An Analysis of the Mechanical Forces in Latch Needle Cam Systems

1992 ◽  
Vol 206 (2) ◽  
pp. 129-137 ◽  
Author(s):  
B L MacCarthy ◽  
J M Sharp ◽  
N D Burns
Keyword(s):  
General Model ◽  
Textile Yarn ◽  
Basic Mechanism ◽  
Normal Operation ◽  
Mechanical Forces ◽  
Knitted Fabrics ◽  
Textile Fabrics ◽  
Cam Profile ◽  
Textile Fabric ◽  
Cam Systems

The majority of textile fabrics are either woven or knitted. Knitted fabrics are most frequently produced on weft knitting machines. The range of machinery is very diverse but the same basic mechanism is employed to convert textile yarn into knitted textile fabric. The mechanism is a specialized needle and cam system known as a latch needle cam system. This paper develops a general model for the mechanical forces that arise in normal operation of a latch needle cam system. The limitations of previous models are noted. The model may be used to predict mechanical forces for any specified cam profile and for the most common needle and cam arrangements. The model will be used in a following paper on yarn forces in latch needle cam systems. The performance of the model will be reported in a following paper describing an experimental programme and experimental results

scholarly journals Unmasking the Mask: Investigating the Role of Physical Properties in the Efficacy of Fabric Masks to Prevent the Spread of the COVID-19 Virus

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7756
Author(s):  
Adine Gericke ◽  
Mohanapriya Venkataraman ◽  
Jiri Militky ◽  
Hester Steyn ◽  
Jana Vermaas
Keyword(s):  
Structural Properties ◽  
Woven Fabrics ◽  
Source Control ◽  
Knitted Fabrics ◽  
Performance Properties ◽  
Nonwoven Fabrics ◽  
Textile Fabrics ◽  
Overall Performance ◽  
Textile Fabric

To function as source control, a fabric mask must be able to filter micro-droplets (≥5 µm) in expiratory secretions and still allow the wearer to breathe normally. This study investigated the effects of fabric structural properties on the filtration efficiency (FE) and air permeability (AP) of a range of textile fabrics, using a new method to measure the filtration of particles in the described conditions. The FE improved significantly when the number of layers increased. The FE of the woven fabrics was generally higher, but double-layer weft knitted fabrics, especially when combined with a third (filter) layer, provided a comparable FE without compromising on breathability. This also confirmed the potential of nonwoven fabrics as filter layers in masks. None of the physical fabric properties studied affected FE significantly more than the others. The variance in results achieved within the sample groups show that the overall performance properties of each textile fabric are a product of its combined physical or structural properties, and assumptions that fabrics which appear to be similar will exhibit the same performance properties cannot be made. The combination of layers of fabric in the design of a mask further contributes to the product performance.

Dynamic modelling of the latch needle cam system of weft knitting machines

2003 ◽  
Vol 217 (2) ◽  
pp. 219-227
Author(s):  
K Y Jeong ◽  
Y-B Kim
Keyword(s):  
Dynamic Modelling ◽  
Textile Yarn ◽  
Basic Mechanism ◽  
Knitted Fabric ◽  
Body Model ◽  
System A ◽  
Textile Fabrics ◽  
Rigid Body Model ◽  
Force Element ◽  
Set Up

Knitted textile fabrics are usually produced on weft knitting machines. The basic mechanism of the machines to convert textile yarn into knitted fabric is called a latch needle cam system. A rigid-body model with five bodies is set up to analyse the motion of the needle of the latch needle cam system. The force element is modelled as a spring damper element between the needle butt and each virtual body on the cam curves. The spring constant is obtained from the cam angle, the friction coefficient and the stiffness of the needle. Numerical examples are given to show the path of the needle butt and the forces between the needle and the cams. For various rotational speeds of the cylinder, the maximum vertical and horizontal forces are obtained.

Influence of sublimation process on air permeability and water absorption dynamics

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Brigita Kalendraite ◽  
Jolita Krisciunaite ◽  
Daiva Mikucioniene
Keyword(s):  
Water Absorption ◽  
Design Methodology ◽  
Air Permeability ◽  
Knitted Fabrics ◽  
Content Type ◽  
Sublimation Process ◽  
Textile Fabrics ◽  
High Temperature And Pressure ◽  
Before And After ◽  
Temperature And Pressure

PurposeThe purpose of this research was to find the influence of sublimation process on air permeability and water absorption dynamics of knitted and woven polyester-based fabrics.Design/methodology/approachThree different sublimation designs were prepared and applied (keeping the same sublimation parameters) for eight variants of knitted and four variants of woven polyester-based fabrics. Air permeability and water absorption dynamics during 180s period was measured and compared before and after the sublimation process.FindingsAccording to the obtained results, high temperature and pressure applied in sublimation process have influence on the porosity and air permeability of knitted fabrics; however, the influence on water absorption dynamics is minimal. Sublimation design dos not have any influence on the mentioned properties.Originality/valueThe obtained results of the sublimation process influence on air permeability and water absorption dynamics of knitted and woven polyester-based fabrics will help to understand how sublimation process can affect comfort properties of textile fabrics.

scholarly journals Image Analysis as a Method of the Assessment of Yarn for Making Flat Textile Fabrics

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Marcin Idzik ◽  
Marek Idzik
Keyword(s):  
Linear Density ◽  
Knitted Fabric ◽  
Test Results ◽  
Knitted Fabrics ◽  
Textile Fabrics ◽  
Yarn Quality ◽  
Computer Aided ◽  
Technological Processing ◽  
Spinning Mill

AbstractDuring the technological processing of staple fibers into yarn drafting, waves are formed which increase the irregularity of yarn linear density and consequently affect the yarn quality. Even a correctly performed technological process does not allow one to completely eliminate yarn faults (thin and thick places, neps) and yarn irregularity. All the yarn imperfections distinctly become apparent in flat textiles made of such a yarn. The quality of the yarn produced should be assessed already in spinning mill, using the results obtained to conclude on the quality of woven or knitted fabrics. Modern metrological laboratories in spinning mills possess Uster Tester 5 (UT5) apparatuses that not only assess the yarn quality with respect to the irregularity of linear density, faults (thin and thick places, neps), or hairiness, but also using the test results obtained make it possible to create a digital image of the predicted appearance of a flat fabric made of the yarn tested. This article presents a computer-aided method of the analysis of the woven and knitted fabric images obtained from UT5 that allows one to assess the significance of particular yarn parameters in the predicted appearance of flat fabrics.

scholarly journals Influence of Screen Printed Layers on the Thermal Conductivity of Textile Fabrics

2018 ◽  
Vol 26 (5(131)) ◽  
pp. 70-74
Author(s):  
Ilda Kazani ◽  
Ilda Kazani ◽  
Gilbert De Mey ◽  
Carla Hertleer ◽  
Lieva Van Langenhove ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Measuring Method ◽  
Conducting Layer ◽  
Metallic Materials ◽  
Textile Fabrics ◽  
Electric Conducting ◽  
Smart Textile ◽  
Thermographic Camera ◽  
Textile Fabric ◽  
Screen Printed

In the smart textile field the combination of textile and metallic materials is rising. In order to conduct electricity in textile, different methods are used. This paper deals with a new measuring method to determine the lateral thermal conductivity of a textile fabric. The technique starts by measuring the temperature distribution on the fabric using a thermographic camera. In addition to that, the method outlined in this paper will also allow to determine the change in thermal conductivity when an electric conducting layer has been screen printed on a textile fabric

scholarly journals Flexible Theoretical Calculation of Loop Length and Area Density of Weft-Knitted Structures: Part I

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3059
Author(s):  
Edgaras Arbataitis ◽  
Daiva Mikucioniene ◽  
Liudmyla Halavska
Keyword(s):  
Theoretical Calculation ◽  
Main Idea ◽  
Geometrical Model ◽  
Structural Parameter ◽  
Loop Length ◽  
Knitted Fabrics ◽  
Area Density ◽  
Textile Fabrics ◽  
Length And Area ◽  
Single Jersey

This work presents a simple and flexible method for theoretical calculation of the main structural parameter of weft-knitted fabrics’—the loop length and one of the main characteristics of textile fabrics—area density, which combines physical and economical aspects. It helps to predict many physical properties and the mechanical behaviour, which is especially important for protective textiles, and allows predicting potential yarn consumption for knitting of one square meter of the fabric. The main idea of the proposed method, based on Čiukas geometrical model, is to calculate different parts of the knitted loop separately, which gives a great flexibility of such modelling. The proposed theoretical formulas can be used for various weft-knitted structures, give very low errors to empirical calculations, and are easy to use. It is a big advantage because known geometric models only allow a loop length of some particular pattern to be calculated, usually of single jersey or rib 1 × 1.

scholarly journals Numerical strength analysis of the roller for textile fabric handling

Mechanik ◽  
2017 ◽  
Vol 90 (7) ◽  
pp. 618-620
Author(s):  
Wiesław Komar ◽  
Wojciech Miąskowski ◽  
Bartosz Moczulak
Keyword(s):  
Stress Analysis ◽  
Production Line ◽  
Strength Analysis ◽  
Numerical Tests ◽  
Textile Fabrics ◽  
Operational Safety ◽  
Textile Fabric ◽  
Fabric Handling

Presented is the methodology of conducted numerical tests and experiments on the stress analysis in the roller for transporting textile fabrics, gained directly from the production line. The results of both analyses were compared and the tested object verified in terms of its operational safety.

Extraction of alginate from brown seaweeds and evolution of bioactive alginate film coated textile fabrics for wound healing application

2018 ◽  
Vol 49 (3) ◽  
pp. 328-351 ◽  
Author(s):  
M Janarthanan ◽  
M Senthil Kumar
Keyword(s):  
Wound Healing ◽  
Antibacterial Properties ◽  
Air Permeability ◽  
Experimental Result ◽  
Flexural Stiffness ◽  
Sargassum Wightii ◽  
Padina Tetrastromatica ◽  
Textile Fabrics ◽  
Coated Fabrics ◽  
Textile Fabric

In this study, the application of textile fabrics coated with biodegradable bioactive alginate film was investigated, which was obtained from natural polysaccharides such as sodium alginate extracted from sargassum wightii and padina tetrastromatica seaweeds. The functional groups present in the bioactive substances of alginate film coated fabrics was assessed using Fourier transform infrared spectroscopy, and the antioxidant and antibacterial properties of alginate film coated fabrics were assessed using DPPH free radical scavenging and EN ISO 20645 test methods, respectively. The effect of coatings on biomaterials was evaluated using field-emission scanning electron microscopy, and the effect of alginate film coated fabrics on comfort properties such as thickness, air permeability, wickability, flexural stiffness, and wettability was studied. The experimental result specifies that the maximum antioxidant activity of 54 ± 0.98% inhibition was achieved and maximum antibacterial activity was attained with the inhibition zone of 44 mm in alginate film coated textile fabrics. The air permeability, flexural stiffness, wettability, and wickability properties were slightly affected in both coated textile fabrics compared with uncoated fabric. The sargassum wightii alginate film coated textile fabric showed 80% of wound healing activity compared with padina tetrastromatica alginate film coated textile fabric. This alginate film coated textile fabrics are preferably suitable for nonimplantable materials such as wound healing, skin grafts, food industry, pharmaceutical industry, and hygienic textiles.

scholarly journals TESTING OF KNITTED FABRICS TO CONFIRM COMPLIANCE

2020 ◽  
pp. 22-25
Author(s):  
M. A. Stasheva ◽  
T. N. Novosad ◽  
N. V. Yevseyeva ◽  
B. N. Gusev
Keyword(s):  
Reliable Information ◽  
Knitted Fabrics ◽  
Rational Scheme ◽  
Synthetic Fibers ◽  
Certification System ◽  
Textile Fabrics ◽  
Manufactured Products

One of the reasons for the low demand for domestic textile fabrics is the incomplete satisfaction of consumers' requirements with regard to the quality and price of products, as well as the insufficient use of the Russian certification system as a source of reliable information (advertising) of quality as a set of consumer properties and safety of manufactured products. The paper tests cotton knitted fabrics with various attachments of synthetic fibers and provides recommendations for choosing a rational scheme for their certification in order to use them for the production of various layers of garments.

scholarly journals Influence of washing on the adhesion between 3D-printed TPU and woven fabrics

2021 ◽  
Vol 2 (1) ◽  
pp. 34-39
Author(s):  
Jannik Störmer ◽  
Daniel Görmer ◽  
Andrea Ehrmann
Keyword(s):  
3D Printing ◽  
Strong Correlation ◽  
Thermoplastic Polyurethane ◽  
Cotton Fabrics ◽  
Woven Fabrics ◽  
Textile Fabrics ◽  
Fabric Structure ◽  
High Adhesion ◽  
3D Printed ◽  
Textile Fabric

3D printing on textile fabrics can be used to create composites with position-dependent mechanical, water-resistant, magnetic or other properties. An important prerequisite to use such composites technologically or for design purposes is a sufficient adhesion between both materials. While previous studies revealed that soft, elastic printing polymers were advantageous to prepare connections with a high adhesion, not much research has been performed yet on the dependence of the adhesion on textile fabric structure, heat post-treatment, and the influence of washing, which is necessary for most applications of such composites. Here we investigate composites from thermoplastic polyurethane (TPU) 3D-printed on two different woven cotton fabrics. Besides the expected strong correlation of the adhesion with the distance between nozzle and printing bed, we find a higher adhesion on the thinner fabric and an increase in the adhesion after one washing cycle.

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