Plain woven fabrics

Like cotton, there are many different linen fabrics made from the basic flax fiber. Most of these are defined only by the type of weave and the fineness of the fiber, such as cambric and damask. The word linen is usually applied only to unbleached plain weave material. Some names are applied to similar fabrics made of cotton and linen. An example of this is canvas, a plainly woven fabric of varying weight made from hard-twisted yam. Canvas may be made from hemp, cotton, jute, or flax (linen). Most fine fabrics, particularly of European or American manufacture, are made from flax. Since its invention in the 1600s, most lace has also been made of flax thread. 

Heat Transfer. Values observed for heat transfer by conduction and the overall coefficient of heat transmission of flexible plastic sheets reinforced with plain woven fabrics demonstrated that a mathematical model was useful for prediction of the conductivity of the plastic sheets however, bulk density of the fabric had no effect on the conductivity. It was also found that the overall coefficient of thermal transmission of the plastic sheets insulated by woven fabrics depended largely on the conductivity of the insulating fabrics (ll). 

Kollegal MG, Sridharan S. Strength prediction of plain woven fabrics. J Compos Mater 2000 34 240-57. 

In general, PET with a high tensile strength, and glass, which both appear as multifilament yams, are used for coated membranes. For load-bearing constructions woven fabrics are mostly qualified twisted multifilaments are processed to plain woven fabrics in plain or in panama weave. 

First of all the structure of the weave and its variations during the test has been considered. Figure 2 presents the cross section schematic of the plain woven fabric in the opposed direction. 

In this study the yam pullout test is applied to investigate internal mechanical properties of the plain woven fabrics. In the first step an analytical model was developed, inputs of which employs simple mechanical properties such as the fabric modtrlus, the weave angle, and the fabric deformation angles during the pullout test. This model predicts important mechanical parameters such as the weave angle variations, the yam-to-yam friction coefficient, the normal load in crossovers, the lateral forces, and the opposed yam strain within the fabric. This approach may be extended to other types of the woven fabrics. 

In the next step, the experimental analysis was employed to evalirate the vahdity of the predicted parameters of the force balance model. Here the force displacemerrt pro Qe of the yam pullout test was simulated using the equations of the force balance model, and the characteristics of the plain woven fabric and its yams. 

In this study, force balance model has been rrsed to calculate the internal yam-to-yam friction coefCtient and the normal load of yams in crossing points of plain woven fabrics, which are actually the reqirired factors of oscillation model. Spring stiffness constant of the pirlled yam is another parameter, estimated rrsing springs in series law. Finally, comparative experimental studies have been represented to investigate the validity of oscillation model. 

To evaluate the oscillation model, the components of its equations ought to be measured experimentally. Some parameters such as, and N can be easily estimated. However, for some internal parameters such as, yam-to-yam friction coefCfcient and normal load in the crossing points, there are no empirical approaches. These parameters are related to the internal mechanical properties of the plain woven fabrics, have not been meastrred directly yet. As an alternative, the force balance model, which has been introduced by Valizadeh et al, is errrployed to estirrtate these parameters [10]. 

Force balance model is capable of predicting the irttemal mechanical parameters of the plain woven fabrics in a similar yam prrllout test based on the force distribution concepts. These parameters are yam-to-yam friction coef ftierrt, normal load at crossovers, lateral forces, lateral strairr, weave angle variatiorrs, arrd pullout force. Crimp angle of yams within the fabric 9 in (Figure 3)), its elastic modulus and linear density and fabric deformation data (a in (Figure 1(a))) are the required empirical factors of force balance model. The main equations of this model are presented in (Table 1) [10] ... 

Five plain woven fabrics, two polyester fabrics, and three cotton fabrics were examined in a yam pullout test, as schematically shown in (Figure 1(a)). Characteristics of these fabrics are presented in (Table 2). Sample PETl is consisted of twisted multi filaments of polyester as weft and warp yams. Sample PET2 has intermingled polyester multi filaments as warp and textured polyester multi filaments as weft yams. The COTl is a scoured cotton fabric with ringspun yams as wefts and warps. The COT2 is a bleached cotton fabric with ringspun weft and warp yams, and finally COTS is a bleached cotton fabric with open-end spun wefts and warps. 

FIGURE 3 Cross section of a plain woven fabric. 

Oscillation model, based on the force balance model, is an analytical method, capable of predicting the pullout behavior of the yams within the plain woven fabrics, fixed from two opposite sides. This method emphasizes on the vibratory behavior of the... 

Analytical approach Analytical model Force-balance analysis Internal mechanical properties Plain-woven fabrics... 

Zhou et modified the plain woven fabrics by manufacturing honeycomb fabrics and by introducing leno structure and double weft insertions at given intervals. This serves to inaease inter-yam friction, via improved yam gripping, between the warp and weft yams. The stmctures are shown in Figs 6.5 and 6.6. It has been found that such structurally modified fabrics led to better ballistic protection than normal plain woven fabrics. 

Gu B. Analytical modeling for the ballistic perforation of planar plain-woven fabric target by projectile. Compos B 2003 34 361-71. 

Cavallaro P V, Sadegh A M and Quigley C J (2007), Decrimping behavior of uncoated plain-woven fabrics subjected to combined biaxial tension and shear stresses . Text Res J, THf), 403 16. 

Leaf G A V, Chen Y and Chen X (1993), The initial bending behaviour of plain-woven fabrics , J Text Inst, 84(3), 419-428. 

Leaf G A V and Kandil K H (1980), The initial load-extension behaviour of plain-woven fabrics ,/ Text Inst, 71(1), 1-7. 

The plain weave is the simplest and most commonly used weave in fabric construction. In the plain weave the warp and filUng threads cross alternatively. The two sides of a plain weave are identical. Plain-woven fabrics are generally the least pliable, but they are also the most stable. This stability permits the fabrics to be woven with a fair degree of porosity without too much sleaziness. However, properties are significantly reduced relative to a weaving pattern with fewer crossovers. 

Figure 13.12 presents the energy absorption of six 3D Kevlar fabrics with comparison to the 2D plain weave fabric, which is widely used for body amour production for police and military personnel. It was foimd that (a) 3D honeycomb fabrics and the same layer 2D plain fabric The two- and four-layered 3D fabrics performed better than the assembly with the same layer 2D plain woven fabric of similar yam density. The twolayered fabric with lower yam density performed less well than the one with higher yam density, (b) AU the 2D woven fabrics have the ability to absorb more projectile impact energy compared to the three 3D angle-interlock fabrics. 

The enhanced ballistic performance of the 3D honeycomb fabrics may be attributed to the conjunction area between adjacent layers, which increases the yam friction in the conjunction area and the dimensional stability of the fabric as a whole. The increased yam friction in the conjimction area restrained yams from pulling out of the fabric in comparison to 2D plain woven fabric. Furthermore, both warp and weft yams in the conjunction area are better controlled with higher friction force caused by the higher yam density in the area. The reduced ballistic performance of 3D angle-interlock may be due to the difference in the number of intersections... 

D honeycomb fabric has also been developed to be used as a device for improving ventilation underneath ballistic body armour (Hearle et al., 1969). The 3D honeycomb woven stmctures used in their study were woven by a conventional loom and composed of three sets of warp yams and one set of weft yam. Each set of the warp yams interlaces with the weft yams, forming plain woven fabric layers. 

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