What you have to know before buying glass
Here are things you have to know before buying glass, for health and saving a lot
First, classified by material classification:
1. ordinary glass:
That is, the traditional glass made mainly of common ordinary glass materials, including:
1. Na2SiO3 (sodium silicon glass)
2. SiO2 (quartz glass)
3. Na2O·CaO·6SiO2 (soda lime glass)
4. CaSiO3 (calcium silica glass)
Their main components are silicate double salts, which are amorphous solids with a random structure. Of course, in the strict sense, all glass is neither crystalline nor non-existent because of the particularity of glass. Crystals, neither solid nor liquid, are a separate classification called glass). When a certain metal oxide or salt is added, the corresponding color will appear, which will become a colored glass. Mainly using a pressing process (those with a thick bottom, a string of letters and numbers at the bottom of the cup are mostly ordinary glass made by a pressing process) and an iron pipe blowing process.
Please note,
Ordinary glasses are lead-free.
Ordinary glasses are lead-free.
Ordinary glasses are lead-free.
There is nothing to do with lead and a glass
2. high borosilicate glass
High borosilicate glass, also called hard glass, is characterized by the use of glass to conduct electricity at high temperatures. The glass is melted by heating inside the glass, and then processed by a certain process (the processes of different manufacturers are not necessarily the same). Its main component is Na2O·B2O3·SIO2. Because of its high content of borosilicate, its content is boron: 12.5~13.5%, silicon: 78~80%, so it is called borosilicate glass. It belongs to PYREX glass (a heat resistant glass) in borosilicate glass. Compared with ordinary glass, it is a low expansion ratio (its thermal expansion coefficient is only one-third of ordinary glass, and the temperature gradient stress caused by thermal expansion and contraction is much smaller than ordinary glass, that is, high borosilicate The possibility of glass bursting due to internal stress is much smaller than that of ordinary glass), small difference in form, high temperature resistance (high borosilicate glass begins to soften at 821 ° C, belongs to heat resistant glass), high thermal stability (good thermal shock resistance) Ordinary glass can withstand the sudden temperature difference of 75 ° C, and borosilicate glass can withstand the sudden temperature difference of 200 ° C, even from the high temperature environment of 100 ° C to the low temperature environment of minus 100 ° C will not burst due to temperature gradient stress Of course, under the higher temperature difference, borosilicate glass can still burst due to the sudden change of temperature difference. When the borosilicate glass breaks, it tends to be broken rather than pulverized), high strength and high hardness. Special glass material with high light transmittance (low dispersion, relatively low color conversion rate), high chemical stability (acid and alkali resistance and corrosion resistance, only corrosive to hydrochloric acid), due to its excellent properties , It is widely used.
The borosilicate glass is usually directly processed from a high borosilicate glass tube made of borosilicate glass. The processing technology is generally manual blowing or semi-automatic line blowing. Because it is blown, the cup wall is generally very thin, only about 1.2-1.8 mm.
3. crystal glass:
It's clear and good at light transmission
The crystal glass is divided into:
(1) Lead-containing crystal glass (also known as crystal glass):
That is, a certain amount of lead oxide is added to the ordinary glass to increase the light transmittance and brightness of the glass. It's cheap and looks very crystal-clear, but the lead used to hold it in the water will melt into the water and cause great damage to the body.
(2) Lead-free crystal glass:
Also divided into:
1 natural crystal glass:
Looks good, but the price is very expensive (a crystal glass of about 300ml is close to a thousand dollars, don't be surprised, in the field of professional wine sommeliers, there are many rich people's wine glasses are crystal glasses, nearly a thousand dollars a wine glass!)
2 artificial crystal glass grown in high pressure reactor:
It is cheaper than natural crystal glass, but it is still much more expensive than ordinary glass.
Second, how to choose a good glass
1. Choose a brand with a regular channel, a good beer, and a brand that has been in business for many years. The quality of the small brands is uneven, completely looking at luck, it is best not to buy small brands.
2. The more transparent of the glass, the better
3. Never buy a glass that is not smooth on the surface
4. Do not buy a glass with a bubble or bubbles inside (that can be pierced with a steel needle)
5. Do not use glass with impurity that you can see through your eyes
6. The cup cannot have a big mouth difference
The maximum diameter and the minimum diameter should be less than 1mm
7. There is no issue if the glass gets heating or cooling slowly, but do not make it hot or cold in a very short time. It can often be destroyed by rapid heat and cold. The thicker the glass is, the worse the quality is. Generally, the glass with a bad material thickness is thick, trying to cover the inferior material. but actually, the thinner, the more easily it breaks (If the glass is made of a lot of high borosilicate, it can be thin and not easy to break). So you should have good knowledge to choose a glass with the right thickness.
8. Do not buy a glass with a cup thickness less than 0.8mm.
9. Do not buy a glass with a deviation of more than 1.5mm at the highest point of the cup and the lowest part of the cup.
10. There are obvious scratches or streaks on the inner and outer walls of the cup body. There are even glass cups with white streaks or dark streaks. It is easy to breed bacteria and the quality is poor.
11. Do not take a cup body seems to have a record texture
12. Do not buy a cup is rugged
13. When the impact is selected, the sound is as pleasant as a metal strike, and even a glass with a residual sound. Leaded glass is relatively dull.
14. For the same model, the lead-containing crystal glass is heavier.
15. Lead-free glass has stronger impact resistance.
First, classified by material classification:
1. ordinary glass:
That is, the traditional glass made mainly of common ordinary glass materials, including:
1. Na2SiO3 (sodium silicon glass)
2. SiO2 (quartz glass)
3. Na2O·CaO·6SiO2 (soda lime glass)
4. CaSiO3 (calcium silica glass)
Their main components are silicate double salts, which are amorphous solids with a random structure. Of course, in the strict sense, all glass is neither crystalline nor non-existent because of the particularity of glass. Crystals, neither solid nor liquid, are a separate classification called glass). When a certain metal oxide or salt is added, the corresponding color will appear, which will become a colored glass. Mainly using a pressing process (those with a thick bottom, a string of letters and numbers at the bottom of the cup are mostly ordinary glass made by a pressing process) and an iron pipe blowing process.
Please note,
Ordinary glasses are lead-free.
Ordinary glasses are lead-free.
Ordinary glasses are lead-free.
There is nothing to do with lead and a glass
2. high borosilicate glass
High borosilicate glass, also called hard glass, is characterized by the use of glass to conduct electricity at high temperatures. The glass is melted by heating inside the glass, and then processed by a certain process (the processes of different manufacturers are not necessarily the same). Its main component is Na2O·B2O3·SIO2. Because of its high content of borosilicate, its content is boron: 12.5~13.5%, silicon: 78~80%, so it is called borosilicate glass. It belongs to PYREX glass (a heat resistant glass) in borosilicate glass. Compared with ordinary glass, it is a low expansion ratio (its thermal expansion coefficient is only one-third of ordinary glass, and the temperature gradient stress caused by thermal expansion and contraction is much smaller than ordinary glass, that is, high borosilicate The possibility of glass bursting due to internal stress is much smaller than that of ordinary glass), small difference in form, high temperature resistance (high borosilicate glass begins to soften at 821 ° C, belongs to heat resistant glass), high thermal stability (good thermal shock resistance) Ordinary glass can withstand the sudden temperature difference of 75 ° C, and borosilicate glass can withstand the sudden temperature difference of 200 ° C, even from the high temperature environment of 100 ° C to the low temperature environment of minus 100 ° C will not burst due to temperature gradient stress Of course, under the higher temperature difference, borosilicate glass can still burst due to the sudden change of temperature difference. When the borosilicate glass breaks, it tends to be broken rather than pulverized), high strength and high hardness. Special glass material with high light transmittance (low dispersion, relatively low color conversion rate), high chemical stability (acid and alkali resistance and corrosion resistance, only corrosive to hydrochloric acid), due to its excellent properties , It is widely used.
The borosilicate glass is usually directly processed from a high borosilicate glass tube made of borosilicate glass. The processing technology is generally manual blowing or semi-automatic line blowing. Because it is blown, the cup wall is generally very thin, only about 1.2-1.8 mm.
3. crystal glass:
It's clear and good at light transmission
The crystal glass is divided into:
(1) Lead-containing crystal glass (also known as crystal glass):
That is, a certain amount of lead oxide is added to the ordinary glass to increase the light transmittance and brightness of the glass. It's cheap and looks very crystal-clear, but the lead used to hold it in the water will melt into the water and cause great damage to the body.
(2) Lead-free crystal glass:
Also divided into:
1 natural crystal glass:
Looks good, but the price is very expensive (a crystal glass of about 300ml is close to a thousand dollars, don't be surprised, in the field of professional wine sommeliers, there are many rich people's wine glasses are crystal glasses, nearly a thousand dollars a wine glass!)
2 artificial crystal glass grown in high pressure reactor:
It is cheaper than natural crystal glass, but it is still much more expensive than ordinary glass.
Second, how to choose a good glass
1. Choose a brand with a regular channel, a good beer, and a brand that has been in business for many years. The quality of the small brands is uneven, completely looking at luck, it is best not to buy small brands.
2. The more transparent of the glass, the better
3. Never buy a glass that is not smooth on the surface
4. Do not buy a glass with a bubble or bubbles inside (that can be pierced with a steel needle)
5. Do not use glass with impurity that you can see through your eyes
6. The cup cannot have a big mouth difference
The maximum diameter and the minimum diameter should be less than 1mm
7. There is no issue if the glass gets heating or cooling slowly, but do not make it hot or cold in a very short time. It can often be destroyed by rapid heat and cold. The thicker the glass is, the worse the quality is. Generally, the glass with a bad material thickness is thick, trying to cover the inferior material. but actually, the thinner, the more easily it breaks (If the glass is made of a lot of high borosilicate, it can be thin and not easy to break). So you should have good knowledge to choose a glass with the right thickness.
8. Do not buy a glass with a cup thickness less than 0.8mm.
9. Do not buy a glass with a deviation of more than 1.5mm at the highest point of the cup and the lowest part of the cup.
10. There are obvious scratches or streaks on the inner and outer walls of the cup body. There are even glass cups with white streaks or dark streaks. It is easy to breed bacteria and the quality is poor.
11. Do not take a cup body seems to have a record texture
12. Do not buy a cup is rugged
13. When the impact is selected, the sound is as pleasant as a metal strike, and even a glass with a residual sound. Leaded glass is relatively dull.
14. For the same model, the lead-containing crystal glass is heavier.
15. Lead-free glass has stronger impact resistance.
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