Product description>>>
Composite geomembrane is an anti-seepage material, which is compounded with geotextile and compound Geomembrane for building construction. It remains the mechanical properties of base fabric and uniformity of film which improve the impermeability. Embossed processing on the film strengthen its friction coefficient, stability and easy for installation. It is mainly used for permeation proof drainage and reinforcement. Composite geomembrane has high tearing resistance, breakage resistance, bursting and other physical and mechanical performance.
Properties and advantages:
Since high molecule material and anti-aging agent are added in its production technology, it can be used in abnormal temperature environment.
Flexibility is good, except of a geotextile`s isolation, drainage, reinforcement, protective functions, it also impermeable.
Production: After far infrared ray heating oven in film one side or both sides, and geotextile and geomembrane pressure together by roller form to composite geomembrane .
Function: Impermeable, reinforcement, protection .
Usage:
Widely used in traffic tunnel, airport, drainage, housing, road construction, river levee, lake dam, sewage dam, waste water dam, channel, liquid storage pool, metro, basement, tunnel, foundation, waste storage, marifarm, seawater farms, freshwater fish farm, fishpond, mine, high way, expressway, motorway, railway, roofing, canal, anti-pollution of waste plant,
environmental protection and many other fields for waterproof protection, reinforcement etc.
Unit weight g/m2
400
500
600
700
800
900
1000
Remarks
Project
Thickness of Membrane mm
0.25~0.35
0.3~0.5
Breaking Strength KN/m
5
7.5
10.0
12.0
14.0
16.0
18.0
MD and CD
Elongation at Break % 30~100
CBR Mullen Burst Strength KN≥
1.1
1.5
1.9
2.2
2.5
2.8
3.0
Tear Strength KN≥
0.15
0.25
0.32
0.4
0.48
0.56
0.62
MD and CD
Peel Strength N/cm
6
Vertical Permeability Coefficient cm/s
K×10-11~-13
K=1.0-9.
Specification:
One piece of geotextile and one piece of membrane;Weight of base geotextile: 100-1000g/m2;
Thickness of geomembrane: 0.1-1.5mm.
2. Two piece of Geotextiles and one piece of membrane;Weight of base geotextile: 80-600g/m2
Thickness of geomembrane: 0.2-1.5mm.
3. One piece of geotextile and two pieces of membranes;Weight of base geotextile: 100-1000g/m2;
Thickness of geomembrane: 0.1-0.8mm.
4. Multi-layers:Weight of base geotextile: 100-1000g/m2;Thickness of geomembrane: 0.1-0.8mm.
Those size can all be customized.
Size of package: 2-6m width, length 50-100m(or at request)
Packaging Details: :rolls or packed at customer`s request
Delivery: 3-20days after deposit
FAQ:
1) Q: Do you provide free samples?
A: Yes, sure, we provide free samples for your testing.
2) Q: How long is your delivery time:
A: Goods in stock: within 3 days, Goods out of stock(7 days), Goods need to be customized(10-15 days).
3) Q: How to transport the goods:
A: By shipping, air-flight, express.
4)Do you provide sample? Is it free or extra?
A: Yes, we could offer the sample for free charge and you only pay for freight. If you place an order we can return the freight fee to you.
5)What is your terms of payment?
A: Payment<=1000USD, 100% in advance. Payment>=1000USD, 30% T/T in advance ,balance before shipment.
If you have any question, please feel free to contact us as below:
Composite Geomembrane Composite Geomembrane And Geotextile,Thin Film Composite Geotextile Membrane,Three Cloth A Geomembrane For Landfill,Compound Geomembrane Floating Cover ZHEJIANG BOYA COMTECH CO.,LTD , http://www.zjbytx.com
Since the acquisition of synthetic diamond by GE in 1955 by high-temperature and high-pressure methods, it has caused worldwide concern, especially for countries lacking natural diamond deposits. In 1957, cubic boron nitride was synthesized by high temperature and high pressure. (CBN). These man-made materials have greatly enriched the treasure trove of materials, especially for the development of cutting tools. At the time, the main use of these materials in the field of machining was abrasives. After more than 20 years of hard work, 1977
In 2006, GE successfully developed diamond sintered bodies (PCD) and CBN sintered bodies (PCBN) and made them into blades, which further expanded the use of artificial superhard materials from grinding to cutting.
Even more gratifying is the synthesis of large particles of single crystal diamond and single crystal CBN, which creates conditions for replacing natural diamond. According to the data, the largest single-crystal diamond that has been synthesized has a maximum weight of 34.2 carats, but it still needs further research and exploration for practical application, and the current cost is also expensive.
China's development in synthetic diamonds is also very rapid. According to statistics, in 1993 the world's output was 900 million carats, and China has reached 2.1 to 230 million carats, ranking first in the world. This shows that our country has considerable potential in this field. The development of this technology has created the premise for promoting the wide application of superhard materials in China.
The breakthrough of chemical vapor deposition (CVD) and physical vapor deposition (PVD) technology is a revolution in the development of cutting tools. First, it has applied various ceramic materials, and now it has developed into diamond-like films, diamond films, and CBN films. A coating of superhard materials. This development has almost increased the surface hardness of all cutting tools. Nowadays, vapor deposition technology is still developing. As far as diamond is concerned, it has expanded from a film to a thick film, and its deposition speed has been developed from a few micrometers per hour to a maximum of 0.93 mm per hour.
Today, technology is developing rapidly, and a large number of new materials are emerging. A large part of them are high-alloy steel, high-silicon aluminum alloy, and high-strength composite materials, all of which are difficult-to-cut materials. For example, the Inconel718 nickel-based alloy commonly used in the aerospace industry is an example. Due to the development of superhard materials, the difficult processing of these materials has been greatly alleviated.
Currently, industrially developed countries have rapidly applied the research results of these new materials to the manufacturing industry, thereby increasing productivity, especially in Europe, America and Japan. Although China has made great progress in this respect, there is a considerable gap in improvement and application. Faced with the challenges of the 21st century, superhard materials such as synthetic diamonds and artificial CBN will play a huge role, and people can wait and see.
Characteristics and functions of diamond and superhard materials
Natural single crystal diamond is the hardest substance in the world, so its performance as an abrasive and cutting tool is unparalleled. Take the diamond turning tool as an example, the radius of the cutting edge can be sharpened to the scanning electron microscope, SEM, also Undetectable, until now, no material has been replaced. It can often be used directly for mirroring. It is widely used in the fields of instrumentation, electronics, optics, etc., and it has become an indispensable tool for cutting tools. Costly, sharpening requires a high level of skill, so it has always hindered its wide range of applications.
Due to its superior performance and superb application, superhard materials have evolved from metal processing to areas where traditional processing such as optical glass processing, stone processing, ceramic processing, hard and brittle materials processing is difficult.
Natural single crystal diamonds have anisotropy, so the hardness of each crystal plane is very different. When the tool is sharpened, the soft side is selected as the grinding surface, and the hard surface is used as the rake face or the flank face. This brings favorable conditions for grinding. Because of its anisotropy, in the use, reasonable choice of crystal plane must be considered. For example, the anvil of the hardness tester, in use, uses the pressure or bounce to measure The hardness of the material is measured, but the results vary depending on the hardness of the working surface. Of course, the hard surface is advantageous for prolonging the life. For example, the wire drawing die made of natural diamond, because the working face of the hole is composed of crystal faces, The hardness is inconsistent, the wear will be uneven, and the stress difference will be caused to the circular section of the wire. The hardness will be uneven, which will affect the use. The diamond sintered body and the thick film diamond will become very useful in this kind of products due to isotropy. favorable.
PCD and PCBN have different properties due to their different crystal grains, and they must be reasonably selected. Thick-film diamond is pure diamond, its hardness is close to that of natural diamond, and PCD and PCDN are sintered by mixing diamond powder and binder. Therefore, the hardness is affected by the binder, and its hardness is not as good as the former.
It is well known that diamond has an affinity for iron and can only be used on non-ferrous metals and non-metallic materials, and CBN is fully capable of cutting ferrous metals even at a high temperature of 1000 °C. It has become the main cutting tool material for difficult materials in the future. Generally superhard materials refer to synthetic diamond, artificial CBN. The simultaneous existence of these two materials plays a complementary role, covering the current and future development of various new materials, which is extremely beneficial to the entire cutting process.
The high-precision sharpening of diamond cutting tools requires a high level of skill. In order to obtain a more precise cutting edge arc radius, especially the accuracy of less than 0.05um, the grinding machine is put into strict requirements and must have a very high rotation. The precision of the spindle shaft system, the old-fashioned grinding machine has not adapted, more of the air bearing is used as the support, the grinding disc must be able to be flattened on the machine tool, so that the end face runout is controlled below 0.5um. The sharpening of PCD and PCBN is relatively easy, because the hardness is relatively low, diamond grinding wheel can be used, and thick film diamond is different, its hardness is close to natural diamond, and it is isotropic, so it is difficult to sharpen. .
Recently, the sharpening of diamond cutting tools has attracted people's attention. New sharpening solutions have been proposed one after another, among which thermochemical methods have been introduced. For example, Professor Yoshikawa Yoshikawa of Tokyo Institute of Technology in Japan used a cast iron plate heated to 800 °C. In the concept of accelerated grinding, it is believed that 70% of the grinding work is coarsely ground, so most of the retention can be removed by thermochemical methods, and then refined, which can greatly improve the work efficiency of diamond sharpening.
Precautions in the application of diamond and superhard materials
Natural single crystal diamond
In the current ultra-precision machining, cutting tools for natural single crystal diamonds are indispensable. It achieves an extremely sharp cutting edge with a radius of the edge of the cutting edge that is not detectable by scanning electron microscopy (SEM). According to Prof. Igawa, Professor of Osaka University, Japan, the minimum is 2~4nm, which is the highest level at present, which is calculated from the chip with a thickness of 1nm obtained by cutting. In 1986, a diamond edge evaluation committee was set up in Japan to solve the measurement problem of the tool tip. It has not been solved very well today, but it has been raised from 0.05um to 2~4nm. In 1992, Toshiba Shoji of Toshiba Machinery also proposed the use of scanning tunneling microscopy (STM) or atomic force microscopy (AFM) for testing. However, it has not been reported. The Chinese Academy of Technology in China reported the use of AFM in 1996. Progress has been made, which is a gratifying achievement.
The sharpening of diamond cutting tools has not been small. But still based on experience, it is still a subject to be solved. The geometric parameters of diamond cutting tools may be under-exercised, so it remains to be explored so far. Generally, the rake angle is 0°, the back angle is 5-6°, and there are two kinds of ends. One is an arc and the other is a straight line. The latter is sometimes called a wiper, and its length is based on the material to be processed. Come choose. The adjustment of the circular turning tool during the cutting process is relatively simple, and the adjustment of the flat blade is relatively time consuming. If applied in high-precision surface machining, the sharpening requirements of the arc are very strict, and the accuracy of its precision will be copied on the surface. According to the data, the Osaka Diamond Manufacturing Co., Ltd. can reach R±0.05um a few years ago, and the UK is even higher, reaching R±0.02um.
During the cutting process, the thermal conductivity of diamond is superior and the heat dissipation is fast, but it should be noted that the cutting heat should not be higher than 700 °C, otherwise graphitization will occur and the tool will wear out quickly. Because diamond reacts with W, Ta, Ti, Zr, Fe, Ni, Co, Mn, Cr, Pt, etc. at high temperatures.
Diamond sintered body (PCD)
The emergence of PCD has replaced natural single crystal diamond in many ways. Compared with natural diamond, PCD is cheaper and sharper than natural diamond, so its application and promotion are particularly rapid. Most of the new materials that emerged are mostly difficult-to-machine materials, such as high-silicon aluminum alloys, which are used extensively in pistons for automotive engines. Generally, an aluminum alloy containing less than 10% silicon can be cut with a cemented carbide tool, but if the silicon content exceeds 10%, the PCD can only be used. Currently, the silicon content of high-silicon aluminum alloys is above 12%, and some have reached more than 18%, so non-PCD is none other than.
However, due to the variety of PCDs, there is a need for reasonable choice. Its particle size, concentration, etc. will affect the hardness, wear resistance and other properties. Therefore, it must also be based on the type of material being processed in the application. Various characteristics such as hardness are considered to consider reasonable parameters. Because of its isotropy, wear resistance is better, and it is even better than natural single crystal diamond.
The production of PCD at home and abroad has been very popular, but the quality is quite different, so the price is very different. In China, the cutting blade of PneumoPreci~sion's SMG325 ultra-precision machine tool was used in the United States with the blade of GE's ultra-fine-grained GE. It has achieved surface roughness close to the mirror surface.
Cubic boron nitride sintered body (PCBN)
PCBN is a sintered CBN particle with a binder. It is resistant to high temperatures and has a hardness second only to diamond and has no affinity with ferrous metals. From a development perspective, many new materials need to be processed with PCBN. For example, the gears of the automobile gearbox adopt the PCBN gear hob, which not only achieves high productivity, but also significantly improves the quality, and the machined surface becomes a mirror surface. According to the data, the surface of the gear cut by PCBN is also hardened due to the infiltration of boron. This is confirmed by the experiment of Harbin Institute of Technology. Due to the high temperature resistance of PCBN, there is no change and stability under 900 °C in the atmosphere and water vapor. Even at 1300 °C, there is almost no reaction with Fe, Ni, Co, etc., and it is not as sharp as diamond. It still retains the hardness of the cemented carbide, so it can not only cut hardened steel parts or chilled cast iron, but also can be widely used in high-speed or ultra-high-speed cutting work. However, PCBN is not suitable for cutting general steel parts, therefore. Care must be taken when selecting tools. The particle size and concentration must be taken into account when purchasing.
The geometry of the PCBN is also special. Generally, the cutting edge needs to be chamfered to -30° or arc to protect the tip from damage. There are many manufacturers producing PCBN. The major foreign companies include GE in the United States, Sumitomo Electric Co., Ltd., DIJET in Japan, DeBeers in the UK, etc. The main tools are Chengdu Tool Research Institute, Guizhou No.6 Grinding Wheel Factory, and Guilin. Institute of Geology, etc.
Superhard material coating cutting tool
The emergence of technologies such as CVD and PVD is a major revolution in the field of cutting tools. Its appearance immediately caused great repercussions in the field of mechanical manufacturing. The ideal cutting tool should have both a hard surface and high toughness, and the coating technology achieved this goal.
The earliest coating materials are ceramic materials, such as TiN, TiC, Al23O, etc. In recent years, coating technology has been greatly developed. Ultra-hard material coatings are being fully applied, and many products have appeared on the market one after another, but the domestic is still in the experimental stage, and it is expected to break through soon. The development of super-hard material coatings makes the performance of the entire existing cutting tools. Both have been significantly improved. In the face of the current large number of difficult-to-machine materials, these newly developed coating technologies will have great adaptability and the prospects are quite gratifying.
There are three main types of superhard material coatings, namely diamond-like, diamond and CBN. These coating materials are pure diamond or pure CBN, so the hardness is the same as the deposited material. Compared with PCD and PCBN, the hardness and wear resistance are greatly improved because they do not contain a binder.
The properties of the diamond coating and the CBN coating are the same as those of the raw materials, but only the film, and the same as the ceramic coating. The diamond-like film is highlighted here.
Diamond-Like Carbon (DLC) film has similar performance to diamond film, its anti-friction and wear performance is good, and the DLC film preparation process is becoming more and more mature, which can obtain large area and rough surface at very low deposition temperature. A small DLC film, while a diamond film requires a higher deposition temperature (about 800 ° C ~ 1000 ° C), therefore, many matrix materials are limited, such as high-speed steel, and it is difficult to deposit evenly over a large area, the surface is also Rough. Therefore, the DLC film is more easily used in many applications, such as a protective film for a magnetic disk.
In the use of coated cutting tools, as with ceramic coatings, the coating substrate must also be handled well. Generally, the cemented carbide of the matrix is ​​YG8. The pretreatment process is firstly polished with W1 diamond micropowder, and the surface is decobalted for 15 min. The decobalted solution is a 1:3 nitric acid aqueous solution, and then ultrasonically cleaned in acetone for 10 min. The cleaning work is extremely important before the substrate is applied. If it is a cutting tool, it must be ensured that it cannot be annealed during sharpening.
Due to the short history of superhard material coating technology, it is still developing. I believe it will be more perfect than the ceramic coating technology.
Thick film diamond
The synthesis technology and application research of diamond thin films have developed rapidly around the world, forming a "diamond film heat". In the past ten years, the method of gas phase synthesis has developed to more than twenty kinds. Generally, the deposition rate is only 1~2um per hour. How to accelerate the deposition rate has been the subject of research. In the near future, the deposition rate has developed to above 100 um/h, with a maximum of 930 um/h. We call it thick film diamond. China Oriental Tiandi Diamond Research Institute successfully mastered this technology, the largest deposition thickness reached 2.3mm. It has now been commercialized and entered the international advanced ranks. Thick film diamond differs from PCD in that it has no binder and is pure diamond, so its hardness is much higher. Unlike natural diamond, it is isotropic and low cost, so it will replace PCD in many aspects. Used as a wire drawing die will be even wear, so the wire quality of the wire drawing is significantly better than the natural diamond die. If the quality of deposition is further improved, there is also the possibility of replacing natural diamond in ultra-precision processing, so it is highly valued in the field of ultra-precision.
In short, the development of diamond and superhard materials will greatly promote the development of various industries, and the prospects are very broad.
Problems and prospects
Every cutting tool material has some abnormalities in its development, so it must be continuously explored and studied. Each material has different characteristics. In use, a reasonable processing method should be selected according to the characteristics of the tool and the material to be processed, and even the processing conditions.
As we all know, diamond is the hardest substance in the world and is an ideal material for cutting tools, so it is now widely used. However, it has affinity with ferrous metals, and at about 700 °C, graphitization will occur, and the wear of diamond will accelerate, so it is only suitable for cutting non-ferrous metals and non-metallic materials. However, people have been trying to break this restricted area. For example, Professor Cassteven of the LLNL National Laboratory in the United States used a carbon-rich environment to directly cut ferrous metals, which has certain effects. Harbin Institute of Technology in China uses liquid nitrogen spray to cut ferrous metals at ultra-low temperature. It has also achieved certain effects. Recently, it has been suggested that diamonds containing a certain amount of boron may cut ferrous metals. In short, it is possible to make breakthroughs in the near future.
Cutting tools with super-hard materials appear earlier than ceramic coatings, but there are still many problems to be solved, especially the strength of the bonding, which directly affects the life of the cutting tool. There are also such problems in the aspect of ceramic coating, such as the clean processing of the cutting tool before coating; and in the sharpening of the cutting tool, the edge annealing is not allowed, no burrs are allowed, and multi-coating is also used. The solution is to be solved, but there is still room for new development in superhard coating.
The birth of ceramic coating technology is a major development in cutting tool materials, and the breakthrough of super-hard material coatings has brought almost all cutting tools closer to the ideal field.
PCD and PCBN are cutting tools that are commonly used in current applications. The development of their technology is still valued. For example, in foreign countries, in the manufacturing process, the blank is directly cut into a prescribed shape by electric wire cutting, but the domestic blank can only be first. Cut the hard alloy portion and cut the rest. Generally, such a cutting tool can achieve a low surface roughness, and the fine-grained blade of GE Corporation of the United States can be used to approach the mirror surface, mainly because the grain size is ultra-fine. The interface is increased to achieve a smoother cutting edge.
The synthesis of thick-film diamond is a breakthrough in the material of a cutting tool, and its emergence will provide more possibilities to replace the natural diamond used in the current ultra-precision machining field, not only because its performance is close to natural diamond, but also The cost is low. For countries with scarce diamond deposits, there is a good prospect.
The diamond deposited substrate must be carefully cleaned prior to deposition. In the case of cemented carbide, cobalt-based cemented carbide is generally used, which affects the nuclear density during diamond synthesis. The density is low, and the deposition quality is obviously poor, and the adhesion of the coating is low. Therefore, corrosion must be taken to remove cobalt from the surface.
Since cobalt is deposited on the interface with the substrate, non-diamond materials such as graphite and pores are formed. Many carbons diffuse in cobalt and cause cracks on the interface. The coefficient of thermal expansion of cobalt-containing WC sintering is 5×10-6/~6×10-6/°C, which is larger than 3.1×10-6/°C of diamond. Therefore, when it is synthesized by °C, it will be cooled to normal temperature and will become residual. The cause of the stress. From these situations, it is still a subject worth exploring to improve the adhesion of the sinking diamond on the cobalt-containing cemented carbide. Recently, Professor Yoshikawa Yoshikawa of the Tokyo Institute of Technology in Japan proposed that by using the discharge sintering method, it is possible to produce a sintered body of WC powder containing no cobalt, which significantly increases the adhesion of the deposited material and the particle size of the deposited diamond is small. It shows that the technology of deposition is moving to a higher level.
The synthetic large-particle single crystal diamond industry has broken through, but the cost is still high and needs to be developed. In short, the development of superhard materials will inevitably lead to great changes in machinery manufacturing, and will undoubtedly make greater contributions to the 21st century.
Package: Packed in woven geotextile with strength belt.
(1)1x20ft(5.89m(L) x2.35m(W) x2.39m(H)) : around 18T
(2)1x40ft (12.03m(L) x2.35m(W) x2.39m(H)) : around 22T
(3)1x40hc (12.03m(L) x2.35m(W) x2.69m(H)) :around 26T
Overview