Varnishes and resins
Impregnation varnishes and resins
Coating varnishes
Specialties and auxiliary chemical materials
VARNISHES AND RESINS
We offer the products of the Swiss holding Von Roll - the world's leading manufacturer of electrical insulation products, including varnishes and resins. VON ROLL varnishes and resins for Europe are produced in Italy (Dolph’s brand) and France (Damival and Damisol brands). They are suitable for generators, high and low voltage motors, transformers and other electrical applications. The variety of VON ROLL products allows customers to use a single supplier for all insulation materials, with proven compatibility of all components of the electrical insulation system and highest expertise about the efficiency of insulation.
ACCORDING TO THEIR PURPOSE, VARNISHES AND RESINS ARE:
- Varnishes and resins for impregnation
- Resins for potting and encapsulation
- Coating varnishes
- Special varnishes and resins
VARNISHES AND RESINS FOR IMPREGNATION
Impregnation varnishes and resins are used for electrical insulation, protection and stabilization of the inductive windings of electrical machines. The impregnation of electric machines is a major part of their electrical insulation and especially for low-voltage electric motors is a mandatory part of their mechanical reinforcement. The choice of impregnation varnish or resin is difficult due to the requirements of the application and environmental considerations (odor, flammability, irritation, toxicity, etc.), process problems (stability, viscosity, reactivity, performance, etc.) and technical properties (thermal class, chemical resistance, electrical properties, bonding strength, etc.)
We offer a large range of resins and varnishes of VON ROLL, with or without solvents, brands Dolphon®, Hi-Therm®, AquaTherm® and Damisol® on polyester, epoxy and silicone basis, which make them suitable for any technological process and requirements.
TYPES OF IMPREGNATION:
- Impregnation by dipping
- Vacuum press impregnation
- Trickling impregnation
- Impregnation by roll through
IMPREGNATION BY DIPPING (immersion)
Immersion is the most common process for impregnating any type of low voltage electrical material, such as motors, generators or transformers. It is comprehensive and very easy to apply, without the need of complex equipment.
The impregnation varnish / resin is in an open tank / container, which can be preheated for greater productivity. The impregnation part is immersed in the container and after completely absorbing the impregnation material it is removed and drained. Then it’s baked in oven or in cases where self-drying varnish is used, the product is left at room temperature for about 24 hours.
VON ROLL offers many Dolphon®, Hi-Therm® and AquaTherm® products for this technology.
VACUUM PRESS IMPREGNATION (VPI)
VPI (vacuum press impregnation) is mainly used when the penetration and filling factor of the resin needs to be improved. The method requires specialized equipment to create underpressure and high pressure in a hermetically closed container where the impregnation part is housed. The impregnating resin is poured from another tank and subsequently withdrawn.
The impregnation process proceeds as follows:
1.The preheated part is placed in an airtight container and a vacuum is created by a vacuum pump. Transfer preheated object to vacuum vessel. Pull vacuum.
2.Stop the vacuum pump. Under vacuum, the part is filled with resin, which is allowed to absorb. Transfer resin under vacuum (the vacuum pump must be closed). Allow time to soak.
3.The vacuum is released and high pressure is applied.Release vacuum. Apply positive pressure.
4.Remove excess resin from the airtight container into the tank. The part is removed and placed in a baking oven. Transfer resin back to storage tank. Put object in oven and cure.
VON ROLL offers many Dolphon® and Damisol® products for VPI technology.
IMPREGNATION BY TRICKLING AND ROLL THROUGH
Trickling and Roll Through impregnation processes are very convenient when high performance is required for standard small / medium sized motors and generators. Both processes allow a higher varnish / resin fill ratio with lower material consumption. Due to the fact that they are hot processes, the quality maintenance of the resin must be carefully controlled.
VON ROLL offers a wide range of resins for these technologies - they combine safety, quality impregnation and fast processing.
COATING VARNISHES
Coating varnishes are mainly used to protect vulnerable and exposed components, both in electrical engineering and electronics. For electric motors, generators and transformers, the coatings protect against moisture, chemicals and dirt. For printed circuit boards, in addition to the specified protections, the coating (so-called "conformal coating") also protects against overheating. We also offer varnishes with UV sensitive fillers, with application for printed circuit boards, which allows UV tracing to control the coating, as well as coating varnishes curing with a UV lamp. Last but not least, the coating varnishes support the better vision of the products, especially of repaired electric motors and generators. A characteristic color of the coating is often used - red, green, gray and with the presence of enamel in the varnish an aesthetic effect is achieved. The top coat can be applied by brush, spray, painting gun or immersion. VON ROLL offers various solutions for coating varnishes of the Synthite® brand, and most of them, in addition to standard containers, can also be delivered in the form of a spray.
RESINS FOR POTTING AND ENCAPSULATION
Potting and encapsulating resins are two-component compounds used when sealing products and mechanical bonding and reinforcement are required. This is a solution for protection against pollution, shock and vibration, high chemical resistance, protection against moisture and last but not least - thermal conductivity. The Damival® and Dolphon® range offers various chemical compositions (polyurethane, epoxy, polybutadiene and silicone) to cover the main applications for engines, generators, electronics, electric vehicles. Von Roll offers on request other formulas than the range of standard chemical compositions. Polyurethane resins offer a cost-effective solution for mass applications. They are more plastic and perfectly absorb vibrations and dissipate heat. They have a large application in electrical machines, and with the advent of electric cars, more and more in the automotive industry. Epoxy resins have a higher hardness and are used where stronger bonding and resistance to extreme loads are required. Polybutadiene resins can largely r eplace silicone ones, offering better mechanical properties.