Polyester core spun yarn is gaining popularity across textile industries for its superior strength, durability, and versatility. While traditionally used in sewing threads and denim production, its use in knitting and circular knitting applications is now expanding.

This article explores whether polyester core spun yarn is suitable for knitting and circular knitting, and what advantages it offers in these areas.

1. What Is Polyester Core Spun Yarn?

Polyester core spun yarn is a composite yarn consisting of a continuous filament polyester core surrounded by a sheath made of natural or synthetic staple fibers—typically cotton, viscose, or polyester.

• Core (polyester filament): Provides strength, elasticity, and dimensional stability.

• Sheath (staple fiber): Offers softness, comfort, dyeability, and a textile-like appearance.

This unique structure combines the best properties of filament and spun yarns, making it suitable for demanding textile processes.

2. Knitting vs. Circular Knitting – A Quick Overview

• Flat Knitting: Produces flat fabric panels using needles aligned in a straight bed. Common in sweaters and fashion knits.

• Circular Knitting: Uses a rotating cylinder with multiple needles to produce tubular fabrics. Used in t-shirts, innerwear, sportswear, etc.

Both require yarns with:

• High uniformity

• Good elongation

• Low hairiness

• Consistent dyeing performance

• Sufficient softness and flexibility

3. Is Polyester Core Spun Yarn Suitable for Knitting?

Yes, and Here's Why:

A. Excellent Yarn Strength and Tenacity

The polyester filament core provides superior tensile strength. This is especially beneficial for knitting machines, which operate at high speeds. It reduces yarn breakage, resulting in:

• Fewer machine stops

• Increased productivity

• Lower wastage

B. Low Hairiness

Compared to 100% spun yarns, core spun yarns have lower surface hairiness, which results in:

• Smoother fabric surfaces

• Better pilling resistance

• Reduced needle clogging in circular knitting machines

This ensures longer machine run-times and higher knitting quality.

C. Uniform Yarn Structure

The uniform construction of polyester core spun yarn contributes to even stitch formation, leading to:

• Improved loop regularity

• Stable fabric GSM (grams per square meter)

• Less fabric distortion during post-processing

D. Good Elasticity and Dimensional Stability

The filament core offers higher elongation at break and excellent recovery. This is ideal for knitwear that undergoes stretching, such as:

• Sportswear

• Undergarments

• Compression garments

The yarn helps fabrics maintain their shape after repeated wear and washing.

E. Soft Hand Feel

Though polyester filaments can feel synthetic, the staple fiber sheath offers the comfort and softness needed in garments. Especially when the sheath is cotton or viscose, the fabric becomes pleasant to wear and breathable.

F. Consistent Dyeing Results

The outer layer determines the fabric’s dye affinity. Polyester core spun yarns made with cotton or viscose sheaths dye well with reactive or disperse dyes, producing vibrant and consistent colors suitable for fashion applications.

4. Applications of Polyester Core Spun Yarn in Knitting

5. Why Polyester Core Spun Yarn Excels in Circular Knitting

Circular knitting machines require yarns that behave predictably under continuous tension and speed. Polyester core spun yarn fits this requirement due to:

• Minimal yarn lapping or snarling

• Excellent heat resistance, enabling smoother fabric processing

• Compatibility with high-speed circular knitting machines (e.g., 24-feeder, 30-feeder machines)

It is especially useful in:

• Interlock and rib structures

• Single jersey fabrics

• Engineered mesh and breathable fabrics

6. Blending Options to Enhance Performance

Polyester core spun yarns can be blended with various sheath materials depending on end-use: