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Etching Metal and the History of Etching
Etching metal is a speciality at Proetch. Etching is the engraving of material such as stone, glass and most importantly to Proetch Services, metal. This method is carried out with acid using a form of resist to put a pattern on a surface goes back thousands of years. This method is known as photo etching or photo fabrication and has been around in one form or another for many years. Allegedly Cleopatra had jewellery made in this manner.
In the fifteen century Linseed oil was used as a resist to mask the area that was not to be affected by the etchant, and a vinegar-based etchant was used to engrave the surface of armour. As the process evolved other resists were developed such as waxes and resins. This allowed the process to be used for intaglio printmaking that was the etching into iron or copper plates using a wax ground cut using a Sharpe point. It was not until the nineteenth century that glass was etched, due to the discovery of hydrofluoric acid.
In the nineteenth century photography as we now know it was being developed, and as a spin from this new stronger and more versatile resists were developed, these new resists were light sensitive and called photoresists. The new photoresist when exposed to ultraviolet light causes polymers in the resist to cross link, so that by the use of a phototool an image can be printed onto the surface. The first person to be credited with the first ever photoetching was JN Niepce having succeeded in 1826. In 1888 John Baynes patented the etching of material from two sides.
In the early twentieth century polymer chemists designed much improved photoresist formulas. This allowed etching by highly corrosive etchants and allowed batch repeatability.
In the 1950s Kodak brought out a resist that was based on a pre-sensitised poly (vinyl cinnamate), which gave the birth to the Photochemical machining (photoetching) industry. The only draw back with this resist was that it used as its solvent Xyaline. The next big break through in resists came with the introduction of dry films which allowed processing with out solvents.
The industry, which now plays such a vital role supplying metal components to wide variety of industries from precision parts to decorative goods. These include integrated circuit lead frames; RF screening; EMI screening; attenuators; shims; washers; gaskets; light choppers; encoder discs; meshes and screens; solder screens; grids; grilles; screens; meshes; gobos; clips; battery contacts; heat sinks; filter discs; fine meshes; electrical contacts; model parts; rosette spring; v spring; cir clips; name plates and labels; mimic boards; the list could be endless but suffice it to say the phrase most associated with chemical etching is “If it can be drawn it can be made” . This is the beauty of etching metal.
Different names same process.
As this technology has grown throughout the world the different names or terminology used are as follows.
Photoetching is known as:-
Photochemical machining (PCM) in the UK
Photo chemical machining (PCM) in USA
Photochemical milling
Photomilling
Photofabrication
Photo fabrication
Chemical blanking (USA)
Photoforming (USA)
Chemical etching
Etching
Acid etch
Acid etching
Chemical Engineering
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photochemical machining ¦ photo chemical machining ¦ photochemical milling ¦ photomilling ¦ photofabrication ¦ chemical milling