Drinking water reasonably is the guarantee of a healthy life. According to scientific recommendations, an adult needs to consume about 2000 ml of water per day. For a long time, many people have been concerned about how much water to drink, but they have not paid much attention to handling the numerous water containers every day. Until now, some people have discussed on the Internet that "making tea with a stainless steel water kettle will be poisoned", and everyone has shifted the focus to the water bottle for drinking. So, is this statement reliable? In addition to stainless steel water bottles, there are also ceramic water bottles, enamel water bottles, glass water bottles, plastic water bottles, disposable paper water bottles and other materials in daily life. Water container, how do we choose to better protect our health?
Are you picky?
Glass machines are based on porcelain water bottles, ceramic water bottles, plastic water bottles, stainless steel water bottles, iron water bottles, aluminum water bottles, wooden water bottles, paper water bottles... When we go to shopping malls to buy water bottles, there are various The water bottle will break into our sight, especially those with bright colors and unique shapes.
In life, the water bottle is really an indispensable daily necessities, we use it every day, its importance can be seen in general.
Glass water jug
Among all the water jugs made of materials, the glass water jug is the healthiest. The glass water bottle is made of inorganic silicate. It does not contain organic chemicals during the firing process. The glass is extremely stable and is the most stable material among all materials. When people drink with a glass When using water or other beverages, you don’t have to worry about chemicals being drunk into your stomach. The glass surface is smooth and easy to clean. Bacteria and dirt are not easy to breed on the wall of the glass. So people drink water from glass is the healthiest and safest. of. Although the glass does not contain chemical substances and is easy to clean, because the glass material has strong thermal conductivity, it is easy for users to accidentally burn themselves, and the glass is most afraid of thermal expansion and contraction. The thermal stability of the glass is extremely poor. The internal stress generated in the glass during the sudden change easily exceeds the strength of the glass. It is easy to burst in the case of rapid cold and hot. Therefore, the glass water bottle with too low temperature should not be filled with hot water immediately to prevent it from bursting.
The glass is not only transparent and beautiful, but also very healthy.
Enamel water jug
The enamel water bottle is made after thousands of degrees of high temperature enamelling. It does not contain harmful substances such as lead. It is easy to carry and clean and is relatively safe. The metal elements contained in the composition of the enamel water bottle are usually relatively stable, but in an acidic environment, they may dissolve out. It is not safe to drink coffee, orange juice and other acidic beverages. There is a safety hazard in the damaged enamel water bottle, please use it with caution!
Is there any harm?
It is well known that lead is a heavy metal that is harmful to human health. According to the experimental results, it can be concluded that the use of an enamel bottle to hold acidic beverages can indeed cause a significant increase in the lead content in the beverage. Although the elevated lead content is far from reaching the national limit of 1 mg/liter, it is due to the enamel The cups are used frequently, and the accumulated poisons still need to be paid enough attention. Therefore, it is recommended to eliminate the broken enamel cups.
In fact, there have been reports about the possible poisoning of enamel bottles, and it is not news. Because the porcelain on the surface of the enamel water bottle is composed of sodium silicate and metal salt, which contains lead, cadmium and other harmful metal elements, these elements will seep out and enter the liquid under acidic conditions or heating. This has long been theoretically Known.
Ceramic water bottle
Advantages: The appearance is defect-free, bright and clean, high gloss, good thermal stability (180 degrees-20 degrees), and it will not react and generate harmful gases when filled with boiling water, which is stronger than plastics. The hardness is high, but the plasticity is poor, it is brittle, does not absorb water, and is resistant to high temperature and corrosion.
Disadvantages: It is brittle, easy to break due to bumps, and it is heavier than plastic bottles, and it is not easy to carry.
The colorful ceramic cups are very flattering, but in fact, there are huge hidden dangers in the bright pigments, especially the inner wall is coated with glaze. When the bottle is filled with boiling water or drinks with high acidity and alkalinity, these pigments The lead and other toxic heavy metal elements in the liquid are easy to dissolve in the liquid. If people drink the liquid with chemical substances, it will cause harm to the human body.
The first choice for drinking water is a ceramic bottle without colored glaze, especially the inner wall should be colorless. Not only the material is safe, it can withstand high temperatures, but also has a relatively good insulation effect. Drinking hot water or tea is a good choice.
The application of ceramics has a long history and occupies a major position in ancient tea sets. Although the application of ceramics is not as popular as in ancient times, due to the special properties of ceramics, new materials are often added to make ceramics have certain special properties and become new types of ceramics. The melting point of ceramics is very high, mostly above 2000 degrees Celsius, so it has high heat resistance. The linear expansion coefficient of ceramics is small, and the thermal conductivity is poor, so that the ceramic water bottle with hot water is not very hot. The vibration is poor, and it is easy to break when subjected to thermal shock. However, in the application of water cups, ceramics are still not expensive for the thermal shock of about 100 degrees Celsius, and the price is not very expensive, so most people can consume them. They are widely used in the design of water cups. Now they often use ceramics to make some special interesting things. Water bottles and ceramics are often used by some famous designers. The disadvantage of using ceramics as water cups is that they are easy to break, but this does not affect the application of ceramics in water bottles. Because of the processing characteristics of ceramics, most of the ceramic water cups have an open shape, with few additional shapes.
Advantages: The color is bright and beautiful, the color is bright and beautiful, the shape is diverse, the material is safer, it can be installed in hot and cold water, and it is resistant to high temperatures and has a good insulation effect.
Disadvantages: Usually when the glaze is coated with water or acidic or alkaline beverages, the potential hazards of aluminum or other heavy metal elements in the glaze: excessive intake of aluminum will accumulate in the brain, liver, and kidneys, and cause more On the one hand, excessive intake of pregnant women is impaired, and it may harm the wisdom of themselves and their children. Use unglazed ceramic cups, and the slices of the glaze should be "underglaze color" first to be painted and then glazed). The safety 30 purple sand bottles (pots) and less bottles (pots) are also good, but they must be made of regular materials.
Investigation of Plastic Water Bottles
Plastic water bottles occupies most of the water bottle market, especially in the occasions where water bottles are often carried. For example, 95% of the water bottles used by students with water in class are plastic water bottles and 5% are non-cast steel water bottles. . Good transparency and strong coloring, so the color of the water bottle can be varied for selection; high abrasion resistance, the water bottle is not easy to change flowers; light transmission and heat preservation; poor heat resistance, no problem for the temperature of about 100 degrees Celsius; part Plastics produce toxic substances under the action of hot water.
As long as in the process of making plastic water bottles, 100% of bisphenol A is converted into plastic structure. If there are a small amount of double products that completely contain bisphenol A, let alone release. Only a small amount of bisphenol A has not been converted into a plastic structure of the weight scale, and it may be released into food and beverages. The residual bisphenol A in the plastic cup, the higher the temperature, the more release and the faster the speed. Because of this, you should not drink whole hot water from a PC water bottle. If the container is accidentally broken or broken, avoid repeated use of aging plastic containers.
Although the surface of the plastic is coated with mercury, there are many pores in the internal structure of the plastic. "It is used to hide the dirty media. When purchasing plastic cups, you must choose food-grade plastic that meets national standards." The made water bottle. The plastic cup is the easiest to hide dirt and dirt, so you must choose a plastic cup with guaranteed quality.
The small signs in this column are hidden in the corners of plastic products. The difficulty of finding is similar to finding the production date. But as far as the plastic water bottle itself is concerned, this is a focus of judging quality. They appear in two places. One; one is the bottom of the water jug, and the other is the inside or outside of the lid of the water jug.
What exactly does it mean to hide such a good logo? Everyone knows that the circular arrow is a recyclable face. The number in the circle indicates which attribute of the water bottle, do you know?
【Bottle Lid】PP (Polypropylene)
- ·PP has the lowest density among synthetic resins and has a light texture, only 0.90~0.91g/cm3, which is about 60% of the density of PVC. This means that with the same weight of raw materials, more products of the same volume can be produced.
- ·PP has unusual resistance to chemical solvents, acid and alkali resistance, and has good thermal stability and insulation.
- ·PP has good tensile strength and rigidity, light weight, good toughness, good heat resistance, and good molding properties.
- ·The part used for the cup lid in this product is frosted on the surface of the material to increase the friction, so that the user can easily and effortlessly open the lid, and the matte effect is also very beautiful. Heat resistance degree: 0~100℃·
Disadvantages: easy to age
Bottle Lid-Bottle Body Material Selection
The performance of PC and PP is better than that of gas barrier and hygienic barrier. Generally good materials, PC/PP has high transparency and high transparency. Generally, heat and temperature are excellent in impact resistance. PP has good chemical stability, high melting point, light weight, good molding processability, can be injection molded, and polypropylene is safer than polycarbonate. The Vicat softening temperature of PP is 150C. Due to the high crystallinity, the surface rigidity and scratch resistance of this material are very good. Therefore, we choose PP as the material of the cup lid, cup body and cup handle.
Metal bottles, such as stainless steel, are more expensive than ceramic bottles.
Advantages: The metal surface is shiny, the surface is smooth and easy to clean (better than plastic), it can be processed into matte or wire drawing, etc., with good ductility. Metal materials have high hardness and good wear resistance. Wear resistance is a good conductor of heat. It conducts heat quickly. Although it is hard, the metal will not break or crack when it falls on the ground.
Disadvantages: The density is high and the mass is heavy, it is not convenient to carry, the texture is heavier than plastic, but it is lighter than ceramics, and the insulation is poor. Although there is a unique metallic color, it lacks color and high processing cost. And easy to produce chemical reactions with certain components. It has good thermal conductivity. When there is hot water in the bottle, it will be hot to hold the bottle.
Stainless Steel is a steel that is resistant to weak corrosive media such as air, steam, and water, and chemically corrosive media such as acid, alkali, and salt. It is also called stainless acid-resistant steel. In practical applications, steel that is resistant to corrosion by weak corrosive media is often called stainless steel, and steel that is corroded by chemical media is called acid steel. Generally speaking, 12% of stainless steel water bottles have the characteristics of stainless steel. Stainless steel can be divided into five categories according to the microstructure after thermal treatment; namely, ferritic stainless steel, Maminite stainless steel, austenitic stainless steel, Austenitic-ferritic stainless steel and precipitation carbonized stainless steel text. Due to the excellent thermal conductivity of steel, the above two bottles are of double-layer stainless steel vacuum construction. The ductility of stainless steel is very good, and it is still not very complicated to make a double-layer stainless steel T art. Attached machine handles are often designed with other materials such as plastics, because in mass production, irregular handles and other shapes are not easy to shape, while plastics are easy to deform. Therefore, in the design, the combination of different materials and low use can fully exploit the advantages of each purpose, and the project will not be too high. The design of the bottle lid with two labels of F is also the combination of stainless steel and rubber plastic, because it is not easy to achieve the sealing effect of stainless steel, and it is easier than stainless steel rubber and plastic. At the same time, the design of the bottle lid is both It can be used as a lid or as a bottle.
Advantages: beautiful, durable and corrosion resistant, not afraid of falling.
Disadvantages: The bottle contains metal chromium, nickel, cadmium and other elements. If it is produced from inferior materials, its heavy metals will seriously exceed the standard. Long-term use, metal elements may accumulate in the human body and be harmful to health.
Recommendation: Although the properties of stainless steel are relatively stable, no harmful substances will be decomposed under normal conditions. However, pregnant women are still not suitable for long-term use as a water bottle, let alone for acidic or high-salt drinks. The stainless steel water bottle is made of alloy.
Is stainless steel water bottle tea toxic?
Metal materials expert of Zhejiang University: Filling with water will inevitably release "chromium", but it will not endanger health." It is now circulating on the Internet. If we use stainless steel water bottles to make tea, the bottle will release some chromium, which will endanger health." When the hot discussion about stainless steel cups was told to the relevant experts of the Institute of Metal Materials of Zhejiang University, he was taken aback for a moment, and then he quickly gave his professional opinions. "When you use a stainless steel bottle to hold things, it is inevitable that some chromium will be released from the bottle. Even if you only fill it with plain water, a certain amount of chromium will be released. What's more, tea will corrode the bottle and accelerate the release of chromium." An expert said that in fact, in addition to chromium, the metal elements released from stainless steel bottles include nickel and iron, among which 70% to 80% is iron, which is one of the trace elements that the human body needs very much.
Because chromium and nickel are slightly toxic in terms of toxicity, everyone is worried that these elements will affect their health. However, the expert explained that although these elements are theoretically described as harmful to the human body, in fact, as long as the stainless steel cups produced by regular manufacturers meet the national standards, the amount of chromium and nickel released from them is very small. Do not cause harm to the human body at all. In this regard, the expert also made a very vivid comparison. Usually when they cut stainless potassium in the laboratory, the temperature will generally reach above 1000°C, while the temperature of the oil pan when cooking at home is around 200-300°C. Looking at the temperature of the hot water in the cup, it is often only 50-60°C. , "The higher the temperature, the more metal elements are released from stainless steel. In contrast, the chromium released when drinking water from a stainless steel water bottle is the least, so you can drink with confidence."
The expert of science of the fruit shell net: the tea will not release excessive chromium until soaking for 10 days. If you still can't let go of seeing this, please continue to look at a set of more accurate data.
Let me introduce a person to you first. He is a scientific man on GuoKai.com, whose net name is "_whyCD". His major is a Bachelor of Engineering in Inorganic Nonmetallic Materials. He has published many popular science articles on GuoKai.com. In response to the claim that the release of chromium from stainless steel cups that everyone is very concerned about is harmful to health, he also specially collected relevant information and posted his views on the Guo shell website.
In fact, considering the health risks of chromium, countries around the world have formulated strict regulations on the amount of chromium in stainless steel food utensils. "_whyCD" said that in the relevant Chinese national standards, it is stipulated that the release of chromium from stainless steel vessels should not exceed 0.4 mg/dm2, and the method for measuring this release is to boil in a 4% acetic acid solution for 30 minutes Then soak for 24 hours, the pH value of 4% acetic acid solution is 2.5.
Unlike acetic acid solution, tea water is only very weakly acidic (the pH of tea water is usually between 5 and 7) and has much less corrosive effect on stainless steel. Assuming that tea water with a pH of 5.5 is used for the soaking experiment, it takes about 246 hours to release 0.4 mg of chromium, which is 10 consecutive days of soaking. In addition, the tea will not boil in the stainless steel bottle for 30 minutes. Therefore, as long as you use a stainless steel bottle that meets the standard, you don't have to worry about the released chromium element exceeding the standard.
Materials Science Expert of Zhejiang University: Not reliable!
In the discussion about the health hazards caused by the release of chromium from stainless steel cups, many people also mentioned many ways to identify the quality of stainless steel, such as the use of stainless steel discriminators or magnets. Considering that the identification method of magnet is the most convenient and easy to operate, the reporter also specially asked the professor of materials science of Zhejiang University to comment during the interview.
The identification method on the Internet believes that the real stainless steel is the weaker magnet, and if the magnet can be firmly attracted, it means that it is "stainless iron" that pretends to be stainless steel. "Such an identification method is definitely unreliable." The professor said. Stainless steel is a general term for a type of alloy steel, which can be subdivided into ferritic steel, austenitic steel, martensitic steel, etc. according to its structure and chemical composition. If you do a magnet experiment, the result must be that ferritic steel, leaustenite steel can be attracted by magnets, and martensitic steel cannot be attracted by magnets. Does this mean that martensitic steel is better than the other two Is it good to plant?
No! The professor said that whether stainless steel can be attracted by magnets depends on the content of nickel. The higher the content, the weaker the magnetism. As for the increase or decrease of nickel, it depends on the actual demand. For example, martensitic steel with strong hardness is often used to make knives, and more nickel is needed; while austenitic steel with good flexibility is often used to make pots and pans, and less nickel is added.
In short, the same sentence, as long as you buy and use white stainless steel products produced by regular manufacturers that meet the national standards, you don't need to worry too much. Don't go to the roadside stalls to buy the "three noes" products from small family workshops because they are likely to simply re-process the recycled steel scrap and miscellaneous steel, and the craftsmanship does not meet the national standards.
Disposable paper bottle
A paper container made of base paper (white cardboard) made of chemical wood pulp by mechanical processing and bonding. The appearance is bottle-shaped. Paper bottles used for frozen foods are coated with wax, which can hold ice cream, jam, butter, etc. Paper bottles for hot drinks are coated with plastic, which can withstand temperatures above 90°C and can even bloom in water. Paper bottles are divided into single-sided PE coated paper bottles and double-sided PE coated paper bottles: single-sided PE coated paper bottles are produced with single-sided PE coated paper, (the common domestic market paper bottles, most of the advertising paper bottles are single-sided PE coated paper Paper bottle), its manifestation is as follows: the water-filled side of the paper bottle has a smooth PE coating; the double-sided PE coating paper bottle is produced with double-sided PE coating paper, and the manifestation is that the paper bottle has PE coating on the inside and outside.
Disposable paper bottles just look hygienic and convenient. In fact, the qualified rate of the product cannot be judged. Whether it is clean and hygienic, it cannot be recognized with the naked eye. From the perspective of environmental protection, disposable paper bottles should be used as little as possible. Some paper bottle manufacturers add a large amount of fluorescent whitening agent to make the bottle look whiter. It is this kind of fluorescent substance that can make cells mutate, and once it enters the human body, it will become a potential carcinogen; secondly, those unqualified paper bottles are generally soft and easily deformed after being poured into water, and some paper bottles have poor sealing. , The bottom of the bottle is easy to seep water, which can easily burn your hands with hot water; what's more, when you touch the inside of the paper bottle with your hand, you can feel the fine powder on it, and the touch of your fingers will also turn white , This is a typical inferior paper bottle.
Investigation of disposable paper bottles or new functional bottles with hidden potential carcinogens
There is also a relatively large group in the water bottle family, which is the "energy bottle" promoted by the merchants. However, not all magnetized water is beneficial to the health of the human body, only the magnetization of the negative electrode. Water can improve the physiological functions of the human body, and the positive power of water should not be consumed too much. Most of the magnetized bottles we see in the market use ordinary magnets, and the positive and negative electrodes are divided into this. Consumers should make careful identification when choosing a magnetized scale. Purchase a unipolar magnet (negative plate) as a magnetization bottle with a magnetization function. In principle, the "energy bottle" can also improve the function of the human body and play a role in health care. However, many companies that produce energy scales on the market have combined There is no verification of the car's efficiency in this field, which exaggerates the function of the functional scale, and some even claim that it can cure all diseases.
Pay attention when buying a water bottle and don't follow it blindly!