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- 1. Guest lecture on FABRIC STRUCTURE AND DESIGN by Gopalakrishnan Duraisamy Quantum Textile Professional & Team Coimbatore 29 May 2023 1
- 2. PART – II TYPES OF WEAVES by Gopalakrishnan Duraisamy Quantum Textile Professional & Team Coimbatore 29 May 2023 2
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- 4. Fundamental Weaves • Weft or warp threads must have only one warp or weft overlapping within the repeat. • The number of warp threads in a repeat must be equal to the number threads. • There are 3 kinds of fundamental weaves: • Plain • Twill • Sateen • Each weave is determined by 2 parameters: • The repeat, R of weave. • The shift, S of overlapping either vertical shift, Sx or Horizontal shift, Sy 29 May 2023 4
- 5. Plain Weave • The simplest weave where the threads interlace in alternate order and classified as balanced and unbalanced. • In trade, such terms as tabby, calico, batiste are applied to plain weave fabrics. 29 May 2023 5
- 6. Twill Weaves • The twill order of interlacing produces diagonal lines on the cloth. • The purpose is to make cloth havier, closer setting and better drapping. • The parameters: R ≥ 3 Sx = Sy = + 1 29 May 2023 6
- 7. Regular Sateen and Satin and Irregular Sateen Weaves Sateen Weaves • In pure sateen weaves the surface of the cloth consists almost entirely of weft floats. • The parameters of sateen weaves: R ≥ 5; 1 < S < (R – 1) • For regular sateen the shift (S) and repeat (R) must be expressed by prime numbers, it’s called weft face fabric. • The sateen weave is denoted by a fraction and the numerator of this fraction is equal to the repeat of weave. • The denominator is equal to the shift (Sy) of overlaps. 29 May 2023 7
- 8. Satin (Warp Face Fabric) • Usually constructed using the vertical shift (Sx). • Satin has the warp effect, and the density of warp is much higher than the density of weft. Sx=3 29 May 2023 8
- 9. Irregular Sateen • Regular sateen cannot be constructed with a repeat of four or six threads, because the repeat and shift cannot be expressed by mutually prime numbers. • It is impossible to construct the regular sateen if R = 6, because among the possible values of shift found from the formula 1 < S < (R - 1), i.e. 1 < S < 5, the number 2, 3, 4 have a common divisor with 6. • In this case, we cannot choose a constant shift, but the sateen with a variable shift can be constructed. • This sateen is called irregular sateen. • 4-shaft irregular sateen can be constructed by using the shifts 1, 2, 3, 2 as shown aside. • 6-shaft irregular sateen with constructed shifts 2, 3, 4, 4, 3, 2 as shown aside. 29 May 2023 9
- 10. Derivatives of Fundamental Weaves “Constructed by means of deriving from plain, twill and sateen weaves, and retain their structural features” 29 May 2023 10
- 11. Plain Weave Derivatives • This group of structure comprises various simple weave which are varieties of the plain weave and can be produced on two heald shafts. Warp Rep Weaves: Denoted by a fraction. The numerator shows the number of warp overlapping and the denominator, the number of weft overlapping on the same thread within repeat. Extending the plain weave vertically. 29 May 2023 11
- 12. Weft Rep Weave: Opposite to warp rep weave. Extending the plain weave horizontally. Denoted by a fraction. Sum of the fraction numerator and denominator equal to the warp repeat. 29 May 2023 12
- 13. Rug from Rep Weave 29 May 2023 13
- 14. Hopsack Weaves: Constructed by extending the plain weave both vertically and horizontally. There are 2 or more warp threads working in the same manner and 2 or more weft threads grouped in the same shed. It’s denoted by a fraction, the numerator is the number of warp overlapping, and the denominator is that of weft overlapping on each thread. The sum of the numerator and denominator shows the repeat on warp and weft. 29 May 2023 14
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- 16. Fabric from Hopsack Weave 29 May 2023 16
- 17. Fabric from Hopsack Weave 29 May 2023 17
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- 19. Weaves Constructed on Twill Bases • Regular twill are often used as the bases for the construction of new weaves. Reinforced Twills: Warp overlaps are added to the single warp overlaps of the basic weft-face twill. The simplest reinforced twill is twill 2/2 (widely used). In producing this twill the same four shafts can be used for making the selvedges on the warp rep weave (necessary to coordinate the operation of shedding and picking mechanisms). Retain the property of the original twill. 29 May 2023 19
- 20. Reinforced twill 2/2 (left hand twill, Sy = -1) 29 May 2023 20
- 21. Compound Twill: It is obtained in parallel construction of two or more twill weaves on the same area. The number of shafts for producing compound twill is equal to its repeat. Retain the property of the original twill. 29 May 2023 21
- 22. Fabric from compound twill 29 May 2023 22
- 23. Angled Twill Constructed by changing the sign of shift from plus to minus, after an assigned number of threads. With the change of sign, the direction of twill diagonal is also changed. To construct: i. Calculate its repeat ii. Weft repeat = Repeat of basic twill iii. Warp repeat can be determined by the formula, Rx = 2Kx - 2 Rx = repeat of warp Kx = number of warp threads after the sign of shift changes. Ryb = repeat of the basic twill Ky = no of weft threads after the sign of shit changes 29 May 2023 23
- 24. Example: Construct the angled twill on the basis of twill 2/4. The repeat of basis twill is 6. Answer: Ry = Ryb = 6 Rx = 2Kx – 2 = 2 (6) – 2 = 10 29 May 2023 24
- 25. Diagonal Twill Construct the basic twill with an increased vertical shift (to increase the inclination angle of the diagonal changes). The increase of the shift from one to two is equivalent to the doubling of warp density (practically the shift can be accepted equal to two or three). Can be constructed into 2 cases: i. The repeat of basic twill can be divided by the increased shift. Warp repeat, Rx = R ÷ So Weft repeat, Ry = R ii. The repeat of the basic twill cannot be divided by the increased shift. 29 May 2023 25
- 26. Example 1: Construct a diagonal weave on the basis of twill 4 . 4 . 1 , if Sx = 2. 1 . 2 . 2 Answer: Warp repeat; Rx = R ÷ Sx R = 14 = 14 ÷ 2 Sx = 2 = 7 Weft repeat; Ry = R = 14 First warp constructed according the basic twill. Second warp constructed according to the same formula but the shift equal to two, and so on. If the repeat of the basis twill is nit divided by the increased shift the diagonal weave will have repeat Rx = Ry = R. 29 May 2023 26
- 27. Example 2: Construct a diagonal weave on the basis of twill 5 . 1 . 1 , if Sx= 2 1 . 2 . 1 Answer: In this case, Rx = 11 and Ry = 11 29 May 2023 27
- 28. Fabric from diagonal twill 29 May 2023 28
- 29. Shaded Twill: Represent a gradual transition from twill with weft effect to the twill with warp effect and vice-versa. Mostly used Jacquard weaving for large-pattern fabrics. The repeat on warp and weft for the shaded twill is determined by the formula; Warp repeat, Rx = Rxb (Rxb – 1) Weft repeat, Ry = Ryb Only straight draft is used. 29 May 2023 29
- 30. Example: Construct a shaded twill weave on the transitions of shaded twill 1 to 4 . 4 1 Answer: Rx = Rxb (Rxb – 1) = 5 (5 -1) = 5 X 4 = 20 Ry = Ryb = 5 29 May 2023 30
- 31. Fabric from shaded twill 29 May 2023 31
- 32. Weaves Constructed on Sateen Bases In simple derivatives, a new design is built up by using the original sateen as the base and adding overlaps, as required to each base overlap. 29 May 2023 32
- 33. Reinforced Sateen: Similar to reinforced twill. If it is necessary to construct the reinforced sateen on the basis of simple sateen 8/5. One more overlap should be added to every overlap of the basis sateen. Widely used in cotton weaving (additional overlaps in the repeat make the fabric structure stronger). 29 May 2023 33
- 34. Shaded Sateen: Like the shaded twill. Shaded sateen represents a gradual transition from the sateen with weft effect to the sateen with warp effect, vice versa. The repeat Ry and Ro of the shaded sateen is determined by the formula; Ry = Ryb Ro = Rob (Rob – 1) Example: Construct a shaded sateen weave on the transitions of shaded sateen 5/3. Answer: Ry – Ryb = 5 Ro = Rob (Rob -1) = 5 (5 – 1) = 5 X 4 = 20 29 May 2023 34
- 35. THANK YOU Email: dgk.psgtech@gmail.com Mobile: +91 9600953305 29 May 2023 35