Application of ebonite

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Treatment with Goncharov's ebonite disc

Physiotherapy is one of the effective means for treating most diseases. This method of treatment does not have the negative aspects of pharmacotherapy, but it does not help everyone.

Table of contents:

It is necessary to compare the positive effect of treatment with physical methods with contraindications and financial costs.

An ebony disk is one of the methods of treatment using the physical properties of nature. This product is made of ebonite material. The substance is of natural origin and consists of rubber and sulfur. Plasticizers, coal and ebonite dust are also used in the manufacture of the disc.

What properties does ebonite have, how should it be treated?

Therapeutic effects

The ebonite material has several beneficial effects used to treat human diseases. Physical properties of the material:

  • Does not absorb moisture.
  • Not exposed to harmful gases, acids and alkalis.
  • Easily amenable to mechanical processing.
  • Has insulating properties.

The last feature of ebonite becomes the basis of treatment. Since our body contains a large number of positive negative ions, ebonite can influence the state of these charged particles.

Mechanism of action of the material:

  1. As the ebonite disk approaches the human body, the number of negatively charged particles in the latter increases.
  2. At the site of impact of the disc, blood circulation increases, arterial blood flows, and venous fluid drainage accelerates.
  3. As a result of intensified blood flow, the healing of damaged tissues is accelerated, the immune response is enhanced, and pathogenic bacteria die faster.
  4. Thanks to the impact of the disc, metabolism and nonspecific defense of the body are enhanced.
  5. The effect of therapy is achieved only if ebonite is part of the electrical circuit. Therefore, if another person is performing the treatment, he should hold the patient with his other hand.

This electrical influence can affect the functioning of the cardiovascular system. Therefore, in the presence of heart disease, the procedure time is limited.

Indications

The ebonite disc must be used according to the indications for its use. The spectrum of action of this product is quite wide, but limited. Read the indications carefully so that you have the right expectations from its use.

Diseases for which ebonite can help include:

  1. Diseases of the ENT organs are the main group of diseases for which ebonite should be used. Among these diseases are acute and chronic laryngitis and pharyngitis, tonsillitis, tonsillitis, lymphadenitis, sinusitis and other sinusitis, otitis media.
  2. Lung diseases: pneumonia, bronchitis, chronic obstructive pulmonary disease, shortness of breath due to interstitial diseases.
  3. Pathology of the musculoskeletal system: rheumatoid arthritis, rheumatism, osteoarthritis, psoriatic arthritis, radiculitis.
  4. Vein diseases - thrombophlebitis and obliterating diseases of the arteries of the lower extremities.
  5. Inflammatory diseases: gangrene, myositis, boils, panaritium, conjunctivitis, barley. Remember that it is important to use antibacterial drugs at the same time.
  6. Diseases of the gastrointestinal tract. Among them are stomach and duodenal ulcers, gastritis, colitis, irritable bowel syndrome, and liver diseases.
  7. Urolithiasis disease.
  8. Migraine and headache.

The ebonite disc should not be considered as the only remedy for treating the listed diseases. The product helps perfectly during the period of remission to avoid a new relapse. If there is an exacerbation of the disease, pharmacological agents should be added to therapy.

Contraindications

There are a number of conditions in which ebonite can only cause harm. Contraindications for using the disc include:

  • Diseases of the cardiovascular system in the period of exacerbation: heart attack and stroke, chronic and acute heart failure, cardiomyopathies. The reason for introducing this restriction is the effect of ebonite on the electrical conductivity of the heart. The effect of the material on the work of the heart is unpredictable.
  • Oncological diseases. Exposure to ebonite tissue always leads to increased blood flow. Increased blood circulation in the area where the tumor is present can lead to tumor growth and the appearance of metastases.
  • The patient's cachexia is a severe general condition of the patient, starvation and exhaustion require intensive care. It is a general contraindication for all methods of physiotherapy.
  • Arrhythmia, heart block, presence of a pacemaker. Conditions sensitive to the effects of magnetic fields on the human body.
  • Hypertension in the third stage. Intensification of blood flow from ebonite can cause acute cardiovascular accidents.

If we exclude the presence of these conditions in the patient, the likelihood of a negative impact of the disc on the body is minimized.

Terms of use

There are various models of ebonite discs on the medical device market. It has been experimentally proven that it is best to use a circle measuring 12 cm and 1 cm thick. It is advisable that a holder be attached to it. It is the shape of the disc that is considered optimal.

There are a number of simple rules that are common to the treatment of any disease:

  • A standard therapy session should last between 30 and 40 minutes. This time is limited only in the presence of pathology of the cardiovascular system. In this case, treatment should be no more than 15 minutes at a time.
  • It is recommended to slowly perform 20 circular movements clockwise around the damaged area and the same number counterclockwise.
  • Do not forget to form a closed electrical circuit if the treatment is performed not by the patient himself, but by another person.
  • There should be no moisture in the area of ​​action; the treatment area should be dried dry. After this, it is recommended to apply talc or powder to it to improve the sliding of the ebonite.
  • After each procedure, the ebonite circle is washed and dried.
  • Store ebonite in a dark, dry place, avoid exposing it to sunlight. Under the influence of the sun, ebonite becomes green and loses its healing properties.

Goncharov's ebonite disc will be most effective if you consult a specialist before treatment.

Instructions for use

Having understood the basic rules for using the disc, you can analyze specific treatment options for various diseases of the body.

In each clinical situation, it is necessary to use an ebonite disk in a special way, instructions for use:

  1. For chronic diseases of the pharynx and trachea, as well as the tonsils and paranasal sinuses, it is necessary to massage the forehead, neck and face. Each area is treated for 10 minutes, so the total session time takes just over half an hour. Follow the rules listed above for the most effective therapy.
  2. Pneumonia, bronchitis, interstitial diseases and chronic obstructive pulmonary pathology. These diseases must be treated with the help of an assistant. He performs circular movements on the back in turn on each side of the spine. The assistant places his free hand on the patient's chest. For purulent bronchitis, massage of the interscapular area on the back is very helpful in removing mucus.
  3. For bronchial asthma, sessions should be alternated. On the first day, the interscapular area is massaged with the help of an assistant; on the second day, the chest is treated from the front. The patient can do this independently.
  4. For diseases of the middle ear, an assistant must insert it into the patient's ear. The second hand takes the ebonite disk. They massage the forehead, left cheek, chin, right cheek. That is, a circle is described by a disk across the face. For acute otitis media, such movements are recommended to be done three times a day.
  5. For sinusitis, it is recommended to carry out the same session as for otitis media. The face and collection area are treated with the disc. At night you can apply the product to the frontal part of the head.

Recommendations for the treatment of other disc diseases can be obtained from a doctor of the appropriate specialty. However, the general rules are no different. The affected area is treated using circular movements for half an hour with an assistant or independently.

Where and how to buy?

Treatment with an ebonite disc is a fairly cheap and effective method of therapy. However, the product itself is not very available in our pharmacy network. Some pharmaceutical establishments sell ebonite discs, but this is quite rare.

You can find devices in numerous online resources where they sell various options for ebonite materials. However, you should not trust such stores one hundred percent; rely on reviews from users and your friends.

Some doctors can advise where to purchase the disc. This product is often found in physiotherapy departments in hospitals and clinics.

The cost of the product averages from one and a half to two thousand rubles.

Source: http://elaxsir.ru/lekarstva/drugie-lekarstva/ebonitovyj-disk.html

Application of ebonite

Ebonite is one of the “plastic substitutes” that were common before modern plastic production.

The properties of ebonite are very similar to those of reactive plastics (such as Bakelite), but the main difference is that it is NOT plastic.

And, among other things, ebonite could have appeared much earlier...

Ebonite is not plastic, but rubber.

There is simply too much sulfur in it - from 30 to 40% (in the usual 1 - 3%). The color of this ebonite is dark brown, and to make it blacker, soot is added (no more than 3%, otherwise the ebonite loses its dielectric properties).

The result is a hard, dark mass that can be easily machined, has very good insulating properties, does not absorb moisture, and is resistant to acids. The main drawback is that it doesn’t like heating, well, it just really doesn’t like it. It softens at a temperature in the region of 70-80oC, becoming elastically similar to ordinary rubber (but hardens again when cooled). And at 200oC it begins to char, but does not melt like plastic.

And among other things, in direct sunlight it oxidizes, becoming dirty yellow-green.

Depending on the purpose, the composition of ebonite may vary. In addition to rubber and sulfur, the composition of dielectric ornamental ebonite also includes various softeners and accelerators. This composition makes it possible to obtain ebonite, which is perfectly amenable to processing and is excellently polished. This type of ebonite is used in the manufacture of radio, telephone or telegraph parts. Available in the form of plates, tubes, rods. Technical ornamental ebonite does not have dielectric properties. It contains less rubber and a larger number of different fillers. This ebonite has lower strength and is less processed and polished. For the production of battery tanks, a special ebonite composition is required, the heat resistance of which must exceed 50°C. Therefore, pumice, kaolin or asbestos are added to sulfur and rubber. The result of these additives is not only the high heat resistance of ebonite, but also an increase in its hardness. Products made from such ebonite can be processed using tips made of hard alloys.

In addition to all the above characteristics, ebonite has several more undoubted advantages. It is non-hygroscopic, meaning it does not absorb vapors from the air, which makes it suitable for use in environments with high humidity. Ebonite also tolerates other aggressive environments, such as acidic, salt, animal and vegetable fats, without harm; it is gas-tight. Therefore, ebonite is in demand, for example, for the production of containers for acids and alkalis.

Among the disadvantages of ebonite, it should be noted that it is degradable under the influence of strong oxidizing agents, aromatic and chlorinated oxidizing agents. Ebonite is also susceptible to sunlight. It oxidizes and turns greenish.

Ebonite sheet is a product of a high degree of vulcanization of natural or synthetic rubber with sulfur. The bound sulfur in ebonite is about 32%, which corresponds to the formula (C6H9S)2. Ebonite is usually dark brown or black in color.

Scope of application of sheet ebonite –

Ebonite is used for the manufacture of parts for electrical appliances, battery tanks and containers for aggressive liquids, as well as for rubberizing chemical equipment.

Ebonite lends itself well to mechanical processing, is non-hygroscopic, gas-tight, resistant to solutions of acids, bases, salts, vegetable and animal fats; is destroyed by strong oxidizing agents, aromatic and chlorinated hydrocarbons.

Ebony rod is a rubber composite that has been vulcanized with sulfur. This process makes ebonite resistant to various aggressive chemical compounds and increases the mechanical and dielectric characteristics of the material. Ebonite is produced both in sheets and in the form of rods of various thicknesses and diameters.

Currently, ebonite is produced according to the following nomenclature:

Name Diameter (thickness), mm.

Ebony rod 8

Ebony rod 10

Ebony rod 14

Ebony rod 17

Ebony rod 20

Ebony rod 26

Ebony rod 30

Ebony rod 40

Ebony rod 50

Ebony rod 75

Ebonite sheet 3

Ebonite sheet 5

Ebonite sheet 10

Ebonite sheet 14

Ebonite sheet 18

Ebonite sheet 20

Ebonite tubes with or without flanges, for example, hollow cylinders with a diameter of 800 mm and a length of 1500 mm with a wall thickness of 30 mm for starting rheostats for bloomings, are manufactured by knurling on mandrels. Before vulcanization, the pipes are tightly rolled up with bandages using a spiral fabric overlay. Sometimes pipes are vulcanized without a mandrel by filling them with fine river sand and closing the ends with wooden plugs. Small holes are made in these plugs to allow the air remaining in the pipe to gradually, as it heats up and expand, exit the pipe. If curved pipes are required, then sand-filled and heated pipes are bent according to appropriate patterns. If it is necessary to manufacture pipes bent without folds or with a small radius of curvature, appropriate zinc mandrels are used, followed by dissolving the zinc by treating the finished product in hydrochloric acid.

Ebonite is an excellent electrical insulating material, used for the manufacture of various parts in electrical engineering.

Ebonite can be cut with a hacksaw, drilled, sharpened on a lathe, or filed with files. When heated, ebonite sheets can be bent and stamped; Young technicians use this property of ebonite to make various parts.

Source: http://electro-izolyaciya.ru/ebonit/

What is an ebonite stick? Its use and properties

When the phrase “ebony stick” is mentioned, most people have only one association: a school lesson, a physics teacher, small pieces of paper that miraculously stick to an electrified stick. The teacher gave us answers to all the questions that arose after seeing the manipulations with the amazing object. We have grown up and forgotten about the existence of such a unique invention of mankind as the ebonite stick. But in vain. Many scientists have devoted their lives to studying and researching the properties of ebonite.

History of origin

At the beginning of the 19th century, the American inventor Charles Goodyear discovered a new substance to the world. He did this by accident. While working in his laboratory, Charles accidentally dropped a mixture of sulfur and rubber onto the stove. The resulting substance is known to all mankind as ebonite. The material turned out to be very hard and durable.

Even in Ancient Greece, the ability of some materials to acquire an electrical charge was known. This concerned amber. If you rub amber with wool, it will attract light objects. "Electron" is the Greek name for amber. The physical body, rubbed with wool and capable of attracting small particles, began to be called electrified. The concept of “electricity” appeared.

Why can an ebonite stick be electrified?

It's all about the dielectric property of this material. An ebonite stick rubbed with wool concentrates all the electricity on itself and acquires a negative charge. Wool has a positive charge, but is a very poor conductor of electricity. An electric field is formed around the stick, so all the charge accumulates on it.

Properties of ebonite

Ebonite is resistant to acids, fats, salts, and is gas-tight. The material may change color. It is produced in a dark brown or black color, but when exposed to sunlight, ebonite oxidizes and acquires a green tint. At the same time, it does not lose its properties. In the dark, the ebonite turns black again.

It contains only rubber and sulfur. Additional ingredients may be white and black soot, coal dust, ebonite dust. Despite the fact that ebonite is a very durable material, it is easily subject to mechanical stress.

Application

Natural and very expensive materials such as turtle shells, elephant tusks, horns, hooves, fangs began to be replaced with ebonite from the beginning of the twentieth century. They began to make crafts and souvenirs from them. Chess sets, combs, pipe mouthpieces, stands, pens, and money holders made of ebonite looked no worse than their counterparts made of natural materials. In the modern world, this unique rubber is used:

  • in electromechanics (as an electrical insulator);
  • in pharmaceuticals (as acid-resistant);
  • in the national economy (production of souvenirs, crafts, billiard balls);
  • in medicine (electrotherapy, reflexology).

Ebonite stick and its medicinal properties

After much research and observation, scientists have established the positive effects of ebonite products on the human body. An improvement in blood quality, an increase in the amount of oxygen in the cell and restoration of its liquid crystal structure were noted. To achieve a therapeutic effect, it is enough for an electrified ebonite stick to rub against a person’s skin in a sore spot. Non-contact use is also possible: you can move the stick over the sore spot 2-3 mm from the body. When a stick rubs against a person’s body, a positive charge arises in it, and a negative charge in the body. Opposite charges attract. Beneficial biocurrents appear in the sore spot. Negative charges leave the body, then form again, leave again, form again. This activates the body's metabolic processes, improves blood circulation and saturates tissues with oxygen.

When is ebonite treatment used?

In medicine, this method is called electrotherapy, or reflexology. An ebonite rod or stick is used to influence biologically active points. Upon contact with skin, beneficial biocurrents arise. In combination with reflexology, the effect of electrotherapy is achieved. This treatment is used:

  • for flu and colds;
  • with pneumonia;
  • for asthma, shortness of breath;
  • with sinusitis;
  • with sore throat;
  • for hypertension and hypotension;
  • after a heart attack;
  • for intestinal problems;
  • for liver diseases;
  • for rheumatism and radiculitis;
  • for joint diseases.

The time of one session should not exceed 15 minutes. All movements are made clockwise. The human body must be dry. After the procedure, the stick should be washed with soap.

This treatment method is not a panacea for all diseases, but a good analogue to traditional chemical medicines that has no contraindications.

Source: http://www.syl.ru/article/298292/chto-takoe-palochka-ebonitovaya-ee-primenenie-i-svoystva

What is ebonite

Speaking about ebonite, from the very beginning it should be noted that although its properties are similar to those of plastics, they are completely different materials.

Ebonite is rubber that contains 30-40% sulfur, that is, quite a lot. Its color is usually dark brown, but it can also be black, for which up to 3% sulfur is added, but in no case more, since in case of an overdose the dielectric properties will be lost.

Manufacturing and properties

Ebonite is obtained by vulcanizing various rubbers with sulfur. The technology was discovered along with rubber vulcanization in 1838.

The process is quite complex, but well-established and long-established. It involves a mixture of ebonite and coal dust, accelerators, activators and plasticizers.

Main properties of the material:

  • ease of processing;
  • hardness;
  • resistance to any aggressive liquids - acids, fats of any origin, drying oil, hydrocarbons, various bases, salt solutions;
  • gas tightness;
  • has high adhesion to metal;
  • does not absorb moisture, that is, not hygroscopic;
  • has excellent insulating qualities;
  • dielectric.

If we talk about negative qualities, then this is a fear of both low and high temperatures. In the first case, ebonite becomes brittle, and in the second, it softens and becomes like ordinary rubber. If the temperature is above two hundred degrees, then it becomes charred.

In addition, when exposed to direct sunlight, ebonite oxidizes, becoming yellow-green in color.

Usage

Ebonite appeared during Victorian England and was adopted by craftsmen making jewelry. The material resembled jet, a popular ornamental stone at that time.

Ebonite was cheaper, looked good and was almost indistinguishable from natural jet. One bad thing - I couldn’t stand sunlight.

It is interesting that when studying antique jewelry, experts have great difficulty identifying substitutions. Often this can be done only by the nature of the assembly of the product.

Nowadays, knife handles, sex toys and more serious things are made from ebonite.

Tips in the article “How to find a broken wire in the wall?” Here.

Ebonite is indispensable for gumming equipment used in the chemical industry. The material is necessary in the production of containers for aggressive liquids. It is also used in various equipment, instruments, electrical equipment in the form of raw materials.

I would never have thought that toys could also be sexually oriented. And taking into account the fact that the material is electrified, some inconvenience may arise in this regard. And the influence of the sun's rays is also very confusing.

Source: http://euroelectrica.ru/chto-takoe-ebonit/

Ebonite

Ebonite, hard rubber, differs from soft rubber by a significantly higher sulfur content. The bound sulfur in ebonite is about 32%, which corresponds to the formula (C 5 H 8 S) 2 . Ebonite is dark brown or black - the color of ebony. In terms of hardness, ebonite approaches ivory; can be processed well on a lathe, sawed, ground, polished; doesn't warp. Specific gravity is not lower than 1.14, on average 1.2. Heat capacity (0-100°C) 0.33125. Linear expansion coefficient (20-60°C) 80·10 -6 ; the amount of heat passing through an ebonite plate in direct sunlight with a thickness of 0.5 mm is 35%; at 1 mm 28%; at 1.5 mm 23%; at 2 mm 15%. Refractive index 1.568. Ebonite is a good electrical insulating material. The smell is detected by friction. Non-porous, non-hygroscopic, does not adsorb gases; moisture absorption in air is 0.005-0.02%, in water 0.08-0.11%. The tensile strength of higher grades of ebonite is 6-8 kg/mm ​​2 and even 10 kg/mm ​​2; average 5-6 kg/mm ​​2; lower ones - drops to 1 kg/mm ​​2. Temporary compressive strength, depending on the quality, is 2-12 kg/mm ​​2, elongation 2-75%. When bent, it quickly returns to its original shape, but does not have the “nerve” characteristic of soft rubber (i.e., rapid compression when stretched and a strong jump and rebound when hitting a hard body). Usually softens between 70 and 80°C; also softens in warm water and begins to bend; When cooled, it hardens again.

At 200°C and above it gradually chars without melting. Air oxygen and light have less effect on hard rubber than on soft rubber; resistant to acids and alkalis, therefore suitable for storing sulfuric acid up to 50° Ве, nitric acid - up to 16° Во, hydrochloric acid of any strength, hydrofluoric, phosphoric, acetic, as well as caustic alkalis; swells in carbon disulfide and petroleum products; dissolves in paraffin at temperatures above 300°C with the release of hydrogen sulfide. The insulating properties of ebonite decrease when exposed to light due to oxidation. The properties of ebonite change little over time; aging of ebonite products is hardly noticeable. Acceptable shelf life without compromising quality is usually 5 years, for ebonite tanks and separators 2 years, for semi-solid tubes 1 year.

The rubber used for the production of ebonite d.b. completely free of contaminants leading to the formation of bubbles and porosity, reducing electrical insulating properties, and complicating mechanical processing (turning, grinding, polishing). Rubber is suitable both vegetable and synthetic. The most valuable grades of ebonite (for example, for electrical insulating plates 0.3-0.4 mm thick for currents of 20 kV and more) contain only rubber and sulfur (approximately 66 parts of rubber and 34 parts of sulfur). Typically, ebonite contains a number of impurities necessary to give ebonite special properties depending on the purpose of the products, to facilitate manufacturing processes (rolling, calendering, extrusion, molding, vulcanization and further mechanical processing), as well as to reduce the cost of products. Impurities (ingredients) must also b. thoroughly cleaned, and powdered ones - thoroughly crushed. The ingredients in ebonite generally have the same meaning as in soft rubber, but their choice and quantity depend on the properties that need to be imparted to the ebonite. Ebonite dust is used in significant quantities (especially in molded products), obtained either from old used ebonite or from reclaimed material, pre-vulcanized with the addition of sulfur by crushing, separating metal impurities and grinding on rollers (for higher grades of ebonite dust) or millstones (for lower grades). , because the millstones may produce an admixture of sand). More complete extraction of metal from ebonite dust is carried out using an electromagnet. Ebony dust of the highest grades contains 65-70% rubber; in the lower grades the rubber content drops to 55%. The standard grinding fineness is determined by a 120 mesh sieve. Ebonite dust is prone to spontaneous combustion during grinding, as well as when stored in large piles and can thus. cause fires and explosions. Signs of incipient spontaneous combustion of ebonite dust are blackening and clumping. The danger of fire is noticeably reduced if the dust is in an atmosphere of inert gases rather than air; According to experimental data, 7% carbon dioxide in the atmosphere is sufficient to avoid an explosion. Vulcanization usually takes longer than for soft rubber, and the use of organic accelerators is especially effective. Usually aldehyde ammonia, guanidines (diphenyl-, ditolyl-, triphenyl guanidine), etc. are used. Softeners are intended not only to facilitate dyeing (mixing) and protect against cracks, but also to give ebonite after machining a smoother, shiny polished appearance and, in addition, make the processing easier. Dark factis, robberax (sometimes almost completely replacing rubber), drying oil, varnish oil, resins, ceresin waxes, petroleum oils, etc. are used as softeners. Ebonite for acid- and alkali-resistant products includes barite, talc, kieselguhr, pumice, asbestos. At the same time, talc protects ebonite products (battery tanks, etc.) from deformation, but with a high talc content, ebonite is difficult to polish. For insulating purposes, it is useful to use kaolin; Kaolin containing ebonite is highly polished. Kaolin is used in ebonite for the manufacture of magnetos and insulating tubes. Magnesium oxide is not only a vulcanization accelerator, but it also prevents blisters by reacting with gases released as a result of the oxidation of sulfur contained in hard rubber; That. Magnesium oxide also protects against a decrease in the electrical insulating qualities of hard rubber. For coloring ebonite, use: zinc white - for light dentalite, cinnabar, antimony sulphide - for red, etc. Usually ebonite is black.

Ease of mechanical processing, chemical indifference, insulating properties, the possibility of cleaning and disinfection determine the scope of use of ebonite as a valuable material for products in electrical, radio engineering, surgical, chemical and other industries. Recently, with the development of the production of cheap artificial resins, plastics, etc., although ebonite is being replaced by them, it remains indispensable for many products and finds new areas of application. The main ebonite products are plates, sticks, tubes and molded products. The plates are obtained by calendering and duplicating (thickness more than 0.8 mm) thin plates. Vulcanization of ebonite plates is carried out in tin foil (or aluminum) in hot water or in a press (plates thicker than 15 mm); vulcanization in foil gives a smooth, shiny plate that does not require polishing; vulcanization in metal frames in a press produces a matte plate that can be machined. Tin foil can be used several times, but it is better to melt it down and repaint it after each vulcanization. Ebony sticks and tubes are formed by extrusion at a temperature higher than for soft rubber. Vulcanization of sticks and tubes is carried out in talc powder in closed metal boxes inserted into the vulcanization boiler. Thin tubes are placed for vulcanization on rods (mandrels) previously moistened with a solution of soda or liquid glass. Large diameter tubes can also be vulcanized in molds (metal tubes), then filled with compressed gas (air or other) or live steam. Molded ebonite products (sets, etc.) are also made by pressing an ebonite mixture in metal molds or by preliminary gluing hand-cut parts from templates and placing them in molds. Ebonite adheres well to metal, therefore it is used for lining tanks, tanks intended for storing acids (at low temperatures), as an intermediate layer for bonding metal with soft rubber (in dense massive tires), etc.

Chemical analysis of ebonite is essentially no different from that used for soft rubber. Physico-mechanical tests are used partly the same as for soft rubber, but other tests are also important for hard rubber, such as determining electrical insulation capacity, hardness (Brinell method), deformation when heated (Martens test), adhesion to metal, etc. In addition to the general test methods for special types of products, special methods are used (for example, battery tanks are tested for acid permeability, integrity of seams, etc.).

Source: Martens. Technical encyclopedia. Tom G.

Source: http://azbukametalla.ru/entsiklopediya/e/ebonit.html

The ebonite wand is famous for its miracles

Ebonite has been used in alternative medicine since ancient times. It is a material obtained by vulcanization of synthetic or natural rubber. A third of its composition is sulfur. The resulting material has a black or dark brown color, it is not susceptible to acids and alkalis, does not emit gases and does not allow water to pass through. This product is available in disc, plate and tube forms.

In addition to highly vulcanized rubber and sulfur, ebonite fillers include: ebonite dust, infusorial earth, talc, white soot, and pumice. To dye it black, a small amount of black soot is added to the composition. Refined rubber is used to make various products. Valuable varieties of ebonite contain exclusively rubber and sulfur.

Healing properties and photos of ebonite

Ebonite (Greek ebenos - ebony). This remedy is used to treat various diseases. The healing properties of the product are based on the restoration of the liquid crystal structure of the cell. The use of ebonite helps improve blood quality and the flow of oxygen to the massaged muscle tissue.

When an ebonite product (often an ebonite disc is used) is passed over the skin, the appearance of beneficial biocurrents is noted. The body responds by producing additional negative charges, which helps normalize blood circulation and activate metabolic processes in the painful area.

For the treatment of various pathologies, an ebonite disk with a wooden or ebonite holder, as in the photo, is usually used. In addition, ebonite is used to make candles, belts, necklaces and other massage devices.

The use of ebonite disk for the treatment of various diseases

Ebonite has an extremely beneficial effect on the human body. It is known about the anti-inflammatory, antispasmodic and analgesic properties of ebonite. Rubber products are used for therapy:

A few rules

The maximum therapeutic effect from the use of ebonite products can be achieved if they are used correctly.

  1. The duration of use is directly related to the condition of the cardiovascular system. For high or low pressure, the duration of the massage is 10 minutes. If there are no problems with the cardiovascular system, the procedure can be performed for 15 minutes or more.
  2. The basic massage movements are twenty circular movements clockwise and ten counterclockwise. If the massage is performed not by the person himself, but by an assistant, his free hand must necessarily touch the patient’s body so that a closed electrical circuit is formed.
  3. Do not wet the affected area before the massage. To make ebonite glide better over the surface of the dermis, you can sprinkle a little talc or powder on it. After the session, the disc must be washed in soapy water and wiped dry.
  4. The product should be stored in a place protected from sunlight. If the disk is exposed to sunlight, it may lose its healing properties and change its color; it will turn green.

Treatment of various pathologies with ebonite

This remedy, if used correctly and regularly, will help cure many ailments. The main thing is to consult your doctor before starting to use the technique.

Ebonite in the fight against felon. The person who will perform the massage should take the patient’s finger in his hand, and with his free hand massage the area above the hand with an ebonite disk. The duration of the procedure is a quarter of an hour. At night, it is recommended to bandage the product to the affected area. The duration of the therapeutic course is one and a half weeks.

Ebonite disc for the treatment of otitis media. The doctor inserts the middle finger of his left hand into the patient's ear, and massages with the other hand. The direction of movements during the massage is from the forehead to the left cheek, chin, right cheek. The duration of the procedure is a quarter of an hour. Next, you need to repeat the same steps, but without contact with the dermis (at a distance of two millimeters). Then the patient's face is massaged again. After the session, it is recommended to apply the disc to the sore ear and secure it with a scarf.

A rubber product against sinusitis, sinusitis and migraines. Move the disc from forehead to forehead to the left and right cheeks. The duration of the procedure is a quarter of an hour. The product can be left on the nose or forehead area overnight.

Treatment of bronchial asthma. The assistant needs to move the disc along the patient's back, first in a clockwise direction, then counterclockwise. The non-involved palm should be on the patient's chest. If a person suffers from shortness of breath, on the first day the massage is performed in the area of ​​the shoulder blades, and on the second - in the chest area.

Treatment of constipation and colitis. Every day it is necessary to massage the abdomen with an ebonite disk, clockwise. After a few minutes, rumbling in the abdomen and the release of gases may appear, and after a quarter of an hour, the urge to have a bowel movement should appear.

Ebonite promotes the removal of stones from the kidneys. It is necessary to massage your lower back every day. The duration of the procedure is ten minutes. Over time, the stones will dissolve and sand will appear in the urine. The duration of the therapeutic course is fifteen procedures.

Treatment of gastric ulcer. It is recommended to massage the abdomen in a clockwise direction every day for a quarter of an hour.

Ebonite in the fight against pneumonia. Massage promotes mucus separation and expectoration. The massage is performed in the area of ​​the shoulder blades for ten minutes every day.

Therapy of liver pathologies. Massage should be done in the liver area for 10 minutes every day. Before going to bed, it is recommended to tie the disc to the painful area.

Ebonite disc in the treatment of radiculitis. It is recommended to massage your lower back every day. In addition, it is useful to wear a belt made of ebonite plates three millimeters thick on your body. Treatment must be continued until the pain stops. At night, tape the disc to the painful area.

Therapy for barley. If there is redness or an immature abscess, massage the face and area around the eye for a quarter of an hour. After opening the stye, you need to rub your palm on the disc and apply it to the eye. Then apply gauze to the eye for about 10 minutes.

Treatment of joint ailments. Massage the affected joints with an ebonite disc. The duration of the therapeutic course is two weeks, then a week break and repetition of the course.

Ebonite for the treatment of hypertension. Massage the top of the shoulder, the back of the head, and the face. The duration of the procedure is 10 minutes.

Treatment of obliterating endarteritis. Tape the ebonite circle to the affected area.

Ebonite is a healing agent that will help in the treatment of a variety of ailments. The main thing is to use it correctly and with the knowledge of the attending physician.

Where can I buy? You can purchase ebonite products in the online store. The average cost of an ebonite disc is 1,500 rubles.

I found an ebonite disk at home. He is about 30 years old. Are its medicinal properties preserved?

Over time and under the influence of external factors, the surface layer of ebonite can oxidize. Boiling in a sodium sulfite solution will remove the problem.

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APPLICATION OF EBONITE

Ebonite is a type of rubber and its properties resemble plastic. For many decades, the use of ebonite was quite widespread. But the creation of modern plastic has significantly reduced the scope of use of ebonite. But despite this, such a substance is still produced and used for many purposes.

In what areas is ebonite used?

This material has many useful characteristics. It does not absorb moisture, is resistant to chemical influences and electric current, is highly polished and easy to process.

The use of ebonite has gained popularity in the following areas:

  • In the chemical industry;
  • In the manufacture of batteries;
  • For the production of souvenirs;
  • In the field of medical technology;
  • In radio electronics.

Modern science makes it possible to add various additives to this substance, changing some of its properties. As a result, there are quite a lot of areas where ebonite is used.

The only drawback of the material is its tendency to oxidize. It can be destroyed when interacting with certain acids. And when exposed to the sun for a long time, this analogue of plastic becomes covered with a green coating.

Forms

This material is resistant to cutting, drilling, grinding, etc. The industry produces mainly ebonite sheets and ebonite rods.

And then other, more complex parts and components are obtained from these forms. Processing of this component can be carried out both on machines and manually.

The material is not well known, but its use is quite developed: many parts of things and mechanisms known to us are made from it. This is one of the few substances that has not been replaced by modern analogues.

Source: http://msel.ru/articles/primenenie-e-bonita/

Features of materials and processes of ebonite production

Ebonite mixtures. Mixing a significant amount of sulfur with natural rubber (40-50 parts by weight) and then heating the mixtures leads to the production of a solid, horn-like substance of a dark color - ebonite. The significant chemical resistance of ebonite, its high dielectric properties and the ability to be well processed and polished made it possible to use it for the manufacture of products used in the battery, low-current industries and in various chemical industries. As a highly polishable material, ebonite has also found application for sanitary and hygienic products. A special feature of ebonite is its low heat resistance (more precisely, temperature resistance). Depending on the composition, ebonite, when heated within 60–120 °C, becomes less durable, softens and then easily undergoes deformation, retaining its given shape after cooling.

An unfilled (pure) mixture of rubber and sulfur produces high-grade hard rubber. However, the requirements for certain types of ebonite products and processing conditions make it necessary to add various ingredients to ebonite mixtures. The most important among them is ebonite dust, which is finely ground waste from ebonite production. The use of ebonite dust facilitates the preparation of the mixture, ensures a quieter course of the reaction between sulfur and rubber, and reduces shrinkage of the product. The content of ebonite dust in mixtures can be 30-300% (mass.) of rubber, depending on the purpose of the products and the requirements placed on them.

In the production of a number of ebonite products, regenerate and, more recently, polymerization resins are widely used. Ebonite dust, regenerate, and mineral fillers are essentially diluents of pure ebonite mixture. Their use facilitates calendering, profiling, molding and casting of mixtures; filled ebonite mixtures conduct heat better, and their shrinkage during vulcanization is reduced. To give ebonite greater heat resistance and hardness, pumice, talc, asbestos and kaolin are used.

Vegetable and mineral oils, pine resin and wax are used as softeners. During the vulcanization of ebonite, vegetable oils - linseed, rapeseed and others - react with sulfur, forming factis. The role of waxes—beeswax, ozokerite and ceresin—used as softeners is very peculiar. Waxes, with their significant content in ebonite products, migrate to the surface of the latter and reduce the wettability of products in humid air, thereby maintaining the dielectric properties of ebonite.

Usually ebonite is produced in black color. The production of colored ebonite is fraught with some difficulties, since in this case it is necessary to cover the black color characteristic of ebonite, which is more intense the higher the quality of the ebonite. To cover the black color in colored ebonite mixtures, zinc sulfide, lithopone and titanium white are used. Red and pink colors are given to ebonite by the addition of cinnabar, yellow - by the addition of cadmium sulfide. As accelerators for the vulcanization of ebonite mixtures, organic accelerators are used: diphenylguanidine, mercaptobenzthiazole, altax and VT sulfenamide, as well as inorganic ones: magnesium carbonate, light (burnt) magnesia, slaked lime, red iron oxide.

Currently, filled ebonite mixtures, but not containing ebonite dust, are produced in closed rubber mixers, but sulfur is introduced into them on rollers. Ebonite is formed both from natural rubber and from synthetic ones: SKV, SKS-ZOA, SKS-50, SKI and SKI with certain features depending on the type of rubber. Ordinary varieties of ebonite from natural rubber soften at 60-70 °C, and special ones - at 85 °C, but are more fragile. Ebonite made from styrene-butadiene rubber, although more heat-resistant, due to its inherent fragility, is rarely used. It is more resistant to oils and organic solvents, compared to ebonite from other rubbers, and is heat resistant up to 150 ° C. Ebonite made from nitrile butadiene rubber containing polar groups has significant dielectric losses. A number of special-purpose ebonites are made from a mixture of NC with butyl rubber and polychloroprene, the latter, acting as plasticizers, form ebonites with high impact resistance and greater elasticity. Ebonite from SKI is closest to ebonite from NK. Its chemical resistance can be improved by introducing additives of chlorinated and saturated rubbers.

In some cases, to obtain impact-resistant ebonites, mixtures of NC with phenolic or high-styrene resins are used. Bakelite spray introduced into ebonite mixtures can partly replace ebonite dust, but leads to an increase in hardness and heat resistance.

In the production of ebonite products, the following main groups of ebonite mixtures are used: for ornamental molded ebonite and for adhesive ebonite products.

Ornamental ebonite (plates, rods and tubes) is used for the manufacture of various telephone, telegraph and radio components. There are two types of ornamental ebonite: dielectric and technical. The mixture for hard rubber of the first type consists of rubber, sulfur, accelerators and softeners. This ebonite is well processed and polished. Ebonites of the second type, used in cases where dielectric properties are not required from the material, contain a smaller amount of rubber and have different amounts of fillers. Ebonites of this type have reduced strength, ability to be polished and processed.

Ebonite mixtures used for the manufacture of battery tanks, parts for them and other molded or cast products are classified as filled mixtures. Battery tanks, according to their operating conditions, must have a heat resistance of at least 50 ° C, which is achieved by adding pumice, kaolin or asbestos to the mixture. The use of the latter significantly increases the heat resistance of ebonite. Similar mixtures (volcano-asbestos) are used for the manufacture of vulcanization molds (matrices) in the production of soft rubber mats. The introduction of ingredients that increase heat resistance simultaneously increases the hardness of ebonite. To process such products, tools made of high-speed steel or with carbide tips are required.

For glued ebonite products, correspondingly less filled mixtures are used.

Features of ebonite vulcanization. The idea of ​​ebonite as an extremely structured product, in which all double bonds are saturated with sulfur, was formed and held for a long time. Calculated on the basis of this assumption, the vulcanization coefficient of ebonite seemed to be several times greater than the vulcanization coefficient of soft rubber. Recent studies have shown that although ebonite is characterized by the presence of a fairly dense network, not all double bonds in it are saturated; at the same time, there is a content of a significant amount of chemically, but not bridged, sulfur.

A. S. Kuzminsky and L. V. Borkova showed that in all ebonites formed from a mixture of rubber with sulfur, both the consumption and formation of double bonds occurs. The higher the vulcanization temperature, the faster the decomposition of double bonds occurs. At the first stages of ebonite vulcanization, polysulfide bonds containing up to 25 sulfur atoms are formed; subsequently the degree of sulfidity decreases.

Depending on the filling, ebonite mixtures are vulcanized at 120–170 °C. The kinetic curves for the formation of bound sulfur have a monotonic course, which accelerates significantly in the case of the addition of accelerators of the ebonite formation process. Simultaneously with the addition of sulfur, a number of physical and mechanical properties of the product change. In Fig. 93 shows the dependence of tensile strength on vulcanization time for natural rubber ebonite. Characteristically, there is a maximum and a minimum in the tensile strength curve. When the amount of bound sulfur reaches 10-15%, a flexible, leathery, but fragile product is obtained. Further vulcanization leads to the gradual formation of a hard, springy product with increasing tensile strength. The physical properties of individual ebonite samples depend on the composition of the mixture and the duration of vulcanization, but the nature of the curves remains the same. Over-vulcanization of ebonite causes increased fragility. In this state, ebonite is prone to cracking and splintering. In a normally vulcanized product, the tensile strength reaches 7.0 kN/cm2, with very low elongation; the latter decreases along a monotonically falling curve.

The kinetics of changes in the hardness of an ebonite mixture without an accelerator is shown in Fig. 94. After approximately half the time required for hard rubber vulcanization, the curve becomes parallel to the x-axis; then the hardness increases rapidly. The use of accelerators, reducing the vulcanization time, evens out the course of the hardness curve; the characteristic inflection of the curve disappears. In Fig. 95 shows the hardness curves of the ebonite mixture, which had the same composition, but a variable (0.5-10%) content of mercaptobenzthiazole (captax). The lower part of the curve and the transition plateau fade out, but the slope of the upper part of the curve increases with increasing accelerator dosage. It is noted that the continuation of the solid lines in Fig. 95 for natural rubber ebonite comes almost to the origin. A study of the kinetics of changes in the hardness of ebonite without vulcanization accelerators (Fig. 94) and with the accelerator mercaptobenzothiazole (captax) also reveals (Fig. 95) three stages in ebonite formation, but not characteristically expressed. With a high accelerator content, the first and second stages are practically impossible to trace.

Changes in the kinetic dependence of the amount of bound sulfur, strength and relative elongation of ebonite made of synthetic rubber (SKS-30), shown in Fig. 96, generally correspond to what was said above. The significant value of the “equilibrium modulus” of ebonite, compared to £oo for soft rubber, indicates that the density of the network created by the completion of ebonite formation is several times higher in density than the spatial network of soft vulcanizate.

Following the ideas developed by B.A. Dogadkin, for mixtures of natural rubber with a low sulfur content, the maximum on the kinetic curve of tensile strength reflects the presence of two simultaneously occurring but differently directed processes: the structuring of rubber chains by sulfur and their destruction by oxygen. The maximum strength of the vulcanizate corresponds to the moment when almost all the sulfur is attached to the rubber.

A different phenomenon is observed for mixtures of natural rubber containing 7% sulfur or more. And in this case, a spatial network is formed from molecular chains, and with increasing density of this network, the tensile strength of the vulcanizate also increases, but only until the increasing density of the network becomes a significant obstacle to the orientation of the chains. Maximum strength will occur when 3.5% sulfur is added to the rubber. Following this, with further addition of sulfur, a drop in tensile strength should be observed, which in fact occurs.

When vulcanizing mixtures with a low sulfur content from sodium-butadiene and butadiene-styrene rubbers, for which molecular oxygen is, like sulfur, a structuring agent, the maximum strength on the kinetic curve appears much later than the complete transition of sulfur to the bound state. Mixtures with a high sulfur content behave in the same way as mixtures based on natural rubber.

Based on the research of B.A. Dogadkin regarding the considered case of vulcanization of ebonite mixtures, it can be assumed that the decrease in tensile strength in the intermediate product, which gradually loses its highly elastic properties, continues until further thickening of the network leads to the disappearance of the ability to form areas with molecular chains, oriented in the direction of tension. This position corresponds to the minimum on the kinetic curve of the tensile strength of the ebonite mixture vulcanizate. Then, since sulfur is present in the mixture in sufficient quantities, and also (for mixtures of synthetic rubbers) due to thermal condensation of the rubber hydrocarbon (at 170 ° C), further addition of sulfur occurs both in bridged form and in another form of chemically bound sulfur .

The external manifestation of these processes is a monotonically increasing increase in the strength of the product, but no longer as a highly elastic body, but as an ordinary elastic body. The nature of the resulting structures is affected by: the type of rubber used, the temperature of the heating medium, as well as the increase in temperature inside the vulcanizing mixture due to the exothermic nature of the sulfur addition reaction. The transition from a plastic mixture to a highly elastic product, and from it, through an intermediate one, to a solid elastic material is characterized by a change in the chemical composition, in particular, an increase in the content of bound sulfur. However, assessing ebonite on this basis by determining the amount of free sulfur is labor-intensive and time-consuming.

Based on the fact that during the formation of ebonite the elastic properties of the material change significantly, the minimum characteristic of this process on the kinetic curve can be clearly and conveniently detected by the change in elastic rebound.

In Fig. Figure 97 shows the kinetics of changes in elastic rebound for five hard rubber mixtures of the following composition:

In Fig. 98 compares changes in elastic rebound, hardness, impact fracture resistance and heat resistance with the duration of vulcanization (mixture No. 1).

By using accelerators, it is possible to reduce the time of the vulcanization process; various accelerators, taken in appropriate quantities, increase the rate of ebonite vulcanization to approximately the same extent. It can be assumed that accelerators facilitate the physical conditions for the interaction of reagents, in particular the diffusion of sulfur, and their function is reduced to a rapid increase in the content of bound sulfur. Mixtures with accelerators require the same amount of sulfur as mixtures without accelerators.

The temperature coefficient of vulcanization of ebonite is slightly higher than for soft rubber, and increases with the vulcanization temperature: at 140–150 °C it is 2.52, and at 160–170 °C it reaches 3.13.

In connection with the observed linear dependence of the change in hardness on the duration of vulcanization at the stage of completion of ebonite formation, a method was proposed for calculating the required duration t of vulcanization time of ebonite from natural rubber to obtain a hardness corresponding to 100 units (Shore) using the following dependence.

Coefficient r depends on the vulcanization temperature. For a zinc oxide mixture (type No. 1 with 0.56 parts by weight of zinc oxide), the value of I corresponds to 0.30 at 140 °C; 0.76 at 150 °C and 2.15 at 160 °C. The value of this coefficient also depends on the type and amount of the accelerator and reaches a maximum close to 1.9, but at different dosages: from 0.7% for tetraethylthiuram disulfide to 7.5% m, m',1 mercaptobenzthiazole.

The value of the coefficient f in unfilled mixtures with normally i(.mystified rubber with an accelerator, for example zinc oxide, is actually close to zero. The introduction of fillers increases f:

The value of the coefficient f when filling:

The greatest effect is provided by magnesium oxide, which also corresponds to its use as a conventional inorganic accelerator of ebonite mixtures. However, equation (4.1) does not take into account the heat released during the vulcanization of hard rubber; therefore, its use is relatively limited.

The formation of a chemical product from a mixture containing sulfur is an exothermic reaction and is accompanied by heat release. The amount of heat released, the moment of maximum temperature rise and the magnitude of its excess over the temperature of the vulcanization coolant are functions of the vulcanization temperature, the thickness of the sample and the presence of an accelerator in the ebonite mixture. The heat release does not proceed evenly; the maximum heat release corresponds to the moment when approximately half of the sulfur is bound to the rubber. With the heat capacity of ebonite equal to 1.42 J/(g-K), heat release leads to significant heating. The need for timely heat removal is a characteristic feature of ebonite vulcanization. This heat removal is especially necessary in the case of thick ebonite products. The thermal conductivity of ebonite is 1.62 J/(cm-s-K). Insufficiently rapid heat removal will lead to the fact that heating the ebonite will accelerate vulcanization in the inner layers; the properties of the vulcanizate in the center of the product and in the outer layers will be different - the result will be a heterogeneous product. In more serious cases, thermal decomposition of the material may occur, accompanied by a significant release of hydrogen sulfide and other gases, the formation of pores and even an explosion. This phenomenon is called “burning” of the mixture. Since heated ebonite is fragile and very soft, the released gases contribute to the formation of pores throughout the entire mass of the product.

The release of hydrogen sulfide into the air can cause poisoning of workers in the workshop. Even its relatively low concentration in the air, about 0.7 cN/m 3, with 15-30-minute exposure causes a number of painful phenomena. At higher concentrations of hydrogen sulfide in the air, severe forms of poisoning with fatal consequences are possible. Hydrogen sulfide can enter the workshop atmosphere either along with steam through a safety valve in the event of a rapid increase in pressure in the boiler (due to abundant gas formation), or when opening the boiler lid after vulcanization is completed, or through condensate - in the case of an unsealed or faulty pipeline. Combustion of ebonite is usually observed at high vulcanization temperatures, with unfilled mixtures, as well as with mixtures with accelerators.

Temperature regimes for vulcanization of ebonite products, set taking into account this feature, are very diverse. The addition of inert ingredients or ebonite dust to the mixture, acting as diluents, reduces the risk of combustion. Vulcanization of such mixtures in metal molds, due to good heat removal by the metal of the mold, successfully occurs at 160-170 °C. Pure ebonite mixtures, in contrast, are characterized by the use of a low vulcanization temperature, its significant duration, stepwise heating and cyclical (repetitive) process. Vulcanization of thick ebonite rods with a diameter of 65-100 mm is carried out for hours and even days, distributing it into cycles with breaks. Uniform heating of the workpiece and a significant improvement in heat removal are achieved by placing the products vulcanized in the boiler in a bath filled with water.

An exothermic reaction that has begun cannot be stopped by lowering the temperature in the vulcanizer; it can only be prevented by a timely decrease in temperature before significant heat generation begins. By studying the temperature of the vulcanized product using thermocouples, it is possible to create a vulcanization regime in which the temperature progression in the ebonite will be almost identical to the temperature progression in the boiler. The use of accelerators requires a particularly clear design of the vulcanization regime.

Vulcanization of ebonite products in boilers requires special attention. A significant amount of sulfur in ebonite mixtures leads to the formation of gaseous sulfur compounds that corrode the walls of vulcanization boilers. For the manufacture of boilers, corrosion-resistant metal should be used, or the inside of the boiler walls should be coated with a protective layer. It is known, for example, that the addition of copper significantly increases the resistance of the boiler metal to the vulcanization environment. In addition to copper steels, chromium-nickel steels and others are distinguished by great resistance. Lead and duralumin are used as protective coatings. A homogeneous and sufficiently thick layer of lead can be firmly applied either by surfacing lead onto a previously well-cleaned and tinned surface of boiler sheets, or by galvanic coating. Duralumin is used for boiler lining. Waste water (condensate) from ebonite production must be cleaned of hydrogen sulfide and sulfur dioxide before being discharged into the sewer system. To do this, the vented gases and condensate are sent to special cleaning devices - absorbers. Absorption of gases is carried out with water or an alkali solution.

Methods for assessing the properties of ebonite. In accordance with the variety of operational requirements placed on ebonite, a number of methods have been proposed for assessing its physical, mechanical and electrical properties.

The following definitions are generally accepted for assessing the physical and mechanical properties of ebonite:

a) temporary resistance during static bending (GOST 255 - 41);

b) hardness on a Schopper hardness tester (GOST 254 - 53);

c) heat resistance according to Marteis (GOST 272 - 41);

d) fragility on a pendulum pile driver (GOST 258 - 41);

e) shear resistance (GOST 211-41);

f) tensile strength.

The principles of definitions and methods of conducting physical and mechanical tests of ebonite are essentially the same as for solids and plastics. More specific is the determination of the heat resistance of ebonite (GOST 272 - 41), based on the bending of standard size samples under the influence of a constant bending moment and with a uniform increase in the temperature of the environment. However, the uncertainty of the time required for proper heating is a disadvantage of this method. The greatest changes (lower heat resistance) are produced by ebonite made from natural rubber. Ebonite made from butadiene-nitrile acrylic rubber is the most heat-resistant.

To assess the dielectric properties of ebonite, the following determinations are made:

a) volumetric and surface resistance (GOST 6433-65);

b) average breakdown voltage (GOST 6433-65);

c) dielectric constant of hard rubber at frequencies of 10 6 Hz (GOST 9141 - 65) and 50 Hz (GOST 6433 - 65).

Dielectric losses are determined by the amount of energy released in a dielectric placed in an electric field. With a constant electric field, a conduction current is established in the dielectric, i.e., the movement of electrons and ions through the dielectric. For most dielectrics, this current is very small and determines the volume resistance of the dielectric. Before this constant conduction current is established, starting from the moment the voltage is applied, a current is observed that is many times greater than the conduction current, but lasts for a short time. This increase in current is determined by the phenomena of displacement and polarization of the dielectric. In an alternating electric field, energy is spent not only on the transfer of electrons and ions through the dielectric, but mainly on the polarization of the dielectric and processes associated with the rotation of dipoles (the active component of the current). Due to the fact that the losses determined by the conduction current are insignificant, dielectric losses are usually understood as losses due to the polarization of the dielectric and rotation of the dipoles.

Polarization of a dielectric occurs under the influence of an electric field created in the dielectric and represents a displacement of charged particles of atoms and molecules of the dielectric. When the field is removed, these charges, moving in the opposite direction, create a current that drops to zero. Changing the direction of the external field causes the opposite phenomenon; this leads to the expenditure of energy on the rearrangement of charged particles. A similar process occurs in the case of dielectric inhomogeneity. The boundary of regions with different dielectric constants serves as a place for accumulation of charges, and the current will arise due to changes in the magnitude of these charges over time. In the presence of dipoles in a dielectric, energy is spent on rotation (orientation of dipoles), i.e., on overcoming friction forces determined by the viscosity of the medium.

If there were no energy losses in the dielectric of the capacitor, then the flowing current would be shifted relative to the voltage by an angle φ = 90°. In this case, the active power P consumed by the dielectric of the capacitor would be equal to zero, since cos ср 90° = 0. But in real conditions, the active power consumed is not zero, and therefore cos f (power factor) is not equal to zero. Since the active power absorbed by a capacitor is proportional to tan6, i.e., the ratio of the active current ta to the reactive current ip, tan6, called the dielectric loss tangent, is a measure of the ability of a dielectric to convert energy supplied to it into heat.

During the vulcanization of an ebonite mixture, tg b increases rapidly at first, but with further vulcanization, as the ebonite hardens, it decreases, reaching a minimum at 100-120 minutes; further there is a slight increase in tg b. The smaller the angle b, the better the ebonite (as a dielectric). It should be noted that the voltage at which breakdown occurs is not a linear function of the thickness of the sample, but grows slowly as the thickness increases; it also depends on the duration of the test.

As a result of the action of light on the surface of ebonite, a decrease in its specific surface resistance is observed. This happens because, under the influence of light, a conductive film of sulfurous acid is formed. Removing such a film restores the previous properties of ebonite. An effective means of protection, apparently superior to waxing, is the use of di-B-naphthyl-n-phenylenediamine (Edgeright white).

Source: http://reziny.ru/stati/tehnologija-proizvodstva/yebonitovye-izdelija/osobennosti-materialov-i-processov-yebon.html