Precision Glass Moulding - Process

Process

The precision glass moulding process consists of six steps:

  1. The glass blank is loaded into the lower side of the moulding tool.
  2. Oxygen is removed from the working area by filling with nitrogen and/or evacuation of the process chamber.
  3. The tool system is nearly closed (no contact of the upper mould) and the entire system of mould, die and glass is heated up. Infrared lamps are used for heating in most systems.
  4. After reaching the working temperature, which is between the transition temperature and the softening point of the glass, the moulds close further and start pressing the glass in a travel-controlled process.
  5. When the final thickness of the part has been achieved, the pressing switches over to a force-controlled process.
  6. After moulding has been completed, the glass is cooled down and the working environment is filled with nitrogen. When the lens has cooled to the point where it can be handled, it is removed from the tool.

The process is executed on a specialized moulding machine, which precisely controls the temperature, travel, and force during the process. The tools used must withstand high temperatures and pressures, and need to be resistant to chemical interaction with the glass. The mold materials also have to be suitable for machining into the precise surface profiles.

Read more about this topic:  Precision Glass Moulding

Famous quotes containing the word process:

    “The process of education in the oldest profession in the world is like any other educational process, in that it requires time and effort and patience; it can only be acquired by taking one step at a time, though the steps become accelerated after the first few.”
    —Madeleine [Blair], U.S. prostitute and “madam.” Madeleine, ch. 4 (1919)

    “The process of writing has something infinite about it. Even though it is interrupted each night, it is one single notation.”
    —Elias Canetti (b. 1905)

    “Because her instinct has told her, or because she has been reliably informed, the faded virgin knows that the supreme joys are not for her; she knows by a process of the intellect; but she can feel her deprivation no more than the young mother can feel the hardship of the virgin’s lot.”
    —Arnold Bennett (1867–1931)