Dispensing Adhesive For Bonding Substrates for Battery Packs

An application test was conducted by Graco Inc. in North Canton, OH, to demonstrate the capability of dispensing Ø4mm beads using Bostik Pliogrip 8300 Adhesive for bonding substrates in a battery pack.
We maintained the necessary ratio within a +/- 1% tolerance and achieved the target 4mm bead dimensions at various speeds.
The test utilized a Graco EVR system and involved dispensing beads and stitching patterns at various speeds to meet the customer's specifications.
Dispensing Challenges
An automotive tier supplier requested a demonstration of dispensing capabilities for bonding substrates in battery packs. Their challenge was to achieve precise beads and stitching patterns at specified dimensions and speeds, using a two-component adhesive.
Methods
- Material Information: Bostik Pliogrip 8300 Adhesive, a two-component material, was used. Rheology tests were conducted to understand material behavior under different conditions.
- Bill of Materials (Graco): Detailed components and part numbers for the dispensing system are provided, including the EVR metering device and associated equipment.
- Test Setup: The test was conducted in a controlled lab environment using a 6-axis robot for programming motion, along with scales and a viscometer for material measurements.
Findings
- Ratio Check: The EVR system successfully maintained a 1:1 ratio for the adhesive components within a +/- 1% tolerance.
- Bead Dispense: Beads were dispensed at various speeds (1000mm/s to 400mm/s) with an average width close to the 4mm target.
- Stitching Pattern Dispense: Stitching patterns were tested at different speeds, with issues of missing stitches at higher speeds (above 450mm/s) noted for further investigation.
Conclusion
The EVR system demonstrated the capability to dispense Bostik Pliogrip 8300 Adhesive in the required bead and stitching patterns for battery pack bonding applications. The system maintained the necessary ratio and achieved the target bead dimensions at various speeds. However, issues with stitching pattern consistency at higher speeds need further investigation.
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Download Application Test Report

The Bostik Pliogrip 8300 Graco Application Lab report includes full details about the scope of work, setups, and data from equipment life testing.