Heat sealing
The engineering brief The unit was to be a self-contained, adaptable, free-standing and a manually operated battery sealing machine. The pouch material to be sealed is a foil laminate: CPP/Al Foil material which has an approximate thickness of 120-µm, with a total thickness as two ply of 240-µm. This is in combination with being able to form a seal around embedded instrumentation, such as fibreoptics and flexible PCB sensor components. The technology The Ceetak team identified that an ImPulse Heat Sealing (IPH) system would be suitable for this project because it offers a compliant weld face compared to the solid metal sealing tools often traditionally used. IPH also promotes hermetic leak-proof seals both around, and over variations in material thickness. The Cell Instrumentation Team embed various types of sensors in their smart cells (temperature, pressure, current etc.), requiring electrical connections to pass through the pouch seal. These variants within the material (such as electrical tabs and sensor wires) need to be carefully heat-sealed over, without damage to these components. IPH technology achieves this critical requirement due to the rubber sealing bar, which compresses and undulates with the material being sealed. With its precise temperature control and accurate heat-seal force adjustment (with a digital gauge showing pressure display), IPH is suitable for many materials including polyethylene, and biodegradable and compostable films. Additionally, the user can control if heat is to be applied from one or both sides of the material, allowing for even more versatility of this technology. The result is a user-friendly and adaptable sealing unit with a vital role to ensure the battery pouch has perfect seal integrity.
Full design, manufacture, and testing process Ceetak Heat Sealing Solutions’ experienced in-house team offer a full bespoke consultancy service incorporating design, materials, technology, and equipment build. Before projects are signed off, the customer is invited to take part in an ‘FAT’ – Factory Acceptance Trial. Dr Timothy Vincent, Assistant Professor in the Cell Instrumentation Team, WMG, attended the FAT on this project. He was shown the seal capabilities using a dye test which demonstrated no fluid leakage through the seals produced by the IPH technology. After FAT approval, the machine was transported to the EIC and Dr Vincent commented, “We have been delighted to work with Ceetak on this project as we continue to innovate our cell manufacturing and instrumentation techniques. The new sealing process developed with Ceetak allows the reliable and repeatable placement of miniature sensors within our pouch cell manufacturing line. We had been conducting many trials to adapt our processes to overcome the variation in material thickness in the seal area when embedding our sensors, however the results were inconsistent. Initial trials in Ceetak’s test lab showed instant improvements in seal quality and consistency”. Ceetak Heat Sealing Solutions supplies heat- sealing technologies for the sealing and cutting of all thermoplastic materials, foil laminates and other biomaterials including plastics, card, and paper. The company produces both modular heat-sealing components to be retrofitted onto existing customer machinery or alternatively, a complete design and build service of bespoke machinery. n
heatsealing.ceetak.com
57 Machinery & Manufacturing
Powered by FlippingBook