Fibers made of polyester. Manufacture of polyester fiber

Chemical production is one of the main sources of human goods. After all, everything from household items to clothing is carried out and manufactured on the basis of this science.

A special role is assigned to various chemical fibers, which are used in numerous branches of science, engineering and industry.

Classification of chemical fibers

All chemical fibers can be divided into two large groups.

1. Artificial ones are those based on a natural polymer, but the processing and shaping of the filaments themselves takes place with the participation of physicochemical methods.
2. Synthetic fibers are fibers that are created directly in laboratory (industrial) conditions. They are constructed on the basis of ordinary low-molecular compounds, transformed into macromolecules as a result of polymerization reactions.

In turn, artificial and synthetic fibers also have their own classification and examples. Consider this for synthetic samples.

They can be divided into two large groups. The basis is the structure of the carbon chain and the ways of forming bonds.

1. Synthetic carbon fiber fibers. The main chain is built strictly of carbon atoms, connected together by ordinary sigma-type bonds. To this group can be attributed a fairly large number of samples. For example, polyacrylonitrile, polyethylene, polyvinyl chloride, polypropylene, polyvinyl alcohol.
2. Synthetic heterochain fibers. They differ in heteroatoms included in carbon macrocycles - nitrogen, sulfur, phosphorus and others. This group includes such fibers: polyester, polyurethane, polyamide.

If we talk about using it in the textile industry, the significance of the representatives described differs. So, artificial fibers are much more applicable for tailoring clothes, bed linen, towels and other household linen items. Although there are exceptions, when such a canvas finds application in engineering.

Synthetic chemical fibers, by contrast, are much more often relevant in construction, engineering, and industry than in everyday life. More specifically, we will consider polyester yarns, fabrics from them and the field of application.

Polyester fibers: general characteristics

From a chemical point of view, this product is the result of the interaction of terephthalic acid C ₈ H ₆ O ₄ and ethylene glycol, a dihydric alcohol C ₂ H ₆ O ₂ . As a result of a complex polymerization reaction, transparent or white crystals are formed, which have an important property - viscosity. To do this, they should be heated. It is on this feature that the production of fibers from a given substance is directly obtained.

The melting point of such materials is above 260 ^° C. This makes them very convenient to use for technical purposes. There are a number of special properties that such fibers possess.

1. Polyester synthetic yarns are able to withstand solutions of acids, alkalis.
2. Absolutely not soluble in water, solvents of organic nature.
3. They are dielectrics, that is, they practically do not conduct electricity.
4. Products made of them are durable, very durable and reliable.

Being fully synthetic in nature, these yarns in many respects surpass in terms of technical and textile characteristics many artificial fibers.

Method of production

According to the previous description, polyester should be based on terephthalic acid. However, its physical properties are somewhat inconvenient for a harmonious and rapid polymerization reaction with ethylene glycol, so it is used not in its pure form but as an ester. Its name is dimethyl terephthalic acid of the same name, abbreviated as DMT.

Therefore, the production of polyester fiber consists of several consecutive chemical stages:

• Oxidation of a mixture of esters and paraxylene, that is, the preparation of starting materials;
• Esterification, i.e., the preparation of DMT ester ;
• Distillation and purification of the product obtained;
• Recrystallization of DMT in order to obtain pure raw materials.

Prepared by this scheme, the substance is ready to enter the next cycle of transformations, resulting in polyester (polyester). This takes place in two main stages.

1. Transesterification of the obtained DMT with ethylene glycol. The result is diglycol and low molecular weight polyesters.
2. Polycondensation of products obtained in the first stage among themselves. As a result, a viscous polyethylene terephthalate is formed.

Now it's up to the technical side. The substance is passed through special small spinnerets, as if pushing, and thereby receive fibers. Upon cooling, they crystallize. Further processing consists in drawing, cleaning and painting.

Material names

In different countries, similar fibers are produced and used. Polyester synthetic threads in each state received their name, so there are many synonyms. Consider what they are.

1. In Russia - polyester, polyester, lavsan.
2. In America - the dacron.
3. The United Kingdom is Terylene.
4. Japan is a theteron.
5. France - tergal.

However, as they are called, and the properties remain the same and the scope of application too.

Material polyester: properties

The main positive aspects of the lavsan include such qualities as:

• Bad crushing;
• Incombustibility;
• Light resistance;
• Wear resistance;
• Strength and softness, smoothness;
• Resistance to the action of most organic solvents, as well as acids and alkalis;
• Absence of abrasion;
• Tissue does not support the development of living microorganisms (fungi, mites, bacteria and others);
• Impact resistance;
• Tensile strength.

Of course, such a set of positive characteristics can not go unnoticed. That is why the field of application of polyester products is very wide, covering most branches of the national economy.

However, there are disadvantages. These should include the following points:

• Difficult to color, so juicy and bright colors in such tissues are not found;
• Strongly electrified, since the dielectrics themselves;
• If you take a true polyester that has not been processed by special methods, then it will be quite a tough material.

All of the above deficiencies are easily eliminated by adding certain substances in the process of fiber production. Therefore, they have no significant meaning.

Hollow fibers

This type of polyester yarn is very important in construction and engineering and finds application there. Although there are exceptions. For example, such as the Holo-Fiber, who found a shelter in the textile industry.

Hollow fibers are used for manufacturing:

• Fiberglass;
• building materials;
• Heat-insulating things;
• Radio engineering products.

They are also used as filters for wastewater treatment. Hollofayber thanks to its characteristics in general has long superseded the natural feather and down from the textile industry. It became the main type of filler for pillows, blankets, outerwear and other things.

Silicone globes

This is the main product for making the most soft, environmentally friendly and non-allergenic bedding. It is these fibers that are used as fillers for blankets and pillows.

Why are they being used? This is due to the excellent technical characteristics.

1. Do not absorb moisture.
2. Elastic and elastic.
3. They are machine washable, simple and convenient to care and apply.
4. Have no smell.
5. Do not cause allergies.
6. They can not develop microorganisms.

All this gives the globular siliconized fiber as a filler of furniture, bedding and clothing a clear advantage over natural natural "colleagues": down, feather.

The disadvantages include a shorter service life than natural materials. However, the cost of such products is an order of magnitude lower.

Staple fiber

Among polyester fibers, a special place is occupied by such a variety of them as staple threads. It is their plant of synthetic fiber that produces in a larger volume than all the others. This is due to the fact that such a product is used for the production of yarn itself, and then also for sewing clothes, textiles and so on.

Often a staple fiber is formed, formed from a harmonious combination of wool or cotton with polyester. Such symbiosis makes it possible to obtain the following types of materials:

• Costume;
• Coats;
• Tulle;
• Short-cut;
• Curtain;
• Floating;
• Felt;
• Carpet;
• Fur.

Obviously, what products can be sewn and made of such components.

Technical thread from polyester

Such fibers are used for manufacturing the following kind of products:

• Fishing nets and trawls;
• Ropes and ropes;
• Hoses for oil refining products;
• Canvas;
• Conveyor belt;
• Seat belts and drive belts;
• Tire cord;
• Heat-insulating and filtering materials.

To such threads can be attributed and discussed above hollow fiber.

Products from polyester materials

What other products can be made from polyester? The special importance of such materials, which are used as a filler, we have already described above. I just want to add that holofayber allows you to get the most soft and comfortable pillow and a warm and light blanket. Polyester fiber in the textile business is simply irreplaceable and every year in its importance rises higher and higher.

Also used lavsan for the following types of fabrics :

• taffeta;
• crepe;
• Knitwear;
• Krimplen;
• Melan.

They make clothes, tulle and curtains, scenic attributes, etc.

Another kind of practical activity of a person in which polyesters are used is surgery. Medicine has considered the possibility of making artificial blood vessels and surgical threads made of polyester. This, of course, facilitates many operations to save lives.

Product Reviews and this fiber

Given that, in addition to the positive characteristics, polyester based materials still have drawbacks, not all people remain satisfied with the products. When it comes to building applications, there can be no disputes: lavsan is the leader. However, speaking of textile products and clothing, it should be noted and disagreements. Negative opinions are also steadily receiving polyester fiber. Reviews of this kind are based on the shortcomings of the fabric itself - electroneability and a limited lifespan.

Nevertheless, most people tend to consider polyester as one of the most comfortable, beautiful and high-quality materials of our time. Therefore, clothing, household items and bedding from these materials only get over the years with popularity.

If you look at the reviews on pillows and blankets based on polyester, then the overwhelming majority of them will still be positive, which is completely justified and fair.