High Stretch, Low Stretch, Interlaced Yarn

1、All High-stretch, Low-stretch and Interlaced Yarns Belong to Textured Yarns

Polyester, nylon and polypropylene filaments are straight and smooth right after extrusion from spinnerets, feeling just like plastic threads. We call yarn in this state straight filament. To endow it with elasticity, bulkiness and warmth, we need to reshape the filament — this is how the textured yarn technology came into being.

Textured yarns fall into two main categories. Bulked yarn focuses on bulk and warmth, and acrylic bulked yarn is widely used for blankets and faux fur. Elastic yarn, by contrast, delivers stretch and extensibility. The high-stretch yarn, low-stretch yarn and interlaced yarn we are discussing today all belong to the elastic yarn family.

These three types of yarn are mainly made from polyester (polyester fiber) and nylon (polyamide fiber). Among all chemical fiber elastic yarns, polyester low-stretch yarn currently sees the largest consumption worldwide. Their core production process is false twist texturing: the filaments are heated, twisted like twisted ropes, and set before the twist is released. The fibers retain a spiral crimp structure, thus gaining stretch and recovery similar to springs.

To sum up simply: high-stretch yarn features superior elasticity, low-stretch yarn prioritizes wearing comfort, and interlaced yarn is designed to imitate wool texture. Though all three adopt false twist texturing, they are produced with different optimized technical parameters.

2、High-Stretch Yarn vs Low-Stretch Yarn: The Control Switch on Texturing Machine

High-stretch yarn and low-stretch yarn share the same origin, both classified as DTY. The full name of DTY is Draw Textured Yarn.

We first use polyester chips to spin POY (Partially Oriented Yarn) as the semi-finished product. Then we feed POY into the draw texturing machine. The yarn goes through drawing, false twisting and heat setting, and finally forms a crimped structure.

Now here comes the question: how do we produce high-stretch yarn and low-stretch yarn on the same texturing machine?

The answer lies in the small second heater box. The machine is equipped with two heater boxes. The first heater softens the yarn before twisting for easier processing. The second one provides additional heat setting after twisting and before untwisting.

When the second heater is turned on, extra heat treatment stabilizes the crimp structure. The yarn gains mild elasticity, so we get low-stretch yarn. When the second heater is off, the yarn cools and sets directly while fully twisted. It keeps tight crimps and delivers maximum elasticity, which is high-stretch yarn.

Besides elasticity difference, high-stretch yarn misses the second heat setting, so its crimp stability is inferior. It also has weaker resilience after long-term stretching. In terms of cost, high-stretch yarn involves fewer procedures and is therefore cheaper than low-stretch yarn.

3、Elasticity vs Bulk: Two Distinct Characteristics

High-stretch Yarn: Rebound Rate Over 300%

High-stretch yarn features an elongation recovery rate above 300%. It snaps back quickly after instant stretching. However, it has limited bulkiness. Its tight crimps take up little space in fabrics, so the material does not feel fluffy.

Low-stretch Yarn: Rebound Rate Below 50% for Balanced Performance

Low-stretch yarn normally has a rebound rate under 50% with moderate elasticity. It delivers a pleasant touch and comfortable wearing experience. It offers just the right stretch without tightness, and creates a soft, voluminous texture with good three-dimensional effect.

Material Application: Nylon High-stretch vs Polyester Low-stretch

Nylon is the primary material for high-stretch yarn, as it boasts better natural elasticity than polyester. By contrast, low-stretch yarn is mostly made of polyester, which enjoys large usage volume and cost advantages. As the most widely used chemical fiber elastic yarn across the globe, polyester low-stretch yarn is commonly applied to outerwear and home textiles.

To make it easier to understand: high-stretch yarn works like sturdy elastic bands with extreme stretch and large deformation. Low-stretch yarn is similar to slightly elastic sponges, featuring mild stretch and a soft, fluffy feel.

4、Interlaced Yarn: Combination of High-Stretch and Low-Stretch Yarns

Interlaced yarn is a versatile member in the elastic yarn family. It is not a standalone type apart from high-stretch and low-stretch yarns. Instead, we process regular high-stretch or low-stretch yarns with an extra air interlacing step. Compressed air jets hit the filament bundle and twist individual filaments into regular interlaced knots, just like small ties spaced along the yarn.

These knots bring distinct strengths. They greatly improve cohesion between filaments, so the yarn rarely splits or sheds lint. We can even weave it directly without additional twisting or sizing. Based on knot density, interlaced yarn falls into three grades: non-interlaced, light-interlaced and heavy-interlaced. Non-interlaced yarn has no knots and pulls apart easily. Light-interlaced yarn features plenty of loose knots that come undone under tension. Heavy-interlaced yarn has tight, firm knots and stays intact when stretched.

Interlaced yarn is best known for wool-like fabrics. Ordinary polyester filament fabrics tend to feel plasticky. Thanks to the interlaced knots, fabrics made from interlaced yarn deliver soft luster and full hand feel, and resist pilling and fuzzing. They closely resemble wool textiles. Polyester DTY interlaced yarn ranges from 50D to 600D in specification, and sees wide use in suits, shirts, curtains, bed covers and sofa fabrics.

5、Comparison of High-Stretch Yarn, Low-Stretch Yarn and Interlaced Yarn

In terms of elasticity, high-stretch yarn delivers the strongest stretch with a recovery rate over 300%. Low-stretch yarn offers moderate elasticity, and its recovery rate is generally below 50%. As for interlaced yarn, its elasticity sits between the two, which mainly depends on its base yarn. Specifically, interlaced yarn made from low-stretch base features similar elasticity to regular low-stretch yarn.

When it comes to bulk and hand feel, high-stretch yarn has average bulk and a firm touch. Low-stretch yarn is fluffy, soft and full to the touch. Interlaced yarn falls in the middle — it is fluffy yet compact with a prominent wool-like texture.

For anti-pilling performance and durability, high-stretch yarn boasts high tenacity and excellent wear resistance. Low-stretch yarn has moderate tenacity and good service life. Thanks to the binding effect of interlaced knots, interlaced yarn hardly pills or fuzzes up.

In application scenarios, high-stretch yarn is widely used for stretch jeans, swimwear, elastic socks, shapewear and compression sportswear. Low-stretch yarn works well for knitted outerwear, T-shirts, casual pants, curtain fabrics, sofa covers and bedding products. Interlaced yarn is ideal for wool-like overcoats, linen-look fabrics, suits and high-end women’s apparel.

In terms of raw materials, high-stretch yarn is mainly produced from nylon. By contrast, polyester serves as the dominant material for both low-stretch yarn and interlaced yarn.

6、Conclusion

The outstanding elasticity of high-stretch yarn, the soft bulk of low-stretch yarn and the wool-like texture of interlaced yarn all come from reshaping synthetic fibers via heat and mechanical force.

High-stretch yarn focuses on extreme stretch and a snug fit, so it perfectly supports every movement during sports. Low-stretch yarn delivers balanced elasticity and superior comfort, ideal for daily leisure and relaxation. As a master of simulation among chemical fibers, interlaced yarn creates premium wool-like feel with its interlaced knots.