For the health-preserving family, the best partner of the thermos cup is no longer the "outstanding" wolfberry. It can also make tea, jujube, ginseng, and coffee... However, a recent survey found that some thermos cups on the market are shoddy. Good quality issue. What? Quality problems? The insulation effect is poor? NO! NO! NO! The heat preservation is almost reluctant to endure, but the problem of excessive heavy metals is a big problem!
The appearance is the basic "responsibility" of a thermos cup, but when you hold it in the palm of your hand, you will find that the material is more important than the appearance.
Most of the thermos cups are made of stainless steel, which is resistant to high temperatures and has good thermal insulation performance. Other materials such as glass, ceramics, purple sand, etc. are affected by factors such as heat preservation, drop resistance, and price, and are only a small part of the army of thermos cups.
Stainless steel materials are usually divided into three types, the "codes" are 201, 304, and 316 respectively.
201 stainless steel, "Li Gui" who is good at camouflage. Most of the unqualified vacuum flasks exposed in the news use 201 stainless steel as the inner liner of the vacuum flask. 201 stainless steel has high manganese content and poor corrosion resistance. If it is used as the inner liner of a vacuum flask, long-term storage of acidic substances may lead to the precipitation of manganese. Manganese metal is an essential trace element for the human body, but excessive intake of manganese can harm the body, especially the nervous system. Just imagine, if you let your child drink this water all day, the consequences are really serious!
304 stainless steel, the real material is very "carrying". When stainless steel comes into contact with food, the potential safety hazard is mainly the migration of heavy metals. Therefore, stainless steel materials that come into contact with food must be food-grade. The most commonly used food-grade stainless steel is 304 stainless steel with better corrosion resistance. To be named 304, it needs to contain 18% chromium and 8% nickel, which is justifiable. However, merchants will mark the word 304 on the obvious position of stainless steel products, but marking 304 does not mean that it meets the requirements for food contact use.
316 stainless steel, the aristocratic origin is not stained with "mortal dust". 304 stainless steel is relatively acid-resistant, but it is prone to pitting corrosion when encountering substances containing chloride ions, such as salt solutions. And 316 stainless steel is an advanced version: it adds metal molybdenum on the basis of 304 stainless steel so that it has better corrosion resistance and is more "carrying". Unfortunately, the cost of 316 stainless steel is relatively high, and it is mostly used in high-precision fields such as medical treatment and the chemical industry.
There are hidden dangers, you should not soak it if you soak it.
A thermos cup is a thermos cup, and you can also get bubble goji berries. Naturally, you can't soak the whole world! Not only that, some things that are commonplace in daily life cannot be soaked in the thermos.
1 tea
Making tea with a stainless steel thermos cup will not cause the migration of metal chromium, nor will it cause corrosion to the stainless steel itself. But even so, it is not recommended to use a thermos to make tea, because tea is usually suitable for brewing, and long-term hot water soaking will destroy the vitamins in the tea, and will also reduce the flavor and taste of the tea. Moreover, if the cleaning is not timely and thorough after brewing tea, the tea scale will adhere to the inner liner of the thermos cup, resulting in a peculiar smell.
2 Carbonated drinks and juices
Carbonated drinks, fruit juices, and some traditional Chinese medicines are mostly acidic, and they will not cause heavy metal migration if they are placed in a thermos for a short time. However, these liquids have complex components, and some are highly acidic. Long-term contact may corrode stainless steel, and heavy metals will migrate into beverages. When using a thermos cup to hold carbonated beverages and other gas-producing liquids, be careful not to put too much or overfill and avoid violent shaking to prevent the dissolved gas from escaping and a safety hazard when the pressure in the cup increases sharply.
3 Milk and soy milk
Milk and soy milk are both high-protein drinks, which are prone to spoilage when kept warm for a long time. If you drink the milk and soy milk that has been in the thermos for a long time, it will be difficult not to have diarrhea! In addition, the protein in milk and soy milk also easy to adhere to the wall of the cup, making cleaning difficult. If you only temporarily use a thermos cup to hold milk and soy milk, you should sterilize the thermos cup with hot water first, drink it as soon as possible, and wash it as soon as possible. Try to be "gentle" when cleaning, and avoid using hard brushes or steel balls to prevent scratching the stainless steel surface and affecting corrosion resistance.