How to Select the Actual Yarn Count for Required GSM

Selecting the appropriate yarn count for a required GSM (grams per square meter) is crucial in textile manufacturing, as it directly influences the fabric's weight, thickness, and quality. Understanding the relationship between yarn count, GSM, and fabric construction ensures the production of textiles that meet specific performance and aesthetic requirements.

Key Factors in Selecting Yarn Count

1. Fabric Type and Construction
• Determine the type of fabric (knit, woven, or non-woven) and its construction details (e.g., single jersey, interlock, twill, or plain weave).
• Understand the desired fabric density and texture, as these are influenced by the yarn count and construction.
2. Desired GSM
• GSM represents the weight of fabric per square meter and is a measure of its thickness and density.
• Higher GSM typically indicates a heavier and thicker fabric, while lower GSM results in lighter and thinner textiles.
3. Yarn Properties
• Yarn count refers to the thickness or fineness of the yarn, commonly measured in Ne (English count) or Tex.
• Finer yarns (higher count) produce lighter fabrics, while coarser yarns (lower count) result in heavier fabrics.
4. End-Use Requirements
• Consider the fabric’s end use, such as durability, comfort, and breathability. For instance, sportswear requires lightweight and breathable fabric, while winter clothing may need thicker, heavier textiles.

Steps to Determine the Yarn Count

1. Calculate the Stitch Density (Knits)
• For knitted fabrics, GSM is influenced by stitch length, loop density, and yarn count.
• Use the formula:

​GSM = Stitch Density × Stitch Length × Yarn Count Factor

​Where Stitch Density = (Course per inch × Wales per inch).

2. Determine the Fabric Weight Factor (Wovens)
• For woven fabrics, the warp and weft yarn counts, fabric width, and picks/inch or ends/inch are crucial.
• Use empirical GSM calculators or software tools to input these parameters and deduce the ideal yarn count.
3. Experiment with Prototypes
• Produce fabric samples with varying yarn counts to achieve the desired GSM while maintaining the required feel and quality.
4. Adjust for Shrinkage and Finishing
• Account for shrinkage during washing or finishing processes, as these can alter the GSM.
• Finishing treatments like brushing, compacting, or calendaring also impact the final weight.

Practical Example

• Requirement: Single jersey fabric with 160 GSM.
• Steps:
1. Determine the stitch density (e.g., 28 courses/inch and 24 wales/inch).
2. Select an initial yarn count, such as Ne 30/1.
3. Adjust the stitch length (e.g., 2.7 mm) to meet the GSM.
4. Test and refine by producing a prototype.

Tools and Resources

• GSM Testing Equipment: Use a GSM cutter and weighing scale to measure sample weights accurately.
• Yarn Count Calculators: Digital tools simplify the relationship between yarn count and GSM.
• Industry Standards: Follow ASTM or ISO standards for fabric weight and quality specifications.

Conclusion

Selecting the right yarn count for the required GSM involves a balance of technical knowledge, practical testing, and attention to detail. By considering fabric construction, yarn properties, and end-use requirements, manufacturers can achieve the desired fabric characteristics, ensuring quality and customer satisfaction.