Three-dimensional composite drainage network is a new type of geosynthetic material. The structure is a three-dimensional geotechnical core, and both sides are adhered with needle-punched non-woven earthwork fabrics. The three-dimensional geotextile core includes a thick vertical rib and a beveled rib at the top and bottom. The groundwater that can be quickly drained from the road itself has a pore maintenance system that can block capillary water at high loads. At the same time, it can also play a role in isolation and foundation reinforcement, is a new type of geosynthetics. Three-dimensional composite drainage network made by the unique three-dimensional geotextile double-sided adhesive geotextile. Combined with geotextile filter effect and geotextile drainage and protection, to provide a complete "filter - drainage - protection" effect.
It is laid between foundation and base, which is used to discharge water between foundation and base, block capillary water and effectively combine it into the marginal drainage system. This structure automatically shortens the foundation drainage, drainage time significantly shorter, and can make the decrease in the number of the use of the material selection of foundation can be used with more fine material, low permeability of materials. Can extend the life of the road.
In the base layer laying three-dimensional composite drainage network to prevent the base of fine material into the ground floor, that is, play a role in isolation. Aggregate grass will enter the upper part of the geonet in a limited degree. In this way, the composite geotextile network also has a potential to limit the lateral movement of the aggregate base, in this way, its role is similar to the strengthening of the Geogrid. In general, the tensile strength and rigidity of the composite geotechnical drainage network is superior to many geogrids for foundation reinforcement, and this restriction will improve the supporting capacity of the foundation.
Road aging, cracks formed, most of the rain will enter the section. In this case, the three-dimensional composite drainage network directly laying under the road, instead of drainage of the foundation. The three-dimensional composite drainage network can be collected before the water enters the foundation / sub-base. But also in the three-dimensional composite drainage network at the bottom of a layer of film, to further prevent the water into the foundation. Whether it is for rigid roads or flexible road systems, this structure can extend the life of the road.
Three-dimensional composite drainage network is a new type of drainage geotechnical materials. To high-density polyethylene (HDPE) as raw materials, a special extrusion process from the processing, with three special structure. The middle ribs are rigid and longitudinally arranged to form drainage channels, and the upper and lower cross bars form support to prevent the geotextile from being embedded in the drainage channel, and maintain high drainage performance even under very high loads. Sided adhesive seepage geotextile composite use, with "filter - drainage - breathable - protection" comprehensive performance, is the most ideal drainage materials.
product usage
Mainly used for railway, highway, tunnel, municipal engineering, reservoirs, slope protection and other drainage works in a significant effect.
Features
1. Drainage strong (equivalent to one meter thick gravel drainage).
2. High tensile strength.
3. To reduce the probability of geotextile embedded core, to maintain long-term stability of the drainage.
4. Long-term high-pressure load (can withstand about 3000Ka compression load).
5. Corrosion-resistant, acid and alkali, long service life.
6. Construction convenience, shorten the construction period, reduce costs.
Seam and lap of three - dimensional composite drainage network
1, adjust the direction of geosynthetics, so that the length of the material roll perpendicular to the road.
2, composite geotechnical drainage network must be terminated, adjacent geotextile geotextile along the material roll lap.
3, the adjacent geotextile material of the geotextile core with white or yellow plastic buckle or polymer tape connected to connect the material roll. Along the length of the material roll, every 3 feet with a tape connected once.
4, The direction of the geotextile lap to overlap with the direction of packing. If the geotextile material is laid between the foundation / base layer and the base layer, continuous wedge welding, flat welding or stitching shall be carried out so that the upper layer of the overlapped geotextile is fixed. If stitching, it is recommended to use a flat seam method or a general seam method to achieve the minimum requirement for pin length.
HDPE 3D Composite Drainage Geonet,3D Composite Geonet Earthwork,3D Composite Dewatering Network,3D Drainage Board ZHEJIANG BOYA COMTECH CO.,LTD , http://www.zjbytx.com
The extremely high hardness of diamonds has been known for a long time in ancient times. However, for a long period of time, people only used natural diamonds as “gemsâ€, which were mainly used to make high-grade decorations. The earliest humans used natural diamonds to make diamond knives, which used natural diamonds to make cutting edges, such as glass knives, jewels and jade carving knives.
With the development of diamond jewellery grinding and polishing technology, natural diamond knives with cutting edges have been artificially refined. After fine grinding, the cutting edge radius can reach 0.01-0.002μm. However, the natural diamond is brittle, its crystal anisotropy, and the crystal hardness of different crystal planes or the same crystal plane in different directions are different. It is necessary to select an appropriate direction for sharpening and use.
During the Second World War, in order to meet the needs of precision machining of military equipment, and to meet the processing needs of watch precision parts, decorative parts and jewelry carving after World War II, the natural diamond tool application market gradually developed.
In the 1970s, many products in the field of modern cutting-edge science and technology, such as gyroscopes used in the aviation industry, metal mirrors in lasers, waveguide cavities in radar, multi-face prisms in laser printers, video recorder heads, copier toner cartridges Ultra-smooth surface and high processing accuracy are required for computer disk substrates and large mirrors in space telescopes. Under the impetus of actual demand, on the basis of the existing diamond turning technology, the ultra-precision mirror cutting technology of natural diamond tools has been rapidly developed. The market for natural diamond ultra-precision tools has expanded rapidly, and the demand for natural diamonds has also increased rapidly. However, to date, the annual production of natural diamonds in the world is about 100 million carats, and the cutting tools suitable for making them must be large particles (mass greater than 0.2 ct, minimum diameter not less than 1.5 mm). Therefore, the proportion of natural diamonds suitable for making cutting tools is very small, accounting for about 3-4%. This has seriously affected the expansion of natural diamond tool applications.
Since polycrystalline diamond compacts have been developed as substitutes for large diamond single crystals, the application fields of polycrystalline diamond compacts can be replaced by large diamond single crystals, and the processing accuracy is higher than that of polycrystals. Diamond composite sheet. In the market research, it is known that since the cost of large single crystals is significantly higher than that of the same size polycrystalline diamond composite sheet cutters, the two currently exist in the tool market.
The non-renewability of natural diamond resources determines that the quantity is less and less, and the price is getting more and more expensive. In terms of product performance, synthetic diamond is identical in crystal structure to natural diamond and close to or exceeds natural diamond in purity, so synthetic diamond also approaches or exceeds natural diamond in performance. The single-piece diamond tool made of single-crystal large-grain synthetic diamond has been successfully applied in the industry, indicating that the era of synthetic diamonds replacing industrial natural diamonds has come.
In the market research, they obtained samples after contact with relevant experts of the Key Laboratory of Superhard Materials of Jilin University. Through contact with the technicians of Yuncheng Litian Century Tool Co., Ltd., they were basically satisfied with the sample size and internal inclusion content provided. And hope to process it into a tool for further performance testing.
Second, the market prospect of large particle industrial diamond
At present, the diamond industry is cruel. Since 2004, the tonnage of presses has expanded rapidly and the number has increased dramatically. Currently, it has exceeded 5,000 units. The synthetic cavity has expanded from the largest φ28mm in the past to more than φ40mm, and the diamond yield has increased from 30 carats to 100 carats. At present, the annual production capacity of diamond single crystals in China exceeds 5 billion carats. In addition to the slight profitability of individual companies due to economies of scale, most of the company's inventory backlog is serious, leading to losses.
With the application of indirect heating technology, expanding the synthetic cavity on the original basis has become the main means for most enterprises in the industry to cope with the current competition. With the expansion of the cavity, the yield per unit is increased, the cost is reduced, etc., 500mm bore diameter. The press will soon face the fate of being eliminated from local interests. It is foreseeable that most of the medium-sized manufacturers in the industry will be eliminated, and the 500mm cylinder diameter press will also withdraw from the historical stage. If new applications cannot be developed in time, Will become a ton of scrap iron. At present, the service life of the industry 500-barrel press is generally less than six years, and the equipment is in good condition. If it can develop new uses, it will inevitably generate huge economic benefits. We hope to use the current industry 500-cylinder press six-face press to develop new products, find new products with high added value, and make full use of the investment and large amount of diamond press resources.
Six-faced synthetic diamond presses currently produce products such as synthetic diamond, cubic boron nitride, diamond composite sheet, cubic boron nitride composite sheet, diamond polycrystalline, cubic boron nitride polycrystalline and other products. At present, the production of abrasive grade diamonds is about to get into trouble. There are more and more domestic manufacturers of composite sheets and polycrystalline crystals. If there is no superiority, it is difficult to achieve success in the market competition. Conventional quality polycrystalline and composite sheets are also Will fall into the situation of abrasive grade diamond production.
Judging from the current domestic market survey, the application of large-grain industrial diamonds has shown an expanding trend, and the source of products mainly relies on imports to meet. The production of large-scale industrial diamonds in China is mostly in the experimental stage. The Zhongnan Diamond Factory, which is said to be able to supply 8/10 diamond single crystals in batches, is currently 14/16 mesh, and the unit price is 14 yuan/carat. To meet the domestic size requirements for large-grain industrial diamonds, the product cost of 8/10 mesh is relatively high, and the price is based on the quality of 260-600 yuan / carat, compared with similar foreign products, does not have obvious competitive advantage.
Single crystal diamond can be divided into natural diamond and synthetic diamond. The single crystal diamond used to make the cutting tool must be large particles (mass greater than 0.2 ct, minimum diameter not less than 1.5 mm).
The natural diamond used as a tool has harsh working conditions, limited resources, and high price. However, as the processing precision requirements continue to increase, the demand for natural diamond large single crystals is increasing. In the process of market research, it was found that Yuncheng area, as the concentration of China's plate-making industry, has a demand of more than 0.2 ct of natural diamond per year up to several hundred million yuan; basically all imported from abroad, and learned about it in the research of Beijing Shipor. The annual processing capacity of large single crystals is also tens of millions of yuan.
From the perspective of crystal composition, synthetic diamond and natural diamond are identical in crystal structure, so as long as the purity is close to or exceeds that of natural diamond, synthetic diamond can approach or exceed natural diamond in performance, and large-particle industrial diamond Synthetic controllability, good consistency in size, shape and performance, can completely replace natural diamonds, and the cost is easy to control.
With the maturity of high-temperature and high-pressure synthetic diamond single crystal technology, Element Six, Sumitomo, and GE of the United States can supply large diamond single crystals (size 3.5×1.5×1.5mm or more) for cutting tools to the market. Since there is no domestic enterprise that can industrially produce large-grain industrial diamonds suitable for cutting tools, the domestic market is basically occupied by foreign products. Moreover, it was learned in the market research process that the large-particle industrial diamond has extremely broad application and development space because the synthetic large-particle industrial diamond can be the same as the natural diamond and has an advantage in price.
The special properties of diamond make other materials irreplaceable. If we can develop large-scale industrial diamond manufacturing technology in China, we can not only win the market with lower market entry conditions, but also fully realize the potential of 500-cylinder diameter reducer and reduce resources. Waste; in the future, it will be able to enter the world market with a large advantage and win excess profits; the subsequent entry into the tool market based on the production of large-grain industrial diamonds will lead to a new revolution in the tool industry; even into the diamond semiconductor chip field. Leading the last revolution in the semiconductor industry.
We believe that large-grain industrial diamond products are relatively developmental. The reasons are mainly due to two points: First, the market demand is very large, the special properties of diamond hardness make other materials irreplaceable; second, large-particle industrial diamond manufacturing technology is currently in the industry. The family has not yet carried out industrial production, and the samples obtained from foreign imported products and domestic tests are expensive and the market is lucrative.
Third, the status quo of large particle industrial diamond technology
Although the synthesis of large-particle industrial diamonds in China is not too late, the progress is not satisfactory. There is still a big gap in the synthesis of large-grain diamonds compared with the international advanced level. The Shanghai Institute of Ceramics of the Chinese Academy of Sciences used the single-source six-face press to synthesize 4mm single crystal diamond in the mid-1970s. However, due to reproducibility and other issues, the research work did not continue. In December 1998, the State Key Laboratory of Superhard Materials of Jilin University used the domestic six-face press to synthesize the gem-quality diamond single crystal with a diameter of 3mm for the first time. In 2001, Jilin University used the temperature gradient method to use metal cobalt as a catalyst to grow a high-grade diamond of about 1 mm for the first time in a 6×800 ton six-face press. Subsequently, after more in-depth research and experiments, it is said that it has been able to stably grow 5mm high-quality large single crystal diamond.
The foreign gem-quality diamond synthesis technology is very mature. Using the temperature gradient method, 1970GE company has grown 1 carat (5mm) diamond single crystal. In 1990, Sumitomo Corporation used the large crystal seed method to grow 9 carat (12mm) diamond single crystal, 1996. In the year DeBeers synthesized 25 carat Ib diamond single crystals in 100h, and in 2000 Sumitomo Company synthesized 8.0 carats (10mm) high quality IIa diamond single crystals. At present, foreign high-temperature and high-pressure synthetic diamond single crystal technology is becoming more and more mature. Element Six, Sumitomo, and GE of the United States can supply large-sized industrial diamonds (size 3.5*1.5*1.5 or more) for cutting tools to the market. ,high profit.
The large-grain diamond single crystal is generally synthesized by seeding method at home and abroad. This synthetic process has a complicated assembly structure and high assembly cost. Due to the temperature gradient method, the diamond seed crystal is in a relatively low temperature region, which makes the synthesis quality difficult to improve. The reproducibility is poor, the success rate is not high, the diamond growth rate is slow, and the unit manufacturing cost is high. The new synthesis method will avoid the above problems, improve the success rate and the single output while reducing the cost, and greatly increase the diamond. Growth rate.
Fourth, large particle industrial diamond synthesis technology
The technology adopts indirect heating spontaneous nucleation technology, which overcomes the defects of complex crystal structure, high cost, slow diamond growth rate and low success rate, and through the assembly structure, pressure transmission system, equipment heat preservation performance and graphite column material. The structural improvement improves the diamond growth conditions, coupled with advanced nucleation and growth process control techniques, while greatly increasing the diamond growth rate while ensuring improved synthesis quality. At present, 0.9*1.2mm, 1*1.4mm single crystals synthesized in forty minutes and fifty minutes, the crystal form is IIb type, the synthesis quality has basically reached the level of fine-grained (40/45) high-grade single crystal, single synthesis The quantity can be effectively controlled in 200-300 grains, the repeatability is good, and no cracking phenomenon occurs during the test. The progress of the current test verifies the rationality and feasibility of the technical theory.
Due to the limitations of equipment performance and other conditions, the test can not continue, the traditional equipment needs to be modified, and the top hammer geometry and assembly structure are redesigned to further increase the speed under the premise of ensuring quality. In the current situation, it can ensure that the growth rate of single crystal reaches 0.2-0.3mm/10 minutes. After analyzing the samples obtained from the test and relevant test data, it is absolutely certain that 1.5*2.1mm will be realized within 2-3 hours. Continuous synthesis of 2*3mm high-grade single crystals, the test cycle is expected to be no more than two months in the case of materials and equipment.
Development of large particle industrial diamond and its application analysis
First, large particle industrial diamond characteristics and uses