Backlack Self Bonding Lamination Stacks In China

From stamping to stacking motor lamination stacks, we innovate step by step. Lamination bonding is a new technology in our company. The self-bonding process without the need for additional adhesives, results in a more streamlined and efficient manufacturing process.

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Self Bonding Lamination Stacks

Bonding Varnish/Backlack Technology To Bonding Lamination Stacks

Lamination bonding represents a groundbreaking advancement in the design and manufacturing of electrical machinery components. Stator rotor stacks the lowest iron loss for high-efficiency motors is important.

Stator and rotor cores are typically constructed from thin sheets of silicon steel, which are stacked together in order to minimize eddy current losses.

The laminations use bonding varnish/backlack to bonded in order to create a stable core. Unlike traditional methods that rely on interlocking teeth or welding points to secure laminations, This bonding lamination technology is used to reduce interlaminar loss and corrosion.

As a professional motor lamination stacks manufacturer, whether you need to integrate into the punching process (interlocking, full-face bonding, or spot bonding stacking process) or those downstream from the punching process (welding, cleating, riveting stacking process).

Motorneo custom tailors manufacturing and assembly solutions for your company’s specific assembly requirements.

self-bonding motor laminiation

Materials Used in Self Bonding Laminations

Bonding materials

EB540, EB546, EB548EB540, EB546, and EB548 are mainly used in large motor cores such as rail transportation and wind power.
EB549EB549 and EB549 Rapid are mainly used in small and medium-sized motor cores such as electric vehicle motors.
Magna-Tac E645Magna-Tac E645 is used for bonding stack laminations used in stators, rotors, gyros, servomechanisms, synchros, transformers, and magnetic amplifiers.
Magna-Tac F310Magna-Tac F310 is also designed for high temperature applications including motor laminates and transformer cores.
3M™ Scotch-Weld™ 22903M™ Scotch-Weld™ 2290 is ideal for coating on laminated steel cores of electric motor stator and rotor assemblies as well as coils.
Magna-Tac TR-8899Magna-Tac TR-8899 is a one part formulated thermosetting epoxy designed to adhere metals and alloys in transformer cores, as well as electric motor rotors and stators.
Z, Backlack, Suralac 9000Suralac 9000 Silicon steel motor stator laminations with C3 Back-lack Type insulation.
PE75W, PE49Waelzholz’s bonding varnish (variations: PE75W, PE49) bonds lamination stacks for electric motors.
Permabond®Permabond single component epoxies, surface activated acrylics, cyanoacrylate, and UV/Anaerobic cure adhesives to adhesives electric motor laminations.
DECJ0705DECJ0705 is suitable for brushing and bonding between silicon steel sheets in the stator core of high-voltage large generators during the lamination process.
DELO DUALBOND HT2990DELO DUALBOND HT2990 is a high temperature resistant structural adhesive capable of light prefixation. It is mainly used for lamination bonding and lamination stacking in motor manufacturing.

electrical steels materials

B20AT1200B20AHV1200B27HAV1400B30AHV1500B30AHV1500 – Z1
B35A250B35A250 – ZB35A270B50A310B50A470 – Z
30SWH150035SW270 – Z135SWH190035SWYS500050SW400
50SW400 – Z120TWV120020TWV1200 – Z125TWV130027TWV1400
27TWV1400 – Z135TWG250 – Z35TW25050TW40010JNEX900

Other materials

Amorphous Metal AlloysNi-Fe Magnetic AlloyCobalt Fe 1J22/Hiperco 50Nickel Fe 1J50/VACOFLUX 50Cobalt-Fe Magnetic Alloy

Adhesive Bonding Process Of Lamination Stacks

electrical steel coating



Our Lamination Bonding process uses a roll coat process that applies an insulating adhesive bonding agent to the motor lamination sheets.




The bonding agent is then hot cured. In case of moderate curing temperature a dry, flexible and still reactive coating can be achieved.

bonding varnish curing
prototype motor lamination


Stamping Or Laser Cutting Or Wire-EDM Cutting

The coated lamination sheets are often punched, laser-cut, or wire-EDM into the desired shapes and dimensions.



Custom-Built Fixtures

We can design lamination fixtures to be custom-built for your application. The fixture holds the lamination in the correct position and ensures that pressure is applied evenly.

lamination fixtures
electrical steel lamination stacking



The laminations are then stacked in a straight or skewed manner based on the customer’s drawing call out.



Second Curing And Bonding

By application of pressure and heat the bonding takes place by intermediate softening and curing of the coating for a second time.

Once the final cure is complete, the self bonding varnish hardens and becomes a stable, highly cross-linked duroplast with high viscosity and high bonding strength between the laminations.

lamination second curing and bonding

Application Of Self Bonding Stator&Rotor Lamination Stacks

Motorneo self-adhesive iron core adopts the method of bonding the motor punching pieces together to form the iron core. At present, it is widely used in the fields of marine exploration, electric vehicles, aviation, rail transit and military aerospace.

motor stator rotor of new energy vehicle driven motor

Bonding lamination for Electric Vehicle Motor

bonding stator lamination stacks for new energy vehicle hub

stator stacks Bonding for new energy vehicle hub Motor

motor lamination bonded core for drone motor

motor lamination bonded core for UAV motor

bonding BLDC motor stator rotor laminations

Self Bonding BLDC motor stator rotor lamination

bonding lamination stacks for linear motor

bonding lamination stacks for linear motor

E Transformer Core bonding lamination

E Transformer Core bonding lamination

wind motor stator lamination

Self bonding Segment stator with EDM Wire Cutting

stator bonding suralac 9000 silicon steel motor lamination

stator bonding Suralac 9000 Silicon steel motor laminations

Quality Control For Electric Motor Lamination

quality control for bonding lamination


Quality control in lamination bonding is a critical facet of ensuring the reliability and durability of laminated products.


Thoroughly inspect electrical steel raw materials for composition, thickness, and quality to ensure they meet specifications.


Test adhesives and coatings for viscosity, curing characteristics, and adhesion strength to ensure consistency and performance.


Conduct pull tests, shear tests, or other methods to assess the adhesive’s ability to withstand mechanical stresses and temperature variations.


Use measurement tools like CMM and laser scanners to confirm product dimensions and alignment.

Advantages Of Self Adhesive Electrical Steel Laminations

High Strength: Tensile shear strength 14-18N/mm², can be used for secondary processing (turning, grinding, drilling).

High Power density: Smaller size, lighter weight, higher stacking coefficient ≥98.5%.

Reduce Vibration: Self-bonding contributes to reduced operational vibrations within the motor core. This leads to quieter motor operation and reduces noise emissions.

High Precision: The surface contact uniformity is better, and the flatness and verticality are improved by more than 50% (feeler gauge thickness: 0.05mm).

Reduce The Temperature: Better thermal conductivity, providing the best axial heat transfer, reducing the temperature by 5-10℃.

Flexible Design: Improved strength, smaller magnetic bridge design of 0.25-0.50mm.

Improve Performance: Motor torque increased by 5%, efficiency increased by 5%. High cleanliness improves motor performance and service life.

Energy Efficient: Longer battery life, no magnetic flux blocking, iron loss reduced by 15-30%, lower energy consumption, can reduce the use of insulating varnish.

Motor Lamination Core Bonding Capabilities

Lamination Bonding Prototypes

Lamination bonding prototypes play a crucial role in the development and refinement of motors, generators, and transformers.

Our lamination prototype uses wire-EDM and laser cutting to cut lamination and use adhesive bonding lamination. We accept commonly used silicon steel for processing and customized services. The sheets include 0.1mm, 0.15mm, 0.2mm, 0.35mm, and 0.5mm series.

Laminated bonding prototyping does not require mass production, avoiding the situation of insufficient adhesive. In addition, we also provide manual gluing and automatic machine gluing to meet your needs.

laminations bonding prototype
glue dot bonding laminations

Glue Dot Bonding

Glue dot bonding is applied in single motor lamination surfaces. This method involves the precise placement of adhesive dots or glue points strategically on one or both sides of laminated materials.

These glue dots serve as bonding agents, the cores are then cured in the oven and fused together to hold the laminations together securely.

The key advantage of this approach minimizing the need for full-surface adhesion, reducing adhesive usage and waste. It is particularly valuable in applications where even distribution of adhesive isn’t required, offering flexibility in design and potentially reducing costs.

Full Surface Bonding

With full surface bonding, the electrical steel lamination material surface has been coated with bonding varnish where no requirement for any additional process to clit the stacks.

Full surface bonding in lamination stacks is a widely used process that involves the coating being applied to the laminations outside of the die and then oven-cured to become fused.

This method ensures a uniform and comprehensive bond between the layers, resulting in high structural integrity and stability.

Full surface bonding is particularly effective when a consistent and strong connection is necessary, such as in the production of electrical transformers, magnetic cores, and certain structural components.

Full Surface Bonding Lamination Stacks

Secondary Processing Technology Of Electric Motor Lamination Stack

Electrostatic Epoxy Insulation Coating Segmented Stator

Electrostatic Epoxy Insulation Coating Stator Stacks

The process involves the application of an epoxy-based insulating coating onto various stator lamination stacks, using electrostatic spraying or powder coating methods. Powder coating has strong chemical and heat resistance to protect motor Coil windings.

Our capabilities to coat various specific powder classes(B, F, H) for motor laminations stacks up to 350mm outside diameter, with or without shafts.

The thickness of the coating could be 0.15mm – 0.6mm thickness. We use materials 3M860, 3M266, 3M260、3M555、3M5230N, and the temperature resistance for the epoxy coating is 180 Degrees Celsius.

We have many automatic electrostatic epoxy coating lines to allow insulation of the iron laminated core.

Injection Molding Of Motor Laminated Iron Core

Lamination bonding represents a groundbreaking advancement in the design and manufacturing of electrical machinery components. Stator rotor stacks the lowest iron loss for high-efficiency motors is important.

Motorneo has the capacity to plastic overmould with different material types: PA, PPS, PET fiberglass high loaded, to allow insulation of the iron laminated core slots with a minimum thickness of 0.5mm.

Injection Molding Of Motor Laminated Iron Core
Electrophoretic Coating Of Motor Lamination Stacks

Electrophoretic Coating(Rust-Proof)) Of Motor Lamination Stacks

Electrophoretic coating, or e-coating, plays a crucial role in safeguarding motor stators because offers exceptional rust-proofing capabilities, providing a robust barrier against environmental factors, such as moisture, humidity, and chemicals.

With coating thickness typically ranging from 0.01mm to 0.025mm. At our facilities, we boast state-of-the-art capabilities in the electrophoretic coating process, equipped with the latest technology to prevent corrosion but also improve the stator’s longevity and overall performance.

Stator Coil Winding

Stator coil winding is a fundamental process in the manufacturing of electric motors, generators, and transformers.

This critical step involves carefully winding copper wire around the stator core’s slots, creating coils that generate the magnetic fields essential for the motor’s operation.

We could manufacture the wound stator by winding machine or manually, all by customer request. The winding stator diameter is 5-450mm, the stator thickness is 5-300mm, the slots number is 4 – 54solts, the wire spec is 0.1mm – 1mm, and the winding lead time is 7 – 40 days.

Stator Coil Winding

Why Choose Us As Your Electric Motor Iron Core China Manufacturer?

Motorneo is capable of full-process stator and rotor sample production and mass production from raw material procurement, wire cutting, stamping, gluing, or welding lamination.

We have multiple various types of high-speed punching machines and multiple disc motor stator punching machines. The largest high-speed punching machine is 350 tons and can produce iron cores with a maximum outer diameter of 1250mm.

We also have three-dimensional coordinate inspection, two-dimensional inspection, core iron loss inspection, stator component voltage withstand inspection, inter-turn inspection, CRH inspection, insulation resistance inspection, and other performance and size inspection capabilities to meet different customer needs.

industry motor core manufacturer

Laminations Stacks FAQs

EB549 self-adhesive coating fluid – the latest product developed by Rembrandt on the basis of EB548 coating fluid. It has the characteristics of thin coating, less glue overflow, fast curing, high lamination coefficient, and can realize online production.

Yes, our advanced manufacturing techniques in China involve automated processes for lamination bonding. These methods ensure consistent alignment and tight tolerances for optimal motor performance.

In China, various rotor and stator bonding methods include riveting, cleating, interlocking, glue fastening (conventional bonding), welding processes (TIG welding, MIG welding, laser welding), and emerging technologies like self-bonding. Each method offers distinct advantages based on the motor’s requirements.

Self-bonding cores have a substantial impact on motor energy efficiency. These innovative cores eliminate the need for adhesives or mechanical fasteners, resulting in reduced core losses and improved magnetic properties. This translates to significantly higher motor efficiency, lower energy consumption, and reduced operating costs.

The self-adhesive iron core also enhances mechanical strength and durability, contributing to a longer motor lifespan. Industries like automotive, industrial manufacturing, and renewable energy are increasingly adopting self-bonding cores to achieve sustainable energy solutions and cost savings.

For factors such as experience, you should consider expertise in various bonding technologies, quality control processes, material selection, and the ability to customize laminations for specific applications when choosing a manufacturer. Assessing their track record and capabilities in delivering high-quality motor cores is also essential.

A wide range of Backlack motor laminations stack solutions

Ready to revolutionize your motor manufacturing with the future-forward technology of self-bonding electric motor laminations? Motorneo has a full-service machine shop and fabrication department that can reverse engineer and reproduce most mechanical fastener designs. We’re here to empower your motor cores with enhanced performance, efficiency, and reliability.