In a recent blog about hot melt adhesives, we discussed how they work, considerations to make and their benefits. We also looked at how to maintain hot melt adhesive performance during equipment downtime: temperature setback guidelines.
Using hot melt adhesives for a range of applications offers the following advantages:
- Optimal holding power to corrugated materials
- Superior flexibility for better performance under constant stress
- Quick adhesion
However, it’s important to follow the proper changeover technique when using hot melt adhesives. Doing so helps ensure reliable adhesive performance, reduces waste and minimizes downtime.
Our technical service team has provided the following step-by-step, best practices procedure for hot melt adhesive changeover:
- Run existing adhesive down to grid level in the melt tank.
- Disconnect the melt hose from the application, and empty the melter completely of all remaining adhesive. Ensure waste is disposed of properly following all applicable company, state and local procedures.
- Add the new adhesive to melt tank until the tank is approximately 25% full. (Typically, this would cover the top of the melt grid.) Set application temperature per TDS recommendations for adhesive to be tested.
- Allow the adhesive to melt, then purge tank again, emptying completely. (Note: Multiple small volume flushes may be more effective than a single large volume purge.)
- Repeat steps 3 and 4 two more times.
- If possible, new or clean hoses should be used to speed changeover and minimize the potential for cross contamination. If clean hoses are not available, then reconnect the existing hose to the application, and purge ¼ of the tank through the entire system.
- Fill the tank with new adhesives, and set at the recommended operating temperature.
- Install clean filters in the melt tank and applicator at this time.
Upon completing these steps, the new adhesive is now ready for testing or production. Bostik recommends that the system be put into use as soon as the changeover is complete.
Please note: This step-by-step, best practices procedure has been developed for compatible adhesive formulations. Additionally, the information given and recommendations made are based on Bostik’s research only and not guaranteed to be accurate. The performance of the product depends on many variables.
Visit www.bostik.com for more information.