Melting/Glass Manufacturing | Fine Annealing & Ceramization | CNC Machining | Pressings | Polishing | Coating | Cementing & Framing | Metrology
SCHOTT has a command of the entire value chain, from customer-specific material development and highly- precise final processing to extremely accurate measurement technology:
With more than 125 years of experience in the area of optics and glass manufacturing, SCHOTT is today the last company in the Western world that actually still melts glass. SCHOTT was the world’s first special glass manufacturer to introduce continuous tank melting way back in 1911.Glass is melted in four phases:
SCHOTT employs the following melting techniques:
Even more precise settings for predefined key properties are achieved by running extremely precise temperature-time programs, for instance on the refractive index, dispersion and tension with optical glass by using the fine annealing referred to here and by way of ceramization for the expansion coefficient of ZERODUR®. SCHOTT has determined the dependence of the properties on shifts in temperature over time quite accurately. This reliable data coupled with profound process expertise makes it possible to keep the target values within extremely narrow tolerances and achieve unmatched homogeneity.
CNC (Computerized Numerical Control) machined components are converted into complex geometrical shapes inside CNC machines with the help of modern CAD software. These include CNC sawing and CNC grinding.
Sawing is used in mass manufacturing and to achieve dimensional accuracy. Grinding makes it possible to manufacture workpieces with a maximum diameter of up to 4.25 m. Carefully-trained employees and extremely precise processes developed by us, together with strict quality controls, result in products of the highest quality and precision.
Pressed blanks are shaped into optical glasses with matte or naturally blank surfaces with the help of hot processing under pressure. Pressings already come in the shape of the optical components, lens pressings, prism pressings, etc. to be used later on.
SCHOTT is capable of polishing all of its products, including zinc sulfide and infrared chalcogenide glasses.Our company uses two different polishing techniques:
a.) Polishing by way of mechanical means used for optical components
b.) Fire-polishing performed while the glass is being manufactured, for thin glasses, for instance
SCHOTT offers single- and double-sided polishing to produce plano and plano-plano-parallel components (with a max. diameter of up to 650 mm, for instance) as well as single-sided polishing of spherical and aspherical surfaces.
SCHOTT offers standard and customer-specific coatings, whereby various coating techniques are used to produce a wave spectrum of between 200 nm and 3,000 nm.The portfolio includes the following types of coatings:
With cementing, two or three optical components (lenses or glass plates, for instance) are bonded together with the help of special synthetic resins or mechanical techniques. For example, when two or three lens elements are cemented together, they produce achromatic doublets or triplets that limit the effect of spherical and chromatic aberration.
With framing, optical elements, for example filters, are typically given a frame made of metal or plastic that makes it easier to use them in the customer’s devices.
SCHOTT is capable of performing extremely accurate and comprehensive measurements on bubbles, striae, transmission, the refraction index and coefficients of expansion by using various measurement techniques and the respective instruments, such as the V-block refractometer, the high-precision spectral goniometer “URIS” or the high-precision dilatometer.
Furthermore, SCHOTT has access to even more measurement techniques and instruments that support processes along the value chain, for instance evenness interferometers or 3-D coordinate measurement devices.
The respective measurement data is available to meet customer-specific demands.