Plexiglass (Polymethyl methacrylate) is a common name, abbreviated as PMMA, the chemical name of this polymer transparent material is polymethyl methacrylate, which is a polymer compound made by the polymerization of methyl methacrylate. It is an important thermoplastic plastic developed earlier. Plexiglass is divided into four types: colorless transparent, tinted transparent, pearlescent, embossed plexiglass. Plexiglass is commonly known as acrylic, acrylic, acrylic, plexiglass has better transparency, chemical stability, mechanical properties and weather resistance, easy to dye, easy to process, beautiful appearance and other advantages. Plexiglass is also known as gelatin glass, acrylic and so on.
Basic introduction Chinese name : Plexiglass Foreign name : methyl methacrylate Abbreviation : PMMA Chemical name : polymethyl methacrylate Composition : methyl methacrylate polymerization and become Performance : such as transparency, chemical stability History, principle, type, characteristics, electrical properties, physical properties, chemical properties, set, structure, use, mechanical, medical, architectural, distinction ,Production Method,Construction Method,Main Impact, History In 1927, chemists from a German company heated acrylate between two panes of glass, and the acrylate underwent a polymerization reaction that produced a sticky, rubber-like interlayer that could be used as shatter-proof safety glass. When they used the same method to make methyl methacrylate polymerization, got the transparency is extremely good, other properties are also good plexiglass plate, it is polymethyl methacrylate. Plexiglass set 1931, the German company built a factory to produce polymethyl methacrylate, first in the aircraft industry to get set, instead of celluloid plastic, used as aircraft cockpit covers and windshields. If the production of plexiglass by adding a variety of coloring agents, can be polymerized into colored plexiglass; if you add a fluorescent agent (such as zinc sulfide), can be polymerized into fluorescent plexiglass; if you add artificial pearl powder (such as alkaline lead carbonate), you can produce pearlescent plexiglass. Principle of plexiglass, English: ( Polymethyl methacrylate ), abbreviation: PMMA; plexiglass chemical name is called polymethyl methacrylate, is polymerized by the polymerization of methacrylate polymer compounds. Smooth surface, colorful, small specific gravity, greater strength, corrosion resistance, moisture resistance, sun resistance, good insulation properties, sound insulation. It can be divided into three types: tube, bar and plate. Acrylic acid and its esters as raw materials polymerization of polymers obtained collectively referred to as acrylic esters, the corresponding plastic collectively referred to as polyacrylic acid plastic, which is the most widely used set of polymethyl methacrylate. Polymethyl methacrylate abbreviation code for PMMA, commonly known as plexiglass, light transmission is good, through more than 92% of the sun, ultraviolet up to 73.5%; high mechanical strength, a certain degree of heat and cold resistance, corrosion resistance, good insulation, dimensional stability, easy to mold, brittle texture, easily soluble in organic solvents, the surface hardness is not enough, easy to rub the hair, can be used for the requirements of a certain degree of strength of the transparent It can be used as transparent structural parts which require certain strength, such as oil cups, car lamps, instrument parts, optical lenses, decorative gifts and so on. Adding some additives to it can improve its performance, such as heat resistance and friction resistance. The material is widely used in advertising light boxes, nameplates and other aspects of the production. Types of plexiglass can be divided into four types in accordance with the appearance: 1. colorless transparent plexiglass the most common, the largest amount of plexiglass material. 2. Tinted transparent plexiglass commonly known as color plate. Translucent soft, made of light boxes, crafts, make people feel comfortable and generous. Tinted plexiglass: transparent tinted, translucent tinted, opaque tinted three. Magnetic plexiglass luster is not as bright as pearlescent plexiglass, brittle, easy to break, suitable for the production of dials, boxes, medical equipment and people, animal modeling materials. Transparent plexiglass: high transparency, suitable for lamps and lanterns. It is made of chandeliers, exquisite, crystal clear. Translucent plexiglass similar to frosted glass, soft reflection, crafts made of it, make people feel comfortable and generous. Chandelier 3. Pearlescent Plexiglass is in general plexiglass with pearlescent powder or fluorescent powder. This kind of plexiglass color is bright, surface finish is high, the outer form of hot pressing by the mold, even after grinding and polishing, still maintain the molded pattern, the formation of a unique artistic effect. It can be used to produce characters, animal modeling, trademarks, decorations and publicity exhibition materials. 4. embossed plexiglass points transparent, translucent colorless, brittle, easy to break, in the interior doors and windows and other decorative use, with both translucent but impervious to the shape of the characteristics of the indoor partition or separation between the interior doors and windows are usually used. Characteristics of polymethyl methacrylate is often referred to as plexiglass, the acronym PMMA, with high transparency, low price, easy to mechanical processing and other advantages, is often used in the usual glass replacement materials. Plexiglass is an important thermoplastic plastic developed earlier, with transparency, stability and weather resistance, easy to color, easy to process, beautiful appearance, in the construction industry has a wide range of applications. ① Highly transparent. Plexiglass is an excellent polymer transparent materials, light transmittance of 92%, higher than the transmittance of glass. Known as the artificial small sun of the sun lamp tube is made of quartz, this is because quartz can completely through the ultraviolet radiation. Ordinary glass can only transmit 0.6% of the ultraviolet light, but plexiglass can transmit 73%. Plexiglass ② high mechanical strength. Plexiglass relative molecular mass of about 2 million, is a long chain of polymer compounds, and the formation of molecules in the chain is very soft, so the strength of plexiglass is relatively high, the ability to resist stretching and impact than ordinary glass 7-18 times higher. There is a kind of heated and stretched plexiglass, in which the molecular chain segments are arranged in a very orderly manner, so that the toughness of the material has a significant improvement. With a nail into this plexiglass, even if the nail penetrates, the plexiglass does not produce cracks. This kind of plexiglass by the bullet will not break into pieces after the same. Therefore, stretching treatment of plexiglass can be used as bulletproof glass, but also used as a cockpit cover on military aircraft. ③ light weight. Plexiglass density of 1.18g/cm3;, the same size of the material, its weight is only half of ordinary glass, metal aluminum (belonging to the light metal) 43%. ④ easy to process. Plexiglass can not only use the lathe for cutting, drilling machine for drilling, and can be acetone, chloroform, etc. bonded into various shapes of appliances, but also can be blown, injected, extruded and other plastic molding methods processed into a large aircraft cockpit cover, as small as the shape of dentures and teeth and other shaped *** products. Advantages a, plexiglass aesthetics: mirror effect, exquisite craftsmanship, no wrinkles, no seams; Second, plexiglass visual effects: a variety of colors, strong visual impact; Third, plexiglass light transmission: light transmission rate of up to 96%, light transmission rate is excellent, the light is relatively soft; Fourth, plexiglass impact resistance: is more than 200 times the ordinary glass products, there is almost no danger of any fracture; Five, plexiglass impact resistance: is more than 200 times the ordinary glass products, almost no risk of fracture; Five, plexiglass impact resistance: is the ordinary glass products, almost no danger of fracture Durability of plexiglass: the product has a very good protection of the built-in light source, to extend the life of the light source products; six, the weather resistance of plexiglass: can be guaranteed for a long time without fading, the good quality of the plate life up to 6-13 years; seven, the flame resistance of plexiglass: there will be no spontaneous combustion and has a self-extinguishing; eight, the energy-saving nature of plexiglass: the transmittance of light is very good, the relative reduction of the source of light, electricity, reduce the cost of use; nine, plexiglass energy saving: light transmission is very good, relatively less light source, power, reduce the cost of use Reduce the cost of using; nine, the rationality of the plexiglass: rational design and rain and moisture, open structure, easy to clean and maintain. Electrical properties of polymethyl methacrylate due to the main chain side position contains a polar methyl ester group, the electrical properties are not as good as non-polar plastics such as polyolefins and polystyrene. The polarity of the methyl ester group is not too large, polymethyl methacrylate still has good dielectric and electrical insulation properties. It is worth pointing out that polymethyl methacrylate and even the entire acrylic plastic, have excellent arc resistance, under the action of the arc, the surface will not produce carbonized conductive pathway and arc trail phenomenon. 20 ℃ is a secondary transition temperature, corresponding to the side of the methyl ester group began to move the temperature, below 20 ℃, the side of the methyl ester group is in a state of freezing, the material's electrical properties than in the 20 ℃ or more when it will be improved. Physical Properties Physical properties polymethyl methacrylate has good overall mechanical properties, in the forefront of general-purpose plastics, tensile, bending, compression and other strengths are higher than polyolefins, but also higher than polystyrene, PVC, etc., the impact toughness of the poorer, but also slightly better than polystyrene. The casting of the body polymerization of polymerized methyl methacrylate sheet (such as aviation with plexiglass sheet) tensile, bending, compression and other mechanical properties are higher, can reach the level of polyamide, polycarbonate and other engineering plastics. Generally speaking, the tensile strength of polymethyl methacrylate can reach the level of 50-77MPa, bending strength can reach 90-130MPa, the upper limit of these performance data has reached or even exceeded some engineering plastics. Its elongation at break is only 2% -3%, so the mechanical properties of the characteristics of the plastic basically belong to the hard and brittle, and notch sensitivity, easy to crack under stress, but the fracture fracture is not like polystyrene and ordinary inorganic glass as sharp and uneven. 40 ° C is a secondary transition temperature, equivalent to the side of the temperature of the methyl group to start the movement of the temperature, more than 40 ° C, the material's toughness, ductility has been improved. The surface hardness of polymethylmethacrylate is low and easily scratched. The strength of poly(methyl methacrylate) is related to the time of stress application, and the strength decreases with increasing time of application. The mechanical properties of polymethylmethacrylate (oriented plexiglass) after tensile orientation are significantly improved, and notch sensitivity is also improved. The heat resistance of poly(methyl methacrylate) is not high, although its glass transition temperature reaches 104℃, but the maximum continuous use temperature changes with different working conditions between 65℃-95℃, the heat distortion temperature is about 96℃ (1.18MPa), and the Vicat softening point is about 113℃. Heat resistance can be improved by polymerizing the monomer with propylene methacrylate or bis ester-based ethylene glycol acrylate***. The cold resistance of polymethyl methacrylate is also poor, and the embrittlement temperature is about 9.2°C. Thermal stability of poly(methyl methacrylate) belongs to the medium, better than polyvinyl chloride and polyformaldehyde, but not as good as polyolefins and polystyrene, the thermal decomposition temperature is slightly higher than 270 ℃, its flow temperature of about 160 ℃, so there is still a wide range of melt processing temperature. Thermal conductivity and specific heat capacity of poly(methyl methacrylate) in plastics belongs to the medium level, respectively 0.19W/M.K and 1464J/Kg.K Chemical properties Chemical and solvent resistance Poly(methyl methacrylate) can be resistant to dilute inorganic acids, but concentrated inorganic acids can make it erode, alkali resistance, but warm sodium hydroxide, potassium hydroxide can make it erode, resistant to salts and fats and oils, resistant to aliphatics, insoluble in water, insoluble in water, insoluble in water, insoluble in oil, insoluble in water, insoluble in aliphatics, resistant to water. hydrocarbons, insoluble in water, methanol, glycerol, etc., but can absorb alcohols to dissolve and produce stress cracking, not resistant to ketones, chlorinated hydrocarbons and aromatic hydrocarbons. Its solubility parameter is about 18.8(J/CM3)1/2 , and it can be dissolved in many chlorinated hydrocarbons and aromatic hydrocarbons, such as ethylene dichloride, trichloroethylene, chloroform, toluene and so on, and ethylene vinyl acetate and acetone can also make it dissolved. Polymethyl methacrylate has good resistance to gases such as ozone and sulfur dioxide. Weathering resistance Polymethyl methacrylate has excellent resistance to atmospheric aging, its specimens by 4 years of natural aging test, weight change, tensile strength, light transmission rate slightly decreased, color slightly yellowish, silver grain resistance decreased more obviously, impact strength also slightly improved, other physical properties are almost unchanged. Combustibility polymethyl methacrylate is easy to burn, the limit of oxygen index is only 17.3. Set of plexiglass set of a wide range, not only in the commercial, light industry, construction, chemical industry and so on. And plexiglass is widely used in advertising and decoration, sand table modeling, such as: signage, billboards, light box panels and Chinese and English letter panels. Plexiglass selection depends on the modeling design, what kind of shape, with what kind of plexiglass, color, variety should be repeatedly tested to achieve the best results. With a good modeling design, but also rely on careful processing and production, in order to become a beautiful craft. 1. building sets: windows, soundproof windows and doors, light covers, telephone booths, etc. 2. advertising sets: light boxes, signboards, signs, display racks, etc. 3. transportation sets: trains, cars and other vehicles, doors and windows, etc. 4. medical sets: baby care boxes, a variety of surgical medical instruments, folk supplies: bathroom facilities, handicrafts, cosmetics, brackets, aquariums, etc. 5. industrial sets: instruments, surface panels and covers, etc. 6. lighting sets: Fluorescent lamps, chandeliers, street lampshades, etc. 7. home sets: fruit plate, tissue box, acrylic art paintings and other household household household products Structure I. Plexiglass is made of polymethyl methacrylate, polymethyl methacrylate contains polar side methyl, has a strong hygroscopic properties, water absorption is generally in the acrylic sheet must be kept dry, the drying conditions required is 78 ℃ -80 ℃ under the drying of 5-6h. II. Plexiglass is an invisible polymer, its shrinkage range are decreasing, generally in the 0.45% -0.9, so for acrylic production when the molding accuracy provides good conditions, generally molding is very accurate. Third, by the adaptation of polymethyl methacrylate to the surrounding temperature range does not have the ordinary fluidity, but has a non-Newtonian fluidity, so in the case of high temperature, the solvency viscosity of the plexiglass will be reduced, which is the performance of the plexiglass is very sensitive to temperature. Fourth, the flow of plexiglass in the process of temperature are generally around 150 ℃, but when the plexiglass began to decompose, the temperature is higher than 270 ℃, so that the change in temperature is still very flexible, will not be affected by the temperature of the production, high temperature resistance is the characteristics of plexiglass. Fifth, plexiglass also has a very good cutting performance, can be measured in the size of the clear situation through laser cutting for processing, simple high quality, this feature is not even glass, . Therefore, acrylic can withstand high and low temperatures in a variety of environments, consumers do not have to worry about the temperature in the production process. Uses Mechanical Plexiglass has the above excellent performance, so it is extremely wide range of uses. In addition to the aircraft used as a cockpit cover, windshield *** window, but also used as a jeep windshield and windows, large building skylights (can be shatter-proof), TV and radar screen, instruments and equipment, protective cover, telecommunication instrumentation, telescopes and cameras on the shell of the optical lens. A wide variety of daily necessities made of plexiglass, such as buttons made of pearlescent plexiglass, a variety of toys, lamps and lanterns are also because of the decorative role of colored plexiglass, but also look extraordinarily beautiful. Medical Plexiglass has a wonderful use in medicine, that is, the manufacture of artificial corneas. If the transparent cornea of the human eye is full of opaque material, light cannot enter the eye. This is the blindness caused by alloplastic leukoplakia, and this disease can not be treated with drugs. So, medical doctors conceived the idea of replacing the cornea with an artificial cornea. The so-called artificial cornea, is a transparent substance made of a few millimeters in diameter only a mirror column, and then in the cornea of the human eye to drill a small hole, the mirror column fixed in the cornea, the light through the mirror column into the eye, the human eye will be able to regain the light. As early as 1771, there are ophthalmologists with optical glass made of lens column, implanted in the cornea, but did not succeed. Later, the use of crystal instead of optical glass, but also only six months after the failure. In World War II, when some airplanes crashed, the cockpit covers made of Plexiglas on the planes were blown up, and pieces of Plexiglas were embedded in the eyes of the pilots. After many years, although these fragments have not been removed, but also did not cause further inflammation or other adverse reactions in the human eye. This fortuitous event demonstrated the good compatibility between Plexiglas and human tissue. At the same time also inspired ophthalmologists, can use plexiglass to manufacture artificial cornea, it's good light transmission, chemical stability, non-toxic to the human body, easy to process into the desired shape, and can be compatible with the human eye for a long time. Artificial cornea made of plexiglass has been commonly used in clinical practice. Architecture In construction, plexiglass is mainly used for light bodies, roofs, roofs, staircases and indoor wall sheathing and other aspects. Plexiglass in the highway and high-level road lighting lampshade and automobile lamps and lanterns in the set is also quite fast. With the construction of big city hotels, hotels and high-level residential construction, the rapid development of the light body, the use of plexiglass extruded plate made of light body has a high overall structural strength, light weight, high light transmittance and good safety performance, etc., compared with the inorganic glass lighting fixtures, with a great deal of superiority. In terms of sanitary ware, plexiglass can make bathtubs, washbasins, vanity and other products. As the plexiglass bathtub has a luxurious appearance, a sense of depth, easy to clean, high strength, light weight and comfortable to use and other characteristics have been widely set. The United States and Japan have made mandatory in the law, China's small and kindergarten buildings must use plexiglass. With the continuous improvement of China's laws, is expected in the near future will also make corresponding provisions. At the same time, China has accelerated the pace of urban construction throughout the country, the use of plexiglass produced by the street signs, advertising light boxes and telephone booths will also appear in large quantities, thus plexiglass development space is very large, the market outlook is very broad! Difference between plexiglass and ordinary glass plexiglass seems like a family, in fact, they are completely different from the two families. Ordinary glass structure is silicate, but plexiglass "parents" is acetone, methanol, sulfuric acid and hydrogen cyanide. Plexiglass character is generally much more stubborn than ordinary glass. Its density is less than half of ordinary glass, but not as easy to break as glass. Its transparency is very good, crystal clear, and has a very good thermoplasticity, it is heated, it can be arbitrarily molded into glass rods, glass tubes or glass panels, because it has a favorite appearance as well as the character, so it has a wide range of uses. Jet aircraft flying at high speed in the clouds, often encountered violent vibration and sudden changes in temperature and airflow pressure and other special circumstances, which is a serious test of the aircraft cockpit window glass. And can withstand this test is plexiglass. If it is a fighter, in pursuit of the enemy, plexiglass was hit by a bullet, it will not rupture the whole piece, but only through a small hole, so that similar glass shards will not happen again to injure the accident. Ordinary glass is more than 15 centimeters thick, it will turn bright green, and can not see through the glass. Plexiglass across 1 meter thick, you can still see clearly across the thing. Because of its light transmittance is quite good, coupled with ultraviolet light can also be penetrated, so commonly used in the manufacture of optical instruments. Plexiglass additionally has an amazing performance, a bent plexiglass rod, as long as the curvature is less than 48 degrees, the light can be along it, like water through the hose as projected. How interesting that light can take a curved path! Utilizing this stunt, it became prized for the manufacture of surgical light-transmitting glass instruments. As a result, doctors didn't have to worry about seeing clearly when they operated in the operating room. Plexiglass is lightweight, but also tough, chemical and quite stable, heat and plasticity, so it is very versatile. If the raw materials in the plexiglass with some appropriate dyes, according to the needs of people made of red, green and purple ...... colorful colored plexiglass. Production methods on the method Plexiglass Plexiglas will be cut into a certain shape, in the plane on the paste and become. Hot pressing method will be plexiglass sheet heating, in the mold in the hot pressing type. This modeling method into the craft has a full-bodied, smooth curves, three-dimensional sense of strong characteristics, the effect of relief. Hot pressing mold can be used wood, oil clay shaping, and then cast lead, gypsum materials for the yin and yang mold, plexiglass can be pressed into shape after heating. Inlaid method will be different colors of plexiglass blocks cut into the required geometric drawings, inlaid on the base plate spliced into. This method requires tight splicing, the corners of the fight, can receive a strong color, but also the effect of one. Vertical grinding method will be stick-shaped Plexiglas or thick plate-shaped Plexiglas bonding, directly on the grinding wheel, polishing molding. Crafts made with this method is similar to some kind of sculpture, by the colorful surface shape, constitute a distinctive artistic image. Broken grinding method will overlap the plate-shaped Plexiglas on the paste together, and then directly grinding section molding. Crafts made of this method can be colorful, simple and natural effect. Hot simmering method will be processed to a certain shape of plexiglass, the plexiglass will be heated, directly by hand quickly nested, pinched into shape. Some of the law requires prior to the composition of a good idea, the action is agile, a breath of fresh air. Crafts made with this method has the advantages of unrestrained lines and simple image. The above methods can be used alternately, according to the artistic requirements of modeling design, set the best method. Construction method There are many kinds of plexiglass materials, imported and domestic difference is very big, imported plexiglass cut out very smooth, some domestic impurities are too much, will bubble. Acrylic cutting generally use low-speed machines, because the laser tube power is not very large, and thin material precision requirements are relatively high. General speed is not more than 3 meters / min. Thick material cutting (10-20mm) More than 10mm plexiglass generally use 75mm focusing lens, more than 25mm plexiglass with 100mm focusing lens, the deepest can cut 32mm plexiglass. 10mm plexiglass cutting: cutting speed is generally 0.08-0.12m/min, light intensity 60-70%. The speed of cutting is generally 0.08-0.12 meters / min, light intensity 60-70%. In the light intensity of 60% of the time the most stable, leaky jet cup to adjust the size of the gas flow, so that the edge is smoother. Because the greater the blowing wind cutting the melted object is aided by high-pressure gas blowing back to the plexiglass to form an unsmooth surface. Try to adjust the wind down. Sometimes, customers need to add paper or film cutting, this time the wind can not be too small, otherwise it will catch fire. Cutting plexiglass speed and light intensity must be matched, the slower the speed, the smoothness is not the better. 15mm or more plexiglass is best to use imported high-power lasers. Plexiglass carving with a leaky jet cup, try not to carve too deep, carve too deep it is difficult to reach the bottom of the flatness, the more the gas will affect the effect of the carving edge, to carve a finer and clearer, can not be too deep and blowing a small amount of gas, acrylic carving need to pay attention to is the resolution of the settings, if the output BMP format, the resolution is generally to be in the 600 dpi or more, at this time, speed for the 8-18 m / min, light intensity for the 20% -30%, sweeping off the blowing to make the bottom smoother. Thin material cutting (2-10mm) 5 mm below the plexiglass with 50 mm focusing lens, cutting speed is generally 0.35-0.8 m / min, light intensity of 45-65%, 5-10 mm plexiglass is generally used in 63.5 mm focusing lens, cutting speed 0.15-0.3 m / min, light intensity of 50-75%, large-area engraving machines, large-area engraving machine, the cutting speed is generally 8-18 m / min, light intensity of 20%-30%, clean off the blowing to make the bottom smoother. 75%, large-area engraving machine, for engraving if there is a more serious **** vibration (vibration), will also cause a big reduction in the accuracy of the engraving machine, so cutting plexiglass models of the width as far as possible do not exceed 1 meter, there is plexiglass engraving character image process produces some white powder, thus feeling more clear, if the carving is to be wiped with water after the carving, it seems to be more fuzzy. To look like the specific effect and which processing. Physical properties of plexiglass:Density: 1.19g/cm 3 Transmittance: 99% Impact strength ≥ 16kg/cm 3 Tensile strength ≥ 61Kg/cm 3 Thermal deformation temperature ≥ 78 ° C Thermal softening temperature of ≥ 105 ° C
Plexiglass adhesive methods for different needs, 502 can be on the requirements of the low, but the requirements of the high Triclocarbon abbreviation. Chloroform is not necessarily the best, acetone is also needed, but it is best to be several mixed formulations Main effects Plexiglass is not harmful to the human body, but the use of some plexiglass daily necessities will be a certain degree of harm to the human body, but the harm is not too great, because plexiglass cups contain organic compounds will not dissolve in water. Plexiglass is a common name, the chemical name of this polymer transparent material called polymethyl methacrylate, the English abbreviation PMMA, is made of methyl methacrylate polymerization, there is also a name on the market - acrylic. Usually, plexiglass is also a substitute for a variety of plastic products. Plastic belongs to the chemical polymer materials, most of the polymer chemical materials normally harmless to human health.