The EI-70 automatic lamination stacking machine is designed for manufacturers of industrial control and isolation transformers, where core quality is not an aspiration but a pass/fail criterion. Built for EI-70 silicon steel laminations, it feeds E-type and I-type sheets alternately into pre-wound bobbins under closed-loop PLC control, completing interleaved stacking at up to 250 stacks per minute with stacking accuracy of plus or minus 0.1 mm and positioning accuracy of plus or minus 0.02 mm. Every lamination is counted and verified in-cycle, so quality is built into the process rather than inspected in afterwards.
Traditional stacking quality is verified by sampling: a few cores per batch are torn down and measured, and the rest are assumed good. This machine replaces sampling with full verification. A high-speed photoelectric sensor counts and confirms the insertion of every single E and I lamination, cycle by cycle. If a misfeed, double-pick, or jam is detected, the machine stops automatically within 0.5 seconds — before a defective core can be completed. The result is a scrap rate below 0.3 percent and, more importantly, cores that do not depend on luck: the lamination count, stacking pattern, and insertion quality of the last core in a batch are identical to the first.
| Parameter | Details |
| Model | EI-70 |
| Lamination Type | EI-70 silicon steel, E & I interleaved stacking |
| Stacking Accuracy | ±0.1 mm |
| Positioning Accuracy | ±0.02 mm |
| Stacking Speed | Up to 250 stacks per minute |
| Applicable Transformer Capacity | 100-300 VA industrial control and isolation transformers |
| Bobbin Window Width | 23 mm (suitable for EI-70 core sets) |
| Silicon Steel Thickness | 0.3 mm, 0.35 mm, 0.5 mm cold-rolled grain-oriented (CRGO) or non-oriented (CRNGO) |
| Stacking Mode | Interleaved (one-by-one E and I lamination insertion) |
| Counting Method | Photoelectric sensor with automatic count verification |
| Power Supply | AC 220V / 380V, 50/60 Hz (customizable for different regions) |
| Service Air Pressure | 0.4-0.65 MPa, dry and clean compressed air |
| Control System | Mitsubishi PLC with 7-inch touch screen HMI |
| Safety Protection | AC220V overload protection, DC24V short-circuit protection, dual grounding, emergency stop |
| Operating Temperature | 0 to 45 degrees Celsius |
| Machine Weight | Approx. 70 kg |
| Warranty | 12 months from delivery |
✅ Recipe Storage on PLC Touch Screen – Lamination count, stacking speed, and dwell time are saved as named recipes on the 7-inch HMI. When a customer order is repeated, the exact parameters from the previous run are recalled in under 30 seconds — no re-setup, no drift between batches.
✅ Deterministic PLC Cycles – Under closed-loop Mitsubishi PLC control, every feeding, insertion, and counting step executes in the same sequence with the same timing. Process variability from operator to operator, shift to shift, is eliminated at the source.
✅ Full Electrical Protection – AC220V overload protection, DC24V short-circuit protection, dual grounding, and an emergency stop button keep the machine itself running within spec, protecting production continuity and audit readiness.
✅ ±0.1 mm Stacking, ±0.02 mm Positioning – Tight lamination columns and minimized air gaps are what transformer efficiency ratings are built on. Consistent mechanical precision makes core loss and excitation current predictable across the whole batch — the numbers your customers measure are the numbers you quoted.
✅ Interleaved Stacking for Electrical Performance – The one-by-one E and I interleaved pattern produces uniform flux distribution and low noise — key acceptance criteria for control transformers that operate continuously in electrical rooms and control panels.
✅ CRGO and CRNGO Dual Compatibility – Both grain-oriented and non-oriented silicon steel from 0.3 mm to 0.5 mm thickness are handled by the same feeding mechanism, letting material choice follow the efficiency and cost targets of each project.
The EI-70 lamination stacking machine is used in the production of:
• 100-300 VA industrial control transformers for machinery and automation panels
• Isolation transformers for machine tools and process equipment
• Step-down transformers for control circuits and instrumentation
• Current and voltage instrument transformer cores
• Specialty electromagnetic components requiring EI-70 core stacking
Custom tooling for other EI sizes (EI-28 through EI-133) is available on request, so production can cover the full EI range on one platform.
Direct factory supply with competitive pricing and CE certification. We have supplied EI lamination stacking equipment to globally recognized transformer manufacturers including GE Vernova, Eaton, CATL, and Chint Electric, with products exported to more than 20 countries. Delivery within 1-15 working days. The after-sales package includes video installation guidance, remote PLC parameter support, spare parts supply, and a 12-month warranty from the date of delivery.