Textile Yarn Count Testing using Wrap Reel Machine

The Wrap Reel Machine is used to measure the yarn’s length, linear density, and count. For this, you have to wind a known length on a wrap reel machine under controlled tension. After winding, just weigh the skein and calculate the yarn linear density through the mass per unit formula.

Yarn Count 

“The representation of yarn thickness by a numerical number is called yarn count.”

It expresses whether the yarn is thick or thin. For example, the 80 Ne yarn will be finer and thinner compared to 52 Ne. In the English count Ne system, as the count number increases, the yarn becomes finer and thinner.

On the other hand, the lower number shows that the yarn is thick and rough, like a 12 Ne count, which is used in thick winter qualities (khaddar).

1. Linear Density 

Yarn count is measured in terms of linear density. In this term, the linear represents the length, and the density represents the weight.

Linear = Length (L)

Density = Weight (W)

2. Yarn Count Types

• Direct Count (W/L) 

A direct system is used for artificial or man-made fibers, such as polyester. Tex and Denier are the units used for filament yarn.

• In-Direct Count (L/W)

An indirect system is used for natural fibers (spun yarn) like cotton. Its examples are English Count (Ne) and Metric Count (Nm).

3. Yarn Length for Count Measurement

Take out 120 yards of yarn from the cone using the wrap reel machine or the manual method. 1 yard has 36 inches, so you need to remove 4320 inches of yarn for the count measurement.

Now we will weigh the 120 yards of yarn.

[120 yards * 0.54] / weight in grams

Denier = 5314 / (Ne)

Test Procedure

Wrap Reel Tester

Step 1: Machine Preparation and Parameter Setting 

Switch on the instrument, and add parameters:

1. • Yarn nominal linear density
   • Required number of turns
   • Rotation speed
   • Number of spindles

After setting all parameters to your required standard, such as GB/T 4743, ISO 2060, or ASTM D1907, click “Reset” on the interface.

Step 2: Sample Conditioning and Pre-Tension Adjustment

The sample is conditioned before winding, and it should be cut from the middle of the yarn length to get accurate results. The pre-tension should be adjusted according to the sample’s nominal linear density.

Step 3: Loading & Threading 

The yarn cone is inserted on the spindle rod, and the initial several meters of yarn length are discarded from the beginning of the sample.

The yarn is passed through the yarn guide hook and then leads to the tension adjuster. The traverse yarn guide is used to insert the sample into the yarn clamp. After that, the blades are restored to their original position.

Step 4: Winding and Calculation

Now click on the “Start” button to begin the test. The reel winds the yarn, and when it reaches a preset number of turns, the machine stops automatically. Skein is ready for weight, and then calculate the yarn count using the formula below.

1. Yarn Linear Density (Tex) using Wrap Reel Method

Tex =           Mass (gm) × 1000

Length (m)

Mass     = Skein weight in grams

Length = Total yarn length in meters

The yarn length is measured by multiplying the number of turns by the reel circumference.

Length (m) =       Number of turns × Reel circumference (m)

Yarn frame circumference = 1000 mm = 1 meter

So, if you give 10 turns, the outcome will be 10 meters of yarn.

2. English Cotton Count (Ne) Formula

Ne =              Length (yards)

840 × Weight (lb)

What affects Wrap Reel Accuracy? 

I have been worked more than 12 years in textile processing and spinning labs, the thing I experienced that wrap reel accuracy does not only depend on the length measurement, but it also depends on controlled tention, and operator technique to handle the yarn.

Modern wrap reel testers, such as YG(B)086C Wrap Reel Machine, provide accurate results for determining yarn length, linear density, and yarn count in accordance with ISO 2060 and ASTM D1907.

1. Tention 

It is the most mismanaged variable in yarn count testing because it directly affects the length. The length of a yarn is directly proportional to the weight in grams. While yarn count is inversely proportional to yarn weight.

So, extra stretching can artificially increase yarn count Ne, while losing yarn can artificially lower yarn count Ne.

2. Airflow and Draft Influence During Winding

Mostly, operators ignore this parameter. If you do high-speed winding, above 250 rpm, then the air flow generated by the reel can alter the lightweight yarn’s stretching behavior.

That’s why in modern testers, the synchronized belt-driven transmission system is used to reduce the vibration at higher speeds.

3. Skipping Discard length Step

It is the operator’s discipline fault. In high-volume testing labs, operators skip the discard step to save time, but this can lead to variation in yarn count. Because a few meters of yarn from the package can contain surface contamination or residual winding stress.

4. Servo Drive vs. Conventional Motor Systems

Traditional wrap reels use a belt pulley system, which is prone to slipping. If you have to wrap a large amount of yarn, then a slight deviation can cause a variation in the results.

On the other hand, the servo-driven synchronous transmission system delivers constant angular velocity, which minimizes the risk of slippage.

Conclusion

Textile yarn count is measured using a wrap reel machine. It makes it easy to take out an accurate 120-yard length from the cone. Using a wrap reel instrument, the controlled tension is a very important parameter. Because it directly affects the yarn length.

Airflow drift at higher speeds above 250 rpm, and skipping discard length parameters, can also alter the results. The modern wrap reel tester helps measure yarn count precisely using a servo-driven synchronous transmission system.

FAQs

Can an electric wrap reel instrument eliminate all count variation?

No, they only minimize the risk of slippage at higher numbers of turns and provide greater mechanical stability. Other parameters, such as environmental conditions, calibration, and careful operator handling, are still essential.

How can excessive winding speed influence yarn count results?

Rotational speeds above 250 rpm generate wind drift and increase dynamic tension, which can elongate the filament yarn and cause count variation.

Is a manual wrap reel still acceptable under ASTM D1907?

Yes, but results are highly dependent on the operator’s skill, reducing repeatability.

Related Resources

Wrap Reel

How to Test Yarn Length

Yarn Testing-A Complete Guide for Textile Labs and Manufacturers

Precision in Textiles: the Advantage of Using Yarn and Thread Counter