Light Industry
Light industry products are closely related to people's lives and are of various types. Because copper has good comprehensive properties, it can be seen everywhere. Here are just a few examples:
Air conditioners and freezers
The temperature control function of air conditioners and freezers is mainly achieved through the evaporation and condensation of the copper tubes of the heat exchanger. The size and heat transfer performance of the heat exchanger heat transfer tube largely determine the efficiency and miniaturization of the entire air conditioner and refrigeration device. These machines use special-shaped copper tubes with high thermal conductivity. Using the good processing properties of steel, heat pipes with inner grooves and high fins are developed and produced for the manufacture of heat exchangers in air conditioners, freezers, chemical and waste heat collection devices. The total thermal conductivity coefficient of the new heat exchanger can be increased to 2 to 3 times that of ordinary tubes and 1.2 to 1.3 times that of ordinary low-fin tubes. It has been used domestically and can save 40% of copper and reduce the volume of the heat exchanger by more than 1/3.
Clocks and watches
Manufactured clocks, timers and clockwork devices, most of the working parts of which are made of "clock brass". The alloy contains 1.5-2% lead, has good processing properties and is suitable for large-scale production. For example, gears are cut from long extruded brass bars, flat wheels are punched from strips of corresponding thickness, and engraved clock faces, screws and joints are made of brass or other copper alloys. A large number of cheap watches are made of gunmetal (tin-zinc bronze) or plated with nickel silver (white copper). Some famous clocks are made of steel and copper alloys. The hour hand of the British "Big Ben" is made of solid gunmetal rods, and the minute hand is made of 14-foot-long copper tubes.
A modern clock factory, using copper alloy as the main material, presses and precise molds, can produce 10,000 to 30,000 clocks a day at a very low cost.
Papermaking
In today's ever-changing information society, paper consumption is very high. Paper may seem simple on the surface, but the papermaking process is very complicated, requiring many steps and the use of many machines, including coolers, evaporators, beaters, paper machines, etc. Many of the components, such as various heat exchange tubes, rollers, beater bars, semi-liquid pumps and wire meshes, are mostly made of steel alloys.
For example, the fourdrinier papermaking machine uses a fast-moving mesh with fine mesh (40-60 mesh). The mesh is woven from brass and phosphor bronze wire. It is very wide, generally more than 20 feet (6 meters), and is required to remain completely straight. The mesh moves on a series of small brass or copper rollers, and when it passes with the pulp sprayed on it, the moisture is sucked out from the bottom. The mesh vibrates at the same time to make the small fibers in the pulp stick together. The mesh size of large papermaking machines is very large, up to 26 feet 8 inches (8.1 meters) wide and 100 feet (30.5 meters) long. Wet pulp not only contains water, but also contains chemicals used in the papermaking process, which is highly corrosive. In order to ensure the quality of paper, the mesh material is very strict. It must not only have high strength and elasticity, but also be resistant to pulp corrosion. Copper alloys are fully capable of this.
Printing
In printing, copper plates are used for phototypesetting. After the polished copper plate is sensitized with photosensitive emulsion, it is photographed on it. The photosensitive copper plate needs to be heated to harden the glue. To avoid softening due to heat, copper often contains a small amount of silver or arsenic to increase the softening temperature. Then, the plate is corroded to form a printing surface with concave and convex dot patterns.
On the automatic typesetting machine, the type is made by arranging brass type blocks, which is another important use of copper in printing. Type blocks are usually made of leaded brass, and sometimes copper or bronze.
Medicine
In the pharmaceutical industry, all kinds of steaming, boiling, vacuum devices, etc. are made of pure copper. In medical devices, zinc white copper is widely used. Copper alloy is also a common material for eyeglass frames.
