Core-Spun Thread

Core-spun thread—sometimes referred to as "polyester core-spun thread," "polyester core thread," or "cotton-wrapped core thread"—is produced by wrapping staple polyester or cotton fibers around a continuous filament polyester core during the spinning process and then plying these yarns together to form the sewing thread. The continuous filament polyester core accounts for approximately 60% of the thread's structure. This core contributes to:

• 1. Higher strength-to-size ratio (greater tenacity)

• 2. Greater uniformity in size, strength, and other physical properties

• 3. Higher initial modulus (resistance to stretching), facilitating better stitch formation and reducing puckering during sewing

• 4. Better ply stability—reducing ply separation

• 5. Excellent abrasion resistance and durability

The core of the thread consists of high-tenacity continuous filament polyester designed specifically for sewing threads. The sheath provides a fibrous surface, offering the following advantages:

• A softer hand-feel compared to 100% continuous filament threads

• A matte finish similar to spun polyester threads

• Superior frictional characteristics compared to continuous filament threads

• Polyester sheath contributes to:

o Excellent color fastness, chemical resistance, and abrasion resistance

o Higher strength compared to cotton-wrapped core-spun threads

o Superior "solid-shade dyeing" performance due to a one-step dyeing process

• Cotton sheath contributes to:

o Excellent resistance to needle heat

o A sewing finish that mimics a washed look