Fully Automatic EI-57 Lamination Stacking Machine with ±0.1 mm Accuracy, 250 Stacks/Min, and PLC Control for Transformer Cores

EI-57 Automatic Interleaved Lamination Stacking Machine for Transformer & Adapter Cores

Positioned between small EI-48 and larger EI-66 sizes, the EI-57 lamination is one of the most widely used core formats for single-phase low-frequency transformers in the approximate 8-45 VA power band. Our EI-57 stacking machine inserts E and I silicon steel sheets into coil bobbins in a fully interleaved (cross-stacked) pattern, so each E-I joint is staggered on alternate layers. This interleaving keeps the magnetic air gap to a minimum, which directly translates into lower no-load loss, lower core loss and quieter operation of the finished transformer - the three quality indicators that end customers feel most.

From Sheet Loading to Finished Core in One Cycle

Instead of describing what the machine is made of, it is easier to see what the machine does every working cycle:

1. Loading - The operator places pre-separated E and I sheets into the two feeding slots and clamps the wound bobbin on the fixture.
2. Interleaved Insertion - Under PLC control, E and I pieces are alternately inserted into the bobbin window, layer by layer, following the industry-standard cross-stacking sequence.
3. Counting & Compaction - A photoelectric sensor counts each inserted sheet; when the preset stack quantity is reached, the machine stops automatically and compacts the core to the target height.
4. Unloading - The operator removes the completed core stack for the following binding and impregnation processes. One operator can attend several machines at the same time.

Key Specifications

What Makes This Machine Different

▶ Consistent Interleaving Quality - Every core is stacked with the same alternating E-I sequence and the same compaction force. Batch-to-batch core consistency stays high, so transformers assembled from these cores show uniform no-load current and magnetizing characteristics.

▶ Preset-Count Auto Stop - Instead of relying on the operator's eyes, a photoelectric counter stops the machine exactly at the programmed lamination count, eliminating over- and under-stacked cores.

▶ Fault Alarms Instead of Silent Jams - If a sheet misfeeds or jams, the machine halts and raises an alarm before the core is damaged; the fault location is easy to clear, minimizing downtime and wasted bobbins.

▶ Recipe-Style Changeover - Stack count, speed and stacking height for a given transformer model can be saved as a recipe and recalled in seconds when that model returns to production.

▶ Quiet & Energy-Saving Operation - With only 30-60 W power consumption and an optimized low-vibration mechanism, the machine fits comfortably into small workshops and keeps electricity costs negligible.

▶ Operator Friendly - A new worker can master sheet loading and startup after a short orientation; no special skills or hand-cranking effort are required, which also reduces labor turnover pressure.

▶ Export-Ready Safety & Packaging - Emergency stop, safety guards and dual grounding come standard; optional protective covers and safety light curtains are available. The compact frame is easy to ship by air or courier.

Typical Applications

Machines of the EI-57 size are the everyday workhorses inside power adapters and chargers, control and isolation transformers, audio power transformers, voltage stabilizers, UPS units, ballasts, household-appliance power boards, and instrument transformers. Because the EI lamination format is the most economical to mass-produce, upgrading the stacking step from manual to automatic gives small and mid-sized transformer factories the fastest return on investment. A full machine series covering EI-19 up to EI-300 is available from the same factory, so the same supplier can support your whole product range as you grow.

After-Sales & Delivery

We are the direct manufacturer, so you buy at factory price with CE-certified quality assurance and a 12-month warranty. Every machine is test-run before shipment and packed for export; delivery normally takes 1-15 working days. Our technical team provides remote support and step-by-step video guidance for installation, commissioning and troubleshooting.