How to measure the absorbency rate of cotton yarn?

As a cotton yarn supplier, understanding the absorbency rate of cotton yarn is crucial. It not only affects the quality of the end - products but also helps our customers make informed decisions. In this blog, I'll share some methods to measure the absorbency rate of cotton yarn.

Importance of Measuring Absorbency Rate

The absorbency rate of cotton yarn is a key factor in various applications. For instance, in the textile industry, yarns with high absorbency are ideal for making towels, bathrobes, and other absorbent products. In the medical field, absorbent cotton yarn is used for bandages and wound dressings. By accurately measuring the absorbency rate, we can ensure that our Macrame Yarn, Combed Cotton Yarn, and Mercerized Cotton Yarn meet the specific requirements of different industries.

Methods for Measuring Absorbency Rate

Gravimetric Method

The gravimetric method is one of the most common ways to measure the absorbency rate of cotton yarn. This method is based on the principle of weighing the yarn before and after it absorbs water.

1. Preparation
   • First, select a representative sample of cotton yarn. Cut the yarn into small pieces of a consistent length, usually around 10 - 20 cm. This ensures that the sample is uniform and the results are reliable.
   • Weigh the dry yarn sample accurately using a high - precision balance. Record this weight as (W_1).
2. Absorption Process
   • Immerse the dry yarn sample in distilled water at room temperature (around 20 - 25°C). Make sure the yarn is completely submerged and there are no air bubbles trapped.
   • Leave the yarn in the water for a specific period, typically 30 minutes to 1 hour. This allows the yarn to reach its maximum water - absorbing capacity.
3. Weighing the Wet Yarn
   • After the soaking time is over, carefully remove the yarn from the water. Let it drain for a short period (about 1 - 2 minutes) to remove excess surface water.
   • Weigh the wet yarn immediately. Record this weight as (W_2).
4. Calculation
   • The absorbency rate ((AR)) can be calculated using the following formula:
     [AR=\frac{W_2 - W_1}{W_1}\times100%]
   • For example, if the dry weight (W_1 = 5) grams and the wet weight (W_2 = 12) grams, then the absorbency rate is (\frac{12 - 5}{5}\times100%=140%).

Capillary Rise Method

The capillary rise method measures the ability of cotton yarn to draw water upwards through capillary action.

1. Apparatus Setup
   • Prepare a vertical glass tube with a small diameter (about 1 - 2 mm). Fill the tube with distilled water.
   • Attach one end of the cotton yarn sample to a fixed support above the water surface in the tube. Make sure the other end of the yarn just touches the water surface.
2. Measurement
   • As the water is drawn up the yarn by capillary action, measure the height ((h)) that the water rises in a given time ((t)). This can be done using a ruler or a scale marked on the glass tube.
   • The capillary rise rate ((CRR)) can be calculated as the ratio of the height of water rise to the time elapsed, i.e., (CRR=\frac{h}{t}). A higher capillary rise rate indicates better absorbency of the yarn.
   • For a more accurate measurement, repeat the experiment several times and take the average value.

Dye Penetration Method

The dye penetration method can also provide an indication of the absorbency rate of cotton yarn.

1. Dye Solution Preparation
   • Prepare a dilute dye solution, such as a solution of methylene blue in water. The concentration of the dye should be relatively low, around 0.1 - 0.5%.
2. Testing
   • Immerse one end of the cotton yarn sample in the dye solution. Observe how far the dye penetrates the yarn over a certain period (e.g., 10 - 15 minutes).
   • Measure the length of the dyed portion of the yarn. A longer dyed length indicates better absorbency as the dye is carried along with the water absorbed by the yarn.

Factors Affecting Absorbency Rate

Several factors can affect the absorbency rate of cotton yarn:

1. Fiber Structure
   • The structure of the cotton fibers in the yarn plays a significant role. Yarns made from longer and finer cotton fibers generally have a higher absorbency rate. Longer fibers provide more surface area for water absorption, and finer fibers have more pores and channels for water to penetrate.
2. Yarn Twist
   • The degree of twist in the yarn can also impact absorbency. A lower twist allows more space between the fibers, which facilitates water absorption. However, too low a twist may result in a weaker yarn.
3. Finishing Treatments
   • Chemical finishing treatments such as mercerization can change the absorbency of cotton yarn. Mercerized cotton yarn usually has a smoother surface and better luster, but its absorbency may be slightly lower compared to untreated yarn due to the partial closure of fiber pores during the mercerization process.

Quality Control and Assurance

As a cotton yarn supplier, we conduct regular quality control checks on the absorbency rate of our products. We test samples from each production batch to ensure consistency and compliance with industry standards.

1. Sampling Plan
   • We follow a strict sampling plan to select representative samples from different parts of the production lot. This helps to minimize sampling errors and obtain accurate results.
2. Documentation
   • All test results are carefully documented. This includes the sample details, test methods used, and the calculated absorbency rates. The documentation serves as a record for quality control and can be provided to customers upon request.

Conclusion

Measuring the absorbency rate of cotton yarn is an essential part of our business as a supplier. By using methods such as the gravimetric method, capillary rise method, and dye penetration method, we can accurately assess the absorbency of our Macrame Yarn, Combed Cotton Yarn, and Mercerized Cotton Yarn. Understanding the factors that affect absorbency and implementing strict quality control measures ensure that we can provide high - quality cotton yarn that meets the diverse needs of our customers.

If you are interested in purchasing our cotton yarn products, we invite you to contact us for further discussion. We can provide detailed information about the absorbency rates and other quality parameters of our yarns. Our team of experts is ready to assist you in finding the most suitable cotton yarn for your specific applications.

References

• Morton, W. E., & Hearle, J. W. S. (1993). Physical Properties of Textile Fibres. Woodhead Publishing.
• Textile Institute. (2009). Handbook of Yarn Production: Spun and Filament Yarns. Woodhead Publishing.