Basic knowledge of mirror frame materials
The materials for manufacturing spectacle frames can be roughly divided into three categories: metal materials, non-metallic materials and natural materials.
The metal materials used for spectacle frames include copper alloy, nickel alloy and precious metal. It is required to have certain hardness, softness, elasticity, wear resistance, corrosion resistance, light weight, luster and good color, etc. Therefore, almost all the metal materials used to make spectacle frames are alloys or used after metal surface processing.
1. Zinc white copper
Also known as white or silver. The main component is copper, which contains 64% copper, 18% nickel and 18% zinc, with a specific gravity of 8.8. It is characterized by certain corrosion resistance and good elasticity, low cost and easy processing. It is mainly used to make hinges, pile heads, nose bridge supports and other components. Most low-grade spectacle frames are made of zinc white copper. When in use, it rusts after being corroded by human sweat and turns copper green. 2. Brass
Also known as copper zinc alloy. It contains 63% ~ 65% copper and 35% ~ 37% zinc, and is yellow. Its advantage is that it is easy to cut and process, and its disadvantage is that it is easy to change color. It is commonly used in low-grade spectacle frames and nose care cores.
2. Copper nickel zinc tin alloy
It is an alloy composed of 62% copper, 23% nickel, 13% zinc and 2% tin. It has good elasticity. After electroplating, it is often used for the nose bridge and leg of the spectacle frame.
3. Bronze
It generally refers to copper tin alloy and contains a small amount of zinc and phosphorus. Because bronze contains a certain amount of tin, its price is high. Its disadvantage is that it is difficult to process and has poor corrosion resistance to acids, but it has good elasticity, diamagnetism and wear resistance. Its corrosion resistance to human body in atmosphere, seawater and steam is better than copper and brass. Therefore, it is suitable for the spring and lens ring materials of glasses frame.
4. Nemon alloy
It belongs to a kind of nickel copper alloy. The specific gravity is 8.9, including 63% ~ 67% nickel, 28% ~ 31% copper, and a small amount of iron and manganese. It is characterized by no chromium. Due to its high nickel content, it has the advantages of good strength, elasticity, corrosion resistance and firm welding, so it is often used to manufacture medium-grade spectacle frames.
5. High nickel alloy
Also known as nickel alloy. The specific gravity is 8.67, containing 84% nickel, 12.5% chromium, 5% silver, 1% copper and other elements. It is a high-grade nickel chromium alloy material, which is more elastic and corrosion resistant than Monel alloy. Some imported spectacle frames and domestic high-grade frames use this material.
6. Stainless steel
It is a kind of nickel chromium alloy. It mainly contains more than 70% iron, 18% chromium, 8% nickel and 0.1% ~ 0.3% other elements. It has good elasticity and corrosion resistance. It is mostly used as mirror leg materials. Stainless steel materials containing 1% ~ 1.5% lead are mostly used as matrix materials for making screws or gold clad frames. Its disadvantages are high strength and difficult welding processing.
7. Titanium
Pure titanium is a white metal. With a specific gravity of 4.5 and light weight, it has high strength, corrosion resistance and good plasticity. It is mostly used in the aerospace industry and is called "space metal". In the early 1980s, it was used to make spectacle frames, which has gradually solved the processing problems such as cutting, polishing, welding and electroplating, so that titanium spectacle frames are basically popularized. The products are mainly from Japan.
Titanium spectacle frames are generally represented by the symbol Ti-P or Titan, which indicates that other parts are made of titanium except the nose bridge bracket, hinge and screw, and ti-c symbol indicates that a part of the spectacle frame is made of titanium.
8. Gold and its alloys
Pure gold is golden yellow with a specific gravity of 19.3. It is one of the heaviest metals and will not be corroded and oxidized in the atmosphere. Gold is softer than silver and has good grindability. Therefore, pure gold is generally not used as glasses frame material, but the alloy of gold, silver, copper, etc.
The gold content of its alloy is generally expressed by "K". 24K is 100% pure gold. Most glasses frames are made of K18, K14 and K12 alloys. The content of pure gold is as follows:
K18:18/24 × 100=75%
K14:14/24 × 100=58.3%
K12:12/24 × 100 = 50%, and so on.
9. Platinum
That is, a kind of gold alloy. Most glasses frames are made of K14 platinum, which contains 58.3% pure gold, 17% nickel, 8.5% zinc and 16% copper.
10. Platinum and platinum group
Pure platinum is as soft as gold and silver. It is generally used as an alloy with other platinum elements. Platinum elements include platinum, palladium, iridium