What are freeze-thaw voids?
Freeze-thaw voiding is associated with the cold storage and thawing process of paste products in syringes. When most paste adhesives are stored at -40°C, they are in a frozen state, and the syringe is in its glassy state below its Tg. During thawing, the syringe wall may heat-up and expand faster than the adhesive. The outer walls of syringe pull away from the still frozen adhesive, which creates air pockets. When the adhesive thaws and re-wets the surface of the syringe wall, air is trapped within the syringe in the adhesive. The trapped air within the syringe and adhesive is called a freeze-thaw void. Freeze-thaw voids have an adverse effect on the dispensability of the adhesive. The chances of freeze-thaw voids can be minimized by following the recommended thaw procedure on the technical data sheet to reduce the thermal shock experienced by the frozen syringe of material.
