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Pure handmade glass-glass development and history
The main component of ordinary glass is silicate double salt, the chemical formula is Na2O·CaO·6SiO2.
In the composition of ordinary glass, 60%~70% is silicon, 15%~25% is sodium oxide, 5%~10%, 0%~3% is magnesium oxide and quicklime, and silicon is the composition of sand. Sand is only used for ordinary glass, which means that sand is the main component of ordinary glass，glass cookware .
The sand also contains some impurities, mainly iron, so the glass will have a turquoise color. To get rid of this color, you can add some manganese dioxide to the glass during firing.
Generally, pure silica sand can be melted into glass, but this requires a high temperature of 1500-2000 degrees Celsius.
If you add laundry soda, lime or borax to the sand, the quartz crystal structure of silicon can be destroyed, and the temperature required to melt can be reduced to about 1100 degrees Celsius.
if added to the sand
The covalent bond between silicon and oxygen is quite strong, and we must add various strongly basic metal oxides to weaken these connections with local ionic bonds to make the glass easier to melt - so starting from the Egyptians, the glass recipe Including sodium, potassium or calcium, 1000 ℃ can be softened. The divalent lead ion introduced by the British has a larger radius, and the weakening effect is of course stronger, and the lead glass becomes soft at 600 ℃.
If you add 0.4~0.7% colorant to the ingredients of ordinary glass, the glass can be colored. Most of the colorants are metal oxides. We have already known that each metal element has its unique "spectrum" "Characteristics", so different metal oxides can show different colors. If these oxides are added to the glass ingredients, the glass will be colored. For example, adding chromium oxide (Cr2O3), the glass is green; adding manganese dioxide (MnO2), the glass is purple; adding cobalt oxide (Co2O3), the glass is blue, the protective eyepieces used by steel workers and welders are made of this glass.
Copper oxide: blue-green in soda lime glass; blue-green in lead glass; cuprous oxide: ruby red; selenium: bright pink in potassium-lime glass; The glass is amber with gold.
The production process of ordinary glass
1. Crushing of raw materials: crushing the above-mentioned raw materials into powder;
2. Weighing: Weigh a certain amount of various powders according to the planned ingredient list;
3. Mixing: mix and stir the weighed powder into batches (colored glass is added with colorant at the same time);
4. Melting: The batch is sent to the glass melting furnace, and it is melted into glass liquid at 1700 degrees;
5. Forming: send the glass liquid into the tin bath (float method), flat drawing machine (grid method), calender (calendering method, adding metal wire is the wired glass), and form it into flat glass;
6. Annealing: The formed glass products are sent to the annealing kiln for annealing to balance the stress and prevent self-breaking and self-cracking.
The main raw materials of flat glass are: silica sand (sandstone), soda ash, feldspar, dolomite, limestone, mirabilite.
Transparent plastics (such as polymethyl methacrylate) are also known as plexiglass
Glass development and history
Around the 30th century BC, the ancestors of the Fertile Crescent accidentally produced a small amount of glass when firing pottery. This shiny new material quickly became a valuable decorative material and was used in the highest religious ceremonies. . The legend of glass making
More than 3,000 years ago, a European Phoenician merchant ship, loaded with the crystalline mineral "natural soda", sailed on the Belus River on the coast of the Mediterranean Sea. Due to the ebb, the merchant ship ran aground, so the crew members went to the beach. Some crew members also carried cauldrons, brought firewood, and used a few pieces of "natural soda" as the supports for the cauldron to cook on the beach. When the crew finished their meal, the tide began to rise. When they were about to pack up and board the ship to continue sailing, someone suddenly shouted: "Everyone, come and see, there is something crystal bright and sparkling on the sand under the pot!"
The crew brought these glittering things to the ship to study them carefully. They found that the shiny things had some quartz sand and melted natural soda stuck to them. It turned out that these shiny things were the natural soda used to make the pot holder when they were cooking. Under the action of the flame, the substance produced by the chemical reaction with the quartz sand on the beach was the earliest glass. Later, the Phoenicians combined quartz sand and natural soda, and then melted them in a special furnace to make glass balls, which made the Phoenicians a fortune.
In the composition of ordinary glass, 60%~70% is silicon, 15%~25% is sodium oxide, 5%~10%, 0%~3% is magnesium oxide and quicklime, and silicon is the composition of sand. Sand is only used for ordinary glass, which means that sand is the main component of ordinary glass，glass cookware .
The sand also contains some impurities, mainly iron, so the glass will have a turquoise color. To get rid of this color, you can add some manganese dioxide to the glass during firing.
Generally, pure silica sand can be melted into glass, but this requires a high temperature of 1500-2000 degrees Celsius.
If you add laundry soda, lime or borax to the sand, the quartz crystal structure of silicon can be destroyed, and the temperature required to melt can be reduced to about 1100 degrees Celsius.
if added to the sand
The covalent bond between silicon and oxygen is quite strong, and we must add various strongly basic metal oxides to weaken these connections with local ionic bonds to make the glass easier to melt - so starting from the Egyptians, the glass recipe Including sodium, potassium or calcium, 1000 ℃ can be softened. The divalent lead ion introduced by the British has a larger radius, and the weakening effect is of course stronger, and the lead glass becomes soft at 600 ℃.
If you add 0.4~0.7% colorant to the ingredients of ordinary glass, the glass can be colored. Most of the colorants are metal oxides. We have already known that each metal element has its unique "spectrum" "Characteristics", so different metal oxides can show different colors. If these oxides are added to the glass ingredients, the glass will be colored. For example, adding chromium oxide (Cr2O3), the glass is green; adding manganese dioxide (MnO2), the glass is purple; adding cobalt oxide (Co2O3), the glass is blue, the protective eyepieces used by steel workers and welders are made of this glass.
Copper oxide: blue-green in soda lime glass; blue-green in lead glass; cuprous oxide: ruby red; selenium: bright pink in potassium-lime glass; The glass is amber with gold.
The production process of ordinary glass
1. Crushing of raw materials: crushing the above-mentioned raw materials into powder;
2. Weighing: Weigh a certain amount of various powders according to the planned ingredient list;
3. Mixing: mix and stir the weighed powder into batches (colored glass is added with colorant at the same time);
4. Melting: The batch is sent to the glass melting furnace, and it is melted into glass liquid at 1700 degrees;
5. Forming: send the glass liquid into the tin bath (float method), flat drawing machine (grid method), calender (calendering method, adding metal wire is the wired glass), and form it into flat glass;
6. Annealing: The formed glass products are sent to the annealing kiln for annealing to balance the stress and prevent self-breaking and self-cracking.
The main raw materials of flat glass are: silica sand (sandstone), soda ash, feldspar, dolomite, limestone, mirabilite.
Transparent plastics (such as polymethyl methacrylate) are also known as plexiglass
Glass development and history
Around the 30th century BC, the ancestors of the Fertile Crescent accidentally produced a small amount of glass when firing pottery. This shiny new material quickly became a valuable decorative material and was used in the highest religious ceremonies. . The legend of glass making
More than 3,000 years ago, a European Phoenician merchant ship, loaded with the crystalline mineral "natural soda", sailed on the Belus River on the coast of the Mediterranean Sea. Due to the ebb, the merchant ship ran aground, so the crew members went to the beach. Some crew members also carried cauldrons, brought firewood, and used a few pieces of "natural soda" as the supports for the cauldron to cook on the beach. When the crew finished their meal, the tide began to rise. When they were about to pack up and board the ship to continue sailing, someone suddenly shouted: "Everyone, come and see, there is something crystal bright and sparkling on the sand under the pot!"
The crew brought these glittering things to the ship to study them carefully. They found that the shiny things had some quartz sand and melted natural soda stuck to them. It turned out that these shiny things were the natural soda used to make the pot holder when they were cooking. Under the action of the flame, the substance produced by the chemical reaction with the quartz sand on the beach was the earliest glass. Later, the Phoenicians combined quartz sand and natural soda, and then melted them in a special furnace to make glass balls, which made the Phoenicians a fortune.
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