TWILL WEAVE
The twill order of interlacing causes diagonal lines to be formed on the cloth.
Comparison with plain weave
As comparison to plain weave, twill weave has greater weight, closer setting and better draping quality
Construction of simple twill- Step-by-Step
Step – 1 : We use a minimum of three threads (i.e. warp and weft) to construct a twill. We first try the twill 1/2 (1 up 2 down). We make a 3x3 square as:
Step – 2 : Now we start from the first end and first pick we make our first mark here (it represents the point of interaction).
Step-3:
Now in next pick the point of intersection is moved one outward and one upward as
In next pick again the point of intersection is moved one outward and one up ward as
The three steps in construction twill are as follows:
Or from left to right as ( also called as right hand twills)
The Twills can be
1. Warp faced Twill: In which quantity of warp is more on the face of the fabric eg 3/1 twill.
2. Weft faced twill: In which quantity of weft is more on the face of the fabric (e.g 1/3 twill)
3. Warp and Weft faced twill: In which warp and weft are in equal quantity on the face of the fabric (eg. 2/2 twill).
Angle of Twill
The angle formed in the cloth by a twill weave depends upon:
(a) The relative ratio of ends and picks per cm.
(b) The rate of advancement of interlacing
If the EPI and PPI are equal, a regular twill runs at an angle of 45º as shown:
In fact the angle of the twill with the horizontal can be calculated by the formula:
Tangent ( Angle) = ((Rate of Advancement of twill upwards x ends per cm)/(Rate of advancement of twill outwards x pics per cm))
Thus if
Step upward = 2
Step onward = 1
Ends/cm = 42
Picks/cm = 21
Then tan(angle of twill) = ((2 x 42)/(1x21)) thus the angle would be = 76º
As in the following twill
Factors influencing the prominence of twills
The relative prominence of twills is chiefly determined by:
(a) The character of weave
(b) The character of yarn
(c) The number of warp and weft threads per inch
(d) The direction of twill in relation to the direction of twist imparted to the yarn.
(a) The Character of Weave
A twill weaves will be relatively more pronounced if developed from longer than from shorter floats of yarn.
(b) Character of yarn
A more pronounced twill will result either from coarse spun of soft spun yarn than from fine spun or hand spun yarns; also from folded yarn than from single yarn.
(c) Number of Threads per inch
A twill will be relatively more or less pronounced in proportion to the number of warp threads and picks of weft per inch.
(d) Direction of twill with relation to the direction of twill in the yarn
If twills are produced in the reverse direction to that of the twist in the yarns, they will be more pronounced and if twills are produced in the same direction as that of the twist in the yarn, they will be less pronounced.
The twill order of interlacing causes diagonal lines to be formed on the cloth.
Comparison with plain weave
As comparison to plain weave, twill weave has greater weight, closer setting and better draping quality
Construction of simple twill- Step-by-Step
Step – 1 : We use a minimum of three threads (i.e. warp and weft) to construct a twill. We first try the twill 1/2 (1 up 2 down). We make a 3x3 square as:
Step – 2 : Now we start from the first end and first pick we make our first mark here (it represents the point of interaction).
Step-3:
Now in next pick the point of intersection is moved one outward and one upward as
In next pick again the point of intersection is moved one outward and one up ward as
The three steps in construction twill are as follows:
Right Hand Twills and Left Hand Twills
The twills can be produced from Right to left (also called as left hand twill) as shown in fig.
Or from left to right as ( also called as right hand twills)
The Twills can be
1. Warp faced Twill: In which quantity of warp is more on the face of the fabric eg 3/1 twill.
2. Weft faced twill: In which quantity of weft is more on the face of the fabric (e.g 1/3 twill)
3. Warp and Weft faced twill: In which warp and weft are in equal quantity on the face of the fabric (eg. 2/2 twill).
Angle of Twill
The angle formed in the cloth by a twill weave depends upon:
(a) The relative ratio of ends and picks per cm.
(b) The rate of advancement of interlacing
If the EPI and PPI are equal, a regular twill runs at an angle of 45º as shown:
In fact the angle of the twill with the horizontal can be calculated by the formula:
Tangent ( Angle) = ((Rate of Advancement of twill upwards x ends per cm)/(Rate of advancement of twill outwards x pics per cm))
Thus if
Step upward = 2
Step onward = 1
Ends/cm = 42
Picks/cm = 21
Then tan(angle of twill) = ((2 x 42)/(1x21)) thus the angle would be = 76º
As in the following twill
Factors influencing the prominence of twills
The relative prominence of twills is chiefly determined by:
(a) The character of weave
(b) The character of yarn
(c) The number of warp and weft threads per inch
(d) The direction of twill in relation to the direction of twist imparted to the yarn.
(a) The Character of Weave
A twill weaves will be relatively more pronounced if developed from longer than from shorter floats of yarn.
(b) Character of yarn
A more pronounced twill will result either from coarse spun of soft spun yarn than from fine spun or hand spun yarns; also from folded yarn than from single yarn.
(c) Number of Threads per inch
A twill will be relatively more or less pronounced in proportion to the number of warp threads and picks of weft per inch.
(d) Direction of twill with relation to the direction of twill in the yarn
If twills are produced in the reverse direction to that of the twist in the yarns, they will be more pronounced and if twills are produced in the same direction as that of the twist in the yarn, they will be less pronounced.
0 comments:
Post a Comment