Covering Yarn

Definition and Overview

Covering yarn is a yarn constructed by wrapping a core buttonhole thread with an outer covering thread. The core thread is often an elastic thread, and the covering thread is often nylon or polyester. Materials and thickness are combined according to the application.

A yarn wrapped with a single covering thread is called single covering, while one wrapped with covering threads from two directions is called double covering. The latter more easily covers the core thread and is used when improving appearance and hand feel.

Features

When an elastic core thread is used, covering yarn can give the fabric stretch and recovery while also providing the surface texture of the covering thread. Because the core thread is less likely to touch the skin directly, it is also useful in designs that consider skin feel and appearance.

Luster, a smooth feel, and resistance to fuzzing are mainly affected by the type and processing of the covering thread. On the other hand, stretch recovery, a snug feel, and durability need to be evaluated together with the type of core thread, covering ratio, knitting structure, and density.

• Single covering is a structure that makes it relatively easy to achieve lightness and softness.
• Double covering is considered for applications that suppress exposure of the core thread and seek a uniform surface feel.
• Even with the same covering yarn, its properties change depending on the material, thickness, and winding density of the core thread and covering thread.

Main Applications

It is used in socks, stockings, innerwear, lingerie, leggings, and similar items where both stretch and surface feel are required. In clothing worn close to the skin, the material and smoothness of the covering thread affect comfort.

It is also used for swimwear, sportswear, and fitted tops and bottoms. From thin items that follow the body to items that require moderate hold, suitability varies depending on the yarn design and fabric structure.

Selection and Handling Notes

When selecting, check not only the yarn structure but also the fabric's stretch ratio, stretch recovery, fabric weight, sheerness, and abrasion durability. It is also important to confirm core thread exposure, surface fuzz, and the appearance of whitening or shine during wear in prototype fabrics and finished products.

Reactions to heat and chemicals differ depending on the constituent materials. Washing, drying, and ironing conditions should be set based on the product's care label and fabric testing. In particular, high heat may affect the core thread that provides stretch, so avoid excessive heat treatment.

In sewing, select a stitch specification, thread, and needle that can follow the fabric's stretch. To prevent seams from breaking because they do not stretch, waviness caused by presser foot pressure or feed differential, and fabric laddering around needle holes, perform sewing tests before mass production.

Differences from Similar Terms

Core spun yarn is also a composite yarn made of a core thread and sheath threads, but it generally refers to yarn made by spinning short fibers around the core thread. By contrast, covering yarn is a term that emphasizes a structure in which another filament yarn or similar yarn is wrapped around the core thread.

Textured yarn is a processed yarn that gives filament yarn bulk and stretch. Covering yarn does not refer to a processing method, but to the yarn structure that combines a core thread and a covering thread.

Frequently Asked Questions