The most conventional method to manufacture seamless 3-Dtextiles is by non-woven technology. But lack of cellular structure innon-woven materials makes it impossible to obtain properties inherent to wovenfabrics. This fact limits the spectrum of seamless shells range.
The woven fabrics can not be completely replaced by theknitted ones as they are characterized by anisotropy of properties, have poortension resistance and as a result there exist a loss of preset shape and theimpairment of the garment appearance.
Therefore to meet all the requirements to 3-dimensionalseamless goods for apparel and industrial use it is advantageous to employseamless 3-axial shells. The existing design methods of such shells did notfind wide application because of such limitations as non-uniformity ofstructure, non-stability to deformation and impossibility to abruptly modifythe curvature of the 3-D shell.
By all these reasons in the Moscow State University ofDesign and Technology the new method of 3-D shells design was worked out.According to it the woven seamless shells consist of three types of basicthreads: initial, right and left wefts, and also of the supplementary mouldingthreads (fig.1). Novelty of the method is in getting the supplementary threadsin two directions at the same time by using the thread with breakpoint. Thisgives the determined three-dimensional form to the shell and stability to thefabric structure. The present method of making shells removes defects, whichprevious methods of shells production had, by replacing warp threads by rightand left wefts. This allows getting the supplementary thread in the fabricstructure with breakpoint so that it crosses each initial thread twice. In thiscase the algorithm of interlacing will be stable and the set changes of shellcurvature will be provided exactly.
Use of three basic threads types in fabric structure allowsextending opportunities of making three-dimensional seamless form, because thecurvature of making shell may change in three dimensions, which are parallel tothe basic threads.
Technology of garment manufacture by weaving is achallenging problem, as manufacture of one-piece woven goods makes it possibleto reduce materials consumption and labour intensity by eliminating a number ofseams and allowances and reducing of materials and labour costs in apparelmanufacture. Design methods for 3-D one-piece woven or braided textiles proveto be highly effective especially in manufacture of special-purpose wovengoods, where the excessive seams negatively effect on the performancecharacteristics and reliability, and in some types of goods they are absolutelyinadmissible.
The present method of making seamless shells is alreadyadopted for reinforcing shell of astronaut suit, carbonic preforms foraircrafts details and braided seamless footwear uppers. But it can receivewider application for making everything that can be made of the threads orstripes and must be three-dimensional.
The newly developed technological process includes thefollowing stages:
1. Creation of products surface in 3-dimentional designspace;
2. Computation of the threads location in 3-D shellstructure;
3. Manufacture of the 3-D textile shell.
Due to the use of this shells production method the textile and sewing processes are combined in one inseparable technological process. The stage of cutting and all technological operations, except finishing ones, are eliminated. So the loom is most important unit in manufacturing process.
An example of designed and manufactured experimental sample of seamless hemisphere is shown on figure 2.
Figure 2 - Position of yarns: a - 3-D virtual model, b - manufactured 3-axial sample.
From the biaxial tension test it has been found that 3-D one-piece three-axial textiles maintain the stability of elementary cells till the moment when the yarns are broken. At that, the elongation of the specimen in all directions is mainly the result of unbending and stretching of yarns. This proves the theory that a triangle elementary cell is a more stable structural element than the rectangular one.
Results of carried out researches showed that three-axial shells, which were made by developed method, are suitable for wide usage both as traditional textile goods and as items for special purposes.
About the Authors:
Ekaterina Lavish and Elena Andreeva are faculty in technology of sewing goods at Moscow State University of Design and Technology
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