EMBOSSING ON PLATEN PRESSES
Both hot and cold embossing can be done successfully on regular platen presses of the Hartford and John Thomson type, although there are special embossing presses made especially for the work.
Hartford Electric Embossing Plate Heater.
The National Machine Company, of Hartford, Conn., are making the “Hartford Electric Embossing Plate Heater,” which may be used on all styles of platen presses for hot embossing. As indicated by its name, the Hartford Electric Heater, while on the press, is heated by electric current supplied from the regular wiring system in the plant. The female die, or several female dies, are attached to the surface plate of the Hartford Electric Heater by means of Bunter-Post Registering Screws. By moving these screws, the die or number of dies may be placed in any position desired.
Hot (electric) embossing will produce more perfect effects than ordinary cold embossing, although cold embossing is good enough for the purpose of box wrappers in many instances.
It should be understood that the Hartford Electric Heater will do for both hot and cold embossing, as it is an excellent device for holding and registering embossing plates.
Cold embossing means simply that no heat is applied to the embossing plates.
The embossing plate, or female die, is usually made of brass, and it contains an intaglio reproduction of the printed subject which is to be embossed. When the embossing plate is to be used on a platen press in the same way as a form of type, the plate is made type-high and is locked up in a chase with furniture and quoins in the usual manner. When the embossing plate is to be attached to a patented base, like the Hartford Electric Heater, the plate is not made type-high, but just high enough to allow for the thickness of the patented base.
MAKING THE MALE DIE, OR COUNTER DIE, FOR EITHER
HOT OR COLD EMBOSSING
The male die, or counter die, for either hot or cold embossing, is made in the same way, as follows:
First, the inking rollers are removed from the press. A regular embossing press, of course, has no inking rollers.
Second, the chase (or patented base) containing the female die is placed on the press. If an electric heater is used, the electric current is turned on immediately so that the embossing plate will become heated while the counter die is being made.
Third, all tympan sheets are removed from the platen of the press, and in place of these a sheet of straw-board or news-board, about one inch larger on all four edges than the sheet that is to be embossed, is glued to the surface of the platen with LePage glue.
Both platen printing presses and regular embossing presses of the Hartford or John Thomson type have removable steel platen plates which are used for either cutting and creasing work, or embossing work. The counter die is made ready on the platen plate instead of being made ready directly on the platen of the press. When printing is done on a Hartford or John Thomson press—a printing press—the steel platen plate (held by counter-sunk screws) is removed.
On all other platen printing presses there is no removable steel platen plate, and when cutting and creasing, or embossing, is to be done, the counter die is made directly on the platen.
In all cases of cutting and creasing, or embossing, a sheet of straw-board or news-board is glued to either the platen of the press, or to the steel platen plate, as the case may be. The counter die is then constructed on this sheet of straw-board or news-board.
Fourth, the next step in making a counter-die for embossing is inking the face of the female die with black printing ink, applying the ink with a hand roller, and then printing an impression of the female die on the sheet of straw-board or newsboard. This impression will show where the embossing composition is to be placed.