In addition to silicon dioxide, boron oxide and other glass formers, lead oxide glass containing large amounts.
Used in the manufacture of optical glass, vacuum glass, low-temperature sealing glass, radiation protection glass, lead crystal glass, flint-based optical glass, low-melting glass, glass delay line, high refraction glass beads and glass containers and other arts.
Lead glass composition formula is: RmOn-PbO-SiO2 (B2O3). Formula SiO2 (B2O3), namely silicon oxide (boron oxide), said network formations, is the basic unit constituting the glass network structure. RmOn, represents an alkali, alkaline earth, rare earth metal oxides, is to make the glass network structure changes, to adjust the characteristics of the network to modify the composition. PbO, namely lead oxide, is characterized by ingredients, gives the basic characteristics of glass. With increasing content of PbO, glass density, refractive index, dispersion, dielectric constant, and the performance of the X-ray absorption coefficient value γ rays increase; decrease its index value hardness, high temperature viscosity, softening temperature, chemical stability and the like; resulting in glass-forming material of variable length, colorants colorful, shiny surface increases, crisp percussion.
China as early as the Warring States period that is lead glass. After the second half of the 17th century, the British system of lead crystal glass art utensils. Later widely used in manufacturing optical instruments, utensils and other arts.
Lead glass in the medical field, also known as medical X-ray radiation lead glass, lead glass is mainly divided into domestic and imported lead glass lead glass, mainly for diagnostic X-ray room, CT, ECT, PET, CT-PET and other rooms as well as X ray photography protection room, window protective shield on the door, and nuclear medicine with shield and other operations. Desired thickness can be determined according to the calculation.
The main common lead glass thickness specifications are 5mm, 10mm, 15mm, 20mm, the main production base is mainly concentrated in the north and central area, there are three main domestic production bases.
Radiation protection glass is divided into two:
1. the general radiation protection glass commonly used nickel alloy mesh technology, good shielding effect, but the light transmittance is generally 60% -80%, or a slight impact on the visual sense, can distinguish colors white, red, orange, yellow, green, cyan, blue, purple, reflective rate is generally less than 8%, after a special surface hardening, impact resistance is strong, surface stress greater than 400MPa.
2. lead oxide glass, the main component of sio2, doped PbO, typically at about 20%, some containing boron oxide, light transmittance is generally more than 98%, more brittle, a large proportion.
On radiology, often used for radiation protection and shielding, or as a lead film viewing room window. Commonly used radiation and radiation protection glass.
Lead glass effect:
The main properties of lead glass is optically clear, transparent protective shield and use a low-attenuation performance with specified optical quality protective glass attenuation performance of each millimeter 0.22mmpb; ScopeIt can be installed on the viewing window laboratory X-ray inspection and CT scans of the protective window goggle lenses Airport security X-ray screens and industrial inspection use protective window.
Lead Glass is a brittle material, a large proportion, when displacing sure gently, it must be surrounded with a wall of glass coating malocclusion radiation during installation to prevent the junction of scattered radiation leakage, due to the rich lead and barium, lead acid glass susceptible to contamination and difficult to install or stored in acid gas or wet environment.
Depending on the lead content of leaded glass, mainly ZF2, ZF3, ZF6, ZF7 four series, now generally are used ZF2 series lead glass, ZF6 and ZF7 two series of high lead content glass high lead content, the same thickness high protection capacity and the weight is also large.
ZF series of high-lead glass products is the use of advanced production technology and optical detection methods, materials selection of high lead content of optical glass processing, having an inner timber cleaning, transparency, and lead when the amount of features, and strong radiation capability , it can effectively block the X-rays, γ-rays, cobalt 60 radiation and isotope scanning. ZF series of high-lead glass have: ZF2, ZF3, ZF6, ZF7 series models.
ZF2, ZF3 series of high-lead glass is widely used in X-ray diagnosis and observation window spiral CT scan room, medical diagnostics shield; ZF6, ZF7 series of high-lead glass is mainly used in the nuclear industry in the field of nuclear power plants, atomic energy applications.
A large number of countries in the world production of lead glass is a combination of phosphate, silicate and borate glass system from the other end. After the combination of some most valuable properties are maintained while to get good chemistry than pure phosphate glass stability.
Small differences in the melt of different chain structure unit space requirements, not to the extent of immiscible appear large, but the phosphate and silicate system if the system, delete the system salt system or a combination of his children, it does not appear immediately -7.4.3 miscible with high lead silicate glass structure given color, high-lead silicate glass is generally done with a yellow-green in transparent optical glass, glass structure changes with copper or chromium ions on also have a significant impact on the transmittance of lead glass.