Yarns in Seamless Technology

Introduction

In this tutorial we will cover the basics about yarns: how yarn is formed, which yarns work best for seamless and circular technology, how to choose the best yarn and best practice.

Read along and become an expert in yarns.

Yarns are the basic element a textile material is made of, specially for seamless and circular knitting, these are manipulated by the machine while knitting to form a textile. According to the Merriam-Webster dictionary, yarn is defined as: “A continuous often plied strand composed of either natural or man-made fibers or filaments and used in weaving and knitting to form cloth.”

There are two different configurations of textile fibers and these depend on the way the yarn is spinned: 

• Staple fibers: staple fibers are short-length fibers, like cotton and wool, and require spinning and twisting together in order to produce a good fiber length with good strength.
• Filament fibers: this is a fiber of indefinite length, like silk, and required to be combined with other fibers in order to produce a sufficient amount.

Human kind started creating fibers using natural sources, both animal and vegetable, such as wool, silk, cotton or flax. It was during the industrial revolution that the first artificial fibers were created, the first ones to appear were the rayons, made with long-chain polymers found in wood pulp and cotton linters. In 1938 Wallace H. Carothers created the first synthetic fiber: the Nylon, based on a synthetically-built long-chain polyamide polymer. It was during the late 1960s to the mid 1970s that the demand for synthetic fibers exploded. 

Ever since, with the help of new technologies and the market demand, many other fibers have been developed until this day including synthetic fiber polymers, polyesters and polyacrylics and the most recent bio-based fibers of all kinds.

The benefits of the synthetic polymers is that they can be made into yarns in continuous filament form, but they can also be cut or broken into staple fiber form and be spun on machines made for natural fibers such as wool or cotton.

Textile fibers can be categorized in two groups: natural and man-made. Natural fibers are grouped into the following subcategories: vegetable, animal and mineral. As man-made fibers can be divided into natural polymers, synthetic polymers and inorganic subcategories.

Vegetable and animal fibers are made of natural polymers, which are composed of large molecules: multiples of simpler chemical units called monomers that are bonded together. They are the basic components of minerals, vegetables, and man-made products:

Once the fibers are interlocked thru a spinning or winding process they form a linear textile structure called yarn. Yarns can be single or folded and can be divided in the following categories:

The yarn count number represents the linear density or fineness of a specific yarn resulting from its spinning process. When selecting a yarn count, an essential factor to consider is the machine gauge, which determines the needle spacing on the needle bed, typically measured as needles per inch. The finer the machine gauge, the finer the required yarn count.

The yarn count defines the cost, opacity, drapability, weight and other characteristics of the yarn. 

There are different yarn counting systems in the market, which are linked to the spinning process. If you work with a yarn that was spinned in a worsted system it must probably use the worsted counting system.

The worsted count system:

The worsted count system is a method used to measure the fineness or thickness of worsted yarns. It is commonly used in the textile industry to express the yarn's linear density. In this system, the count is defined as the number of 560-yard (or 560 meters) hanks that weigh one pound (or one kilogram). The higher the count number, the finer the yarn, and vice versa.

For example, if a worsted yarn is labeled as 40s worsted, it means that 40 hanks of 560 yards each would weigh one pound. A finer yarn, such as 80s worsted, would require 80 hanks of the same length to weigh one pound. In general, higher worsted count numbers indicate finer and more delicate yarns, while lower count numbers represent thicker and heavier yarns.

The denier count system:

This is another method used to measure the fineness of yarn or fibers, particularly in the context of synthetic fibers. It is commonly used to express the linear density of filament yarns, which are continuous strands of fibers, in the textile industry.

Denier is defined as the weight in grams of a 9,000-meter (or 9-kilometer) length of the yarn or fiber. A lower denier number indicates a finer and lighter yarn or fiber, while a higher denier number signifies a thicker and heavier one. For example, a 20-denier yarn is finer and lighter than a 40-denier yarn.

The denier count system is particularly relevant when dealing with synthetic fibers like nylon, polyester, and polypropylene, where the denier value helps classify the fiber's thickness and properties. It is widely used in the production of hosiery, apparel, and various other textile applications.

The tex system:

The tex system was designed to be a universal replacement for all existing systems. To address the occasional occurrence of decimal points in the count numbers, it has been found more practical to multiply the count by 10, resulting in a deci-tex number. However, the tex system has not been universally embraced, especially for spun yarns. In Europe, the metric system is commonly used for measuring these yarns instead.

Current technology allows us to integrate two or more different types of fibers either in the spinning process or knitting process, in this way we incorporate the characteristics of each fiber as well, developing unique materials, tailor them down to the specific needs of a project.

Because the knitting process needs fine, smooth, elastic but also strong yarns, the worsted spinning process has proven to be suitable for this, this is a process that uses long-staple fibers to produce fine yarns, which later can be used to knit lightweight fabrics for knitwear, outerwear, activewear, socks and underwear.

Seamless technology is known for being able to develop the most intricate and unique textiles, and everything starts from the yarn-up. Knowing how to select the best yarns for this type of technology is key in order to create the best developments. It is worth noting that any type of yarns can be used with seamless and circular technology, as long as the yarn count and the production process matches.

In seamless technology the yarn count is selected according to the machine gauge:

Conclusion:

Working with yarns is the fundamental base of any knitted development. Yarns provide not only the texture, color and thickness to our projects, but also unique characteristics that, when used well, can be reflected in innovative applications.

To learn more about compatible yarns for seamless technology visit our dedicated yarn library here. Stay in touch to learn more about the latest yarn innovations.

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