I. Process Principles and Production Process Differences
1. Air-Wrapped Yarn:
- Using air-spinning technology, short fibers (such as cotton and polyester) are wrapped around the surface of filaments (such as spandex) using high-pressure air, forming a "core-sheath structure."
- Typical parameters: Air pressure must be controlled between 0.3-0.6 MPa (data source: Journal of Textile Research, 2021 study), and fiber coverage can reach over 80%.
- Advantages: No physical twisting is required, reducing fiber damage and resulting in a softer finished yarn.
2. Mechanical Yarn:
- Relying on traditional ring or rotor spinning machinery, twisting is used to tightly enwrap the fibers. For example, the twist in ring spinning is typically 600-800 twists/meter (see the Textile Industry Technical Handbook).
- Disadvantages: The high twist makes the yarn stiff, but the breaking strength is 15%-20% higher than that of air-wrapped yarn.
II. Structure and Performance Comparison
1. Appearance and Touch:
- Air-covered yarn has a fluffy, downy surface and is suitable for skin-friendly clothing (such as underwear and sportswear);
- Mechanical yarn has a smooth surface and a compact structure and is commonly used in industrial applications such as canvas and tire cord.
2. Elasticity and Strength:
- Air-covered yarn can achieve an elastic elongation of 150%-200% (when containing a spandex core), but has lower strength;
- Mechanical yarn has insufficient elasticity (elongation is typically <10%), but offers superior abrasion resistance.
III. Application Scenarios and Market Trends
1. Cost and Efficiency:
- Air-covered yarn has a faster production speed (up to 450 m/min), but requires higher equipment investment;
- Mechanical yarn equipment is widely available, with a cost per ton approximately 20%-30% lower.
2. Emerging Demand:
- Environmental trends are driving the development of air-wrapped yarns due to their higher utilization of recycled fibers.
- Mechanical yarns remain irreplaceable in high-performance applications such as automotive seat belts and ballistic materials.