Fiber skeleton material for tape and its bonding technology (1) Development history, current status and latest technological trends of Gao Yiyi (Beijing Rubber Industry Research and Design Institute, Beijing, 100039). The gap between the bonding technology of the fiber-based skeleton materials used in the limb belt industry in China and the foreign countries were analyzed. 1 Classification of the tape and the skeleton material used 111 The tape is divided into two categories according to the function of use: conveyor belt and power transmission tape. Power transmission belts are divided into flat belts and V belts (including the evolution of narrow V belts, joint belts, V-ribbed belts, internal gear type continuously variable belts, timing belts, etc.). The conveyor belt is used to transport solid materials at close distances, and the power transmission belt is used to transmit power from the power source to the working machine. The skeleton materials used in the conveyor belt include canvas, heavy duty cord, integral core, straight straight fabric, anti-drop tear fabric for wire rope conveyor (referred to as ripstop fabric) polyester or polyamide base, steel wire rope. Except for the steel wire rope belonging to the metal skeleton material, the other six kinds of fiber skeleton materials. The fabric structure of the canvas can be further divided into plain canvas, oxford canvas, twill and broken twill fabric structure. Plain canvas is suitable for medium and lightweight conveyor belts. Oxford woven canvas is suitable for heavyweight conveyor belts, which have high tear strength and strong transverse tear resistance. The twill weave fabric is firm, which overcomes the shortcomings of the synthetic fiber filament fabric which is easy to slide due to the smooth surface of the fiber, and has the advantages of high tear strength. Such canvases are typically woven into heavyweight fabrics suitable for making weight grade conveyor belts and reducing the number of canvas layers used. Broken twill weaves are designed to improve a defect in Oxford and twill canvas, that is, the number of knots dropped, which increases the tear strength of the fabric, and the fabric is mechanically added by the addition of knots. The fastening strength of the fastener joint is greatly enhanced, which is advantageous for the joint strength of the large conveyor belt. The material of woven canvas is very wide. At present, the textile materials used in the rubber industry include some synthetic fiber short fibers and cotton or polyvinyl alcohol short fiber blended yarn and synthetic fiber brown silk can be woven canvas. Most of the canvas for conveyor belts in China currently use the first two types of canvas. Strong conveyor belts with heavy curtain fabrics are used in Europe and the United States. The density of such curtains and the weight of the cords are much larger than those of tire cords. The warp is equivalent to the cords for V belts. This has not been done in China at present. In recent years, there have been many conveyor belts with strong steel cords. In order to improve the lateral tear resistance of such conveyor belts, a mesh-type special cloth is used. The cloth is deflected into a high-density polyester or polyamide cord, which is a thinner two-strand cord that is dropped between the two strands of the warp. This structure can overcome the disadvantage of easy sliding displacement due to thinning of the warp and the drop density. The conveyor belt for coal mine roadway requires good flame retardant performance. Since there is no canvas with good flame retardant performance in China, the whole core is used as the strong material of this flame retardant conveyor belt. The overall core is treated with a flame retardant-containing polyvinyl chloride emulsion to strongly adhere to the rubber-plastic tape and improve flame retardancy. The overall core-filled rubber peg bone addition research product 擂 standardization work alElectonic Kechi organization structure is very complicated, the bearing level of the MU belt is divided into double-layer net line and three-layer warp. Most of the materials used for weaving use cotton, polyvinyl alcohol, polyamide, polyester, and aramid. Among them, the spun yarn is also used for the polyvinyl alcohol short fiber yarn, and the warp yarn is also blended with the polyamide (or polyester) short fiber and the cotton (or polyvinyl alcohol short fiber). At present, there is a weaving technique in which most of the cotton or polyvinyl alcohol is placed on the surface of the core to adhere the core to the tape. The looms used in China's overall core industry are imported from the UK and domestically produced. Domestic looms can only produce integral cores with low and medium load ratings. In foreign countries, it is useful to manufacture conveyor belts from fabrics that are straight through the structure. The characteristic of this structure is that two layers are dropped by one layer of warp threads, and the warp and the dropped lines are respectively on three levels, which are not interwoven, and are connected by warp threads (the general line density is much smaller than the warp line density, also called the hanging line). It is connected on the drop line on the warp and the bottom. This fabric is characterized in that the strength of the fiber, that is, the strength retention of the fiber after weaving into the fabric, is high because the warp and the thread are aligned and not woven. And because there is no bending, the fabric has good dimensional stability. Weaving such fabrics generally uses polyester as the warp, polyamide 66 as the strand, and aramid as the warp. The flat belt is made of canvas as the skeleton material, and the fiber materials used are cotton, polyvinyl alcohol, rayon and polyester. The canvas structure is plain, which can be used for purely woven canvas (the same fiber is used for both warp and thread drop) or woven into blended canvas or blended canvas with different twisted fabrics. The cloth type V belt is divided into two types: the cord type and the cord type. The former is a product that is eliminated, and the latter is a technically representative product. It is the development direction of the V-belt and has not been replaced by a product that has not been updated so far. The V-belt curtains are made of polyester cord and polyvinyl alcohol cord, but the density and technical specifications of the V-belt are different from those of the tire. The cord is a polyester cord, and there are also polyamide cords for the manufacturer, but it is deformed after being stressed, which affects the performance and service life of the V-belt. The V-belt for agricultural machinery and the oilfield drilling rig V are equipped with aramid rope as the skeleton material. The cutting type V belt is made of polyester hard wire rope, and the aramid hard wire rope is also used abroad. The internal tooth type timing belt (also known as the timing belt) that appeared after the 1960s is generally required to use a wire with a small amount of deformation as a skeleton material because of the requirement for precise tape size and excellent dimensional stability during operation. Such as aramid cord, glass fiber rope. Micro timing belts (such as timing belts for printer head drives) also use polyester cords. Rope developed polyester cords in the mid-1980s, and polyester hard cords were developed in the late 1980s. Polyester and polyester cord fabrics were developed in the mid-1980s and early 1990s. Due to resource constraints, rayon fabrics are no longer used in the V-belt industry. The V-belt is light canvas, and the woven material is cotton yarn, polyvinyl alcohol/cotton blended yarn, polyester staple fiber/cotton blended yarn. The glass fiber ropes for timing belts are produced by three enterprises in Nanjing, Hangzhou and Shandong. In recent years, the aramid ropes have been used in the synchronous belt materials, and the sources are both imported and domestically processed by foreign dipping technology. . The synchronous toothed bread cloth is a high-elastic fabric, the back cloth is a light canvas, and the woven material is a high-elastic polyamide filament yarn, which was produced in China after the 1980s. The skeleton material for domestic flat tape is canvas, and the textile materials include cotton fiber, polyvinyl alcohol (scission yarn, short fiber yarn), polyamide, polyester, and synthetic fiber canvas developed in the 1980s. The conveyor belt skeleton material can not be produced except for straight-through fabrics. The various skeleton materials described above are produced. The textile materials used cover all fibers except rayon and aramid. The use of anti-transverse tearing fabrics for wire rope conveyor belts has recently been successfully developed. 2 Development history of fiber skeleton material for tape 丨 2 2.1 Development history of fiber frame material for power transmission tape The flat belt for strong material is used for power transmission between steam engine and work machine. The advantage of flat belt is that it can be centered. The power of the power machine is transmitted to several working machines, and the transmission distance can be far. The flat belt is suitable for power transmission between a central power machine with a large power and a plurality of working machines. With the advent of electric motors, the power of the power machine is easier to adjust than the steam engine. The power range of a motor is large, which creates conditions for one-to-one matching between the working machine and the power source. At this point, the flat belt does not seem to adapt to this demand. In 1917, the invention of the V-type power transmission tape solved this problem. The V-belt can cause different cross-sectional dimensions (ie, different power transmission capabilities). Under the same transmission capacity, the V-belt has a smaller volume than the flat-belt and satisfies the requirement of one-to-one short-distance transmission between the power source and the working machine. The timing belt that began to appear in the 1960s is a combination of 1 domestic tapes and M-bone bones. The status quo is: belt mechanical transmission (gear, chain) transmission, angle and tape transmission noise. The belt realizes the synchronous transmission of power. In the late 1970s, the cutting V-belt appeared, which was a revolution in the V-belt manufacturing technology. It changed the V-belt individual forming process into a form of flat tape with multiple V-belts together. After vulcanization, it is cut into a V-belt, which has the advantages of high work efficiency, good dimensional stability of the tape, etc. For more than 20 years, V-belts have been derived from such as narrow V-belts, V-ribbed belts, joint belts, and continuously variable transmission belts. The type of tape makes the belt a wide variety of products with distinctive features. In the 1980s, Israel invented the V-belt manufacturing technology using EPDM-PP rubber blending system as the material. This technology changes the traditional rubber V-belt manufacturing process: the belt material is dynamically vulcanized in the blending and part extrusion process, and the V-belt is formed with three components, a bottom rubber strip, a top rubber strip and The wire rope is "welded" together by the hot melt method to become the finished V belt. The advantages of this manufacturing process are: 1 The manufacturing process is greatly simplified. Since the rubber in the belt material has been dynamically vulcanized during the blending and extrusion process. The parts are "welded" to be the finished V-belt without vulcanization. 2Because the belt material is a rubber-plastic blending system, the waste generated in the V-belt forming can be recycled and reused, which is impossible in the conventional rubber V-belt. The production efficiency of the V-belt can be greatly increased. The V-belt parts can be extruded to any length. The seller can produce V-belts of the same specification of any size with only one hot-melt forming machine. It can be produced at industrial speed. Parts and distributors have greatly improved production efficiency according to the rapid production and sales of on-site processing and delivery. In addition, due to the excellent temperature resistance and weather resistance of EPDM rubber, the working life of this tape can be increased by 3 times to 5 times compared with the traditional rubber V belt. 3. The fiber material of the fiber frame material of the power transmission tape has experienced The process of cotton a rayon-polyamide-polyester-aramid. Polyvinyl alcohol has also been used in the past, and glass fiber is still in use. Due to the different emphasis of the physical properties of the products, the choice of textile materials as the skeleton material of different rubber products should also be focused. The structure of the flat belt is similar to that of the conveyor belt. The skeleton material has always used cotton canvas. After the advent of synthetic fiber, synthetic fiber canvas was used. Since the main technical requirements of the flat power transmission belt are high strength, low elongation deformation and good adhesion to rubber, the use of purified fiber canvas is less used. A large number of canvases are currently used. The main technical requirements of the V belt are high strength, low elongation and good adhesion to rubber. Therefore, fibers with low deformation should be used as the skeleton material. In the development of the V-belt, cotton cords were initially used, followed by rayon cord fabrics, polyvinyl alcohol cords and polyester cords. After the 1960s, the ropes were used as the V-belt skeleton material, and the development process of cotton cord, rayon cord, polyester cord to aramid cord was experienced. At present, the V-belt manufacturing industry in developed countries mostly uses polyester cord and rayon rope as the skeleton material. Special-purpose tapes or large V-belts have used aramid cords. The amount of aramid used in the tube belt industry in Western Europe and North America has more than ten times that of the tire industry. In 1999, the synchronous transmission characteristics of the 1st timing belt were required. The skeleton material has a smaller deformation amount than the V-belt skeleton material. Therefore, the timing belt generally uses an aramid rope or a glass fiber rope as a skeleton material. Some micro-synchronous belts, such as recorders and computer print head belts, use polyester cords as the skeleton material because of the small power of the transmission. 2.2 Development history of fiber skeletal materials for conveyor belts In the history of conveyor belts, cotton canvas has been used as the skeleton material for a long time. With the increasing carrying capacity of conveyor belts, the structural changes and the continuous emergence of special-purpose conveyor belts, many fabrics have evolved from canvas. The structure is straight through the fabric and the core with a core. The canvas has also changed from a single plain structure to a plain weave and an oxford fabric. There are also four fabrics with a broken twill structure and a double plain structure. In recent years, with the increasing demand for the anti-dropping requirements of heavy-duty conveyor belts with strong steel wire ropes, special fabrics for fiber materials have emerged, which are similar in structure and different from tire cord fabrics. The similarity is that the linear density difference between the warp and the dropped line is large, the ordinary cord is used for the warp, and the cord with high linear density is used for the drop. The difference is that the density of the warp and the drop is low, and the fabric is Mesh type, the mesh size is generally 10mm ~ 15mm square or rectangular. In recent years, a light-weight conveyor belt has been made of a brown silk canvas or a polyester (polyamide) base as a skeleton material, but the amount used is much less than other canvas fabrics. Regarding the fiber material of the strong fabric of the conveyor belt, all the fibers (except glass fiber) used in the power transmission belt frame material have been used until now, not only chemical fiber filaments but also polyester staple fibers and cotton fibers or polyethylene. Yarns such as blended yarns of short staple fibers and polyvinyl spun yarns. The future development direction is an interwoven fabric in which the warp is polyester and the polyamide is dropped. Of course, it is polyvinyl alcohol i-vinyl alcohol / cotton blended polyester! Spinning is suitable for some special% will also be a certain amount of cotton fiber. Net polyvinyl alcohol even uses aramid. 3 Adhesive technology for fiber frame material for tape 14 3.1 Development of fiber frame material adhesion technology for tape The history of frame material provides sufficient strength for rubber products and maintains its fixed geometry and dimensional stability. These effects must be achieved. The excellent adhesion strength between the skeleton material and the compound is a prerequisite. The history of continuous development of fiber skeleton materials, especially chemical fiber skeleton materials, is also a history of continuous development and improvement of adhesive technology. The development of adhesive technology plays an important role in the development of skeleton materials. Fiber skeleton materials have been applied to tape for nearly 100 years. From the early development of the tape skeleton material to the 1950s, cotton fiber has been the main fiber material of the skeleton material. Because the strength of the cotton fiber itself is not high, the surface of the cotton fiber fabric has a lot of fiber fluff which can penetrate into the rubber compound to play the role of “an anchoring effect. At that time, the synthetic rubber is not as diverse as today, and natural rubber and cotton fiber have The similar polarity thus has a natural affinity, all of which determine the use of the cotton fiber skeleton material to obtain a satisfactory adhesion to the compound without the need to adhere it. In the 1930s, the world's first chemical fiber* rayon (natural cellulose regenerated fiber) was used as a fibrous material for the skeleton material. Since the rayon is filament and the surface is smooth, the problem of adhesion to the rubber begins to appear in the skeleton material industry. At the beginning, people treated the rayon fabric with a casein-natural latex mixture to strongly adhere to the rubber. In 1935, Charch and Maney of DuPont, USA, invented a water-soluble thermosetting phenolic resin-elastic latex impregnating solution (RFL). The fiber skeleton material was used as a method for adhering to the rubber compound and was patented in 1938. In the development of RFL impregnating liquid, people have studied the water-soluble thermosetting resin formed by condensation reaction between phenol, urea, aniline and other aldehydes, but finally selected and used until now is resorcinol Formaldehyde resin. During World War II, the source and storage of natural latex became a problem, stimulating the development of synthetic latex. The impregnated styrene-butadiene latex was developed during this period and successfully applied to the impregnation and adhesion treatment of chemical fiber skeleton materials. In order to ensure the reliability of military aircraft, fiber frame materials with higher strength should be developed. In the 1930s, the polyamide 66 fiber developed by DuPont in the United States was the world's first synthetic fiber. Its light weight and high strength meet the requirements of military aircraft tires. US military aircraft were gradually equipped during the Second World War. The amide 66 cord was strong in the tires, and the polyamide 66 cord was gradually applied to heavy-duty trucks and off-road tires after the war. Since then, rayon has been gradually applied to tube-and-belt rubber products. The strength of the polyamide 66 fiber is doubled higher than that of the rayon, and thus it is required to have a higher adhesion strength with the rubber compound, and the original impregnation system is insufficient. In the meantime, General Rubber Tyre Company of the United States developed a butyl pyrene latex, and introduced a third monomer-polar 2-vinyl pyridine into the styrene-butadiene latex molecular chain to form a ternary copolymer latex. The appearance of the butyl pyridine latex satisfies the requirement for the increasing adhesion of the synthetic fiber skeleton material, and has become a general-purpose impregnated latex which is still used in the adhesive immersion treatment of the synthetic fiber skeleton material. In the United States, polyester industrial filaments were developed in 1953, but because the reactive groups on the polyester molecular chain are less than polyamides and there are no groups that can form hydrogen bonds with rubber molecules, the original polyamide or rayon cords are used. The designed impregnation treatment system can not achieve good adhesion between polyester and rubber. Therefore, many chemical companies have been developing and researching polyester fabric impregnation technology from the mid-1950s to the mid-1960s. How to achieve the adhesion between polyester and rubber becomes the key to whether polyester can become a new generation of skeleton materials. The Americans first found a way to treat the adhesive properties of polyesters with isocyanate compounds, but this method uses a benzene-based organic solvent to dilute the isocyanate. From the perspective of safety and environmental protection, this method cannot obviously be used on industrial scale. Immersion treatment of skeleton materials such as canvas. Polyester adhesive treatment requires the use of isocyanate-based active substances. Firstly, the problem of chemical stability of isocyanate to water is solved. It has been studied to modify isocyanate to produce water-based isocyanate impregnating agent, which will lose its binding activity against isocyanate. The chemical properties of the isocyanate end-blocking treatment with phenol or caprolactam have been developed. The polyester fabric is treated with an isocyanate aqueous dispersion impregnating solution sealed with a terminal group, and the water is dried at 120*C~150*C, and then heat treated at a temperature above the softening temperature of the polyester and under the melting temperature to close the end. The isocyanate of the base is unblocked at around 190 C, and the appearance of the bonded rayon is restored, so that the strength of the skeleton material of the rubber product is improved as compared with the cotton fiber. The water that has been destroyed by the isocyanate when it is rich in cockroaches has been washed away by net. Therefore, the development of end-blocking isocyanates has undoubtedly contributed to the industrial application of polyester matrix materials. In terms of adhesion properties, the isocyanate having a water-based blocked end group is slightly inferior to the polyester skeleton material treated with a solvent-based isocyanate, but can satisfy the use requirements. In order to make up for this deficiency, the developers of DuPont in the United States continue to work along this route, adding water-soluble epoxy resin and proper amount of wetting agent to the impregnant to improve the dispersion effect of the end-blocking isocyanate in water and improve the stability of the impregnation solution. Sex. So far, the water-based impregnation system plus the conventional RFL system has been used for the two-bath immersion treatment of the polyester skeleton material, and the adhesion property with the rubber compound is no worse than that of the solvent-based isocyanate treatment. In 1967 DuPont acquired the invention patent for this impregnation system and named it D-417 formulation or Shoaf system. In the 1970s, fiber manufacturing companies and tire manufacturing companies in various countries invented more than 20 dipping formula patents, such as resorcinol-polysulfide, trialkyl melamine, ethylene urea, polyethylene. A compound such as amine, piperazine or trimethylolurea is used as a bonding agent for the first bath of the two-bath dipping process, but it has been widely used in the polyester curtain canvas industry to guide the D-417 system of DuPont of the United States. The carbon black aqueous dispersion was introduced into the second bath RFL impregnant to improve the adhesion of the polyester or aramid skeleton material to the rubber and was successful. The theory holds that the difference in modulus between the rubber-impregnated film and the three materials is one of the reasons for the failure of adhesion. The flatter the modulus gradient of the three materials, the better the adhesion effect. The addition of an appropriate amount of aqueous carbon black dispersion to the RFL immersion fluid can make the modulus gradients of the three materials more gradual. This method is applicable to fiber materials with low tensile strain and good dimensional stability. Polyester and aramid are all such fibers. The dimensional stability of rayon is better than that of polyester, but its own tensile strength is low. The adhesion property of the skeleton material after treatment with traditional RFL impregnant has fully met the requirements of use. Therefore, this method is not used for rayon skeleton. The immersion treatment of the material. In the history of the development of fiber matrix material adhesion technology, the development of precondensation resin has been successfully applied and widely used. In addition to the cotton fiber skeleton material, various chemical fiber skeleton materials are inseparable from the thermosetting phenolic resin-lacking system. Synthetic phenolic resin resorcinol and formaldehyde are condensed into a network structure phenolic resin in an alkaline environment with a molar ratio of formaldehyde to resorcinol greater than one. Resorcinol is a highly toxic substance, and environmental pollution and human damage are obvious. To this end, foreign chemists have invented pre-condensation resins, that is, in an acidic environment, the ratio of resorcinol is greater than the molar ratio of formaldehyde, so that the condensation reaction can only form a linear phenolic resin with a low degree of polymerization. Since the resorcinol excess is an acidic environment, the resin can be stored for a relatively long period of time without crosslinking or even solidification, and is concentrated and sold to the fiber skeleton material manufacturer. The phenolic resin of the network structure can be produced in a short time by diluting with a concentrated ammonia or sodium hydroxide solution and adding a certain amount of formaldehyde before use. The pre-condensation resin is used to prepare the RFL impregnating solution. The fiber skeleton material manufacturer can no longer contact resorcinol and simplify the preparation process and shorten the reaction time. Therefore, foreign fiber skeleton material manufacturers have widely used, and China's V-belt polyester. The wire rope manufacturer has also fully applied this material. (To be continued) Polyester filament textiles with metallic luster Spain BrfnandNuiel Chemical Fiber Co., Ltd. has developed a polyester filament with a metallic luster, which can add luster to fabrics, as well as natural fibers and others. Synthetic fiber yarns are blended to produce textile products with a clear metallic luster on some surfaces. The polyester filaments can be processed like other polyester fibers, still retaining their own metallic luster and having a soft hand. They will mainly develop silk products, knitwear and swimwear products with this polyester filament. Xu Yuanju translation Silicone Lamp,Kids Night Light,Colorful Silicone Lamp,Rechargeable Silicone Lamp Yuyao Flylit Appliance Co.,Ltd , https://www.yyflylit.com
Fiber skeleton material for tape and its bonding technology (1) Development history, current status and latest technological trends of Gao Yiyi (Beijing Rubber Industry Research and Design Institute, Beijing, 100039). The gap between the bonding technology of the fiber-based skeleton materials used in the limb belt industry in China and the foreign countries were analyzed. 1 glue