Plastic bento boxes usually have four icons on the bottom: a snowflake, a wavy line, a triangle and a QS logo. Among them, the snowflake logo plastic bento box can be stored in a low-temperature environment; the Wavy line means bento boxes can be heated in the microwave; The triangle represents the lunchbox is recyclable; QS said the quality of bento boxes is in line with national standards. On the bottom of some plastic bento boxes, there will also be a wine glass logo, indicating that the plastic bento boxes are dishwasher safe.
There will also be a symbol with the number 5 in the triangular icon at the bottom of the lunch box, which means the main manufacturing material is PP. The material can make bento boxes of permeability, heat resistance, and impact resistance better, and can resist many kinds of organic solvent and acid and alkali corrosion. The material will be much used in making microwave oven boxes, bottles and other plastic products. In addition to the number 5, the triangle at the bottom of the plastic product is marked with a different number depending on the type.
ⅰ. The number 1. Commonly found in bottled water. The main ingredient is polyethene terephthalate, which makes plastic bottles suitable for temperatures between 65 degrees and minus 20 degrees. But the material is disposable and can cause carcinogens if reused.
ⅱ. Number 2. Commonly found in cleaning products, such as common shower gel, shampoo and other cleaning products packaging bottles. The main ingredient is high-density polyethene,
ⅲ. The number 3. Commonly found in raincoats, film and other decoration materials. The main component is PVC.
ⅳ. The number 4. Commonly found in plastic wrap. The main ingredient is low-density polyethene, and it can withstand temperatures of -60 degrees to 110 degrees, so when heating food, try not to use plastic wrap.
ⅴ. Number 5. Commonly found in chewing-gum boxes and plastic bento boxes. The main ingredient is polypropylene, the only material that can be heated.
ⅵ. Number 6. Commonly found in bucket tops, packaged coffee, etc. The main ingredient is polystyrene. It should be noted that this material is not suitable for microwave heating.
ⅶ. Number 7. Commonly found in all kinds of plastic cups, PC plastic products. This is one of the safest plastic, and it can be reused many times.