国产精品一级AA毛片不收费,声之形,毛片大全高清免费,国产91流白浆喷水免费观看

The 1990s was an important stage in the development of my country's winding wire industry. From the 1960s to the mid-1980s, due to the establishment of a good foundation for self-reliance, my country already has all the basic varieties of winding wires in the world, as well as the basic settings and professional talents for the development of new varieties. Development has created the necessary conditions. The general characteristics of the winding wire industry in the 1990s are as follows:

1. In advanced industrial countries, a complete set of technologies for the production of winding wires has been introduced, from raw and auxiliary materials (such as the production of conductor cores and insulating materials), production equipment (including wire drawing machines, enameling machines and winding machines, etc.) to finished product testing equipment Entered the advanced ranks of the world.

2. In the process of the national economy's transformation from planned to market-oriented, my country's winding wire production plants have also undergone major reorganization and rearrangement, and enterprises with technological advancement and advanced management have emerged.

3. The output of winding wires has grown from more than 100,000 tons in the mid-1980s to nearly 300,000 tons in the late 1990s, which basically met domestic needs, and part of it was exported. my country has become the world's largest producer of winding wires. It can be said that the late 1980s to the 1990s was a period of great development in my country's winding wire industry.

However, in terms of product structure and product quality, there is still a big gap between my country and advanced industrial countries. For example, in the winding wire, the ratio of enameled wire to winding wire is estimated to be around 85:15 in my country in recent years, while the ratio in the United States was around 95:5 in 1987, and the ratio in Japan was around 90:10 in 1997;

In enameled wire, the thermal grade of the main product and its proportion, in recent years, it is estimated that the 130 grade polyester enameled wire accounts for about 80%. In the United States in 1987, the 200-class enameled wire accounted for 41.2%, and the F-class and above heat-resistant enameled wire was calculated to be 70.4%. Japan's statistics in 1997 accounted for 33% of heat-resistant enameled wires of class 18 and above; some of the enameled wires used in the production lines of some electrical products imported from China still need to be imported, and domestic enameled wires are often unusable due to various reasons.