Polymers synthesized from petroleum, gas and coal processing products can also be used to manufacture a special type of material - synthetic fiber. Such products are used in the production of yarn for the manufacture of fabrics for various purposes. An example of common types of such material is nylon and polyester.
Recently, scientists have developed several new types of synthetic fibers. All of these varieties are distinguished by excellent performance and can be used very widely. For example, one of the most popular types of such material at the moment is inexpensive polypropylene fiber.
What is a
This modern material belongs to the group of polyolefins - high molecular weight aliphatic hydrocarbons. This type of fiber is much more resistant to double bends and elastic than polyamide. The melting point of this material is 165 ° C, the ignition temperature is 325-385 ° C. The density of the polypropylene fiber is 900-910 kg / m 3 .
What are the advantages and disadvantages
The advantages of this material, in addition to a fairly high degree of elasticity, include:
resistance to acids, organic solvents, alkalis;
strength;
excellent heat-insulating qualities.
The main disadvantage of polypropylene fiber is low light resistance. Under the influence of UV rays, such a material begins to collapse very quickly. Also, the lack of synthetic fiber of this variety includes a not too high degree of wear resistance. In addition, such a material, unfortunately, does not lend itself well to surface staining.
What is the composition
This modern material is made, as can already be judged by its name, from polypropylene. Also, special stabilizing substances designed to increase them can be added to the composition of such synthetic yarns:
wear resistance;
light fastness.
How is it made
Propylene is a cheap material, but very multifaceted in terms of physical and chemical properties. They make it using quite sophisticated structurally modern equipment. At the same time, there are two ways to draw the polypropylene fiber itself:
from solution;
from the melt.
Solution making
This manufacturing method has several disadvantages. In industrial conditions, it is used, but rather rarely. Using this technique, fibers are spun from concentrated propylene solutions, which are known to dissolve at high temperatures in many organic liquid formulations. It can be, for example, mineral oil or gasoline. Using this technology, a heated solution with a special metering pump can be forced through a filter and narrow nozzle openings:
In the latter case, thin polypropylene trickles are blown with air before they enter the liquid at a distance of about 10 cm. In an alcohol mixture, they are freed from residual solvent.
When using the first manufacturing method, called dry, the finished yarn is first wound into bobbins. Then the material is placed in a wash bath with boiling water. This operation is also necessary to remove residual solvent.
Melt fabrication
Using this production technique, polypropylene fiber is made on special spinning extrusion machines. The main structural elements of such equipment are:
screw extruder;
spinning gear pump.
High viscosity polypropylene melt in such a machine is fed to the pump using a worm, which allows it to lower its temperature. Further, the material is passed through a die. Coming out of the last strand evenly blown by the flow of the cooling agent (most often air with constant humidity and temperature).
This method of manufacturing polypropylene fiber, in comparison with the above, is primarily distinguished by greater productivity. Therefore, it is he who is most often used when releasing such material.
Polypropylene fiber properties
Among other things, the material of this variety has the following technical characteristics:
strength - 35-80 gf / tex;
the degree of elongation in the wet and dry state (the same indicator) - 30-40%;
density - 0.91 g / cm 3 ;
degree of frost resistance - up to -70 ° ;
hygroscopicity - 0.01-0.02%.
Products from such material, in turn, have:
The weight of the woven polypropylene fiber material is so light that it does not sink in water. In terms of wear resistance, fabric from such threads, for example, of the same polyamide, is somewhat inferior. But at the same time, it can still serve for a long time.
Among other things, materials made from polypropylene fiber are resistant to infection by fungus and microbes. Accordingly, they have good hygienic properties. Polypropylene is also resistant to acids, alkalis and even aqua regia. Another undoubted advantage of fabrics from this material is that they are not electrified and have dust and dirt-repellent properties.
The use of polypropylene fiber
30% of all polypropylene produced by modern industry is used today for the manufacture of fiber. The material is actually very much in demand. It can be used for the production of:
Clothing from this material, since it is difficult to stain and poorly absorbs moisture, is rarely made. Basically, such threads are used for the production of technical fabrics. In addition to substrates, polypropylene fiber can be used for the manufacture of:
Car brushes made of polypropylene fiber are more expensive than bristles. But at the same time, they are 10-20 times longer. In terms of strength, the polypropylene bristles are 5 times higher than the fairly common polystyrene bristles. It is very rare to change brushes made with its use.
Where else can be applied
In construction, polypropylene fiber is quite often used in the preparation of cement. Its application in this case allows achieving a uniform stress distribution over the entire mass of material.
This material can also be used for the manufacture of fillers. Faux cotton is spun from polypropylene fiber. In the future, it is used for stuffing upholstered furniture. Also, filler from hard thick polypropylene fibers is often used to make knife stands. In this case, a thick "bristle" is simply inserted into a plastic tall narrow box. Polypropylene fibers in such supports easily hold the knives in an upright position.