Waelzholz Backlack (variations: PE75W, PE49) bonds lamination stacks for electric motors with an impressive technique. Backlack bonds steel plates made from electrical steel strip without damaging the material, as opposed to conventional bonding processes such as welding, stamping and riveting, which leave contact spots behind. The advantage: The key material properties of electrical steel strip remain 100% intact when Backlack is used.
Lamination bonding with Backlack has a wide array of advantages: Not only does our bonding varnish technique leave the highly-important magnetic flux undisturbed, it applies no stress and does not deform the material, ensuring that the magnetic properties remain entirely intact. It also prevents frequency buzzing, which can be an issue with mechanical bonding methods. Our Backlack technology makes complex stack geometries possible without the need for follow-up fine-tuning to meet precision requirements. Lamination stacks bonded using Backlack are compact and waterproof. Innovative testing methods such as the LILIT system help us ensure that the Backlack is applied in a highly uniform manner over the entire length of a coil’s core and across batches.
Below is a comparison of the magnetic flux in mechanically bonded electrical steel strip stacks and those bonded using Backlack. The stacks bonded with Backlack enable undisturbed magnetic flux and keep the magnetic properties of the electrical steel strip intact.
The peeling test determines the peel resistance of electrical steel strip laminations bonded with Backlack. A minimum adhesive strength of 2 N/mm must be exceeded to peel away a lamination.
