galvanische ontwikkeling
- Thread starter jerzz
- Start date
Ik weet niet veel van platen persen maar wel van (elektro)chemie:
Wat je nodig hebt zijn verschillende electroless- en electro-plating (of electrodeposition) stappen.
Eerst moet het oppervlak van de "laquer" geleidend gemaakt worden. Dat kan door er een fijn laagje koolstof (of een metaal) op te dampen of d.m.v. van een redoxreaktie met tinchloride en zilvernitraat een dun laagje zilver aan te brengen. Zilvernitraat is een redelijk onstabiel goedje, het zit bijvoorbeeld ook in fotographische films waar het onder belichting gereduceerd wordt tot kleine zilver deeltjes. Het tinchloride reduceerd het zilvernitraat zodat er een dun laagje zilver op de laquer achterblijft.
Nu de laquer geleidend is kan je d.m.v. een stroompje meer metaal op de laquer deponeren tot de metaallaag dik genoeg is om eraf te halen. Je kan bijvoorbeeld vanuit een goudchloride of goudcyanide bad goud deponeren of koper of tin of whatever.
Dit had ik nog op het net gevonden:
http://eil.com/explore/guide/vinyl_making.asp
Depositing metal upon metal by means of an electric current that transfers metal through a plating solution directly to the actual surface being plated. At this point record making is surrounded by tanks. Rows and rows of containers filled with multi coloured liquids, some steaming, some sloshing about, as objects are swished through the depths. To make an actual metal impression the lacquer must either flow on the metal and let it harden or plate it on cold. The first process obviously being impossible (lacquer is a soft, highly inflammable plastic!), some form of plating is the only answer. But how do you plate metal onto a non-metal? A number of methods have been used. The oldest, when master records were cut into wax blocks, was to apply an extremely thin coating of graphite, a form of carbon that we know as pencil lead, which conducts electricity. To this coating, thin enough not to disturb the record groove shape unduly, one could actually plate metal, which would take on the shape of the record grooves. When enough metal had been backed up on the plating, it was an easy matter to strip it from the wax and the graphite, leaving a mold of metal. Three ways are used to get the first microscopic layer of metal onto the lacquer. Silver spray is the newest and trickiest and also the silver pan bath is still used, similar in its chemistry; it takes longer, and is not as accurate . Lacquers are treated in a different way, to give metal coatings at first only a molecule or so thick.
The most dazzling to watch involves silver nitrate and a simple spray gun. The lacquer surface is "sensitized" by being dipped into a solution of stannous chloride which is washed off in a water spray, leaving a very thin coating. Silver nitrate solution is sprayed at the disk and the black becomes a mirror of silver in seconds. Silver has been deposited in an extremely thin layer by chemical (replacement) action, the stannous chloride acting as a catalyst to promote the process. The newly silvered disk is washed and moves on to its next treatment. The next objective is to build up a solid metal backing on the thin silver coat. This may be confusing, since this "backing" is actually being deposited on the front of the original disk. Remember, that we are making a negative mold, its surface now of silver, in direct contact with the lacquer surface and facing away from us as we look at the record. We are really looking at the silver from the rear, and we are about to add more metal to that rear in order to stiffen it. The original record will eventually be stripped away, leaving the other side of the silver, the facing-down side, as the mold. The beginning of the build-up of the metal backing support, a layer of very fine-grained and delicate copper or sometimes nickel, is laid down slowly on the silver surface just produced. It's fine-grained in order so not to disturb the tiny groove patterns and to hold them accurately in place.
After this, a more coarse grained metal can be piled on, although in some plants, another layer of fine grained "pre-plating" is added first. The coarse coating is desirably much faster, since at the slow fine-grain pre plating speed, it may take weeks to build up a strong enough layer of metal. One company used special rotating disk anodes that swish around close to the surface of the metal record and do the plating job to required thickness in a few hours. Other much slower systems use the usual immersion tanks with moving arms to swish the contents about. Enough metal is put on the back of the silver surface to support it rigidly. and with a quick blow of a special hammer and with a shaking of the inserting tool, the entire silver-copper mold breaks free from the lacquer, and we have a negative in metal, the back side or down-surface of the silver a mirror-image the original grooves. The lacquer is usually damaged in this separating process and cannot be used again; so the new metal negative, or "matrix", is now the only form in which the grooves exist. Being a negative, the grooves become sharp ridges with flat valleys between. This metal negative or "matrix" can now be used to stamp out actual records! Since it is now the only existing copy of the original lacquer disc, in most cases it is used to produce a "mother", a positive metal record that can actually be played for testing purposes. Playing is not this mother's destined role and instead, the mother is submitted to another plating operation much like the first, ending in another metal negative which is the desired "stamper". Since the mother, unlike the fragile lacquer original, is made of metal, it can be re-plated many times over, producing negative after negative in metal, all identical with the first.
Wat je nodig hebt zijn verschillende electroless- en electro-plating (of electrodeposition) stappen.
Eerst moet het oppervlak van de "laquer" geleidend gemaakt worden. Dat kan door er een fijn laagje koolstof (of een metaal) op te dampen of d.m.v. van een redoxreaktie met tinchloride en zilvernitraat een dun laagje zilver aan te brengen. Zilvernitraat is een redelijk onstabiel goedje, het zit bijvoorbeeld ook in fotographische films waar het onder belichting gereduceerd wordt tot kleine zilver deeltjes. Het tinchloride reduceerd het zilvernitraat zodat er een dun laagje zilver op de laquer achterblijft.
Nu de laquer geleidend is kan je d.m.v. een stroompje meer metaal op de laquer deponeren tot de metaallaag dik genoeg is om eraf te halen. Je kan bijvoorbeeld vanuit een goudchloride of goudcyanide bad goud deponeren of koper of tin of whatever.
Dit had ik nog op het net gevonden:
http://eil.com/explore/guide/vinyl_making.asp
Depositing metal upon metal by means of an electric current that transfers metal through a plating solution directly to the actual surface being plated. At this point record making is surrounded by tanks. Rows and rows of containers filled with multi coloured liquids, some steaming, some sloshing about, as objects are swished through the depths. To make an actual metal impression the lacquer must either flow on the metal and let it harden or plate it on cold. The first process obviously being impossible (lacquer is a soft, highly inflammable plastic!), some form of plating is the only answer. But how do you plate metal onto a non-metal? A number of methods have been used. The oldest, when master records were cut into wax blocks, was to apply an extremely thin coating of graphite, a form of carbon that we know as pencil lead, which conducts electricity. To this coating, thin enough not to disturb the record groove shape unduly, one could actually plate metal, which would take on the shape of the record grooves. When enough metal had been backed up on the plating, it was an easy matter to strip it from the wax and the graphite, leaving a mold of metal. Three ways are used to get the first microscopic layer of metal onto the lacquer. Silver spray is the newest and trickiest and also the silver pan bath is still used, similar in its chemistry; it takes longer, and is not as accurate . Lacquers are treated in a different way, to give metal coatings at first only a molecule or so thick.
The most dazzling to watch involves silver nitrate and a simple spray gun. The lacquer surface is "sensitized" by being dipped into a solution of stannous chloride which is washed off in a water spray, leaving a very thin coating. Silver nitrate solution is sprayed at the disk and the black becomes a mirror of silver in seconds. Silver has been deposited in an extremely thin layer by chemical (replacement) action, the stannous chloride acting as a catalyst to promote the process. The newly silvered disk is washed and moves on to its next treatment. The next objective is to build up a solid metal backing on the thin silver coat. This may be confusing, since this "backing" is actually being deposited on the front of the original disk. Remember, that we are making a negative mold, its surface now of silver, in direct contact with the lacquer surface and facing away from us as we look at the record. We are really looking at the silver from the rear, and we are about to add more metal to that rear in order to stiffen it. The original record will eventually be stripped away, leaving the other side of the silver, the facing-down side, as the mold. The beginning of the build-up of the metal backing support, a layer of very fine-grained and delicate copper or sometimes nickel, is laid down slowly on the silver surface just produced. It's fine-grained in order so not to disturb the tiny groove patterns and to hold them accurately in place.
After this, a more coarse grained metal can be piled on, although in some plants, another layer of fine grained "pre-plating" is added first. The coarse coating is desirably much faster, since at the slow fine-grain pre plating speed, it may take weeks to build up a strong enough layer of metal. One company used special rotating disk anodes that swish around close to the surface of the metal record and do the plating job to required thickness in a few hours. Other much slower systems use the usual immersion tanks with moving arms to swish the contents about. Enough metal is put on the back of the silver surface to support it rigidly. and with a quick blow of a special hammer and with a shaking of the inserting tool, the entire silver-copper mold breaks free from the lacquer, and we have a negative in metal, the back side or down-surface of the silver a mirror-image the original grooves. The lacquer is usually damaged in this separating process and cannot be used again; so the new metal negative, or "matrix", is now the only form in which the grooves exist. Being a negative, the grooves become sharp ridges with flat valleys between. This metal negative or "matrix" can now be used to stamp out actual records! Since it is now the only existing copy of the original lacquer disc, in most cases it is used to produce a "mother", a positive metal record that can actually be played for testing purposes. Playing is not this mother's destined role and instead, the mother is submitted to another plating operation much like the first, ending in another metal negative which is the desired "stamper". Since the mother, unlike the fragile lacquer original, is made of metal, it can be re-plated many times over, producing negative after negative in metal, all identical with the first.
MrM
Ouwe rot
Re: galvanische ontwikkeling
http://www.youtube.com/watch?v=xUGRRUecBik
en
http://www.youtube.com/watch?v=IReDh9ec_rk
Met dank aan Chinetti voor het posten van deze links in bovengenoemde thread
In het grote Google video topic zijn er een tweetal leuke filmpjes over...
http://www.youtube.com/watch?v=xUGRRUecBik
en
http://www.youtube.com/watch?v=IReDh9ec_rk
Met dank aan Chinetti voor het posten van deze links in bovengenoemde thread
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