuli. Hypothesizing that verbal habits of thought are reflected in the structural integrity of white matter tracts and cortical regions of interest, we used diffusion tensor imaging and volumetric analyses to assess this prediction. Using a whole-brain approach, we show that word bias is associated with increased volume in several bilateral language regions, in both white and grey matter parcels. Additionally, connectivity within white matter tracts within an a priori speech production network increased as a function of word bias. These results demonstrate long-term structural and morphological differences associated with verbal habits of thought.

Quantitative relations between structure and antiinflammatory activity of aryloxoalkanoic acids

1988 ◽  
Vol 53 (8) ◽  
pp. 1862-1872 ◽  
Author(s):  
Miroslav Kuchař ◽  
Eva Maturová ◽  
Bohumila Brunová ◽  
Jaroslava Grimová ◽  
Hana Tomková ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Structural Changes ◽  
Antiinflammatory Activity ◽  
Structural Parameters ◽  
Considerable Effect ◽  
Antiinflammatory Effect ◽  
Prolonged Action ◽  
Preclinical Development ◽  
Indicator Variables ◽  
Inhibitory Activities

The antiinflammatory effect of a series of aryloxoalkanoic acids II and of their biphenyl derivatives III was examined by measuring the inhibition of the development of carageenan- and adjuvant-induced edemas. The quantitative relations between the antiinflammatory effect and physicochemical and structural parameters of the compounds tested were evaluated. The equations obtained by the method of regression analysis showed a significant linear dependence of both inhibitory activities on the lipophilicity of the compounds and a considerable effect of some structural changes as expressed by indicator variables. The antiinflammatory effect is especially enhanced in both tests by the presence of a cyclic substituent at the aromatic ring. The high antiinflammatory effect of biphenylyl derivatives III is paralleled by their prolonged action. The prolongation of the effect is most likely a result of a suitable biotransformation of acid III to an efficient metabolite. The structural requirements which resulted from both the regression analysis and from the hypothesis of biotransformation of acids III were utilized in the synthesis of suitably substituted biphenylyloxoalkanoic acids. By this approach derivatives IIIe-i were obtained some of which showed a high antiinflammatory and also protracted effect. 4-(2',4'-Difluorbiphenylyl)-4-oxo-2-methylbutanoic acid (VÚFB-16 066, Flobufen) was chosen for further preclinical development.

Influence of ageing treatment on microstructure, mechanical properties and adhesive wear behaviour of 6063 aluminium alloy

2014 ◽  
Vol 66 (4) ◽  
pp. 520-524 ◽  
Author(s):  
Serkan Büyükdoğan ◽  
Süleyman Gündüz ◽  
Mustafa Türkmen
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
High Speed ◽  
Al Alloys ◽  
Wear Behaviour ◽  
Al Alloy ◽  
Strain Ageing ◽  
Content Type ◽  
Static Strain ◽  
Structural Applications

Purpose – The paper aims to provide new observations about static strain ageing in aluminium (Al) alloys which are widely used in structural applications. Design/methodology/approach – The present work aims to provide theoretical and practical information to industries or researchers who may be interested in the effect of static strain ageing on mechanical properties of Al alloys. The data are sorted into the following sections: introduction, materials and experimental procedure, results and discussion and conclusions. Findings – Tensile strength, proof strength (0.2 per cent) and percentage elongation measurement were used to investigate the effect of strain ageing on the mechanical properties. Wear tests were performed by sliding the pin specimens, which were prepared from as-received, solution heat-treated, deformed and undeformed specimens after ageing, on high-speed tool steel (64 HRC). It is concluded that the variations in ageing time improved the strength and wear resistance of the 6063 Al alloy; however, a plastically deformed solution-treated alloy has higher strength and wear resistance than undeformed specimens for different ageing times at 180°C. Practical implications – A very useful source of information for industries using or planning to produce Al alloys. Originality/value – This paper fulfils an identified resource need and offers practical help to the industries.

Changes of Selected Structural and Mechanical Properties of the Strzelin Granites As Induced By Thermal Loads / Wpływ Obciążeń Termicznych Na Zmiany Niektórych Strukturalnych I Mechanicznych Właściwości Granitów Strzelińskich

2012 ◽  
Vol 57 (4) ◽  
pp. 951-974 ◽  
Author(s):  
Andrzej Nowakowski ◽  
Mariusz Młynarczuk
Keyword(s):  
Mechanical Properties ◽  
Nuclear Waste ◽  
Structural Changes ◽  
Structural Parameters ◽  
Total Porosity ◽  
Fracture Network ◽  
Qualitative Description ◽  
Temperature Changes ◽  
Heating And Cooling ◽  
Waste Repositories

Abstract Temperature is one of the basic factors influencing physical and structural properties of rocks. A quantitative and qualitative description of this influence becomes essential in underground construction and, in particular, in the construction of various underground storage facilities, including nuclear waste repositories. The present paper discusses the effects of temperature changes on selected mechanical and structural parameters of the Strzelin granites. Its authors focused on analyzing the changes of granite properties that accompany rapid temperature changes, for temperatures lower than 573ºC, which is the value at which the β - α phase transition in quartz occurs. Some of the criteria for selecting the temperature range were the results of measurements carried out at nuclear waste repositories. It was demonstrated that, as a result of the adopted procedure of heating and cooling of samples, the examined rock starts to reveal measurable structural changes, which, in turn, induces vital changes of its selected mechanical properties. In particular, it was shown that one of the quantities describing the structure of the rock - namely, the fracture network - grew significantly. As a consequence, vital changes could be observed in the following physical quantities characterizing the rock: primary wave velocity (vp), permeability coefficient (k), total porosity (n) and fracture porosity (η), limit of compressive strength (Rσ1) and the accompanying deformation (Rε1), Young’s modulus (E), and Poisson’s ratio (ν).

Sign in / Sign up

Export Citation Format

Share Document