Compound is a reliable protection of equipment from an aggressive environment

In electrical engineering, we often meet with the concept of "compound". What is it? Compound is an insulating compound, which at the time of use is liquid, and after curing, does not have solvents in its composition. The compound does not lose its properties under temperature conditions from -50 to +200 degrees Celsius, has a radiation resistance, is intended for impregnation, filling of components, radio equipment, electrical equipment, to protect printed circuit boards and their components from external influences (mechanical, thermal, Chemical, from vibration), especially under conditions of an aggressive environment. After all, the conditions under which it is necessary to operate radioelectronic and electrical devices and devices are far from laboratory. This is the low temperature of the Far North, and the high humidity of the tropical climate, and the corrosive environment of outer space, etc. All of the above compels the development engineers to use compound materials for filling and sealing elements and equipment along with moisture-repellent coatings. Most often, two-component mixtures are used for these purposes.

By properties, the compounds are divided into:

- impregnating;

- electrical insulating;

- filling;

- Elastic;

- plasticized with rubber;

- with a low-molecular plasticizer.

Impregnating compound is a compound that is used for impregnating windings of electric motors and apparatus.

Electrical insulating, in turn, are divided into:

- thermosetting (do not soften after hardening). These include epoxy, polyester and other resins;

- thermoplastic (softened by heating) - bitumen, waxy dielectrics, thermoplastic polymers (polystyrene, polyisobutylene).

Pouring compound is a compound intended for filling cavities of cable joints, as well as for sealing in electric machines and devices.

Electrical insulating mixtures are made from methacrylic esters, used as impregnating agents as well as for casting. Such compounds, after solidification at a temperature of 70-100 degrees Celsius (with a special hardener this threshold is reduced to 20 degrees), become thermosetting and can be used at temperatures from -55 to + 105 degrees. They are used for impregnation of various types of rotating equipment (coils and windings of electric motors, etc.), which gives an effective protection against electric current.

Compound pouring on the basis of bitumen by the level of heat resistance (105 degrees) belongs to the class "A". The highest heat resistance is possessed by epoxy and organosilicon compounds.

Elastic, plasticized rubber compounds have found particular application. Today the compound for forms is very popular. From it, flexible silicone molds of various configurations are made. The temperature regime of such a compound reaches a limit of + 200 ° C, it is not recommended to heat it above 250 ° C, because the polymer bonds are destroyed.

At present, various brands of compounds are produced, each of which has found its application field and possesses the properties characteristic of it.

The most popular epoxy compound is a polymer with a low shrinkage, excellent dielectric characteristics and high adhesion. It is able to work under conditions of constant deformation. Epoxy resins are widely used in various kinds of equipment, installations, structures. These mixtures are compatible with other oligomers, and their solidification is accelerated by mixing with other compounds. The disadvantage of the epoxy compound is the low operating temperature, which makes it impossible to use it in a technique that operates under rather harsh conditions.

Summarizing, we can say that the use of compounds increases the reliability of work and increases the service life of electronic devices and electrical equipment, provides their sealing and protection from vibrations, helps protect consumers from electric current.