In July of 2011, employees from Cardinal Health’s packaging division in Waukegan, Illinois had a volunteer project day at the Seed Bank. While assisting cleaning seeds and learning about the seed banking process, they discovered that they were in a position to help improve our seed packaging technique. David Rudd and Michael Capp recommended that, to ensure we attain an airtight seal, we purchase a hospital grade heat sealing machine to replace the hand held clothes iron that we were using to seal our seeds in foil packets. Also, David and Michael offered to use their lab equipment and techniques at Cardinal to test our foil packets to determine the optimal temperature required to produce the best, airtight seal. Since maintaining a low relative humidity within the packets is critical to long-term, cold seed storage we are grateful for their contribution in making this part of the seed banking process the best it can be.
Fig. 1. Sealing sections of foil packets at different temperatures on our Rennco heat sealer in preparation for testing seal strength.
Fig. 2. Pouring Tortelene Blue solution into a foil packet to test a seal for air tightness.
Fig. 3. An Instron material testing insturment testing the seal strength of a strip of foil packet by measuring the force required to pull apart the seal.