MT-EL-HLF59R is a one part, 100 % solids, epoxy powder coating for insulation of wire and busbars. Designed for electrostatic spray application it has excellent resistance against heat, chemicals and moisture. The coating has a good edge coverage and flexibility. It is serviceable up to 130° C.
| Typical value | Method | |
| Binder System | Epoxy resin | |
| Density | 1.75 – 1.85 g/cm³ | ISO 8130-2 |
| Gel time at 200° C | 30 – 50 sec. | modified ISO 8130-6 |
| Storage stability | 6 months from date of manufacture at ≤ 23° C | |
| Preheating temperature | 190 – 235° C object temperature | |
| Post cure conditions | 5 – 10 min. at above temperature | |
| Particle size distribution | < 32 µm = 25 – 40 % < 160 µm > 99.5 % | Malvern ISO 8130-1 |
| Color | grey, ca. RAL 7047 | |
| Recommended film thickness | 200 – 300 µm | |
| Flow | smooth | |
| Gloss at 60° angle | 40 – 60 units | ISO 2813 |
| Cross cut | Gt 0 | DIN EN ISO 2409 |
| Impact resistance | > 5 Joule | DIN 3476-1 |
| Elongation | > 5 % | DIN 3476-1 |
| Hardness | > 100 | DIN EN ISO 2815 |
| Pencil hardness | 5 H | DIN EN 13523-4 |
| Glass transition temperature |
65 ± 7° C (Tg1) 112 ± 5° C (Tg2) 40 – 60 J/g (Delta H) |
ISO 11357-2 Inflection point Inflection point |
| Temperature index | 130° C (Class B) | IEC 60216-1 |
|
Water absorption (40 h / 23° C) |
< 1 % | ASTM D 570 |
| Thermal conductivity | 0.4 – 0.5 W/(m·K) | DIN EN 821 |
| Specific surface resistivity | > 1013 Ω | IEC 60093 |
| Dielectric strength | 45 kV/mm | IEC 60243-1 |
|
Dissipation factor tan δ, 25° C Dissipation factor tan δ, 105° C |
< 0.01 < 0.01 |
ASTM D 150 ASTM D 150 |
| Dielectric constant (100 Hz – 1 MHZ) | 4.0 | ASTM D 149 |
| Comparative tracking index (CTI) | CTI 600 / CTI 175M-1.1 | IEC 60112 |
| UL 94 Vertical Burning Test | V-0 | IEC 60695-11-10 |
| Hot wire ignition (HWI) | ≥ 120 sec. | IEC 60695-2-20 |
| High current arc ignition (HAI) | ≥ 150 | UL 746A Section 32 |
Busbars are metallic conductors used in power distribution systems (switchgear, panels, electrical enclosures) that carry high currents. Applying a powder coating by electrostatic spray provides both insulation and environmental protection, enabling reliable performance in industrial and electrical equipment environments. Powder coatings form a smooth dielectric layer that improves insulation and protects against corrosion, moisture, and mechanical damage.
Epoxy powder coatings are widely used to insulate busbars because they provide a continuous, crack‑free protective film with excellent dielectric strength and mechanical resistance. The coating adheres uniformly to the conductor surface, which is important for maintaining electrical insulation and protecting against environmental stress such as moisture and corrosive agents.
Key advantages of epoxy powder coatings in busbar applications include:
High dielectric strength and electrical insulation
Smooth coverage even on complex geometries
Heat resistance suitable for elevated operating temperatures
Corrosion and moisture resistance enhancing lifespan
There are two common powder coating methods used for busbars: electrostatic spray application and fluidized bed dipping.
Electrostatic spray is especially effective for busbars with complex shapes and detailed geometries; it charges the powder and attracts it to the grounded part for high transfer efficiency (>95%).
Fluidized bed coating is often used when very thick insulating layers are required on simpler shapes and for mass production.
Electrostatic powder coating is favored when precise control over film thickness and localized insulation performance is required.
Powder‑coated busbars provide critical electrical performance improvements:
High dielectric strength: Good epoxy formulations withstand high voltages and reduce surface tracking and breakdown risk.
Increased insulation reliability: Uniform coatings prevent partial discharge and leakage current paths.
High surface resistivity: Excellent resistivity (>10¹³ Ω) supports reliable insulation.
Tracking and arc resistance: High CTI values reduce the risk of surface arcing in high‑voltage environments.
Flame retardancy: Some epoxy coatings achieve UL 94 V‑0 classification for fire safety.
These electrical properties are critical in ensuring safe, long‑term operation of power distribution systems.
Beyond insulation, epoxy coatings on busbars also support thermal and environmental performance:
Heat resistance: Well‑formulated coatings tolerate elevated current loads without degradation of insulation properties.
Moisture and corrosion resistance: Protective film shields busbar metals from environmental moisture and chemical exposure.
Lower temperature rise: By providing uniform insulation, powder coatings help reduce thermal hotspots and improve heat dissipation compared with uneven or inadequate insulating systems.
Applying powder coatings via electrostatic spray in a production setting offers these tangible benefits:
High transfer efficiency and minimal waste due to electrostatic attraction of the powder to the grounded busbar.
Consistent thickness control when process parameters (gun voltage, airflow, part positioning) are stable.
Rapid curing cycles when paired with controlled ovens, improving throughput.
Environmental compliance due to solvent‑free, low VOC emission processes.
Consistency in coating thickness is crucial: uneven thickness can create weak spots in insulation that lead to hotspots, partial discharge, premature failure, or arcing, affecting the safe performance of the electrical system. Process control in surface preparation, spray settings, and curing is key to achieving reliable electrical insulation performance.
Powder coatings can be categorized by resin system (epoxy, polyester, hybrid, polyurethane), appearance (smooth, texture, hammer, metallic, pearlescent), or performance level (anti-corrosion, heat-resistant, UV-resistant, architectural grade, automotive grade).
Powder coatings offer thousands of colors in gloss, matte, satin, metallic, candy, texture, wrinkle, hammer tone, wood grain, fluorescent, and other custom effects. Special powders can create soft-touch, anti-scratch, anti-fingerprint, or anti-graffiti surfaces.
The process generally includes surface pretreatment (degreasing, phosphating, chromating, sandblasting), drying, electrostatic spraying, curing in an oven, and cooling. A well-controlled pretreatment and curing process ensures strong adhesion and long service life.
Powder coatings are environmentally friendly, solvent-free, and produce minimal waste. They offer excellent corrosion resistance, weather durability, mechanical strength, and uniform film appearance. The coating is tough, impact-resistant, scratch-resistant, and has a long lifespan.
Powder coatings are widely used in appliances, aluminum profiles, architectural components, automotive parts, bicycles, furniture, outdoor equipment, machinery, electrical cabinets, pipeline systems, and general industrial and consumer goods.
Powder coating is a dry finishing technology where finely ground powder is electrostatically sprayed onto a metal or non-metal surface and then cured at high temperature. After curing, the powder melts into a continuous, durable, and decorative coating layer.
Powder coating protects the substrate from corrosion, weathering, chemical attack, and mechanical wear. It also provides decorative appearance with rich colors, gloss levels, textures, and special effects.
In many industrial applications, powder coating outperforms liquid paint. It forms a thicker and tougher coating, resists corrosion and chemicals better, and does not contain VOCs. It also provides excellent consistency and cost-effective mass production.
It is called powder coating because the coating material is a solid powder instead of a liquid paint. The coating is formed by melting and curing powder particles under heat.
Powder coatings include several families depending on resin chemistry:
• Epoxy powders
• Polyester powders
• Epoxy-polyester hybrid powders
• Polyurethane powders
• Acrylic powders
• Fluorocarbon (PVDF) powders
Each type has its own performance features such as corrosion resistance, UV resistance, chemical resistance, outdoor durability, or decorative properties.
Powder coatings are based on thermoset or thermoplastic resins combined with pigments, curing agents, fillers, additives, and in some cases metallic or effect particles. Common substrates include steel, aluminum, galvanized metal, MDF, and certain heat-resistant plastics.
The lifespan depends on powder type, film thickness, application method, pretreatment, and service environment. Indoor coatings can last more than 10–20 years. High-grade outdoor polyester or fluorocarbon powders can last 15–25 years or longer under UV exposure.
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