Does the glass contain lead? The glass is divided into ordinary glass and crystal glass, and crystal glass is divided into two types: lead-free crystal glass and leaded crystal glass. So how do we identify lead-free glasses? To identify glasses, you must first understand the types of glasses. When you buy, you can know what kind of glasses you choose, and then quickly learn to identify glasses. Is it a method containing lead?
At present, from the perspective of materials, the glass generally includes ordinary glass, double glass and crystal glass. In terms of function, the popular glass includes tea cups, wine glasses, juice glasses, portable portable glasses. The following is a detailed introduction to the selection of three glasses with different materials.
1 ordinary glass
Most common glass materials are fired from high temperature silicon, using high boron heat-resistant glass, which has excellent heat resistance and corrosion resistance. As a green glass material, the glass body is crystal clear, feels soft, and looks elegant. Is a good companion for tea and healthy drinking.
1. The material quality should be pure: the glass material is not pure, and there will be lines, bubbles or sand on the glass drinking utensils. The rough lines can be felt by hand, and the fine lines can be seen by facing the light. The material bubble resides in a relatively deep place in the glass body, and looks like a small circle from the outside. The operation bubbles are relatively exposed, some are like fish-eye bulges, which will pierce with a light poke; some like small scars on fruits are also easy to peel off layer by layer. "Sand" refers to the white granular silica sand that is not dissolved in the glass body, and also refers to other granular impurities.
2. The thickness should be the same: when selecting, observe the drinking utensils against the light. If the light feeling is consistent and integrated, it means that the thickness is consistent. Viewed from the outside, the bottom should be level, not slope or pan bottom; flick the walls with your fingers, and it should make a pleasant sound.
3. The appearance should be beautiful: the surface should be smooth; the gloss of the cup should be good; the geometric shape should be flat; the lid should not be too loose or too tight, and the shape of the teapot and cup should be coordinated.
2 double glass
The double-layer glass is clear and transparent, not easy to be hot, easy to clean, no tea stains, and resistant to friction. High-quality products that integrate environmental protection and practical application.
Double-layer glass, the biggest advantage is heat insulation. The middle of the two layers is a vacuum barrier, which can protect the water temperature of the cup body, and it is heat-insulated and not hot.
1. Appearance recognition. First, check whether the inner and outer bladder are polished uniformly, whether there are bumps and scratches or burrs; second, whether the mouth welding is smooth and consistent, which is related to the feeling of comfort when drinking water; third, whether the internal seal is tight, Whether the screw plug matches the cup body; look at the cup mouth, the more round the better, the immature process will appear round.
2. Tightness test: First twist the lid to see if the lid completely matches the cup body, then add boiling water (preferably boiling water) to the cup, and then invert the cup for two to three minutes to see if there is water Exudate
3. Insulation test: Put boiling water in the cup. After two or three minutes, touch each part of the cup with your hands to see if the heat is not hot. If any part is hot, the temperature will be lost from that place. It is normal that there is a slight fever in the place like the mouth of the cup;
4.Capacity test: first check whether the depth of the inner layer of the insulation cup and the height of the outer layer are not much different (generally 18-22mm). In order to reduce costs, many small factories often work on materials, which may affect the cup. capacity;
5. Identification of double-layer glass material stainless steel: There are many types of stainless steel materials, of which 18/8 indicates that this stainless steel material contains 18% chromium and 8% nickel. Materials that meet this standard are green products that meet national food-grade standards. Products Anti-rust and corrosion resistance. The body color of ordinary stainless steel cups (pots) is white or dark. If you put it in salt water with a concentration of 1% for 24 hours, it will produce rust spots. Some of the elements contained in it are beyond the standard, which directly endangers human health.
3 crystal glass
The crystal cup is mostly used as a wine glass. When distinguishing the quality of such cups, you can start with the following points:
1.Sound: Tap lightly or use your fingers to hit the vessel. The crystal glass can make a light and crisp metal sound, and linger in the breath.
2. Feel: Hold a crystal goblet lightly, you will feel a kind of heavy hand.
3. Gloss: Lift a crystal cup and rotate it towards the light, you will find it is like a delicate handicraft, white and transparent, reflecting the charming colorful light.
4. High crystal hardness. Through scientific experiments to measure their relative hardness, it is concluded that the crystal hardness is 7 Mohs.
5. The crystal has good stability and will not change color for a long time.
6. Different physical properties. Crystals can make marks on glass, but not vice versa.