• History of glue

    Once in the laboratory of a small American town was sent to study a sample of an unknown substance of cream color and unusually dense consistency.

    The conclusion of the laboratory read: "The unknown material sent to us for analysis in the solidified state has exceptional astringent properties. It can be successfully applied as an adhesive. "

    The grateful client replied: "With your analysis, I did not hesitate to acquaint my wife. Sent a sample, unfortunately, is not a material used in construction or elsewhere. It's just a piece of Sunday cake, in the baking of which my wife puts so much soul, that requires me to admire her culinary talent. "

    Construction of a stone building. Medieval engraving.

    Hardly experts are interested in this "discovery" of the diligent housewife. And yet, to be serious, today it is not so easy to invent a new kind of glue, because people knew it already in the Neolithic Age! They "boiled" the glue from the bones and tendons of animals. Primorye peoples, engaged in fishing, noticed that the decoction of fish scales possesses stickiness. In addition to fish glue, they also used various natural and vegetable resins.

    In the tomb of the 18-year-old Pharaoh Tutankhamun, among the items that were to be useful to him in the afterlife, well-preserved adhesives such as tar, wax and animal glue were found. In ancient Egypt, they were used to join incrustations of wood, ivory and other materials. Great popularity as an asphalt used asphalt. They were sealed with jars of wine, covered with cracks in earthenware, and polished the bottoms of ships.

    To the services of glue-asphalt, ancient builders often resorted. So to our days have reached the ruins of one of the towers, built around 15 centuries before our era. Once the bright tiles collapsed, bricks were showered, layers between the rows of masonry were exposed, but the frozen asphalt still held the palm leaves paved in the seams of the building. ..

    And the clay, the gypsum? They can be called stone glues. And among these glues the first place belongs to a gray soft powder, as if soft powder. If it is mixed with water, it acquires an amazing property to bind sand, bricks, metal fittings into a solid monolith and keep them together for many years. It turns out the main building material - concrete, in which the connecting element - cement. From concrete people have been building structures for several thousand years.

    The famous ancient Roman scholar and writer Pliny the Elder left us with information that in the 3600 years BC from the concrete galleries of the Egyptian labyrinth were built;of small stones, bound with cement mortar, the walls of ancient Babylon were erected. In the state of Urartu in the VII century BC built fortresses and temples of concrete, it was used to build most of the Great Wall of China. In a word, thanks to the "stone glue", concrete has become an eternal material, but the problems connected with it, unfortunately, are also eternal.200 years before Christ, the Roman scientist Cato drew attention to one of them( although then concrete was called cement, and lime was an astringent material): "The main reason for the ruins of our city is that the lime is stolen during construction and makes cement without a binder! "

    Ancient Roman builders assembled cement near Vesuvius, where after eruptions it settled in the form of a powder. In Russia, as is known, there were no volcanoes. The builders of Kiev, Novgorod and other cities injected cement mortar into the mortar - milled bricks and pottery wreath.

    Intercession Cathedral in Moscow. The end of the XVI century. Constructed using a gluing solution.

    Under Peter I in Russia, many factories appeared - weapons, textiles, paper, sugar. In 1719, a certain Gerasim Pustynnikov applied to the Bergcollegium - the institution that operated the ore-digging business, who reported that he had found a substance suitable for the production of cement."And what is the seed made of this stone of the doer, then I apply for it a trial," he wrote. The stone found was marl - a valuable raw material for the production of cement. Today, cement produces a variety of varieties. There are cements that are not afraid of frost, aggressive environments, resistant to vibration.

    We use glue, probably every day. Most often simple, clerical. But there are many glues. Some of them fasten paper, others - fabrics, glass, metal. With the help of glue, without a single rivet, the body of the aircraft was built 13 meters long. All aluminum parts are glued together. In experimental flights, such an aircraft withstood loads and overloads better than riveted aircraft. In addition, the joining of aluminum sheets with such glue is much cheaper than joining with rivets.

    There is an adhesive that can connect rails to install various cranes used in factories and in construction. Such rail tracks, despite the heavy loads, are reliable and almost do not require repair.

    Adhesives are used instead of welding and soldering when repairing cars. There are vibration resistant glues, which connect parts of motors, bolts, tools.

    And can not the merits of different adhesives be combined in one? People have long dreamed of this. Recollect a fairy tale, the characters of which were tightly glued to the bull-calf with a tarry cask. Do you think that there is no such glue? There is. It is called "Tsiakrin" and glues together instantly( without pressure and heating) practically any materials: glass, metal, concrete, leather, cardboard. The metal parts fastened to them, for example, can work not only in the air, but even in sea water. If you squeeze a drop of such glue with your fingers and hold for about 20 seconds, they will have to be disconnected with a scalpel! Therefore, doctors were interested in this glue. It is not inferior to the strongest surgical threads and reliably connects the edges of surgical wounds. In addition, it also has healing properties. Dissolving in dissected tissues, it envelops their edges with an elastic elastic film and thus protects against the action of the external environment and microbes and greatly accelerates the healing.

    On one of the November days of 1941, a 13-year-old girl, during an air raid, exploded both ears with a bomb blast. The girl was doomed almost to total deafness. After the war, the doctors have repeatedly tried to help her, but how to penetrate the needle and thread into the ears, in order to seam the broken eardrums? And after 40 years, "Циакарин" has returned to the person hearing.

    Similar glue once used London burglars. Forcing the cashier of the post office to open the safe, they "borrowed" from there 60 thousand pounds sterling. Having committed the theft, the criminals literally glued to the wall the hands of a postal employee, trembling with fear, with some viscous ointment and disappeared. The policemen who arrived in time could not tear the poor fellow away from the wall. This could only be done by the doctors from the local surgical clinic who were forced to the scene, who had to resort to a special potent solvent.

    What properties should the adhesive have? Specialists from different industries will answer this question in different ways. One needs high heat resistance, another - electrical conductivity, the third - the ability to withstand in aggressive environments. Adhesives with such properties are produced all over the world. But the consumer also waited a long time for such glue: that if necessary it could be easily removed, and the glued objects be disconnected without damage to them. And it would not hurt that the solvent was very simple and cheap - preferably pure water. Now such a temporary glue is created. He immediately gained popularity in industry and. .. from teachers. With his help, they clearly demonstrate how the house, the bridge, how the parts of the cars are assembled. After class, all the details are literally poured into the water. And what glues will be needed tomorrow?

    Take note of

    The bonding points must be carefully cleaned of dust and especially grease stains;The wooden object should be dried by the time of gluing;the thinner and more uniform the layer of glue, the stronger it is;On porous materials it is necessary to put more glue than on metals, glass and other materials with a smooth surface.