Como complemento a todas las aportaciones realizadas hasta ahora, añado lo que comenta Peter Bock, respecto a las puntos (plumines, plumillas) de oro de 18k que no tienen porque ser más flexibles que los de 14K y asimismo los de acero. La flexibilidad la da el templado y la forma de la punta (plumilla, plumín).
Aquí están los 11 pasos que emplean para la fabricación de puntas (plumines, plumillas) de oro.
Lo siento pero no tengo tiempo para la traducción, marcho de viaje. (si algún voluntario lo hace perfecto de lo contrario será a mi regreso)
1. The gold used to make nibs arrives in the form of long, flat gold bands round into large rolls. The gold band is somewhat wider than the finished nib length. It is thicker on the side that will become the writing end of the nib, and thinner on the side that will be inserted into the section. (This saves money on the costly gold and allows for a better fit of the nib into the section.) The gold band has been treated to give the combination of flexibility and hardness needed to make proper nibs.
2. We watched the gold banding unwind and feed into presses that punch out nib blanks. At the same time, the "breather hole" was made and the flat blanks were imprinted with their "nib art" (decoration, logos, nib size, carat content of the gold).
3. Then, the nib blanks are inserted into hydraulic presses that use 25 tons of pressure to form the gold nibs into their final convex shape.
4. A small ball of iridium is welded to the soft gold on the point of the nib. The size of the ball determines the width of the nib. The tip material is commonly called iridium, but is actually an alloy of various metals from the platinum family of metals. A specially-designed electrical resistance welding machine meets the challenge of making sure the very hard iridium tip is firmly attached to the relatively soft gold nib. The result is a tip that can withstand many years of abrasion as the nib slides across paper.
5. Grinding machines, shape the bottom, top and sides of the nib tip. We remembered that some nib manufacturers do not finish the top of the tip since it is does not touch the paper. Bock nibs are so well finished on the top that you can turn the nib over and nearly always write with the top surface of the nib!
6. A slit is cut from the tip to the breather hole of the nib using a diamond cutting disk no thicker than a human hair. This machine, is a marvel of engineering design. It is so precise that designers can create "nib art" that depends upon the slit being precisely in the middle of the nib. We looked at a modern Pelikan gold nib, where it was easy to see that the decorative pattern would have been spoiled if the slit had been cut off-center.
7. Once the nib is split, another grinding operation gives both sides of the tip the best shape for writing performance. It is another engineering marvel to see the nibs do an intricate dance on the grinders to achieve just the right shape.
8. A technician take a container of nibs and electronically measure each one to ensure that the nib widths to meet tight quality standards. It was a testament to the maxim that quality must be built in. Nib after nib was made exactly to specification. None had to be rejected.
9. Next, the nibs are thoroughly polished. One method looks similar to an old-fashioned ice freezer ... without the cold. Loose nibs are dumped into a cylindrical container filled with what looks like thick pancake batter. A paddle rotates in the container, stirring a slurry of walnut shells in an industrial abrasive similar to toothpaste. The second method reminds me of a miniature car wash. Nibs are mounted in small holders where they rotate while moving in an orbit. As they move, the nibs are sprayed with liquid abrasive and tiny cloth wheels whirl around them polishing every surface. In either case, the results are excellent.
10. If the nibs are to be "two tone", an extra step is required. For example, a gold nib can have a portion of the nib decoration plated in rhodium in order to create a color contrast between the gold and silver colored metals. Typically, the part that will not be plated is masked so that the plating will not adhere to the gold in those areas. After the decorative overlay is plated, the mask is removed to reveal the original metal. This work is very challenging, so we were particularly impressed when we looked at two- tone nibs under 10x magnification and saw the precision with which it was done.
11. Finished nibs are cleaned, then mounted in foam holders that protect them for shipment to the fountain pen manufacturers.
Saludos
