The earliest insulation cup is made of glass, its principle and hot water bottle is actually similar, hot water bottle is also called Dewar bottle, which is a British physicist Sir James Dewar is carrying out a gas liquefaction in 1892, the need for a special insulation container and invented by chance!
Later German glass technician Berg realized that this thermal insulation apparatus is very commercial value, so in 1904 after obtaining a patent to market this glass product thermos, but also in the internal silver plating, and in his competition held in the name selected "Thermos" this name, the translation is hot, phonetic also quite like, so the hot water bottle this origin!
And hot water bottle, stainless steel insulation cup is also inside and outside the two-layer structure, the middle is a vacuum, heat can only be transmitted by conduction and radiation and convection, after sealing, no convection conduction to the vacuum can only radiation, and the cup mouth thin metal layer of heat dissipation is very slow, so the insulation cup of hot water can be insulated for a long time, and it is also much better than the glass material, because the fall is not broken, hot water bottle dropped underground on the broken!
Such a good stainless steel insulation cup, why is toxic?
The author's son's insulation cup, once fell from the second floor, fell on the cement floor, in addition to some deformation of the shell, insulation effect is still the same as just bought, so good insulation cup, how toxic it is?
The material used to make the insulation cup is stainless steel, because you can not choose aluminum or zinc, or iron, either easy to rust or strength is not enough, so in 1916 the British scientist Henry Brierley invented stainless steel became the best choice, but then the stainless steel is not a cup, but used to solve the problem of rusting gun chamber!
But it is not what you want, this stainless steel although not rust, but also can not do the chamber, because not enough wear resistance, strength is not enough, but it is because very resistant to acid, alkali, salt corrosion! Henry Brierley made it into stainless steel fruit knives, forks, spoons, fruit plates and folding knives, etc., and gradually took the world by storm!
There are many types of stainless steel, but do cup stainless steel requirements are very high, because it is loaded with food in the drinking water, and a short time contact with the basin knife and fork is not the same, the water cup will be used to soak hot water, and even sometimes will be loaded with drinks as well as milk with liquid medicine, so it also has a heavy metal precipitation problem!
Because only the ideal alloy is free of metals other than alloy, but this can not do at all, so stainless steel contains lead, arsenic, cadmium and other impurity elements is also normal, so different levels of stainless steel represents a different corrosion resistance, we commonly have 201, 304 and 316 stainless steel! Generally we can find on the street there are two kinds of 201 and 304, for machining both are too good to process, but there are considerable differences between these stainless steels!
See the difference between the two? In addition to 304 is 19 chromium 10 nickel, 201 stainless steel is 17 chromium 5 nickel difference, 304 stainless steel does not contain manganese, so 201 stainless steel will be a little darker than 304, because the manganese element gray, so the color is slightly darker than 304! But with the naked eye are very difficult to distinguish!
In addition, the amount of nickel is not the same, 201 stainless steel corrosion resistance is worse than 304, acid and alkali resistance 201 is not 304 good, in addition 304 than 201 hardness is also higher, because the carbon content of 201 than 304 high, 304 better toughness, 201 is more brittle!
So do cup material is obviously 304 better, it is not only high hardness, good ductility, and more resistant to acid and alkali corrosion, of course, 316 stainless steel than it is better, which is slightly more expensive!
So 201 stainless steel to do cups have problems?
Not only is there a problem, and the problem is also big, CCTV reported in 2019 a survey, Beijing Consumer Association in the market to buy 50 kinds of common insulation cup, which has 19 kinds of failure! The reason for the failure is simple, is that the heavy metal exceeds the standard, most of these failed cups are made of 201 stainless steel as 304 stainless steel!
Although 201 is also stainless steel, but it will rust in a humid or salty environment, so the heavy metals inside the material is more likely to be corrosive migration, so there is this risk when using 201 stainless steel cups soak! Although once or twice heavy metals and will not have any effect on the human body, but long-term use will have a cumulative effect on the human body is not to be underestimated! So do not just buy stainless steel insulation cup!
Recommended Reading：
9 electric lunchbox comparative evaluation
Used for so many years towels, actually have been using the wrong
|
