E-mobility: Adhesive and sealant application opportunities in battery module and battery pack manufacturing
At SM Klebetechnik, students have the chance to conduct practical research to complete their Bachelor’s or Master’s degree. This year, Tobias Palmen, an industrial engineering student specialising in technical sales in Mechanical Engineering at Aachen University of Applied Sciences, investigated “Gluing and sealing in battery module and battery pack manufacturing (e-mobility)” for his Bachelor’s thesis. In the course of this research in our in-house technical centre, a high-viscosity butyl was applied using our GX 78 screw spindle drum melter and the KP 81 pump application head during battery module and battery pack production. The tests confirm the practical suitability of our equipment:
Sealing the battery for use in e-mobility applications is an important processing step during production. Precise sealant application safeguards the interior of the battery pack from ambient conditions whilst also protecting passengers from gases or other toxins that the battery pack might otherwise release should it fail. Along with their air- and gas-sealing function, the butyl-based sealants used to seal the battery cover also provide high resistance to ambient effects such as salt, stone impacts or temperatures below the freezing point. Sealant viscosities of 1.5 – 3 million mPa*s are not uncommon. Despite their high viscosity, when applying these high-viscosity sealants, it is important to ensure uniform application in a reproducible process to achieve the sealing effect across the full sealing surface. Moreover, processing speeds and path feed rates of up to 400 mm/s are required in order to satisfy cycle times in the automotive industry.
SM Klebetechnik: Systems already meet a broad range of requirements in battery pack sealing
Based on initial applications in the area of battery pack sealing, SM Klebetechnik optimised its equipment engineering for the specific requirements in this field. The result is a usage-oriented application solution that satisfies the broad range of battery sealing requirements. SM Klebetechnik’s KP 81 pump application head with its gear pump built into the head has proven effective in applying butyl. The bead module makes it easy to change the application nozzle, thereby enabling different bead patterns. That means both round beads with diameters of up to 20 mm and also other bead geometries such as square or triangular beads are possible.
The integrated gear pump allows for a very short control system between nozzle discharge and pump. This, in turn, makes it possible to apply sealant precisely with minimal pressure fluctuations during application. Moreover, a front closing needle valve ensures clean start-stop action without stringing over the component.
To melt and pump high-viscosity sealants, drum melters for 20 or 200-litre packages are used in the most common applications. Along with the required melting capacity, the drum melter must also have a suitable ram force to achieve continuous mass flow and optimal pump inflow as well as filling level. Its screw spindle drive enables SM Klebetechnik’s GX 78 screw spindle drum melter to melt and pump these highly viscous materials in high discharge volumes. When processing hot butyl, the discharge volume of the screw spindle drum melter is six times greater than that of the pneumatic drum melter (107 kg/h versus 16.8 kg/h). This is due to both the ram force of up to 130,000 N and the high-capacity melting plate. These melting plates are characterised by a heating capacity of 19.5 kW and flow-optimised material guidance.