The triangular sign at the bottom of plastic products is equivalent to the "ID card" of the product. A triangle with three arrows means "recyclable". In addition, the numbers in the triangle, such as "1", are digital signs. The plastic digital signs are 1 to 7, and each number represents a plastic material, mainly to facilitate recycling and understand its use conditions.

Among them, the recycling marked with "5" indicates that its main manufacturing material is PP. The plastic container made of this material has good air permeability, high heat resistance, high impact resistance, strong mechanical properties and resistance to various organic solvents and acid and alkali corrosion. Lunch box mostly use in microwave oven