Conductive paste is used to reduce resistance at electrical contact points.
What is the paste for
Even in the second half of the 20th century, scientists calculated that the loss of electricity in all areas of production is up to 10% of the total electricity consumption. This value increases as equipment ages and wiring deteriorates.
The easiest way to minimize losses without serious financial outlay was the use of special electrically conductive means. There is no need to repair equipment or replace wiring.
Electrical contacts have a lifetime. And it shrinks as the contact resistance changes. When exposed to electricity, the junction of the wires begins to warm up. This can even lead to fires. Statistics say that in 10% of cases, industrial accidents occur precisely because of the destruction of the contacts of the electrical network. And the destruction of this kind occurs precisely because of the excesslimit of electrical resistance.
For the treatment of contacts, the standards provide for substances such as lithol, cyatim, technical vaseline. All of them have a fat base. Due to this, such funds melt and burn out, leaving the contact unprotected. As a replacement for them, conductive contact paste has recently been increasingly used.
General concept
Conductive paste allows you to increase the life of electrical wiring contacts up to seven years. It reduces by half the value of the contact resistance at the points of electrical contacts. This tool works in temperature conditions up to 350-4000 degrees. In such conditions, it allows you to save all the functional features of the contact connections.
Separately, there is such a type of product as anti-corrosion conductive paste. In addition to the main tasks of reducing contact resistance, it protects contacts from moisture and aggressive environments.
Electrically conductive lubricants also perform an energy-saving function. Experts have calculated that the use of only 1 kg of the product can save up to 100 thousand kW of electricity per year.
Scope of application
Conductive paste for contacts is used in various areas of production and industry. The main ones are:
Metallurgical
Petrochemical
Mining and processing plant
Power plants of various kinds(thermal, nuclear, hydro)
Military equipment
Utilities
Transport
Repair of electrical circuits
Classification
Electrical conductive paste has two kinds. They differ from each other in the way they influence contacts:
Passive (it is also called neutral) is a kind of prophylactic that will protect contacts from oxidation under the influence of atmospheric oxygen. This group includes KBT contact conductive paste
Active does not affect the metal of the wires, but affect the oxidized areas located on the surface
Using the product
Conductive paste is easy to use. First of all, the surface to which the product will be applied must be degreased and dried.
Next, the pasta itself is prepared. As a rule, it consists of two components: a powder with the addition of metal, a liquid for diluting the powder. Therefore, the components must be connected. This is done in a dry container. You can even on cardboard, if the quantity is small. The paste should have a consistency similar to toothpaste.
The paste is applied to the prepared surface in a layer 2-3 mm thick. When connecting the contacts, their ends are simply lowered into the tool.
It is necessary to work with ready-made pasta quickly. It seizes in two minutes. Full dry time is two hours.
Making your own pasta
Conductive paste is commercially available ina wide range of products from various manufacturers. But you can also make your own.
The main component of the glue is synthetic resin. It does not conduct electricity in its pure form. Therefore, particles of metals are added to it - gold, copper, silver, nickel. To ensure good electrical conductivity, the powder volume should be at least 70%.
Silver is the most commonly used. This choice is based only on the economic side of the issue. The simplest and cheapest way to obtain it is by the chemical reaction of formalin reduction. For this, one part of silver nitrate and one part of formalin (1%) is taken. Their mixture is heated to a temperature of 80 degrees. After that, ammonia (5%) is added there. As a result of the reaction, a dark-colored silver precipitate will fall to the bottom. This precipitate is filtered, washed and dried.
When all the ingredients are ready, you can cook the pasta. To do this, combine 100 grams of epoxy resin, 250 grams of silver powder, 10 grams of dibutyl flatate (to make the resin more liquid consistency). Before use, add 10 grams of polyethylenepolyamine as a hardener. Without it, the mixture can be stored indefinitely.
You can increase the electrical conductivity of the paste if you dry it after application at an elevated temperature (up to 100 degrees).
Conductive media are chemicals that must be handled with basic safety precautions. The paste should not come into contact with the skin and mucous membranes.shells. If this happens, wash thoroughly with warm soapy water.
