Moniruddoza Ashir*, Cornelia Sennewald, Development of Woven Spacer Fabrics Gerald Hoffmann, Chokri Cherif Based on Steel Wires and Carbon Rovings DOI: 10.5604/01.3001.0010.1710 Institute of Textile Machinery Abstract and High Performance Material Technology, Woven spacer fabrics are used as reinforcing materials for fiber-reinforced plastics. These Technische Universität Dresden, fabrics consist of mostly pliable textile fibers, which still require defined rigidity for different 01069 Dresden, Germany crash applications. In this regard, multi-material woven spacer fabrics present a promising * E-Mail: [email protected] approach. This paper presents the development of multi-material woven spacer fabrics using steel wire and carbon rovings. For the development of such woven spacer fabrics, a syste- matic structure realization based on the weave pattern was performed. Selected structures were produced on a modified weaving machine. Key words: multi-material woven spacer fabrics, structure realization, profiled wire, pull-out test. als for lightweight constructions such as process optimization, the development aluminum or magnesium, which makes of woven spacer fabrics and their com- them highly suited as panel structures for prehensive characterization were carried aeroplane, train or automotive body con- out. Very few publications on woven struction [1]. Spacer fabrics are a class spacer fabrics for lightweight applica- of three-dimensional fabrics where two tions are readily available in literature [8- surface layers are connected to each oth- 12]. One of the first examples of woven er by means of pile yarns or fabric lay- spacer fabrics was presented in [9]. Here ers [2]. Such fabrics are characterized by the development of a weaving machine better resilience properties than classical for the production of spacer fabrics for two-dimensional textile fabrics [3]. Typ- FRP is described. These fabrics consist ically spacer fabrics used for FRP appli- of polyester and viscose yarns. Mounta- cation are made of high-performance fib- sir et al. [8] exclusively investigated the ers, such as carbon, glass or aramid fibers mechanical properties of woven spacer characterized by lower density as well fabrics. The spacer fabrics developed are as a higher tensile strength and Young´s composed of glass-polypropylene hybrid Modulus [4]. yarns. Similar to woven spacer fabrics, 3D woven wire structures have also been Studies on spacer fabrics show a vari- studied [13-17]. The development of 3D ety of approaches for their production, woven wire structures of a cellular de- characterisation and varied application sign for multifunctional multi compo- possibilities. Spacer fabrics for technical nent-composite semi-finished products is applications are commonly produced by reported in [13]. However, this paper pre- the circular knitting process (weft-knitted sents a fundamental approach that aims spacer fabrics), double needle bar warp to provide a novel fundamental tech- knitting process (warp-knitted spac- nological basis for the production and er fabrics) or weaving process (woven characterization of such structures. This spacer fabrics) [5-7]. However, woven paper is organised into 3 sections, where spacer fabrics exhibit superior mechan- the structure development is presented in ical properties, for instance higher stiff- the Theoretical structural realization ness, strength and dimensional stability, for the development of multi-material than those of knitted spacer fabrics [8]. woven spacer fabrics (MWSF) section, Woven spacer fabrics typically consist the implementation of structures – in the of two sets of warp and weft yarns each. Technology development section, and These yarn systems are used for the fabri- fabrics developed are analysed in the Re- cation of two layers of spacer fabrics (up- sults and discussion section. per and lower layer) and the warp yarns Introduction interchange their position after a certain Theoretical structural In recent years, research on spacer fab- interval to make a fabric layer in the ver- rics as a reinforcement structure for fiber tical direction between them. realization for the development reinforced plastics (FRP) application has of MWSF become increasingly popular because of In previous works executed at the Insti- The MWSF proposed also consists of two the better mechanical properties on offer tute of Textile Machinery and High per- fabric layers, in which the top and bottom such as tensile, flexural and compression formance Material Technology at Tech- are similar to conventional woven spac- strength when compared to other materi- nische Universität Dresden, machine and er fabrics. These layers are connected Ashir M, Sennewald C, Hoffmann G, Cherif Ch. Development of Woven Spacer Fabrics Based on Steel Wires and Carbon Rovings. 49 FIBRES & TEXTILES in Eastern Europe 2017; 25, 1(121): 49-55. DOI: 10.5604/01.3001.0010.1710 fabrics (MWSF) section, the implementation of structures - in the Technology development section, and fabrics developed are analysed in the Results and discussion section. Theoretical structural realization for the development of MWSF The MWSF proposed also consists of two fabric layers, in which the top and bottom are similar to conventional woven spacer fabrics. These layers are connected together by profiled wires as opposed to pile yarns or fabric layers, which are used in conventional woven spacer fabrics. Structural variation possibilities Theoretical structural variation possibilities for the development of MWSF can be realised by the interlacement of yarns, profiled wire geometry, direction of insertion of the profiled wire in between the top and bottom layer of fabrics, the number of yarns per repeat and the undulation Further structural variation of MWSF structures can be realized considering the direction of profiledof weft wire yarnsinsertion. in between the upper and lower layer of MWSF during weaving. Profiled wire can be inserted in either warp or weft as well in both directions. For the realization of The interlacement variation of warp yarns, weft yarns and profiled wires in MWSF structures MWSF structures, profiled wire insertions between two layers of MWSF are considered only in the canweft bedirection implemented, so that the bygeometrical plain, twillshape or of satin the profiled weave wire patterns can be retain. Theed structuralduring deformation, slippage picking. resistance, yarn pull-out force, bending resistance and handling stability of plain woven fabric is Differentbetter MWSF than structures that of cantwill also or besatin realized fabrics by varying [16] .theFor arrangement this reason, of the theprofile plaind wire weave pattern is taken into and the number of warp yarns in a repeat. Different variation possibilities in this aspect are as consideration for further structural realization of MWSF. follows: i. AllProfiled profiled wire wire in a geometryMWSF structure variations can be arranged such in asan identicaltrapezium manner (flat and warptop yarnssurface), zigzag (pointed top can be interlaced with weft yarns as well as profile structures at the peak of the profiled surface) or combined (combination of a flat and pointed top surface) profiled wire (c.f. Figure 1), structure – (A), can be used. In this work, however, only zigzag and trapezium profiled wire were considered in ii. All profiled wire in a MWSF structure can be arranged in an identical manner and warp yarns canorder be interlaced to reveal with weftthe yarns effect as ofwell the as profileprofiled structures wire atgeometry the peak of (flat the profiled or pointed wire in top surface) on the sliding additionresistance to the space of warp between yarns two ,peakwhichs of thein turnprofile determinesd wire – (B). In the this structurevariation, the stability. warp yarn density is twice that of variation (A). well in both directions. For the realiza- tion of MWSF structures, profiled wire insertions between two layers of MWSF iii. Two profiled wires are placed face-to-face but turned upside downare consideredin a repeat only, and in thewarp weft direc- tion, so that the geometrical shape of yarns are interlaced with weft yarns and profiled wire at the peak of the profiled wire – (C). Here Trapezium Zigzag Combined the profiled wire can be retained during profiled wire profiled wire profile wire picking. the profiled wire density is twice that of variations (A) and (B). Figure 1. Different profiled wires for realization of the MWSF structure. Different MWSF structures can also be Variations (A), (B) and (C) are shown in Figure 2, where dots indicate realizedwarp yarns. by varying the arrangement of the profiled wire and the number of warp Figure 1. Different profiled wires for realizationyarns of in the a repeat. MWSF Different structure. variation pos- i. MWSF structures with undulated weft yarns – (U) or sibilities in this aspect are as follows: n All profiled wires in a MWSF struc- ii. MWSF structures with straight weft yarns – (S). ture can be arranged in an identical manner and warp yarns can be inter- Variation A Variation B Variation C laced with weft yarns as well as pro- Sample construction of structure proposed file structures at the peak of the pro- Figure 2. Structural variation possibilities based on the arrangement of profiled wires and filed structure – (A), 3 theA number Figureproposed of warp2 .MWSF Structural yarns. structure variation is shown possibilities in Figure 3. basedThis is ona r epresentativethe arrangement samplen All of profiledof