What is impregnation process?
Impregnation is the classic and the simplest procedure to load a given porous support with the metal component in the solid-state way (physical mixture of both component in solid state) or more commonly via wet impregnation (physical mixture of the support in solid state and the metal component dissolved in a liquid …
What is VPI varnish?
VPI (Vacuum Pressure Impregnation) is a process that is a technological step forward from varnishing electric motors. The old dip and bake (in varnish) method of “insulating” motors is replaced by the VPI process for specific reasons: Harsh Environment. Improved Efficiency (through better heat transfer)
What is the difference between impregnation and embedding?
Impregnation is the process of complete removal of clearing reagents by substitution of paraffin or any such similar media such as beeswax. After complete impregnation with a suitable medium, solid block of suitable medium containing impregnated tissue is obtained by a process called embedding.
Is used for impregnation process?
Styrene- based, vinyltoluene-based and low emission systems can be used for the impregnation of electrical windings in motors and transformers. And it’s possible to have an environmentally responsible impregnating process with our monomer-free and low viscosity impregnating resins.
What is VPI process?
Vacuum Pressure Impregnation (V.P.I) is a process by which a fully wound electric apparatus stator or rotor is completely submerged in a Resin. Through a combination of dry and wet vacuum and pressure cycles, the resin is assimilated throughout the insulation system.
What is VPI treatment?
VPI – VIP treatment for windings There are usually two ways motors are treated to resist moisture. One is dipping the winding in a polyester or epoxy resin, to creates a moisture-resistant coating. The other – more effective method – is Vacuum Pressure Impregnation (VPI) of the winding.
What is an Autotechnicon?
Overview. Autotechnicons make sample processing quick and painless. The various solutions used for processing tissue are placed into ten separate nylon beakers. These beakers are placed on the circular deck of the instrument. There are also two paraffin baths that are mounted on the deck.
What are disadvantages of automatic tissue processing?
Disadvantages include inability to cut thin sections, storage of blocks in alcohol and speed of technique (which can take several weeks or months). This is harder than paraffin wax and has a lower melting point (46-48oC). Good for cutting hard tissues since it does not crumble.
What is metal impregnation?
Resin impregnation refers to the sealing of porosity which occurs in manufacturing processes such as casting and sintering. Through vacuum and/or pressure methods, polymer resin is forced into the porosity and then cured to form a pressure tight part.
What is vacuum impregnation plant?
Vacuum Pressure Impregnation (VPI) is a process that uses vacuum and pressure to seal porous materials with varnish or resin. The process is used primarily for high-voltage motors and generators to fill gaps in materials to create a void free insulation in various devices.
What causes VPI?
What causes velopharyngeal insufficiency (VPI)? The most common cause of VPI is a cleft palate, a birth defect in which there is an opening in the roof of the mouth because the palate didn’t form properly. Repair of the cleft palate may or may not also eliminate the VPI problem.
What is the function of Autotechnicon?
This method makes use of an automatic tissue processing machine (i.e. Autotechnicon) which fixes, dehydrates, clears and infiltrates tissues, thereby, decreasing the time and labor needed during the processing of tissues, resulting in a more rapid diagnosis with less technicality.
How is vacuum pressure impregnation used in electric motors?
The Vacuum Pressure Impregnation (VPI) Process. The VPI process is a significant technological advancement over the traditional “dip in varnish and then bake” approach used to insulate electric motors. In place of standard insulating varnish for electric motors, a special VPI epoxy insulation is used on the coils.
What are the four steps of vacuum impregnation?
In general, all vacuum impregnation process types follow the same four steps: Impregnation-Impregnate the sealant into the porosity/leak path using vacuum (and pressure). Excess Sealant Recovery-Remove excess sealant through gravity, rotation or centrifugal force.
What is used to impregnate a vacuum chamber?
In place of standard insulating varnish for electric motors, a special VPI epoxy insulation is used on the coils. The preheated stator or rotor is then lowered into the VPI pressure chamber and a vacuum is drawn. As that occurs, a solventless epoxy resin is drawn into the chamber until the unit is completely submerged.
How does vacuum impregnation work in DVP system?
As in the DVP system, vacuum is held until all of the air is evacuated and upon completion of the vacuum cycle the transfer valve is opened, and the sealant (shown in green) is de-gassed and pulled from the reservoir to the autoclave while the vacuum is maintained. Next, the vacuum is released. No pressure is applied.