Evaluation of Yarn & Fabric Hairiness

Summary

This video discusses the concept of yarn and fabric hairiness, a significant factor in textile material evaluation. Hairiness is generally an undesirable property, as it negatively impacts fabric appearance, yarn strength, and production processes. However, in certain applications, hairiness can be beneficial for special effects or textures. The video explores various measurement techniques to assess hairiness, including the number and length of protruding hairs. It also covers the causes of hairiness, such as fiber maturity, uniformity ratio, and micronaire value, and their effect on yarn and fabric performance. Methods to reduce hairiness, like singeing and shearing, are also highlighted to ensure quality production.

Takeaways

• 😀 Hairiness is typically an undesirable property in yarn and fabric, as it affects appearance and performance.
• 😀 There are applications where hairiness is intentionally required, such as for special fabric effects or added warmth.
• 😀 Yarn and fabric hairiness can negatively impact the fabric’s appearance, creating a dull, uneven surface.
• 😀 Hairiness measurement depends on the method used, and different techniques can yield different results.
• 😀 The two main methods of measuring hairiness are counting the number of hairs protruding and measuring the total length of protruding hairs.
• 😀 It is important to choose the correct measurement technique, as comparing results from different methods may lead to confusion.
• 😀 Hairiness can vary based on factors such as yarn type, fiber maturity, and uniformity ratio of the fibers.
• 😀 Immature cotton fibers contribute to increased hairiness because they do not integrate well into the yarn structure.
• 😀 Higher fiber micronaire variability can cause hairiness, especially when coarse and fine fibers are mixed.
• 😀 High hairiness can reduce yarn strength, as protruding hairs do not contribute to the yarn's tensile strength.
• 😀 Hairiness can cause problems in the sizing process, leading to poor penetration of sizing agents and potential yarn breakage during weaving.

Q & A

What is yarn and fabric hairiness, and why is it significant?

Yarn and fabric hairiness refer to the protruding fibers on the surface of yarn or fabric. It is generally considered undesirable because it affects the fabric's appearance, making it dull, and can lead to problems during fabric production, such as increased breakage and poor strength.

In which applications is hairiness desirable?

Hairiness is desirable in certain fabric applications where a specific texture or effect is needed, such as velvet-like fabrics or those requiring extra warmth or softness.

What are the causes of yarn and fabric hairiness?

The primary causes of hairiness include the maturity of cotton fibers, uniformity ratio, micronaire values, and the type of yarn spun. Immature fibers, a mix of coarse and fine fibers, and low uniformity ratios tend to create more hairiness.

How does fiber maturity affect hairiness?

Immature cotton fibers do not properly integrate into the yarn structure, which results in these fibers remaining on the surface and contributing to increased hairiness.

What is the role of micronaire in hairiness?

Micronaire is a measure of fiber maturity and fineness. A wide range in micronaire values indicates a mixture of coarse and fine fibers, which can cause hairiness as the coarser fibers tend to protrude from the yarn surface.

How does the uniformity ratio affect hairiness in yarn?

A low uniformity ratio, which means a higher proportion of short fibers, leads to hairiness because the short fibers do not integrate well into the yarn structure and instead protrude from the surface.

What are the effects of hairiness on fabric strength?

Hairiness weakens the yarn's strength, as the protruding fibers do not contribute to the tensile strength. As a result, the yarn with more hairiness has a lower effective strength despite having the same linear density.

What challenges does hairiness create during fabric production?

Hairiness causes difficulties in the sizing process, leading to poor penetration of size material, increased friction during weaving, and a higher likelihood of yarn breakage. It can also damage machine parts like knitting needles and heald wires.

What are the different techniques for measuring yarn hairiness?

Hairiness can be measured by counting the number of hairs protruding from the yarn or by measuring the total length of these protruding hairs. However, each method has its limitations and must be carefully selected based on the specific requirements.

Why is it important to select the right hairiness measurement technique?

Selecting the right technique is crucial because different methods (e.g., counting hairs versus measuring their length) can yield different results. Understanding which method is used helps ensure accurate interpretation of the data and comparison between yarn samples.