The New Third Board market is under construction, the bond market is relatively underdeveloped, and the derivatives market is still in the trial phase. Various defects and shortcomings exist in the capital market, restricting the development of the national economy, thus, a major transformation is brewing. Another widely used structured packing is the grid packing, which is composed of horizontally stacked grid panels, such as the Glitsch Grid developed by the American Glitsch Company, including three models: EF-25A, EF-25C, and EF-25AP. The grid layers are interlaced at 45°, providing excellent redistribution performance for each layer and enhancing the rigidity of the packing layer. It is mainly used in systems requiring heat transfer, purification, dehumidification, and those prone to clogging.

Filling materials can be traced back to the primitive stage of amorphous substances like coke and stone. The introduction of Raschig rings in 1914 marked a significant breakthrough in the filling tower. Raschig rings are solid wall rings with both inner and outer surfaces, which, compared to the original filling materials, have a larger surface area. However, when placed horizontally, the inner surface is not easily wetted by the liquid. The advent of the Pall ring filling material initiated a new era of ring-shaped packing with holes in the wall and a tongue piece inside. Since then, improved Pall rings and step rings have been developed. The step rings feature a high-to-diameter ratio of only 0.3, a low center of gravity, and a certain degree of regular arrangement in the random stacking process, thus offering low resistance, high throughput, and excellent performance.

Hollow ring structured packing features a circular surface with windows and a tongue piece inside the ring, which enhances the turbulence of the gas phase and the wetting of the liquid phase. In recent years, as the scope of application for precise distillation has expanded, the production processes utilizing this technology have been increasingly adopted, driving the development of precise packing towers towards larger sizes. The design philosophy of the towers has shifted from primarily focusing on high separation efficiency to pursuing high overall benefits, meaning both separation efficiency and processing capacity are equally emphasized. Based on this philosophy, new multi-tube structured packing towers have been developed. Our country has also made significant contributions to the industrial bulk packing, with the expansion of the use of annular and flat rings broadening the application range of bulk packing. By the late 1970s, the development of regular packing was mainly used to address low-pressure distillation, and it has now been widely applied, with numerous suppliers entering the market, and over the years, the prices have also dropped to a highly competitive level. These products generally share similar geometric shapes and dimensions.

Ripple packing, widely used in various applications, originated from the metal wire ripple packing developed by Sulzer AG in Switzerland in the 1960s. In 1977, the company introduced the plate-type packing. Due to its excellent performance, ease of manufacturing, and low cost, many companies have subsequently developed ripple packings with different structures. The main differences among these packings lie in the material of the plates, their geometric structure and parameters, and the unique processing techniques and treatment methods of their surfaces.

In addition to being manufactured from metal thin plates, they are also constructed from plastics, ceramics, or metal wire meshes, yet all possess a high specific surface area and low friction resistance. Regularly arranged patterns create numerous discontinuous gas and liquid channels, thereby achieving high efficiency, low pressure drop, and large flux. China's capital market for environmental protection fillers is relatively new and has a short history, still in its infancy of development. Issues such as an unbalanced capital market structure and a single level are quite prominent. The GEM board is still in its early development stage.