Acrylic plastic refers to a family of synthetic, or man-made, plastic materials containing one or more derivatives of acrylic acid. The most common acrylic plastic is polymethyl methacrylate (PMMA), which is sold under the brand names of Plexiglas, Lucite, Perspex, and Crystallite. PMMA is a tough, highly transparent material with excellent resistance to ultraviolet radiation and weathering. It can be colored, molded, cut, drilled, and formed. These properties make it ideal for many applications including airplane windshields, skylights, automobile taillights, and outdoor signs. One notable application is the ceiling of the Houston Astrodome which is composed of hundreds of double-insulating panels of PMMA acrylic plastic.
Like all plastics, Acrylic Rod plastics are polymers. The word polymer comes from the Greek words poly, meaning many, and meros, meaning apart. A polymer, therefore, is a material made up of many molecules, or parts, linked together like a chain. Polymers may have hundreds, or even thousands, of molecules linked together. More importantly, a polymer is a material that has properties entirely different than its component parts. The process of making a polymer, known as polymerization, has been likened to shoveling scrap glass, copper, and other materials into a box, shaking the box, and coming back in an hour to find a working color television set. The glass, copper, and other component parts are still there, but they have been reassembled into something that looks and functions entirely differently.
The first plastic polymer, celluloid, a combination of cellulose nitrate and camphor, was developed in 1869. It was based on the natural polymer cellulose, which is present in plants. Celluloid was used to make many items including photographic film, combs, and men's shirt collars.
In 1909, Leo Baekeland developed the first commercially successful synthetic plastic polymer when he patented phenol-formaldehyde resin, which he named Bakelite. Bakelite was an immediate success. It could be machined and molded. It was an excellent electrical insulator and was resistant to heat, acids, and weather. It could also be colored and dyed for use in decorative objects. Bakelite plastic was used in radio, telephone, and electrical equipment, as well as countertops, buttons, and knife handles.
Acrylic acid was first prepared in 1843. Methacrylic acid, which is a derivative of acrylic acid, was formulated in 1865. When methacrylic acid is reacted with methyl alcohol, it results in an ester known as methyl methacrylate. The polymerization process to turn methyl methacrylate into polymethyl methacrylate was discovered by the German chemists Fitting and Paul in 1877, but it wasn't until 1936 that the process was used to produce sheets of Clear Acrylic Rod safety glass commercially. During World War II, acrylic glass was used for periscope ports on submarines and for windshields, canopies, and gun turrets on airplanes.
Acrylic Line Rod plastic polymers are formed by reacting a monomer, such as methyl methacrylate, with a catalyst. A typical catalyst would be an organic peroxide. The catalyst starts the reaction and enters into it to keep it going, but does not become part of the resulting polymer.
Acrylic plastics are available in three forms: flat sheets, elongated shapes (rods and tubes), and molding powder. Molding powders are sometimes made by a process known as suspension polymerization in which the reaction takes place between tiny droplets of the monomer suspended in a solution of water and catalyst. This results in grains of polymer with tightly controlled molecular weight suitable for molding or extrusion.
Acrylic plastic sheets are formed by a process known as bulk polymerization. In this process, the monomer and catalyst are poured into a mold where the reaction takes place. Two methods of bulk polymerization may be used: batch cell or continuous. The batch cell is the most common because it is simple and is easily adapted for making Acrylic Tubes in thicknesses from 0.06 to 6.0 inches (0.16-15 cm) and widths from 3 feet (0.9 m) up to several hundred feet. The batch cell method may also be used to form rods and Acrylic Diffuser Tubes. The continuous method is quicker and involves less labor. It is used to make sheets of thinner thicknesses and smaller widths than those produced by the batch cell method.
The storage, handling, and processing of the chemicals that make Opal Acrylic Tubes are done under controlled environmental conditions to prevent contamination of the material or unsafe chemical reactions. The control of temperature is especially critical to the polymerization process. Even the initial temperatures of the monomer and catalyst are controlled before they are introduced into the mold. During the entire process, the temperature of the reacting material is monitored and controlled to ensure the heating and cooling cycles are the proper temperature and duration. Samples of finished acrylic materials are also given periodic laboratory analysis to confirm physical, optical, and chemical properties.
PC Tubes are the clearest extruded tubes on the market today delivering brilliant quality, superior performance, and durability. Polycarbonate tubes are characterized by their flawless optics, and a perfectly smooth surface free of striations.
Clear PC Tubes are optically pure. Our transparent Polycarbonate tubes are often used in the stand- and exhibition building, in the furniture/interior design branches, and mostly for technical applications such as reactors. Polycarbonate tubes are reasonable UV stable and weatherproof but are not designed for long-term outdoor applications. They will yellow if they are outside for a long period.
High-quality, design-orientated applications within the architectural lighting industry can be easily created with our Polycarbonate tubes. You can create impressive lighting effects using our PC Color Tubes which are an innovative solution that fits particularly well for Lighting and architectural applications. White or frosted satin surface finishes provide excellent diffused light creating a velvety nonglare surface.
Polycarbonate tubes can be cut, sanded, drilled, etc. with the appropriate tools. They require high cutting speeds and effective cooling as their low heat conduction can easily lead to overheating and local thermal stress.
Excess friction, especially with Polycarbonate tubes can cause melting which leads to a tacky surface and difficulty machining. Drilling should never be performed without using some water-based cooling lubricant (i.e. an emulsion). For eliminating internal stress annealing may be necessary.
- ایجاد شده: 21/11/12
- آخرین ورود: 21/11/12