Fast-bonding varnish: accelerating the electrical steel strip plate stamping and bonding process
Compared to conventional bonding varnish technology, the new high-speed bonding varnish offers a significantly faster curing reaction when bonding electrical steel strip plates into lamination stacks. This is made possible thanks to innovative advancements to the previous coating system. Depending on the processing method and component size, the time needed to cure electrical steel strip coated with the new bonding varnish has been reduced from 1.5 hours to just a few minutes.
The advantage of this is that stamping and bonding the electrical steel strip lamination stacks can be carried out in only one process step thanks to the shortened curing reaction. In this context, other parameters such as temperature and pressure remain similar to conventional bonding varnish processing. The considerable time savings make the production of lamination stacks particularly cost-effective for customers.
Like all of the coatings for electrical steel strip used by Waelzholz, the new fast-bonding varnish is water-based and thus also meets the high environmental compatibility requirements of modern bonding processes.
Electrical steel strip lamination stack manufacturing process
Stamping and bonding process of lamination stacks made of electrical steel strip coated with fast-bonding varnish.
Undisturbed magnetic flux maximizes efficiency of high-performance electric motors
For more than 20 years, Waelzholz has been offering its customers bonding varnish technology as a method of joining electrical steel strip plates. Unlike stamping, welding, or riveting, bonding with bonding varnish does not cause any stresses or material deformation due to contact points between the plates that could damage the material. This preserves the key material properties of the electrical steel strip and thus its undisturbed magnetic flux. In addition, the “frequency hum” that can occur with conventional bonding technologies does not occur.
Coating systems
| ASTM class |
IEC class | Waelzholz- coating type |
Color | Thickness per side |
Continuous thermal resistance under air |
Annealing resistance under inert gas |
Weldability | ||
| [µm] | IEC 60404-12 [°C] | IEC 60404-12 [°C] | SEP 1210 | ||||||
| C-3 | EC-3 | PE75W (bonding varnish) | transparent | 3 - 6 | 180 (*) | ○ | ○ | ||
| PE49 (bonding varnish) | transparent | 3 - 6 | 180 (*) | ○ | ○ | ||||
| PE75W-Fast (fast-bonding varnish) | transparent | 3 - 6 | 180 (*) | ○ | ○ | ||||
| PE49-Rapid (fast-bonding varnish) | transparent | 3 - 6 | 180 (*) | ○ | ○ | ||||
○Less suitable
Our electrical steel strip with bonding varnish coating plays a key role in many applications, such as in the automotive industry, the energy sector, as well as the industrial sector. For example, Waelzholz’s bonding varnish technology is particularly suitable for the production of high-performance lamination stacks for generators in the electric motors of cars, wind turbines, or high-quality household appliances.
Visit us at Coiltech in Pordenone, Italy from September 22 – 23, 2021, Hall 5, Booth D32-D34, to learn more about the new fast-bonding varnish from Waelzholz. Or contact our electrical steel strip specialist directly: