To Compare the tensile strength of 100 % pure cotton and its blends, also calculating their CLSP values.

This experiment is done to see how same count of different types of yarns has different strength and CLSP. We will also see the factors on which tensile strength of a product depends upon and when to use which yarns for different applications.

In this experiment, different types of yarns were studied under the parameters of tensile strength and CLSP. The yarns that were studied in this experiment are 100% cotton yarns, nylon/cotton blended yarns and CVC yarns, all having 20's count. CVC means Chief-value-cotton these are Cotton and Viscose Rayon blended yarns in which major portion of yarn is cotton.

English Count(Ne) is indirect method of measuring the yarn quality. It is used to measure the fineness of yarn. English count of 20's represents that the yarns has 20 hanks per pound(lbs) of yarn. Through the lea method the tensile strength of these yarns were calculated. Results shows us that the nylon/cotton yarns has the highest strength. While the strength of CVC yarns and pure cotton yarns was less than nylon/cotton yarns.

Objectives:

• To calculate the tensile strength of 100% cotton yarns.
• To calculate the tensile strength of nylon/cotton blended yarns.
• To calculate the tensile strength of CVC yarns.
• To compare their tensile strength and CLSP.

Materials:

• 100% Cotton yarn package.
• Nylon/cotton blended yarn package. (40:60 blend)
• CVC yarn package. (60:40 blend)
• Wrapping Reel
• Lea Tensile Testing Machine.
• Weighing Balance.

Procedure:

• 100% cotton yarn package was taken.
• The package was placed on the wrapping reel.
• 5 sample leas was made of that yarn package.
• These were weighed one by one on the weighing balance.
• The tensile strength of the leas was determined one by one on the lea tensile testing machine.
• The same procedure was done for the nylon/cotton and CVC blends.

Observations & Calculations:

English Count (Ne) = 64.428 / (lea weight in grams)=20's

1 Kg = 2.2 lbs.

CLSP = Count × Lea Strength in lbs.

Co-officient of Variation = (S.D)/X' ×100

Results:

Tensile Strength for 100% cotton yarn = 88.88 lbs.

CLSP for 100% cotton yarn = 1777.6

Tensile Strength for nylon/cotton yarn = 138.16 lbs.

CLSP for nylon/cotton yarn= 2763.2

Tensile Strength for CVC yarn = 135.08 lbs.

CLSP for CVC yarn = 2701

Discussion:

The results show us that the nylon/cotton yarns are the strongest yarns between the given yarns, while the pure cotton yarns are the weakest one. As the nylon and polyester are the synthetic fibers and they have high tensile strength properties, so when blended with cotton fibers they provide the strength to the yarns produced by them. Between nylon and polyester, nylon is stronger as it is a poly-amide fiber and is also in many mechanical instruments where strength and stiffness is required and also where flame resistance is required to some extent.