As with other textile raw materials, fineness is the leading technological feature of wool fiber. Fiber fineness plays an important role in wool classification and determination of its quality. The thinness of wool in sheep breeds and its uniformity in terms of this feature are due to the difference in their genetic structures. However, fleece fineness may indicate gender, age, different parts of the body, nutrition and care. It is known that the number of sheep fleece in the same flock is thinner and softer than ram fleece, and lamb fleece has a finer and softer fiber shirt than adult sheep fleece.
In addition, the thinnest fleece is on the shoulder, and the coarsest fleece is on the thigh. Under the snow, at the transition to the feet, the fleece becomes coarse to a certain extent. Again in well-fed sheep, the fleece is flexible, soft, shiny, oily and of normal thickness;
Fiber fineness is important in terms of determining the thickness of the yarn to be made, that is, its number. The finer the fibers, the finer the yarn can be produced. Fine and good quality yarns and fabrics can be obtained from fine fibers.. In other words, fiber fineness determines the use of the fiber in the textile industry. Merino fleece is a fine fiber.
The fiber fineness of wool is very variable and varies according to the type of animal it is obtained from, the region of the coat and its age. In general, fine fibers are long and thick fibers are short. The thinner the fibers, the higher their quality.
Fineness is important in wool fibers and determines the quality of the fiber.
The fineness of the fibers is determined by measuring their diameter.
The smaller the diameter of the fiber, the higher its quality.
The fineness of the fibers is measured in microns (μ= 10-4 cm) and expressed in S grade.
The thicknesses of the fibers in microns according to the „S degree are shown below.
As can be seen above, the fineness of the fiber increases as the 'S degree increases. Wool fibers are divided into five classes in terms of their fineness.
Merino wool
These wools, also called fine wool type, are obtained from a breed of sheep called merino, whose homeland is Australia.
Merino sheep are bred for their wool alone.
The finest fibers are obtained from this animal.
It has more folds and high felting feature.
It is used in the production of fabrics with a soft handle (touched), with a high ability to be finished and dyed.
Merino wool, with a fineness of 60-100 S, constitutes 40% of the world's wool production.
Medium wool type
These wools are between fine wools and long wools. The curves are less. It is obtained from various sheep breeds.
It is used in making blankets with men's and women's fabrics. It is 44-60 S degrees.
long wool type
They are fibers with a length of 180-230 mm.
It is thicker and brighter than medium wools. It has a grade of 44-50 S and is obtained from various English sheep breeds.
It is used in the production of overcoat and overcoat fabrics, blankets and felt.
Crossbred(hybrid) wool
These wools are of medium wool type fineness, but have more folds.
It is produced from sheep obtained from the crossing of British domestic sheep in Merinos.
It is generally used for making worsted fabric. It is 50-60 S degrees.
carpet wool
It is produced from sheep of various breeds grown almost all over the world.
In this type of wool, besides fine, medium and long fibers, dog hair (kemp) is also found.
Inexpensive wool fabrics are used to make upholstery, blankets and felt. Its thickness varies between 70 and 200 microns.
Carpet type wool is obtained from domestic sheep breeds in Turkey.
It is produced from the best quality domestic wool, curly and mountaineer types.
In practice, the average fineness is measured subjectively in the classification of wool fiber.
The fineness of the wool fiber is expressed in microns of its diameter, expressed by the „S degree.
According to the number of yarn to be produced, the fiber fineness must be determined.
Wool Fiber Fineness Determination Methods
In determining the fineness of wool fiber, it is absolutely necessary to make use of the measuring instruments and the methods used in order to have a clear information. These methods are:
1-Fineness determination of single fiber
2-Fibre Fineness Detection with Microscope
3-Detection of fiber fineness by microprojection methods
4-Thinness measurement with a lanameter
5-Fineness determination of fibers in clusters
6-Thickness measurement by air permeability method (measurement with Microner device)
7-Thickness measurement by air permeability method (measurement with Wira device)
Fineness Detection in One Lift
The fineness of the wool fiber is measured one by one with a microscope, microprejector and lanometer and the average of the fineness is taken in microns.
Microscopes that measure thinness are called lanometers in the market.
Fiber Fineness determination by microscope
The microscope is one of the most used devices in many laboratories and research areas.
In the fineness measurement, adjustments are made for the image clarity of the fibers placed in the microscope.
The ocular micrometer is brought perpendicular to the fiber axis and the range of the fiber width of the ocular is recorded on the rulers.
The values found at the end of the process are multiplied by the micrometer value to determine the average fineness of the fibers.
Fiber fineness measurement with microprojection methods
short section method
Microprojection is a device found in all textile laboratories.
In order to measure the fiber fineness with microprojection, the preparation is prepared as in the microscope method, and the measurements are made with the help of a special ruler on a surface on which the image is reflected vertically.
For this purpose, sections not exceeding 1-2 mm in length are taken from the thoroughly mixed and cleaned sample with the Hardy microtome.
The sections are taken on a slide and their thinness is measured in the microprojection, which has a certain magnification power, as in the microscope.
In this method, it is necessary to measure the fineness of 1200–1500 fibers in coarse mixed fleeces, and 400–500 fibers in fine and uniform fleeces.
The point to be considered while working with this method is to read only the thinness of the fibers whose diameter falls within a certain circle in the center on the ground where the image is dropped.
Because the growth rates of the fiber images in the center and on the sides are different.
Cross-section counting method
It is an extremely fast method.
The basis of this method is;
Since the cross-sections of wool fibers are close to circles, it is to determine the average fineness according to the number of fiber sections in a certain area.
In laboratory studies, it is necessary to cut the fiber bundle by compressing it in a normal way.
For this Hardy sectioning device used.
In order to get a section, a pinch of fiber is taken from the wool sample.
The fibers are pulled between the fingers and made parallel to each other.
400-500 fibers are made into bundles or rovings.
These fibers are inserted into the slot of the Hardy device and compressed.
The fiber ends that come out of the slit of the device are cut in such a way as to leave a 2-3 mm margin.
A few drops of adhesive collodion solution is dripped onto the fiber bundle, which has been compressed and prepared in this way.
Since this solution is volatile, it dries up after a short time and the fibers become stuck together.
The fiber section is prepared by cutting the ends on both sides of the fiber bundle from the bottom with a cutter.
While working with this method, the cross-section preparation was placed in a microprojection adjusted to magnify 500 times and 125 cm.2 The fiber sections in the image that hit an area of .
Thus, the average thinness is determined according to the number of sections in this area.
Cross section method
In order to determine the fineness of wool fibers with this method, microprojection method used.
Preparations of wool fibers are prepared in the same way and images of fiber sections are obtained.
These are photographed and their average thinness is determined by comparing them with the samples that were previously photographed as film strips for this purpose and their thicknesses were prepared according to certain standards.
Thus, since the cross-section method has been made more practical and faster, it has found application in the wool trade.
Fineness measurement with a lanometer
The fineness measuring system in the lanometer is similar to the microscope system.
For this purpose, the necessary preparations are prepared as in the microscope and placed in the device and the same amount of measurement is made on the same wool types.
In order to measure the fineness of the fibers seen on the screen, there is a ruler that has markings on it at regular intervals and can move left and right from a center.
The fiber fineness is measured with the help of it.
The important thing here is the need to make a large number of measurements in order to get the correct result in fineness determination.
Fineness Detection in Stacked Fibers
In this method, a certain weight of fiber sample is compressed to a certain volume under constant pressure and the fiber fineness is determined according to the speed of air passing through the fiber. The thinness measurement is done with two different devices working with the same method.
Wool fiber fineness measurement with Wira device
WIRA wool fiber fineness measuring device is a digital display electronic test device with an improved microprosor control system.
Thanks to the air flow principle, it quickly measures the average micron fineness of the wool fiber under certain weight and pressure.
The microprocessor on the Wira wool fiber fineness measuring device automatically controls the testing process and displays the average fiber diameter results directly on the liquid crystal display.
The operation of the device is automatically controlled and the test results can be read directly from the LCD screen or optionally, printout or PC connection data transfer can be made.
Wira wool fiber fineness measuring device is first calibrated.
The combed, parallelized wool fiber weighing 2.5 grams is placed in the sample chamber.
The air is sucked through the sample with the vacuum pump that comes with the device. Electronic sensors measure air flow and air pressure and automatically calculate the fiber diameter.
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