The weather is so cold, so that the children can drink warm water anytime and anywhere. Every day when the children go to school, the first thing they do when they go out is that the mother stuffs a thermos cup into the side of the child’s schoolbag. A small thermos cup not only It is just filled with warm boiling water, but it also contains the fiery hearts of parents caring for their children! However, as a parent, do you really know about thermos cups? Let’s take a look at this experiment first:
The experimenter numbered the thermos cup,
Test whether adding acidic substances to the thermos cup will migrate heavy metals
The experimenter poured the proportioned acetic acid solution in the thermos cup into the quantitative bottle.
Experiment location: Chemistry laboratory of a university in Beijing
Experimental samples: 8 thermos cups of different brands
Experimental results: The manganese content of cup “juice” exceeds the standard by up to 34 times
Where do the heavy metals in solution come from?
Qu Qing, a professor at the School of Chemical Science and Engineering at Yunnan University, analyzed that manganese may be added to the stainless steel of the thermos cup. He introduced that different metal elements will be added to stainless steel according to needs. For example, manganese can increase the corrosion resistance of stainless steel; adding chromium and molybdenum can make the surface of stainless steel easy to passivate and form an oxide film. Qu Qing believes that the content of metals is related to factors such as storage time and solution concentration. In daily life, acidic solutions such as juices and carbonated drinks can precipitate metal ions in stainless steel. It cannot be judged whether the limit has been reached, but it will accelerate the precipitation of stainless steel thermos cups. Heavy metal time.
Keep in mind the “four things you don’t need” for a thermos cup
1. The thermos cup should not be used to hold acidic drinks
The inner tank of the thermos cup is mostly made of stainless steel. Stainless steel has a higher melting point and will not release harmful substances due to high temperature melting. However, stainless steel is most afraid of strong acid. If it is loaded with highly acidic drinks for a long time, its inner tank is likely to be damaged. The acidic drinks mentioned here include orange juice, cola, Sprite, etc.
2. The thermos cup should not be filled with milk.
Some parents will put hot milk in a thermos cup. However, this method will allow the microorganisms in the milk to multiply rapidly at the appropriate temperature, leading to corruption and easily causing diarrhea and abdominal pain in children. The principle is that in high-temperature environments, vitamins and other nutrients in milk will be destroyed. At the same time, the acidic substances in the milk will also react chemically with the inner wall of the thermos cup, thereby releasing substances harmful to the human body.
3. The thermos cup is not suitable for making tea.
It has been reported that tea contains a large amount of tannic acid, theophylline, aromatic oils and multiple vitamins, and should only be brewed with water around 80°C. If you use a thermos cup to make tea, the tea leaves will be soaked in high-temperature, constant-temperature water for a long time, just like boiling over a warm fire. A large number of vitamins in tea are destroyed, aromatic oils volatilize, and tannins and theophylline are leached out in large quantities. This not only reduces the nutritional value of tea, but also makes the tea juice flavorless, bitter and astringent, and increases harmful substances. Elderly people who love brewing tea at home must keep this in mind.
4. It is not suitable to carry traditional Chinese medicine in a thermos cup
The weather is bad in winter, and more and more children are sick. A few parents like to soak traditional Chinese medicine in thermos cups so that their children can take it to kindergarten for drinking. However, a large amount of acidic substances are dissolved in the decoction of traditional Chinese medicine, which easily reacts with the chemicals contained in the inner wall of the thermos cup and dissolves into the soup. If a child drinks such a soup, it will do more harm than good.
Remember the “little common sense” when choosing a thermos cup
First of all, it is recommended to buy from regular merchants and choose brand products with good reputation for better health and security. Of course, to be on the safe side, parents are best to read the quality inspection report of the product themselves.
Material: For young babies, the cup itself is non-toxic and harmless, and the best material is anti-fall. Stainless steel is the first choice. 304 stainless steel is the internationally recognized food-grade stainless steel as the first choice. It can be rust-proof, corrosion-resistant, and environmentally friendly. Such products, in addition to stainless steel, also use plastic and silicone materials, and their quality must also meet relevant standards.
304, 316: The outer packaging will indicate the materials used, especially the inner pot. These numbers represent food grade. Do not consider those starting with 2.
18. 8: Numbers such as “Cr18″ and “Ni8″ are commonly seen on infant thermos cups. 18 refers to metal chromium and 8 refers to metal nickel. These two determine the performance of stainless steel, indicating that this thermos cup is green and environmentally friendly. Rust-proof and corrosion-resistant, it is a relatively excellent material. Of course, the chromium and nickel content cannot be too high. In ordinary stainless steel, the chromium content does not exceed 18% and the nickel content does not exceed 12%.
Workmanship: A good product has good appearance, smooth inside and outside, evenly printed patterns on the cup body, clear edges, and accurate color registration. And the workmanship is very meticulous, the edge of the cup mouth is smooth and flat, easy to clean, and it is not suitable for harboring dirt and breeding bacteria. Touch the mouth of the cup lightly with your hand, the rounder the better, there should be no obvious welding seam, otherwise the child will feel uncomfortable drinking water. A true expert will check carefully whether the connection between the lid and the cup body is tight, and whether the screw plug matches the cup body. Be beautiful where it should be, and don’t look good where it shouldn’t be. For example, the liner must not have patterns.
Capacity: There is no need to choose a large-capacity thermos cup for your baby, otherwise the child will be tired of lifting it when drinking water and carrying it in his schoolbag. The capacity is appropriate and can meet the child’s hydration needs.
Drinking port method: Choosing a thermos cup for your baby should be based on its age: before teething, it is suitable to use a sippy cup, so that the child can easily drink water by himself; after teething, it is better to change to a direct drinking mouth, otherwise it will easily cause teeth to protrude. Straw-type thermos cups are a must-have style for young babies. The unreasonable design of the drinking mouth will hurt the baby’s lips and mouth. There are soft and hard suction nozzles. The hose is comfortable but easy to wear. The hard suction nozzle grinds teeth but is not easy to be bitten off. In addition to the material, the shape and angle are also different. Generally speaking, those with a bending angle are more suitable for the baby’s drinking posture. The material of the internal straw can also be soft or hard, the difference is not big, but the length should not be too short, otherwise it will not be easy to absorb the water at the bottom of the cup.
Insulation effect: Children often use children’s straw thermos cups, and they are anxious to drink water. Therefore, it is not recommended to choose products with too good thermal insulation effect to prevent children from getting burned.
Sealing: Fill a cup of water, tighten the lid, turn it upside down for a few minutes, or shake it hard a few times. If there is no leakage, it proves that the sealing performance is good.