Application of copper in light industry
Light industry products are closely related to people's life and are of various varieties. Because steel has a good comprehensive performance, it can be seen everywhere to show off its skills. Here are only the following examples:
※ Air conditioner and refrigerator
The temperature control function of air conditioner and refrigerator is mainly realized through the evaporation and condensation of copper tube of heat exchanger. The size and heat transfer performance of heat exchange tube largely determine the efficiency and miniaturization of the whole air conditioner and refrigeration unit. In these machines are the use of high thermal conductivity of the special-shaped copper pipe. Taking advantage of the good processing performance of steel, recently developed and produced a heat dissipating pipe with inner groove and high fin, which is used in the manufacture of heat exchangers in air conditioner, refrigerator, chemical industry and waste heat receiver, etc. The total heat conduction coefficient of the new heat exchanger can be improved to 2 ~ 3 times that of the ordinary tube, and 1.2 ~ 1.3 times that of the ordinary low fin tube. It has been used in China. Copper can be saved by 40%, and the volume of the heat exchanger can be reduced by more than 1/3.
Most of the working parts of clocks, timepieces and clockwork devices currently produced are made of "clock brass". The alloy contains 1.5-2% lead and has good workability, which is suitable for mass production. For example, gears are extruded from long brass rods, flat wheels are cut from strips of corresponding thickness, engraved clock faces, screws and joints are made from brass or other copper alloys, etc. A large number of inexpensive watches were made of guncopper (tin zinc bronze) or plated with nickel silver (white copper). Some famous timepieces are made of steel and copper alloys. The hour hand of Big Ben is made of solid brass, and the minute hand is made of 14-foot copper pipe.
A modern watch factory, with copper alloys as its main material, working with presses and precise moulds, can produce 10,000 to 30,000 clocks a day at a fraction of the cost.
※ Paper making
In today's information-changing society, paper consumption is high. The paper looks simple on the surface, but the papermaking process is complex, requiring many steps and the application of many machines, including coolers, evaporators, beaters, paper machines and so on. Many of these components, such as various heat exchange tubes, rollers, percussion rods, semi-liquid pumps and screen, are mostly made of steel alloys.
For example, the fourdrinier paper machine currently in use sprays the pulp onto a fast-moving mesh with a very small mesh (40-60 mesh). Made of braided brass and phosphor bronze wire, the net cloth is large in width, generally more than 20 feet (6 meters), and must be kept perfectly straight. The web moves over a series of small brass or copper rollers, and as it passes the pulp sprayed on top, the moisture is sucked out of the air below. The screens vibrate simultaneously, binding together the fine fibers in the pulp. Large paper machines have large mesh sizes, reaching 26 feet 8 inches (8. l m) wide and 100 feet (3. 5 m) long. Wet pulp contains not only water, but also chemicals used in the papermaking process, which are highly corrosive. In order to ensure the quality of paper, the mesh material requirements are very strict, not only to have high strength and elasticity; And to resist pulp corrosion, copper alloy can be fully competent.
Photoplatemaking with copper plates in printing. A surface polished copper plate is sensitized with a sensitive emulsion and photographed on it. The photosensitive plate needs to be heated to harden the glue. To avoid softening with heat, copper often contains small amounts of silver or arsenic to raise the softening temperature. The plate is then etched to form a printed surface with a pattern of relief dots.
On automatic typesetters, plates are made by the arrangement of brass type blocks, which is another important use of copper in printing. Font blocks are usually made of leaded brass, but sometimes copper or bronze.
※ Wine making
Copper plays an important role in beer brewing around the world. Uchimura, where copper is often used as a malt barrel and fermenter. There are more than a dozen of these vats with a capacity of more than 20, 000 gallons in some famous breweries. In the fermenter, in order to cool down, steel pipes are commonly used for water cooling. Pipes are also used to steam water to heat beer brewing, and pipes to transport liquor, etc.
When whisky and other spirits are distilled, a steel still is usually used. Whisky malt is distilled twice, in two large copper stills.
In the pharmaceutical industry, all kinds of steaming, boiling and vacuum devices are made of pure copper. Zinc cupronickel is widely used in medical devices. Copper alloy or commonly used materials for glasses frames and so on.