Cooler bag is basically served as a functional bag for maintaining the temperature while keeping hot and staying cool are the basic functions of insulation packages. The bags are normally isolated and stuffed with paddings or sponges or foams to curb the speed of air flow. Most of cooler bags will also add at least one layer of thermal metallic silver Aluminium foil and sheet to preserve the heat release or prevent against the heat penetration.What's more, seams of inside liner were normally locked by welding/heat sealing instead of stitching to create an airtight and watertight space. Heat-retaining time: 4-6h(temperature fluctuation between 1-10 Celsius Degree). Chill-preserving time: 8-10h ((temperature fluctuation between 1-10 Celsius Degree). so it widely is used in food, drink packaging, carrying, storage and dispatchment, and delivery industry. As a professional cooler bag manufacturers in China, Chiterion offers the best custom cooler bag for worldwide customers.