What are the technical advantages of an spandex double-covered yarn machine compared to a single-covered yarn machine?

1. Comprehensive Upgrade of Product Performance

1. Elastic response rate improved by 15%-20%

2. The double-coating uses a symmetrical structure of "S-twist + Z-twist," achieving an elastic recovery rate of over 95% (compared to about 85% for single-coating). For example:

   • After being stretched five times (with a 30% elongation rate), the deformation rate of the double-covered yarn in the sportswear fabric remained ≤3%, while the single-covered yarn showed a deformation rate of 5%-8%.

   • After wearing for 12 hours, the double-covered stockings maintained a 90% recovery rate at the leg opening, while the single-covered ones retained only 75%.

3. Significantly improved dimensional stability

    

   The residual torsion of double-covered yarns is reduced by 60% compared to single-covered yarns, and the fabric shrinkage after washing drops from 3%-5% to 1%-2% (tested according to GB/T 8628-2013 standards), effectively addressing the industry's longstanding issue of "post-wash deformation" commonly seen in single-covered products.

4. Improved surface finish and wear resistance

    

   Two outer yarns are interwoven and wrapped together to form a dense structure, reducing pilling by 40% (test standard: GB/T 14342-2008) and improving abrasion resistance by 25% (Martindale abrasion tester: double-wrapped yarns withstand up to 5,000 cycles without damage, while single-wrapped yarns last approximately 4,000 cycles).

II. Production Efficiency and Cost Advantages

1. Single-machine capacity doubles, saving 50% of the floor space.

    

   The actual production capacity of a single 48-spindle double-coating machine is equivalent to two 48-spindle single-coating machines (with the double-coating machine achieving a single-spindle speed of 150 meters per minute, while each single-coating machine also operates at 150 meters per minute). Importantly, under the same factory floor space, this setup boosts productivity by 100%.

2. Roll capacity increased by 20%-30%

    

   Using edgeless forming technology, the double-coated yarn package can weigh up to 3.5–4 kg (compared to about 3 kg for a single-coated machine), reducing the number of roll changes by 20%. This makes it ideal for continuous production equipment such as large circular knitting machines and warp knitting machines, helping to minimize non-productive downtime.

3. Overall energy consumption reduced by 15%

    

   The double-coating machine optimizes its transmission structure—replacing the oil-bath gearbox with a two-stage transmission, for instance—reducing the power consumption per spindle from 0.25 kW in the single-coating machine to 0.2 kW. As a result, the 48-spindle unit sees an annual electricity reduction of approximately 15,000 kWh, calculated based on 300 days of operation per year.