Crimp Percentage %:
Crimp Percentage is defined as the mean difference between the straightened thread length and the distance between the ends of the thread while in cloth, expressed as a percentage. There is a relation between crimp% and take up % with will be discussed following.
……………………L-p
Crimp%, C =……….. X 100 ……………………….(1)
……………………..p
…..Straightened length – crimped length
= …………………………………………………………
…………………Crimped length
Take up percentage:
Take up a percentage or crimp rigidity is a measure of the ability of textured yarn to receive from stretch and is related to the bulking properties of the yarn before weaving and the length of yarn in the fabric after weaving expressed as a percentage of the length of yarn before weaving is called take-up percentage.
…………………………………….L-p
Take up percentage, T = ……….. X 100 ……………………… (2)
………………………………………L
Where,
T = Take up percentage
L = Length of yarn before weaving
p = Length of yarn in the fabric after weaving
Relation between Crimp% and Take up %:
From equation (1)
……..L-p
C = …….. X 100
……….p
=> C/100 = L/p – 1
=> L/p = C/100 + 1
………………100 + C
=> L/p = ……………… …………………(3)
…………………100
From equation (2)
……..L-p
T = ……….. X 100
……….L
= (1- p/L) X 100
= {1 – 100/(100+C)} X 100 ……………………….. [from equation 3]
…………..100C
So, T = ………….. ……………………………(4)
…………..100+C
To express percentage crimp in terms of take-up %, equation (4) is solved as follows:
………100 C
T = …………….
……..100+C
=> 100 C = 100T + CT
=> 100 C – CT = 100 T
…………….100 T
=> C = ……………… ……………………..(5)
……………100 – T
Equation (4) and (5) are two relations between Crimp% and Take up%
Author of this Article: Raju Tex Knitting Technologist, B.J.Group, Mawna, Gazipur Chittagong Textile Engineering College Facebook: https://www.facebook.com/ERZRAZU