The most important basis for judging whether tableware can be heated is the product material.
1. The commonly used microwave heating plastic material is polypropylene (PP), which is generally indicated by the number 5 at the bottom of the container. The food grade polypropylene material is cheap, non-toxic and tasteless, and the temperature range is -30～140℃, which can be set. It can be heated in a microwave oven or placed in a freezer for low-temperature refrigeration.
Polyethylene (PE) plastic tableware has excellent low temperature resistance, but it is slightly less resistant to high temperature. Generally, it is used as a refrigerated food container. Please judge whether it can be used as a heating tableware according to the product manual.
There is also a kind of melamine tableware (melamine tableware) on the market that is also a plastic tableware, but it cannot be heated in a microwave oven. This is because of the special molecular structure of melamine plastic. Microwave will cause its chemical reaction and change its physical properties. Cracking will occur during use.
It should be noted that the food container box
itself and the lid of the container may not be made of the same type of plastic. Please confirm carefully or remove the lid and reheat. The heating temperature must not exceed its heat-resistant limit temperature. In addition, plastic products will become discolored and brittle after being used repeatedly for a period of time. If the plastic lunch box is found to be yellow or the transparency is obviously reduced, it should be replaced in time.
2. Glass and ceramic tableware that can be used for heating need to be clearly marked on the product or the smallest sales package. Please read the instructions on the product package carefully. Generally, the glass material that can be used for microwave heating is high borosilicate glass, commonly known as heat-resistant glass.
It should be noted that refrigerated storage boxes, glasses and other products made of soda lime glass (ordinary glass) cannot be used for heating. Sudden cold, sudden heat, and excessive temperature difference between cold and heat can easily cause soda lime glass to break and cause injury.
3. Metal tableware can be heated by an open flame or steaming, but it cannot pass through microwaves. Therefore, stainless steel, aluminum and other metal tableware cannot be microwaved, and metal tableware will also cause the microwave to generate electric spark discharge and reflect microwaves. Damage the furnace body.
note! Tableware with gold thread cannot be heated in a microwave oven. At the same time, this kind of tableware is not suitable for dishwashers and disinfection cabinets.
4. Paper products and bamboo and wood tableware can be heated in a microwave oven when they are wet, but they cannot be used as a container for microwave heating of food for a long time. If the heating time is too long or the container is dry, it may cause the tableware to burn.