To increase the time to save products in the proper quality, refrigerator bags are supplied with cold or dry batteries ice. The former are briquettes or plastic bags filled with saline solution. Some manufacturers complete the products with regular batteries, which give an attractive design and easy-to-use shape. This battery can be used as a tray for cooling drinks at the table. Before the upcoming trip, the cold battery must be sustained in the freezer of a regular household refrigerator for 8-10 hours.
Note the temperature bag parameter, such as the capacity, which is determined by the weight of the product. The weight of a small bag for transporting several containers with drinks is not more than 400 g. Up to 15 kg of products can be placed in a bag weighing about 5 kg. In such bags without cold batteries at moderate ambient temperatures, the products remain cold for 3 to 5 hours. Using batteries under the same conditions increases the period of saving products in a large bag to 12-24 hours, in a small – from 7 to 12 hours.
Special polymer materials are used for the manufacture of rigid bags, for elastic – durable fabrics such as polyester and nylon. Thermal insulation is achieved by creating two-layer structures. Reliable materials in this regard are foam polymers — polyethylene and polyurethane foam.
Choosing a thermal bag, decide which transport device is more preferable for you. These may be articles with one or two handles or shoulder straps, equipped with comfortable linings and adjustable. Large thermopouches may have retractable handles with several fixed positions, as well as support rollers for easy movement. Some models of bags can be carried as backpacks.