3 d knitted textiles

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3 d knitted textiles

  1. 1. BAHIR DAR UNIVERSITY Ethiopian Institute of Textiles and Fashion Technology(EITEX) SEMINAR ON 3D KNITTING PREPARED BY: SELAMU TEMESGEN SUBMITTED TO : Dr.S.Kathirrvelu (Professor Textile Tech. 1
  2. 2. Contents  Introduction  Classification of 3D knitted fabrics  Manufacturing method for 3d textiles  Properties of weft and warp knitted 3D fabrics  Types of machines used for 3D weft and warp knitting  Application of 3D fabrics  Principles to obtain 3d knitted fabrics
  3. 3. 3D-Textiles 1.Introduction Development of three-dimensional knitted fabrics dates from the 19thcentury • The concept of three-dimensional of the textile materials is not related to the intrinsic value of dimensions found on the three axes (x, y, z), but to the relationship between them. • This relation characterises the importance of the dimensions in the geometry of the material. 3
  4. 4. 4 • A three-dimensional fabric, regardless of the process used, is “a continuous ensemble, with fully integrated fibre, characterised by multiaxial spatial orientation” Creating a three-dimensional effect on knits is based on the following techniques: • I. Insertion of additional yarns along multiple directions; • II. Knitting and linking independent layers in different ways; • III. Spatial shaping.
  5. 5. 2. Classification of 3D knitted fabrics 5
  6. 6. 3.3D Textiles - Manufacturing Methods  Manufacturing methods: Braiding Weft knitting Warp knitting Weaving Stitched assemblies 6
  7. 7. Manufacturing Methods –Weft Knitting • Basic technique: – Forming a loop through previously formed such loops. • One yarn makes one row of the fabric. General properties: – The specific shape of the individual loops results in an elastic material – Fabric thickness is low – 3D geometry – Patterning allows manufacturing of tailor-made shapes 7
  8. 8. Fabric Formation Elements– Weft Knitting Individually controlled needles Consecutive knitting on every next needle  One thread per row 8
  9. 9. 4. Machines used –Weft Knitting  Two kinds of machines: • – Flat bed • Possibility to make tubular products, shells, thickness reinforced (spacer knits) and some complex structures as a combination of these • Patterning of shape and loop architecture • – Circular • Tubular and spacer tubular fabrics 9
  10. 10. 5.Application Scope –Weft Knitting  Weft Knitting: • – Somewhat limited 3D application due to the relatively low thickness of the material Biomedical Composites (formable matrix)  Reinforcement (Y-pipe, T-Pipe) 10
  11. 11. Manufacturing Methods –Warp Knitting • Basic technique: • – Fabric formed by interconnecting loops. • Machine used-Double needle bar raschel is commonly used • A set of individual yarns for every needle. • General properties: • – Less elastic fabrics • – Products with considerable thickness – 3D structures • – Patterning allows repeated structures to be manufactured 11
  12. 12. Fabric Formation Elements– Warp Knitting 12
  13. 13. Application Scope –Warp Knitting • Warp Knitting:  Composite materials  Aerospace industry – composite matrix  Civil engineering – concrete reinforcement, acoustic insulation  Military - ballistic protection Biomedical – vascular stents 13
  14. 14. 5.Principles for Obtaining Three- Dimensional Knitted Fabrics • To produce three-dimensional fabrics, the knitted material can be formed by the technique called spatial fashioning technique (also known as flechage). Three-dimensional structures can be created also by knitting stitches and loops combined with the lateral movement of the needle bed. By increasing or decreasing the number of working needles it is possible to create three dimensional knitted items on intarsia knits. 14
  15. 15. Conti…… The methods of making three-dimensional items on flat knitting machines are: 1. Incomplete knitted rows technique (spatial fashioning); 2. The use of patterns with 3D effects – egg. Knitting tuck stitches patterns combined with racking; 3. Knitting separate fabrics connected in between – sandwich/spacer fabrics; 4. Integral knitting /wholegarment. 15
  16. 16. Conti……… 1. Incomplete Rows Knitting Technique • Incomplete rows knitting technique is a technique used by designers of knits to create three-dimensional knitted items or tubular knits 16
  17. 17. 2.Use of Patterned Structures with 3D Effects • The most known example is the so called egg nest fabric, created by Shima Seiki. • The pattern is based on cardigan evolutions combined with successive racking in opposite directions. • Another example isajerseyfabric witha zonewithmissstitcheswhile the carriersproduce stitcheson the opposite bed. • When the missing stitches are discharges, the stitches produced on the opposite bed are transferred to the working bed. 17
  18. 18. 3. Sandwich Fabrics • A knitted layered item (sandwich) is a 3D structure, composed from two outer layers knitted together independent, connected by byarns or other knitted layers, as shown below 18 Sandwich fabrics with connection through knitted layers present a large range of development possibilities : − increase in the fabric thickness based on the length of the connection layers; − modification of the geometry of external fabrics due to the use of connecting layers with different length;
  19. 19. 4. Integral Knitting Technique Integral knitting technique is an improved stage in the development of technologies for flat knitting machines . So far it is the most advanced knitting technology through which a garment is completely assembled on a knitting machine without the need of sewing. Seamless knitting technology is a method that cuts off waste and reduces costs. • The seamless garment is very comfortable and resistant to wear. 19
  20. 20. THE END THANKS 20

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