Understanding D, T, and S in Sleeping Bag Fabrics

Key Fabric Terminology:

1. D – Denier
   1. Definition: Denier is a unit that measures the thickness of fibers or filaments. It refers to the weight (in grams) of 9,000 meters of a fiber at standard moisture content.
   2. Formula: Denier (D) = 9,000 * (Weight in grams) / Length (in meters).
   3. Purpose: A higher Denier number indicates thicker fibers.
   4. Example: If a fiber has a Denier of 40D, it means that 9,000 meters of this fiber weigh 40 grams.
   
2. Tex
   1. Definition: Tex is a metric unit used to measure the thickness of yarn or fiber. It represents the weight (in grams) of 1,000 meters of fiber.
   2. Formula: Tex = 1,000 * (Weight in grams) / Length (in meters).
   3. Purpose: Like Denier, a higher Tex number means thicker fibers.
   4. Conversion: 1 Tex = 9 Denier.
   5. Example: A fiber with a Tex of 20 means 1,000 meters of this fiber weigh 20 grams.
   
3. N – Metric Count (公制支数)
   1. Definition: This is a metric-based unit used to describe the fineness of yarn. It indicates how many meters of yarn weigh one gram.
   2. Formula: N = Length (meters) / Weight (grams).
   3. Purpose: Higher N values mean finer yarn (i.e., the yarn is lighter and longer per unit weight).
   4. Example: If a yarn has an N value of 100, it means that 1 gram of yarn is 100 meters long.
4. S – English Count (英制支数)
   1. Definition: This is an imperial-based unit used to measure the thickness of yarn. It specifies how many pounds of yarn are required to make 840 yards of the yarn.
   2. Formula: S = Length (yards) / (Weight (pounds) * 840).
   3. Purpose: Like N, higher S values represent finer yarn. It’s primarily used in the cotton industry.
   4. Example: A yarn with an S value of 30 means that 1 pound of yarn would stretch to 30 * 840 yards.

Fabric Composition Examples:

• 109/9665, 1/1
  • This means:
    • Warp yarn is 10 English count (S) yarn, and the weft yarn is 9 S.
    • The fabric has 96 warp threads and 65 weft threads per inch.
    • 1/1 weave: plain weave (every warp thread interlaces with every weft thread).
• 109/40D/9665, 2/1S Stretch
  • This means:
    • Warp yarn is 10 S, and the weft is 9 S, with 40 Denier stretch yarn (likely spandex or elastane) in the fabric.
    • 2/1S weave: a 2-up, 1-down twill weave (a diagonal pattern).
• 10/40D300D/40D/9665, 3/1Z Stretch
  • This means:
    • Warp yarn is 10 S, using a 40D spandex stretch yarn; the weft is 300 Denier synthetic fiber (e.g., polyester), with a 40D stretch yarn.
    • 3/1Z weave: a 3-up, 1-down twill weave with a Z twist (clockwise twist).
• 20/2(9 Long Bamboo + 10JC Plain)/9665, 5/3 Satin**
  • This means:
    • Warp yarn is a 2-ply 20 S yarn with specific twists.
    • The weft is a combination of 9 S long bamboo yarn and 10 S combed plain yarn.
    • 5/3 Satin weave: a satin weave where the warp yarns float over 5 weft threads and under 3, creating a smooth, shiny surface.

Important Conversions:

• 1 Denier (D) = 9 Tex
• 1 Tex = 1/9 Denier
• 1 Tex = 590.5/S (for cotton-like materials)
• 1 S = 590.5/tex (for cotton-like fibers)
• 1 N = 9000/D
• 1 N = 1000/tex

Summary:

• Denier (D) and Tex are used to describe the thickness of fibers, with Denier using 9,000 meters as the reference length and Tex using 1,000 meters.
• Metric Count (N) and English Count (S) refer to yarn fineness based on weight and length, with N being a metric unit and S being an imperial unit.
• Understanding these measurements helps in determining the fabric's texture, durability, and application, especially in specialized textiles like those used in sleeping bags or performance gear.