Compound is a reliable protection of equipment from aggressive environment

2024 Author: Sierra Becker | [email protected]. Last modified: 2024-02-26 03:46

In electrical engineering, we often come across the concept of "compound". What is it? A compound is an insulating composition that is liquid at the time of use, and then hardens, does not contain solvents. The compound does not lose its properties at temperatures from -50 to +200 degrees Celsius, is resistant to radiation, is intended for impregnation, casting of components, parts of radio equipment, electrical engineering, for protecting printed circuit boards and their components from external influences (mechanical, thermal, chemical, vibration), especially in aggressive environments. After all, the conditions under which it is necessary to operate radio-electronic and electrical devices and apparatuses are far from laboratory ones. These are the low temperature of the Far North, and the high humidity of the tropical climate, and the aggressive environment of outer space, etc. All of the above forces development engineers to use, along with moisture-repellent coatings, compound materials for pouring and sealing elements and equipment for protection. Most often, two-componentmixes.

By properties, compounds are divided into:

- impregnation;

- electrical insulating;

- filling;

- elastic;

- plasticized with rubber;

- with low molecular weight plasticizer.

Impregnation compound is a composition that is used to impregnate the windings of electric motors and devices.

Insulating, in turn, are divided into:

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

- thermoplastic (soften when heated) - bitumen, waxy dielectrics, thermoplastic polymers (polystyrene, polyisobutylene).

Sealing compound is a compound designed for filling cavities in cable joints, as well as for sealing in electrical machines and devices.

Electrical insulating mixtures are made from methacrylic esters, used as both impregnating and filling. Such compounds, after hardening at a temperature of 70-100 degrees Celsius (with a special hardener, this threshold drops to 20 degrees), become thermosetting and can be used at temperatures from -55 to +105 degrees. They are used to impregnate various types of rotating equipment (coils and windings of electric motors, etc.), which provides effective protection against electric current.

Filling compound based on bitumen in terms of heat resistance (105 degrees) belongs to class "A". Epoxy resins have the highest heat resistance.organosilicon compounds.

Elastic, rubber-plasticized compounds have found particular use. Today, mold compound is very popular. Flexible silicone injection molds of various configurations are made from it. The temperature regime of such a compound reaches a limit of up to +200°C, it is not recommended to heat it above 250°C, because polymer bonds are destroyed.

Currently, various brands of compounds are produced, each of which has found its own field of application and has properties characteristic of it.

Epoxy compound has become the most popular - it is a polymer with low shrinkage, excellent dielectric characteristics and high adhesion. It is able to work in conditions of constant deformation. Epoxy resins are widely used in various types of equipment, installations, structures. These mixtures are also compatible with other oligomers, and their curing 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 equipment that operates in rather harsh conditions.

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