Crimp

Definition and Overview

Crimp refers to the state in which fibers or yarn are not straight but finely crinkled or wavy. In addition to the natural crimp inherent in natural fibers, crimp can also be imparted to synthetic fibers through processing, and it becomes a factor that adjusts the properties of yarn and textile.

In synthetic fibers, yarns given crimp through processing such as false twisting are used. In particular, highly crimped yarn easily holds air inside the yarn, making it a material that allows lightness, loft, and stretch to be designed more easily by taking advantage of the force that tries to return after extension.

Hand and Function

Yarn with crimp creates spaces between fibers, so it generally tends to have a voluminous, soft hand. By including air layers, it may also feel lighter than its apparent thickness suggests.

Crimp is related to the stretch and recovery of the yarn itself. In knitted fabrics and tricot, it is used to supplement stretch and rebound, either without polyurethane or in combination with it. However, the actual stretch recovery rate is also affected by the knit structure, density, and blend ratio.

The appearance varies depending on the degree of crimp and the thickness of the yarn. Fine shadows and loft may appear on the surface, or it may act inside the textile and result in a relatively smooth appearance.

Main Applications

Materials using highly crimped yarn are used for cut-and-sew items, sportswear, innerwear, pants, outerwear, and other items that require ease of movement, light weight, and loft. They are also used in textiles that need to reduce sheerness even when thin, and in knitted materials with a three-dimensional look.

When making use of air layers that contribute to warmth retention, they are suitable for autumn and winter materials, but they are also used in lightweight materials that take advantage of lightness and a dry touch against the skin. Applications are not determined by the presence or absence of crimp alone; the type of fiber, fabric weight, structure, and finishing process are considered together.

How to Choose and Handling Precautions

When selecting a material, confirm not only the strength of the crimp but also the required stretch direction, rebound, thickness, fabric weight, and surface texture. For products that require stretch, it is important to confirm not only stretch during wear but also dimensional change after repeated stretching through testing and prototyping.

Textiles made with crimp yarn may change in dimensions and hand due to washing or heat. Before mass production, carry out a washing test and confirm shrinkage and appearance changes, then consider pattern settings and care labels.

In sewing, when the textile stretches well, seam puckering and waviness may occur. Align the grain and cut accordingly, choose sewing specifications, sewing thread, needles, and feeding conditions that suit the stretch of the textile, and allow sufficient relaxation time before and after sewing.

Differences from Similar Terms

Crimp is a term that describes the form of crinkling in fibers or yarn, and it is not the name of a fabric structure. Stretch refers to the overall performance of a textile in terms of extensibility, and crimp is one of the factors that creates that performance. Its elasticity from polyurethane uses a different mechanism of stretch and recovery.

High-twist yarn is yarn given strong twist, and it is related to a crisp touch and a textured surface feel. Crimp, on the other hand, is related to the wavy structure of the fiber. The two are sometimes combined, but they do not mean the same thing.

Frequently Asked Questions