Moisture content in yarns, conditioning of cashmere yarns (natural yarns and fine yarns)
All
textile fibers tend to absorb moisture from their environment. Determining the moisture content of textile fibers is a parameter of paramount commercial importance. Wool fiber, for example, can absorb up to 30% by weight of water without any tactile change compared to the fiber under hygrometric equilibrium conditions.
It is clear that in a commercial transaction of a quantity of hygroscopic textile fiber (all fibers in general), the mass of the material found by simple weighing cannot represent the "commercial weight" that should be subject to economic quotation.
Many factors influence yarn moisture, including temperature and the internal and external humidity of the premises where they are stored. Yarns can decrease or increase in weight based on the moisture they have absorbed or lost, even during transport from supplier to customer. In winter, the yarn will have a noticeable, but not excessive, increase in weight, the opposite in summer when the temperature is warmer and the climate drier.
A bobbin of yarn can vary by as much as 2, 3, or even 5% in weight from one day to the next based on changes in the air humidity level in its storage location.
For the scouring of pure Cashmere yarns, it is very important that the processing takes place in an environment with controlled temperature and humidity. When temperature and humidity are not controlled in the workplace, a high number of breakages can occur, even compromising the success of the scouring.
The physical-mechanical characteristics of textile fibers are varied, such as fineness, thermal stability, felting, insulation, tenacity, elongation and breaking, elastic resistance, etc.
Among these, the hygroscopicity of the textile material is very important.
Hygroscopicity is the ability of a textile fiber to absorb moisture from the environment.
Natural fibers, in particular, have a certain degree (percentage) of moisture.
It is measured based on the maximum percentage of water that the fiber can absorb without appearing wet.
Wool and alginic fibers are the most hygroscopic.
For example, wool can absorb up to 33% of its weight without feeling wet.
Related to hygroscopicity is the regain rate, which represents the maximum percentage of water a fiber can contain to be commercialized. It is measured as a percentage of the dry weight of the material, meaning the amount of water absorbed at 20°C by 100 g of fiber, previously dried, then exposed for one hour to 65% humidity. Law 883 of 26.11.73 (and subsequent amendments - Directive 96/74/CE) defines the conventional values.
Moisture can vary from 18% for wool to 1.5% for synthetic fibers like polyester.
For example, silk has a regain rate of 11% and a moisture content of 9.91%, while worsted wool has a rate of 18.25% and a moisture content of 15.43%.
It is important to ensure that yarns have constant and uniform moisture, as the varying quality of raw materials and different environmental conditions in which the yarn is produced mean it is never in optimal moisture conditions.
When the yarn passes from the spinning phase to the subsequent processing phase, it is essential to control the yarn's moisture, verifying its regain rate by treating it in such a way as to ensure conventional values.
The system for conditioning the yarn consists of introducing it into special regain chambers where the yarn is subjected to humidification treatment with particular precautions.
To build a chamber, it is essential to remember that the absorption of moisture by a textile fiber occurs in 3 distinct phases: the first rapid and superficial, the second slower and deeper, the third of diffusion by means of osmotic absorption of water that spreads within the fiber itself, penetrating intimately and reaching all pores and capillary channels.
For these reasons, the regain chambers must ensure contact of the fiber with air humidity and not directly with water, because the yarn would become too wet and only superficially so, with an excessive increase in humidity, which would result in non-uniform humidification of the yarn.
The advantages obtained with good moisture regain are not only to ensure a certain constant weight in yarn packages but, above all, to improve the technical characteristics of the fiber. Furthermore, the yarn will be in ideal conditions to make it much easier to work with.
Hircus Filati
Moisture content in yarns, conditioning of cashmere yarns (natural yarns and fine yarns)
All textile fibers tend to absorb moisture from their environment. Determining the moisture content of textile fibers is a parameter of paramount commercial importance. Wool fiber, for example, can absorb up to 30% by weight of water without any tactile change compared to the fiber under hygrometric equilibrium conditions.
It is clear that in a commercial transaction of a quantity of hygroscopic textile fiber (all fibers in general), the mass of the material found by simple weighing cannot represent the "commercial weight" that should be subject to economic quotation.
Many factors influence yarn moisture, including temperature and the internal and external humidity of the premises where they are stored. Yarns can decrease or increase in weight based on the moisture they have absorbed or lost, even during transport from supplier to customer. In winter, the yarn will have a noticeable, but not excessive, increase in weight, the opposite in summer when the temperature is warmer and the climate drier.
A bobbin of yarn can vary by as much as 2, 3, or even 5% in weight from one day to the next based on changes in the air humidity level in its storage location.
For the scouring of pure Cashmere yarns, it is very important that the processing takes place in an environment with controlled temperature and humidity. When temperature and humidity are not controlled in the workplace, a high number of breakages can occur, even compromising the success of the scouring.
The physical-mechanical characteristics of textile fibers are varied, such as fineness, thermal stability, felting, insulation, tenacity, elongation and breaking, elastic resistance, etc.
Among these, the hygroscopicity of the textile material is very important.
Hygroscopicity is the ability of a textile fiber to absorb moisture from the environment.
Natural fibers, in particular, have a certain degree (percentage) of moisture.
It is measured based on the maximum percentage of water that the fiber can absorb without appearing wet.
Wool and alginic fibers are the most hygroscopic.
For example, wool can absorb up to 33% of its weight without feeling wet.
Related to hygroscopicity is the regain rate, which represents the maximum percentage of water a fiber can contain to be commercialized. It is measured as a percentage of the dry weight of the material, meaning the amount of water absorbed at 20°C by 100 g of fiber, previously dried, then exposed for one hour to 65% humidity. Law 883 of 26.11.73 (and subsequent amendments - Directive 96/74/CE) defines the conventional values.
Moisture can vary from 18% for wool to 1.5% for synthetic fibers like polyester.
For example, silk has a regain rate of 11% and a moisture content of 9.91%, while worsted wool has a rate of 18.25% and a moisture content of 15.43%.
It is important to ensure that yarns have constant and uniform moisture, as the varying quality of raw materials and different environmental conditions in which the yarn is produced mean it is never in optimal moisture conditions.
When the yarn passes from the spinning phase to the subsequent processing phase, it is essential to control the yarn's moisture, verifying its regain rate by treating it in such a way as to ensure conventional values.
The system for conditioning the yarn consists of introducing it into special regain chambers where the yarn is subjected to humidification treatment with particular precautions.
To build a chamber, it is essential to remember that the absorption of moisture by a textile fiber occurs in 3 distinct phases: the first rapid and superficial, the second slower and deeper, the third of diffusion by means of osmotic absorption of water that spreads within the fiber itself, penetrating intimately and reaching all pores and capillary channels.
For these reasons, the regain chambers must ensure contact of the fiber with air humidity and not directly with water, because the yarn would become too wet and only superficially so, with an excessive increase in humidity, which would result in non-uniform humidification of the yarn.
The advantages obtained with good moisture regain are not only to ensure a certain constant weight in yarn packages but, above all, to improve the technical characteristics of the fiber. Furthermore, the yarn will be in ideal conditions to make it much easier to work with.
Hircus Filati