scholarly journals The analysis of dimensional stability of 1x1 RIB Co and Co/LY knitwear

2018 ◽  
Vol 69 (04) ◽  
pp. 293-297
Author(s):  
PEŠIĆ MARIJA ◽  
PETROVIĆ VASILIJE ◽  
STEPANOVIĆ JOVAN ◽  
BEŠIĆ CARIŠA
Keyword(s):  
Dimensional Stability ◽  
Linear Density ◽  
Knitted Fabric ◽  
Multiple Indicators ◽  
Fiber Composition ◽  
Dimensional Instability ◽  
The Impact

This paper analyzes the impact of knitwear’s fiber composition, linear density and finishing of yarn used in the dimensional stability of the 1x1 RIB knitwear made on the same circular knitting machine. Dimensional stability of these samples was analysed by FAST 4 method. Different samples were compared across multiple indicators. The results show that the most stable dyed knitted fabric are made of cotton 96% and 4% of Lycra and of yarn with linear density 19.14 tex. Tightness factor’s values in the dry relaxation stood at 17.90, in the wet 18.45, in total 18.73 and 18.59 in air conditioned terms. Knitwear with the highest values of dimensional instability are raw knitted fabric made of 100% CO, and yarn with linear density of 13.39 tex. Tightness factor’s values in the dry relaxation stood at 12.16, in the wet 12.36, in total 13.26 and 13.35 in air conditioned terms

Response and failure modes of biaxial warp-knitted flexible composite subject to low-velocity impact

2021 ◽  
pp. 152808372110154
Author(s):  
Ziyu Zhao ◽  
Tianming Liu ◽  
Pibo Ma
Keyword(s):  
Impact Energy ◽  
Linear Density ◽  
Failure Modes ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Minor Effect ◽  
Low Velocity ◽  
Velocity Impact ◽  
Flexible Composites ◽  
The Impact

In this paper, biaxial warp-knitted fabrics were produced with different high tenacity polyester linear density and inserted yarns density. The low-velocity impact property of flexible composites made of polyurethane as matrix and biaxial warp-knitted fabric as reinforcement has been investigated. The effect of impactor shape and initial impact energy on the impact response of flexible composite is tested. The results show that the initial impact energy have minor effect on the impact response of the biaxial warp-knitted flexible composites. The impact resistance of flexible composite specimen increases with the increase of high tenacity polyester linear density and inserted yarns density. The damage morphology of flexible composite materials is completely different under different impactor shapes. The findings have theoretical and practical significance for the applications of biaxial warp-knitted flexible composite.

The Effect of Yarn Linear Density on Mechanical Properties of Plain Woven Kenaf Reinforced Unsaturated Polyester Composite

2013 ◽  
Vol 465-466 ◽  
pp. 962-966 ◽  
Author(s):  
Mohd Pahmi bin Saiman ◽  
Mohd Saidin Bin Wahab ◽  
Mat Uzir Wahit
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Linear Density ◽  
Unsaturated Polyester ◽  
Composite Panel ◽  
Composite Yarn ◽  
Polyester Composite ◽  
The Impact ◽  
Woven Kenaf

To produce a good quality of dry fabric for reinforced material in a natural-based polymer composite, yarn linear density should be in consideration. A woven kenaf dry fabric with three different linear densities of 276tex, 413.4tex and 759tex were produced. The fabrics with different linear densities were been optimize with the assistance of WiseTex software. The optimized dry fabrics were infused with unsaturated polyester to produce composite panel using vacuum infusion process. The composites properties were tested on the tensile strength, flexural strength and the impact strength. The result shows that the mechanical properties of the composite increased when the yarn linear densities increased.

The durability of press-formed paperboard trays – Effects of sealing and drying

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 236-248
Author(s):  
Arvo Niini ◽  
Ville Leminin ◽  
Panu Tanninen ◽  
Juha Varis ◽  
Teija Laukala
Keyword(s):  
Dimensional Stability ◽  
Food Processing ◽  
Positive Impact ◽  
Processing Conditions ◽  
Optical Analysis ◽  
Heating And Cooling ◽  
The Press ◽  
Heat Sealing ◽  
Dimensional Measurements ◽  
The Impact

Dimensional measurements were recorded to observe the durability of press-formed paperboard trays used for food processing via heating and cooling of the paperboard trays containing oatmeal. A set of the studied press-formed paperboard trays were dried before being heated, and a set of the paperboard trays were heat-sealed before being cooled to compare the effects of drying and sealing on the durability of the tray. In addition, empty trays were heated to observe the impact of food processing conditions on its durability via leak tests with a colouring solution as well as optical analysis of the material coating on the surface of the trays. The drying process of the trays was observed to improve the dimensional stability of the trays while being heated, and heat-sealing the trays yielded a major positive impact on the dimensional stability of the trays while being cooled. The leak tests and optical analysis results on the heated empty trays showed a negative durability impact from the food processing conditions. It was concluded that adjusting the heat-sealing parameters and food processing conditions is necessary in order to achieve improved durability of the press-formed paperboard trays for food processing purposes.

scholarly journals Income or Assets—What Determines the Approach to the Environment among Farmers in A Region in Poland?

2020 ◽  
Vol 12 (12) ◽  
pp. 4917 ◽  
Author(s):  
Aleksander Grzelak ◽  
Jakub Staniszewski ◽  
Michał Borychowski
Keyword(s):  
Structural Equation Modelling ◽  
Structural Equation ◽  
Agricultural Land ◽  
Positive Impact ◽  
Farm Size ◽  
Agricultural Producers ◽  
Multiple Indicators ◽  
Equation Modelling ◽  
The Impact ◽  
Heterogeneous Factor

The theory about the impact of farm size, income and assets on the environmental approach of farmers is ambiguous. We contribute to the existing discussion in two ways. Firstly, we look for the determinants of the environmental approach. Secondly, we treat farm size as a heterogeneous factor, affected not only by the value of assets but also flows of incomes. The main objective of the article is, therefore, to recognize the impact of assets and income on the environmental approach of agricultural producers. We analyze the results of surveys carried out in 2020 on a group of 120 farms from the Wielkopolska region (Poland), using structural equation modelling (generalized structural equation modelling (GSEM)-multiple indicators and multiple causes (MIMIC) model). Our results indicate that both the income and assets of the agricultural producers have a positive impact on their approach to the environment. However, to a greater extent, the farmer’s approach to the environment is influenced more by income than by assets. This may be influenced by the capitalization of subsidies in the price of agricultural land, which makes this element of farm assets detached from real processes. It is easier for farms with a higher income and assets to realize the orientation towards sustainability.

scholarly journals Influence of Site Conditions and Quality of Birch Wood on Its Properties and Utilization after Heat Treatment. Part I—Elastic and Strength Properties, Relationship to Water and Dimensional Stability

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 189 ◽  
Author(s):  
Vlastimil Borůvka ◽  
Roman Dudík ◽  
Aleš Zeidler ◽  
Tomáš Holeček
Keyword(s):  
Heat Treatment ◽  
Dimensional Stability ◽  
Bending Strength ◽  
Color Change ◽  
Untreated Wood ◽  
Strength Properties ◽  
Treatment Temperature ◽  
Impact Bending ◽  
The Impact

This work deals with the quality of birch (Betula pendula) wood from different sites and the impact of heat treatment on it. Two degrees of heat treatment were used, 170 °C and 190 °C. The resulting property values were compared with reference to untreated wood samples. These values were wood density, compressive strength, modulus of elasticity (MOE), bending strength (MOR), impact bending strength (toughness), hardness, swelling, limit of hygroscopicity, moisture content and color change. It was supposed that an increase in heat-treatment temperature could reduce strength properties and, adversely, lead to better shape and dimensional stability, which was confirmed by experiments. It was also shown that the properties of the wood before treatment affected their condition after heat treatment, and that the characteristic values and variability of birch properties from 4 sites, 8 stems totally, were reflected in the properties of the heat-treated wood. Values of static MOR were the exception, where the quality of the input wood was less significant at a higher temperature, and this was even more significant in impact bending strength, where it manifested at a lower temperature degree. Impact bending strength also proved to be significantly negatively affected by heat treatment, about 48% at 170 °C, and up to 67% at 190 °C. On the contrary, the most positive results were the MOE and hardness increases at 170 °C by about 30% and about 21%, respectively, with a decrease in swelling at 190 °C by about 31%. On the basis of color change and other ascertained properties, there is a possibility that, after suitable heat treatment, birch could replace other woods (e.g., beech) for certain specific purposes, particularly in the furniture industry.

Shape stability of chosen thin wood based panels after heating

2019 ◽  
Vol 106 ◽  
pp. 85-89
Author(s):  
MACIEJ SYDOR ◽  
Bartosz Pałubicki
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Thin Plate ◽  
Dimensional Stability ◽  
Power Supplies ◽  
Short Term ◽  
Shape Stability ◽  
Short Term Exposure ◽  
The Impact

Shape stability of chosen thin wood based panels after heating. Lignocellulose board materials are commonly used for furniture construction. Typically, these are particle boards, fibreboard or plywood with thicknesses from 10 to 20 mm, however, some furniture elements are made of thin boards with a thickness of 3-4 mm (back walls, bottoms of drawers and others). Modern furniture uses built-in components that are a source of heat, such as lamps, power supplies, ovens. Local high temperature may negatively affect the shape stability of thin lignocellulose plates. The aim of the research described in this article was to determine the impact of shortterm exposure to high temperature on the dimensional stability of selected thin plate furniture materials. Four different HDF boards with nominal thicknesses of 3 mm and four different plywood boards with nominal thicknesses of 2 to 4 mm were tested. The test samples were subjected to a short-term exposure to temperatures of up to 250°C. As a result of the tests, it was found that HDF boards are characterized by a much higher shape stability at elevated temperature than boards made of plywood.

A New Technique for Feeding Yarn in a Flat Bed Knitting Machine

1995 ◽  
Vol 209 (2) ◽  
pp. 151-154 ◽  
Author(s):  
P K Choy ◽  
J Atkinson ◽  
T Dias
Keyword(s):  
Dimensional Stability ◽  
Knitted Fabric ◽  
Feed Speed ◽  
Yarn Tension ◽  
Factors Influencing ◽  
Exact Shape ◽  
A New Technique ◽  
Shape And Size ◽  
Significant Factors

The quality of knitted fabric panels is of considerable importance to the knitwear industries. The latest development in flat bed knitting technology improves the efficiency of the production by knitting fully fashioned fabric panels that are to exact shape and size. This greatly reduces the cutting waste and length of time for the making-up process, but garment manufacturers are still facing the difficulty of retaining dimensional stability of the knitted panels. One of the significant factors influencing this undesired property is input yarn tension variation. The analysis of this problem is described and a new method of yarn feeding is also suggested. This method utilizes storage yarn feed to eliminate the undesired effect of yarn feed speed variation and has been applied as a prototype. The results show a promising and satisfactory improvement in the fabric quality.

scholarly journals Impact of COVID-19 Pandemic on the Psychological Outcomes: Multiple Indicators and Multiple Causes (MIMIC) Modeling

2021 ◽  
Author(s):  
Musheer A. Aljaberi ◽  
Naser A. Alareqe ◽  
Mousa A. Qasem ◽  
Abdulsamad Alsalahi ◽  
Sarah Noman ◽  
...  
Keyword(s):  
Structural Equation ◽  
Online Survey ◽  
Psychological Impact ◽  
Psychological Outcomes ◽  
Post Traumatic Stress ◽  
Latent Factors ◽  
Event Scale ◽  
Multiple Indicators ◽  
The Impact ◽  
Multiple Causes

Abstract Background: Due to the limited research examining the psychological impact of coronavirus disease 2019 (COVID-19), our study aims to investigate the effect of the COVID-19 pandemic on psychological outcomes and assess the differences between participants with and without post-traumatic stress disorder (PTSD) on the psychological outcomes as latent factors and items. Methods: An online survey was conducted on 999 participants. The Impact of Event Scale-Revised (IES-R) assessed the psychological impact, while outcomes were measured by Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder (GAD-7), and Insomnia Severity Index (ISI). A series of Confirmatory Factor Analysis (CFA), structural equation model (SEM), Multiple Indicators and Multiple Causes (MIMIC), and Differential Item Functioning (DIF) were conducted. Results: The IES-R has significant effects on the psychological outcomes. Participants with PTSD have a higher impact on latent factors (depression, anxiety, and insomnia) than those without PTSD. Among participants, 36.5% experienced moderate to severe symptoms of depression, and 32.6% had mild depressive symptoms. For anxiety, 23.7% of respondents experienced moderate to severe anxiety symptoms, and 33.1% had mild symptoms of anxiety. For the ISI, 51.5% of participants experienced symptoms of insomnia. Conclusion: the IES-R for COVID-19 has a significant impact on depression, anxiety, and insomnia at the level of latent constructs and observed variables.

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.

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