EI Core Lamination Stacks Manufacturer

As Sino, a top Chinese maker of high-quality transformer laminations, we are proud to show you everything we can do to provide excellent EI core laminations to transformer makers around the world. We focus on making things very accurately, using the best materials, and doing strict quality checks. This makes sure our products are the dependable core of your magnetic parts, helping them work better and more efficiently in many different uses.

Introduction to EI Core Laminations

At Sino, we know that the core is the most important part of any top-quality magnetic component. EI core laminations, named for their special E and I shapes, are a key part of making magnetic circuits work well. Their main job is to reduce energy loss from eddy currents, a big problem that was found in the late 1800s as electrical machines got bigger. Solid iron cores, while good at letting magnetic fields pass through, wasted a lot of energy as heat because of these swirling currents, which greatly reduced how well they worked.

How Sino's Laminations Tackle Energy Waste

At Sino, we offer EI laminations in a variety of standard thicknesses – from 0.35mm (often designated as M36 or similar) to 0.5mm (like M47) and even thinner for specialized needs – allowing you to balance cost against efficiency requirements. We ensure that the insulating coating applied to our steel, or inherent in its mill processing, maintains its integrity even after stamping and stacking. This focus on insulation integrity is critical for an efficient ei transformer core.

Where Sino's EI Cores Make a Difference

Our EI Core Lamination Products

The Sino Material Palette: Choosing the Right Steel

The heart of any EI core lamination is the electrical steel. The silicon content (typically a few percent) increases the electrical resistivity of the steel, which helps to reduce eddy current losses.

At Sino, we don’t just stamp steel; we partner with you to select the optimal grade and thickness for your specific scenario. Our technical team can discuss your operating frequency, flux density, efficiency targets, and cost constraints to recommend the most suitable material for your ei transformer core or inductor. We source our steel from reputable mills, ensuring consistent quality and adherence to international standards, which is a cornerstone of our product quality.

At Sino, we offer a wide variety of electrical steels. Each one is chosen and prepared to get the best magnetic performance for what you need.

Silicon Steels: The Main Choice for Magnetic Cores

Silicon steel (Fe-Si alloys, usually with 3–4% Si) is still the most common material for EI laminations because it has a great mix of magnetic properties and is a good value for the money. When Silicon steel was first used in the early 1900s, it greatly lowered both eddy current and hysteresis losses compared to plain iron. This was a big help for modern electrical engineering.

Non-Grain-Oriented (NGO) Silicon Steel: NGO Silicon Steel has tiny crystals (grains) that point in random directions. This gives it magnetic properties that are the same in all directions. This means its magnetic performance isn’t really affected by the direction of the magnetic field compared to the direction the steel was rolled.

Basic Properties:
- Saturation Flux Density (B_sat): Similar to GO steel, about 2.0 T for steel with 3% Si.
- Permeability: Lower than GO steel, usually 3,000–6,000 at 1.5 T, 50 Hz.
- Core Loss: Higher than GO steel, usually 2.0–3.5 W/kg at 1.5 T, 50 Hz for standard types.
Manufacturing: It’s made by rolling the steel while it’s hot and then cold, followed by a final heating process called annealing. It doesn’t need the difficult secondary recrystallization step that GO steel does.
Best For: It’s great for uses where the magnetic field travels in many directions, like in rotating machines (motors, generators), small transformers, and inductors. Because its properties are the same in all directions, it’s easier to make and design with, since the cutting direction doesn’t matter much. Sino offers advanced NGO types (like 0.20 mm thick, with more silicon, and laser scribing) for frequencies up to 400 Hz, with core losses as low as 1.0 W/kg at 1.5 T, 50 Hz.

Grain-Oriented (GO) Silicon Steel: GO Silicon Steel is known for its highly organized crystal structure (called Goss texture, {110}<001>). This gives it very different magnetic properties in different directions. This means it has much better magnetic performance along the direction it was rolled (RD).

Basic Properties:
- Saturation Flux Density (B_sat): Similar to NGO steel, about 2.0 T for steel with 3% Si.
- Permeability: Extremely high along the rolling direction, often over 30,000 at 1.5 T, 50 Hz.
- Core Loss: Much lower along the rolling direction, as low as 0.90 W/kg at 1.7 T, 50 Hz for high-quality GO steel. Better grades can have even lower losses.
Manufacturing: It’s made through a long and difficult series of steps including hot rolling, cold rolling, removing carbon, and a high-temperature secondary recrystallization annealing to create the Goss texture.
Best For: It’s the best choice for large power and distribution transformer cores, where the magnetic field flows mostly in one direction and efficiency is extremely important. Sino makes sure that GO steel EI cores are carefully lined up so that the E and I parts match the rolling direction to get the most out of its better properties. We know that if it’s not lined up right, the core loss can go up by 2–3 times and permeability can drop by 80%.
Advanced Grades: We use high-permeability, low-loss GO grades (like 0.23 mm thick, <0.90 W/kg at 1.7 T, 50 Hz) to meet the strictest efficiency needs.

Amorphous Alloys and Nanocrystalline Materials

Sino is also looking into and offering advanced materials for applications that need extremely low energy loss:

Amorphous Alloys: These materials have atoms that are jumbled up, like in glass, instead of being in an organized crystal structure. This leads to very low core losses, especially at higher frequencies. They are usually made by cooling them down very quickly.
Nanocrystalline Materials: These materials are made of extremely tiny, nanometer-sized crystals. They offer a special mix of high permeability and low core loss, and often work better than Amorphous Alloys at higher frequencies.
Properties: These materials can have core losses as low as 0.7 W/kg at 1.5 T/50 Hz.
Things to Consider: While they have great magnetic performance, they break easily and cost more, which is why they aren’t used everywhere. Sino is working hard to study special low-stress cutting and annealing methods to solve these problems.

Here’s a quick rundown of common material types Sino works with, and their typical deployment:

Lamination Material Type	Key Characteristics	Typical Scenarios
Grain-Oriented Silicon Steel (GOSS)	Highest permeability in the rolling direction, very low core loss. More expensive.	High-efficiency power transformers, distribution transformers, premium audio transformers.
Non-Oriented Silicon Steel (e.g., M36, M47, etc.)	Uniform magnetic properties in all directions. Good balance of cost and performance.	General purpose transformers, motors, generators, chokes, ballasts, appliance transformers.
Thinner Gauge Non-Oriented Steel (e.g., 0.2mm, 0.35mm)	Lower eddy current losses at higher frequencies than standard 0.5mm.	Higher frequency transformers (up to a few kHz), some SMPS applications, specialized motors.
Nickel-Iron Alloys (e.g., MuMetal, Permalloy – on request)	Extremely high permeability at low field strengths, excellent for shielding.	Very sensitive audio transformers, magnetic shielding, precision current sensors (less common for standard EI laminations but possible for custom projects).

Sino’s Commitment to Your Success

Choosing Sino for your EI core lamination needs means more than just getting a box of steel parts. We see ourselves as your partners in creating effective magnetic solutions.

Customization is Key

While we stock many standard EI lamination sizes (from tiny EI-28s up to large industrial sizes), we excel at custom projects. Need a specific stack height? A unique interleaving pattern? Non-standard mounting holes? Talk to us. Our engineering team loves a challenge.

Responsive Support

Got a technical question about material selection for your ei core lamination? Need a quote for a new project? Our sales and technical support teams are here to provide prompt, knowledgeable assistance.

Quality You Can Trust

Our ISO 9001 certified quality management system ensures that every batch of EI laminations leaving our factory meets stringent quality standards. From raw material inspection to final dimensional checks, we leave no stone unturned.

Competitive Pricing & Reliable Delivery

Thanks to our efficient manufacturing processes and strong supplier relationships, we offer competitive pricing without compromising on quality. We also understand the importance of on-time delivery to keep your production lines running.

Manufacturing Processes and Quality Checks

Sino’s skill in making things comes from decades of experience, always putting money into the newest technology, and a strong dedication to quality. Our all-in-one production process makes sure that every EI core lamination has the right size and shape, good magnetic quality, and a smooth surface.

Material Cutting and Prep

The process starts with cutting the electrical steel coils into the right widths. Our advanced cutting machines ensure the size is very accurate and we waste as little material as possible, getting the strips ready for the next step.

Advanced Stamping Methods

Our stamping machines are the key to creating the exact EI shapes:

Fine Blanking and Progressive Die Stamping: We use top-of-the-line Fine Blanking and Progressive Die Stamping machines. These machines can make parts with very small, smooth edges (below 5 µm) and exact sizes (within ±0.01 mm). Computer-controlled presses that monitor force, position, and temperature help line up the tools perfectly and reduce wear. This directly affects how flat and easy to stack the laminations are.
Laser Cutting: For making prototypes quickly and for special production runs, we use fiber laser systems. Laser cutting allows for a fast turnaround with very little stress on the material. We carefully control the laser settings (like pulse length, power, and gas) to limit the heat-affected areas, which can otherwise lower the magnetic permeability by up to 10%.
Burr Control and Edge Quality: We use built-in camera systems to check the edge quality and look for tiny rough spots (burrs) in real-time. This information helps us adjust the tools right away, which cuts down on waste by up to 30% and keeps the insulation between layers consistent.

Precision Heating Processes (Annealing)

Annealing is a key heating step that brings back the steel’s magnetic quality after it has been worked on. It also helps the tiny crystals inside the steel grow in the best way:

Continuous Annealing Furnaces: The continuous annealing machines we use use a controlled hydrogen/nitrogen atmosphere with very low oxygen (below 5 ppm). These systems let us precisely control the heating temperature (usually 800–900°C) and cooling speed. This helps the crystals grow to the right size (average size >150 µm) and relieves stress. This can lower core loss by 15–20% compared to older annealing methods.
Vacuum Annealing: For parts that need very low core loss, we use vacuum annealing furnaces, which create a near-perfect vacuum (pressures below 10^-4 mbar). This process gets rid of any oxidation and lets us use steels with a high amount of silicon (>3.5% Si). This leads to core loss reductions of up to 25% and a better insulation layer.
Custom Annealing Cycles: Recent studies show that using controlled, multi-step annealing cycles can adjust the crystal direction and reduce defects. This can lead to a 10–15% increase in permeability and a 20–30% reduction in coercivity. Sino uses these advanced annealing plans to get the best magnetic performance.

Surface Insulation Coating

After annealing, the laminations are coated with a high-quality electrical insulation layer:

New Coating Methods: We use advanced inorganic phosphate and silicate-based coatings, as well as electrophoretic deposition (EPD) processes from companies like AkzoNobel and Axalta. These give an inter-laminar resistance of over 1000 Ω·cm² and can handle heat up to 800°C.
Cleanliness: Before coating, we use plasma cleaning and ultrasonic degreasing to remove any leftover oils or tiny particles. These can cause problems with the insulation and lead to localized eddy current losses. Our systems can verify that the surface is clean down to the sub-micron level.

To stop unwanted currents between the layers (inter-laminar eddy currents) and make sure they last a long time, all our laminations are coated with high-quality insulation. We use:

Inorganic Coatings: Like phosphate or MgO, which can handle heat well and are good electrical insulators.
Organic Coatings: Like C-5 or C-6, which are easy to stamp and stick well.
Advanced Coatings: We are testing thin-film PVD (Physical Vapor Deposition) coatings for very thin laminations (<0.18 mm). These coatings are very even and have almost no change in thickness (<0.5 µm). Our coatings have an inter-laminar resistance of over 1000 Ω·cm² and can handle heat up to 800°C.

Choosing the right material and coating is an important decision. Sino’s experts are here to help you weigh the costs and benefits to pick the best choice for your specific needs.

Automated Stacking and Assembly

Our assembly process is mostly automated to make sure everything is consistent and high-quality:

Robotic Handling: Robotic systems are used for stacking, checking, and packing. This reduces mistakes and contamination from human handling.
Stacking Pressure Control: Automated stacking presses with real-time force feedback make sure the pressure stays in the best range (usually 1–2 MPa). This prevents the insulation from being crushed and stops shorts between the layers.
Cleanroom Environment: We use ISO 7 cleanroom standards where we assemble our cores. Since 2022, this has reduced shorts caused by tiny particles by over 80%.

Quality Checks and Industry 4.0

Quality is a part of every step of our manufacturing process:

In-line Monitoring: We check important things (like edge quality, size, and insulation resistance) in real-time. This helps us find and fix any problems right away.
Digital Twins and MES: We are using Manufacturing Execution Systems (MES) and digital twins. This helps us predict when machines need fixing, improve our processes in real-time, and lets us track every single batch of laminations.
AI-Driven Process Control (Future Plan): We have pilot projects using machine learning to connect process settings with the final magnetic and mechanical quality. This will allow for automatic process improvements and quick problem-solving.
Environmental Responsibility: Our new annealing furnace designs are made to reuse heat and have cleaner burners. This reduces energy use by up to 25% for every ton of laminations we make. We are also looking into using green hydrogen in our furnaces to further reduce our carbon footprint.

Sino’s advanced manufacturing skills and strict quality checks make sure that our EI core laminations are not just parts, but dependable foundations for your high-quality magnetic products.

Why Sino is Your Ideal Partner for EI Core Laminations

In a world demanding ever-greater efficiency and reliability from electrical devices, the quality of every component matters. EI core laminations from Sino provide a robust, cost-effective, and high-performance foundation for your transformers, inductors, and motors.

We combine:

Decades of Manufacturing Experience: We know EI laminations inside and out.
Precision Engineering: From die design to stamping and stacking, accuracy is paramount.
Material Expertise: We help you choose the right electrical steel for your specific ei transformer core scenario.
A Commitment to Quality: Our processes ensure consistent, reliable products.
Customer-Centric Approach: We work with you to meet your unique requirements.

Get in Touch with Us Today!

So, when your design calls for proven, dependable magnetic cores, look no further than Sino. Let us put our expertise in ei core lamination manufacturing to work for you. Reach out to our team today to discuss your project, request a sample, or get a quote. We’re ready to help you power your innovations!

Note: To speed up your project, you can label Lamination Stacks with details such as tolerance, material, surface finish, whether or not oxidized insulation is required, quantity, and more.

EI Core Lamination Stacks Manufacturer

Introduction to EI Core Laminations

How Sino's Laminations Tackle Energy Waste

Where Sino's EI Cores Make a Difference

Everyday Gadgets Powering

Industrial Controls

Audio Applications

Lighting System

Renewable Energy Components

Our EI Core Lamination Products

The Sino Material Palette: Choosing the Right Steel

Silicon Steels: The Main Choice for Magnetic Cores

Amorphous Alloys and Nanocrystalline Materials