Today I saw a message from a friend. The original text asked: Is it better to use No. 5 plastic or No. 7 plastic for water cups? Regarding this issue, I have explained in detail what the numbers and symbols at the bottom of the plastic water cup mean in several previous articles. Today I will share with you about numbers 5 and 7. We will not go into details about the other numbers. At the same time, Friends who can ask questions about 5 and 7 are also very professional.
The number 5 on the bottom of the plastic water cup means that the body of the water cup is made of PP material. PP material is widely used in the production of plastic water cups. Due to the high temperature resistance of PP material, many semi-finished products that can be heated in the microwave oven in the early days The transparent plastic square box is made of PP material. PP material has stable performance and is food grade recognized by various countries and regions around the world. Therefore, in the production of water cups, PP material is not only used for the cup body. If friends pay attention, they will find that whether it is plastic water cups, glass water cups, or stainless steel water cups. 90% of the plastic cup lids are also made of PP material. PP material is soft and has good temperature difference resistance. Even if it is taken out of minus 20℃ and immediately added to 96℃ hot water, the material will not crack. However, if it is AS material, it will crack severely and it will explode directly. open. Because the PP material is relatively soft, water cups made of PP, whether the cup body or the lid, are prone to scratches during use.
The number 7 on the bottom of the plastic water cup is relatively complicated, because in addition to the material, the number 7 also has another meaning, representing other plastic materials that are food-grade safe. At present, the plastic water cups marked with the number 7 on the market usually represent these two materials, one is PC and the other is Tritan. So if the two materials are compared to PP, which is the number 5 material, it can be said that the gap is very big.
Food-grade PC is also used more in plastic water cups and plastic household appliances, but PC materials contain bisphenol A, which will be released when the contact temperature exceeds 75°C. So why is it still used as a water cup material? Manufacturers that usually use PC materials to produce plastic water cups will have clear remarks when selling, indicating that such water cups can only hold room temperature water and cold water, and cannot add hot water with a water temperature exceeding 75°C. At the same time, due to the relatively high permeability of PC materials , the water cup produced has a clear and more beautiful appearance.
Post time: Feb-02-2024