In the composition of the fabrics indicated on the labels of many types of clothing, you can often see the word lavsan. What it is? In addition to being one of the most popular synthetic materials, most people do not know much about it.
What is lavsan?
Scientifically, it is called polyethylene terephthalate. This is a polycondensation product of terephthalic acid (DMT) and ethylene glycol. It is a solid substance which is colorless in an amorphous state and has a white color in a crystalline state. As a result of the chemical process, at a certain temperature, polyester fibers are formed that have high strength and wear resistance.
Name history
Dacron material got its name thanks to the Laboratory of High Molecular Compounds of the Academy of Sciences, where it first appeared. The first letters of the name of the laboratory gave the name of the new substance. In other countries, polyethylene terephthalate has different names - dacron in America, tergal in France, trevira in Germany.
In the process of improving this material, a great merit belongs to E. M. Aizenshtein, under whose leadership at one time a technical lavsan thread was obtained, which has special properties.
Making lavsan
In one of the shops of the plant, a chemical reaction occurs, as a result of which the DMT and ethylene glycol substances turn into a viscous, resinous mass. In the spinning mill with the help of special equipment, fibers are formed from it. The resin flows in trickles through the smallest holes. The thickness of the future thread depends on their size. The fiber spinning speed is 500 to 1200 meters per minute. Thin cobwebs quickly stick together in a thread and wound on a bobbin.
These fibers have not yet been made. What it is? So far, the resulting substance can be called an amorphous polymer, which is still unsuitable for the manufacture of products. At a certain temperature it is subjected to stretching, then heat-setting with hot air, and only after that it is sent to weaving mills and other enterprises.
Threads that will become wool in the future are unwound from bobbins, collecting into bundles. Then it is pulled, corrugated, and the fiber becomes similar to natural wool. The bundles are cut into pieces, the size of which depends on which natural fiber they will be mixed in the future.
Properties of lavsan fibers
This material has several advantages over polyamide fibers. It is valued for its resistance to moisture, light, high temperatures and good elasticity, perfectly preserving folds and pleats during washing.
Products from this material resemble woolen. But, unlike them, they are much more durable, they are not damaged by moth or mold, they are not ignited and are more resistant to abrasion. Lavsan is a fiber that is deformed only at a temperature of more than 260 ° C. It feels great in an acidic and slightly alkaline environment.
High crystallinity and small pore sizes do not allow high-quality coloring of the material under ordinary conditions. This is best done before fiber formation or at high pressure and a temperature of 200 ° C.
Biologically indifferent substance is lavsan. What it is is well known to medical professionals. This material does not interact with the human body, so dacron threads are widely used in surgery. Unlike conventional surgical sutures , they do not deform after surgery and preserve the appearance of the suture.
Application of lavsan
In which only industries and national economy does lavsan not find application due to its unique properties! He is in special demand in the textile industry for the manufacture of sewing threads, curtains and tulle fabrics, decorative fabrics and faux fur. Fabric lavsan is successfully used in the production of knitwear, shirts, suits, dresses, etc.
The insulating properties of this material make it indispensable in the electrical industry. Fire hoses, irrigation machine hoses made of lavsan are not susceptible to decay and have a very long service life.
Dacron in medicine is in great demand. It is used as a substitute for blood vessels. In surgery, lavsan thread is increasingly replacing the usual.
Polyethylene terephthalate has found the widest application in the field of creating food films, plastic containers and bottles. In addition, this is the most important component in the manufacture of modern storage media (disks, photographic films, magnetic tapes).
In the chemical industry, medical and mechanical engineering today they can not do without the use of lavsan. It is used in the manufacture of household appliances, food processing equipment, conveyor belts. Filling polyethylene terephthalate with various additives (fiberglass, fluoroplastic, molybdenum disulfide) significantly improves its mechanical and electrical properties. It is difficult to name today the area of production wherever the lavsan is used. What it is and what properties it has - was considered in detail in the article.