Textiles spacer fabrics

The main purpose of middle layers is to provide additional (thermal) insulation. Nowadays, these layers are often made of fleece materials with good air entrapment properties. Their thermal conductivity (typically 0.03-0.04 W/mK) is near from air (0.026 W/mK). The thermal resistance of such layers is directly correlated with their thickness, provided that no air movement occurs within the fabric. Thermal conductivity and air permeability also are generally dependent on the fabric density (Yip and Ng, 2008). Conduction has been shown to be the main heat transfer mechanism through textile layers as long as the fibre volume fraction is higher than 9% (Woo et al., 1994). However, materials with very low density (like spacer materials) allow radiant and convective heat transfer. This was demonstrated by Das et al. (2012) who compared a spacer fabric middle layer with two non-woven middle layers and showed that the contribution of this spacer fabric to the overall insulation was higher than the two other samples in a non-convective mode, while it was the lowest in a forced convective mode. The positive effect of metallised interlayers with low emissivity on the reduction of... 

During recent years, there have been new developments in the area of spacer textiles ITV Denkendorf has developed a process in which two separated textile fabric layers, covered by transparent foils, are connected by a spacer fabric. Due to this specific construction, an air space is created which provides a high degree of heat and acoustic insulation. Spacer fabrics, laminated or coated with transparent foil on both sides, are increasingly used for transparent thermal insulation. Woven spacer fabrics can be produced up to 600 mm in width and are used, sometimes with filUng, for sound damping (Fig. 2.8). 

Barauskas R and Abraitiene A (2011), A model for numerical simulation of heat and water vapor exchange in multilayer textile packages with three-dimensional spacer fabric ventilation layer . Text Res J, 81(12), 1195-1215. 

D knitted textiles have already been widely used as technical textiles in different fields. The future work should be on the development of new 3D knitted structures with more extra functions to meet the requirements of new application fields. For example, warp-knitted spacer fabrics have great structural variations. By using different structures and fibre materials, they have been developed to have various physical functions to be used in different fields, such as cushioning, sound absorption, smart textiles and thermal collection. New potential application fields should be identified first in the future, and then fabric stmctures can be designed to better match the specific applicatimis. 

Wollina, U., et al., 2004. Spacer fabrics and related textile solutions. AktueUe Dermatol. 30, 8-10. 

Figure 12.1 An example of a 3D textile system produced in one weaving process using a customised manual loom. The 3D textile system consists of spacer fabrics - t3tpe electrodes protruding from the woven band at predetermined positions according to clinical requirements. The cross section of the electrodes shown in the circle illustrates how four different warp systems have been arranged to create four specific layers of the electrode (from top to bottom) the electrically conductive electrode surface, an isolating and moisture supplying layer, an intermediate protmding/resilient layer and the protecting layer, which is in the same layer as the woven band.

For an illustrative representation of all the aforementioned aspects, examples of individual products are shown. Products like shoes, underwear, diving clothes and other applications are partly composed of 3D textiles, which are in most cases warp-knitted spacer fabrics. In addition to warp-knitted spacer fabrics, knitted spacer fabrics are also processed. The individual design allows the manufacmrer to combine more demands on the products and thus cover a wide range of applications. Generally there is great diversity in the field of sports and leisure clothing. 

The 3D structure between two textile surfaces can be produced with the flock technology. In this technology, short cut fibres (flock fibres) are electrostatically charged and applied on adhesive coated substrate using an electric field. The flock technology is over 100 years old and is used in various technical, medical and textile sectors. The so-called filter-flock method is a process to improve the characteristics of spacer fabrics. The ribs made with flock, also known as rib-flock , allow for a greater conduction of excess heat and body moisture from the body due to their channel-shaped structure (cf. Section 14.3 Krel et ah, 2005 Machova et ah, 2006). 

The Gehring Textiles Inc./Militex Inc., New York, produces the so-called Spacer Fabric for diving suits as an alternative to neoprene. Furthermore, a possible development has been reported in the field of yams and stmctures, where in addition to the aesthetic properties, technical properties are also improved. This includes strength, ductility, density and elasticity, which have to be adapted to the requirements of the suit (Anon., 2002a,c, 2003a,b Gehring Textiles, 2013). 

Fig. 24.17 presents the colours obtained with polydithieno(3,2-b 2 -3 -d)thiophene (pDTT) and this electrolyte, impregnating a cotton spacer fabric. The flexible structure switches from green at the neutral, oxidized state to red at the doped, reduced state [78]. Acceptable lifetime results are obtained for up to several hundreds of cycles. This structure can be adapted in order to realize an electrochromic textile display. 

Keywords Biotextile Fibers and filaments Melt spinning Bicomponent spinning Textile structures Braids Knits Nonwovens Spacer fabric... 

Due to the strict long term durability requirements (chemical resistance against highly concentrated liquid media) the fabric for geotextiles can be made of HDPE tape yarn. The geo textile packing material is a double woven spacer fabric with a uniform cross section, based on a defined spacer length between the two fabric layers. 

Starting from plain cotton-based products, medical textiles have seen rapid development over the last few decades. Nowadays, new biodegradable fibers have enabled the development of novel types of implants, and modem textile machines can produce three-dimensional spacer fabrics that give superior performance over traditional textile materials. These and many other advances have made medical textiles an essential element in modem disease management, and they are becoming more and more important with the increasing number of elderly people in the populations of developed countries. 

Spacer fabrics contain a combination of textile sheets and distance fibers, with a porons strnctnre that can offer high absorption capacities for medical textile... 

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