Poliedrica s.r.l, Lucite (PMMA) processing and works
We have been operating in the field of plastics processing for many years . More precisely, what the Poliedrica s.r.l is specialised in is the processing of Lucite, even known as Plexiglas or Perspex depending on the number of commercial or informal ways in which it PMMA is called. But what is this material? How do you get it? Which is the use one can make of it? Let’s see below some information about these concerns:
Polymethyl methacrylate (PMMA) or poly (methyl 2-methylpropanoate) is the synthetic polymer of methyl methacrylate. This thermoplastic and transparent plastic is sold by the tradenames Plexiglas, Limacryl, R-Cast, Perspex, Plazcryl, Acrylex, Acrylite, Acrylplast, Altuglas, Polycast and Lucite and is commonly called acrylic glass or simply acrylic. The material was developed in 1928 in various laboratories and was brought to market in 1933 by Rohm and Haas
PROPERTIES
Polymethyl methacrylate (PMMA) or poly (methyl 2-methylpropanoate) is the synthetic polymer of methyl methacrylate. This thermoplastic and transparent plastic is sold by the tradenames Plexiglas, Limacryl, R-Cast, Perspex, Plazcryl, Acrylex, Acrylite, Acrylplast, Altuglas, Polycast and Lucite and is commonly called acrylic glass or simply acrylic. The material was developed in 1928 in various laboratories and was brought to market in 1933 by Rohm and Haas
PROPERTIES
The material is often used as an alternative to glass. Differences in the properties of the two materials include
• PMMA is less dense; its density can range from 1150-1190 kg/m3. This is less than half the density of glass which ranges 2400 to 2800 kg/m3
• PMMA has a higher impact strength than glass and does not shatter but instead breaks into large dull pieces.
• PMMA is softer and more easily scratched than glass.
• PMMA is typically processed at a lower temperature than glass, just 240-250 °C.
• PMMA transmits up to 93% of visible light (per metre). A simple comparison with glass is not possible as glass is not a substance with a single composition and is made with an extreme range of optical transmittances from 0% to practically 100% (at least 99.99% infrared in long distance optical fibers). Doped PMMA can achieve transmittances of 91% to 98%, suitable for consumer fiber.
• Unlike glass, PMMA does not filter ultraviolet (UV) light. PMMA transmits UV light down to 300 nm. Some manufacturers add a coating to PMMA sheets to make them absorb UV light. PMMA molecules have great UV stability compared to polycarbonate.
• PMMA allows infrared light of up to 2800 nm wavelength to pass. IR of longer wavelengths, up to 25,000 nm, are essentially blocked. Special formulations of colored PMMA exist to allow specific IR wavelengths to pass while blocking visible light (for remote control or heat sensor applications, for example).
PMMA can be joined using cyanoacrylate cement (so-called “Superglue”), or by using liquid di- or trichloromethane to dissolve the plastic at the joint which then fuses and sets, forming an almost invisible weld. PMMA can also be easily polished to restore cut edges to full transparency.
The refractive index of PMMA compounds usually ranges from 1.4893 to 1.4899 (a vacuum’s is 1).
To produce 1 kg of PMMA, about 2 kg of petroleum is needed. In the presence of oxygen, PMMA ignites at 460° C and burns completely to form only carbon dioxide and water.
USES
PMMA or Acrylic is a versatile material and has been used in a wide range of fields and applications.
IMPACT RESISTANT SUBSTITUTE FOR GLASS
• PMMA Acrylic glass is commonly used for constructing residential and commercial aquariums.
• PMMA is used in the lenses of exterior lights of automobiles.
• The spectator protection in ice hockey stadiums is made of PMMA.
• Motorcycle helmet visors
• Police vehicles for riot control often have the regular glass replaced with acrylic to protect the occupants from thrown objects.
• Acrylic is used for viewing ports and even complete hulls of submersibles, such as the Alicia submarine’s viewing spheres and the Bathyscaphe Trieste’s windows.
• Polycast acrylic sheet is the most widely used material in aircraft transparencies (windows). In applications where the aircraft is pressurized, stretched acrylic is used.
ARTISTIC AND AESTETHIC USES
• Acrylic paint essentially consists of PMMA suspended in water; however since PMMA is hydrophobic, a substance with both hydrophobic and hydrophilic groups needs to be added to facilitate the suspension.
• Modern furniture makers, especially in the 1960s and 1970s, seeking to give their products a space age esthetic incorporated Lucite and other PMMA products into their designs, especially office chairs. Many other products (for example, guitars) are sometimes made with acrylic glass, giving otherwise ordinary objects a transparent or futuristic look.
• Perspex has been used as a surface to paint on, for example by Salvador Dalí.
• Occasionally used as a glass substitute in picture framing, due to its relatively inexpensive cost, light weight, and shatter-resistant nature, as well as the fact that it can be ordered in larger sizes than standard picture-framing glass. Conventional glass may or may not be preferred.
• From approximately the 1960s onward, sculptors and glass artists began using acrylics, especially taking advantage of the material’s flexibility, light weight, cost and its capacity to refract and filter light.
by Wikipedia
