Views: 199 Author: Site Editor Publish Time: 2021-02-17 Origin: Site
Unlike old plastic or brown lunch bags, insulated beach bags can keep your food warm or cold for a longer time to prevent deterioration. Thermal lunch bags are even better than classic lunch boxes in heat preservation and freshness preservation because they are embedded with insulation layer. But how do they work?
Most promotional cooler bags have multiple layers of insulation, including an outer layer, a lining, and an intermediate layer to provide insulation. One of the most important is the middle layer because it is the most important difference from other ordinary lunch boxes.
Thermos bottles and foldable cooler bags rely on the vacuum generated between the outer layer and the inner layer to prevent energy dissipation, while the thermal lunch bags rely on the core layer made of dense foam to keep food or drink warm or cold. The thicker the foam or the greater the density, the better the heat insulation effect.
The foam layer prevents heat from infiltrating the outer layer and prevents the surrounding cold or heat from reaching the food in the bag. You may notice that the outer layer of most lunch bags is usually made of non-woven, vinyl, or thick fabric, which reduces the loss of food heat into the air.
As an additional protective layer, many of the cheap insulated cooler bags have a waterproof and heat reflective lining made of aluminum foil, heavy vinyl, or plastic.
Heat reflection means that the foil like inner layer of the branded cooler bag can reflect the radiant heat of the food back instead of absorbing heat and losing it to the air. The food in the thermal bag can be kept its original temperature, taste, and moisture for a long time, which means that a small thermal bag can also prevent food deterioration like tinfoil.
Similarly, the soft sided cooler bag is suitable for those who like to pack their own lunch on the journey, children who go to school with homemade lunch, and those who like to have a good home-made meal on the journey but do not want to order takeout.
There is no simple answer to this question because the amount of time food can be stored in a thermal bag for sale depends on several factors:
Is there any heating or freezing gel bag in the insulation bag?
According to experience, the hot food in the heat thermal cooler bag should be kept for 2 to 3 hours and cold food can be kept for 4 to 5 hours if you do not add gelatin bags. Besides, heating or freezing gel bags can extend the heat preservation time for 3 to 4 hours, but these figures depend largely on the quality of the bag and the ambient temperature, so you had better test your insulation bag in advance.
If you want your food to stay warm or refrigerate longer in a personalized cooler bag, here are some tips:
l Place a cold or warm source in a bag, such as a heated gel bag / water bottle (if the food is hot) or a frozen gel bag / water bottle / juice box (if the food needs to be refrigerated).
l Reheat food before packaging or pack frozen food into lunch bag directly from refrigerator or freezer.
l Wrap food with aluminum foil to add a layer of insulation and continue to wrap food with tea towel to further prevent heat loss.
l Don't open the lunch bag before you really need to consume food to prevent heat from escaping from the bag.
