Techni Ice Reusable Dry Ice Pack Techni Ice reusable dry ice packs/gel pack 4ply comprises of 2 non-woven textile layers, which encapsulates a specially formulated cross-linked polyacrylate polyalcohol co-polymer refrigerant combined with a post treated trade secret formula. Additional 2 heavy duty plastic layers, containing a one-way microperforation technology are bonded to the textile layers. This ensures that this new model can withstand the harshest of operational climates with performance that can only be described as revolutionary. "Re-usable dry ice?" A remarkable leap forward in ice pack technology utilising a cross-linked polyacrylate polymer that can be frozen right down to minus 190C (that's more than twice as cold as dry ice!). Techni Ice reusable dry ice packs/gel packs are often frozen in blast freezers to minus 80C when used in dry ice applications. How do I activate my new Techni Ice reusable dry ice packs / gel packs? Techni Ice reusable dry ice packs/gel pack start as a flat sheet and absorbs water through a special perforation technology in the surface of the product. This is achieved by scrunching the sheets between your hands whilst immersed in warm water for a few minutes until the air bubbles have escaped. The hydration process will now begin and the cells will swell ready for the products to be used both cold or hot. The water enters through the surface and activates the polymer, which then swells the sheet into 24 individually sealed cells. This process enables the product to be flexible when frozen and cut to any size. Techni Ice reusable dry ice packs/gel packs can be used hot, cold or frozen and can not only keep your food and drinks icy cold for days on end in cooler but is also very effective at reducing battery consumption when placed in 12 volt fridge/freezers due to its eutectic qualities which minimises thermostat activity.