Thermal insulation lunch box is also a daily necessities that will be used in life. Thermal insulation lunch box can keep our food temperature. In order to keep thermal insulation lunch box in direct contact with food, we need to pay special attention to material and details.
Under normal circumstances, a good quality heat preservation lunch box can keep for 5 hours or so. According to the different quality of the heat preservation lunch boxes, the heat preservation effect is different. Now, the heat preservation lunch boxes on the market are added to a common lunch box with a thermal insulation shell, and inside and outside two layers are filled with foam plastics, and then the inner layer is plated with metal film. Reduce heat loss from conduction, radiation and convection. An electric heating device is installed between the lunch box and the shell to supplement the heat loss and keep the food at a certain high temperature.
As a professional manufacturer of lunch box, we will teach you how to buy insulated lunch box.
1. For thermal insulation test, you can put boiled water into a thermal insulation lunch box, then cover it, stand still for about 3 minutes, and touch the outer surface of the cup body with your hand. If you feel that the box body is obviously warm and hot at the bottom, it means that the product has lost vacuum and can not achieve good thermal insulation effect, and the bottom of the thermal insulation cup is always cool.
2. Check the tightness. After adding water, cover the cover, place the cover flat on the table to see if there is water seepage, and then check the screw in and screw out of the cover and the cup mouth. The screw in and screw out should be flexible without gap. Fill a glass of water and turn it upside down for four or five minutes, or toss it hard to verify whether there is water leakage.
3. Plastic identification: food grade plastics should have small smell, smooth surface, no barbs, long service life and not easy to aging.
4. In the judgment of stainless steel materials, there are many specifications of stainless steel. Select those that meet the standards and meet the national food grade. The product is rust proof and corrosion-resistant. The color of ordinary stainless steel is white or dark. If it is soaked in salt water with a concentration of 1% for 24 hours, it will produce rust spots, and some elements contained in it exceed the standard, which will directly endanger human health.
Post time: Oct-11-2021