Highland Barley Paper: The "Life Saver" of Cylindrical Cells (Engineering Guide)
Release time:
2026-01-13
In a Cylindrical Battery Module (18650 or 21700), the positive terminal is dangerously close to the negative casing. The gap is often less than 0.5mm. A single vibration can cause a short circuit.
In a Cylindrical Battery Module (18650 or 21700), the positive terminal is dangerously close to the negative casing. The gap is often less than 0.5mm. A single vibration can cause a short circuit.
That is why Highland Barley Paper is not optional—it is critical. But how you apply it defines your line's efficiency.
1. Material Science: Why Barley Paper? (Not PVC)
Engineers often ask: "Why don't we just use standard PVC stickers?"
While PVC is cheaper, Highland Barley Paper (a specialized cellulose composite) offers superior mechanical properties for EV battery safety.
While Highland Barley Paper is standard for Cylindrical cells, Blue Film (PET) wrapping is the choice for Prismatic cells.
Table 1: Barley Paper vs. Common Insulators
| Feature | Highland Barley Paper | PVC / PET Sticker | Why it matters? |
| Heat Resistance | High (>120°C) | Low (~60-80°C) | Won't melt during Laser Welding heat. |
| Adhesion | Excellent (Porous) | Good (Smooth) | Stays on the cell for 10+ years. |
| Dielectric Strength | High | Medium | Prevents arcing at high voltage. |
| Thickness | 0.2mm - 0.3mm | 0.1mm | Better physical buffer against vibration. |
2. Common Process Defects (And How to Fix Them)
If you are using standalone, tabletop pasting machines, you likely face these three nightmares. We solved them in our integrated line.
Defect A: "The Flying Sticker" (Low Adhesion)
Cause: Oil residue on the cell pole or old glue on the paper roll.
Huiyao Fix: Our line includes an inline Plasma Cleaning station right before pasting to activate the surface.
Defect B: "The Half-Moon" (Skewed Pasting)
Cause: Mechanical feed mechanism drift.
Huiyao Fix: We use a Servo-Driven Rotary Drum with vacuum suction cups that hold the paper firmly until the exact moment of contact. Accuracy is locked at ±0.1mm.
Defect C: "The Jam" (Static Electricity)
Cause: Paper sticking to the blade due to static.
Huiyao Fix: Integrated Ionizing Air Knives remove static charge continuously.
3. The Huiyao Solution: High-Speed Integration
In our Cylindrical Battery Module Assembly Line, the Barley Paper station isn't a separate machine—it's a seamless module.
Speed:400+ Cells Per Minute (PPM).
Mechanism: Continuous Rotary Motion (not Stop-and-Go).
Validation: Keyence Cameras inspect 100% of cells.
No Paper?-> Reject.
Off-Center?-> Reject.
4. Why Integration Matters for Laser Welding
Why do we obsess over a $0.01 piece of paper?
Because of the Laser.
If the Barley Paper is misaligned by even 0.2mm, it might cover the welding zone (Negative Pole). When the laser beam hits the paper instead of the steel shell:
1. The paper burns (Carbonization).
2. The laser energy is blocked.
3. You get a "False Weld" or a fire hazard.
By integrating the pasting station with our specific Pallet System, we ensure the paper is perfectly centered, leaving the weld zone clean for the laser.
5. Technical Specifications
Applicable Cells:18650, 21700, 26650, 32140
Paper Thickness:0.1mm – 0.3mm
Cycle Time:0.15s / cell
Control System: PLC + Touch Screen (Recipe Storage)
Summary
Don't let a cheap sticker ruin a $500 battery pack. Upgrade from standalone machines to a fully integrated Insulation & Assembly Line.
AUTHOR: The Huiyao Laser Engineering Team
A collective of solution architects and process engineers at Huiyao Laser, 100% dedicated to solving the core bottlenecks in EV and ESS battery manufacturing.
© 2026 Huiyao Laser Technology Co., Ltd. All Rights Reserved.
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