| 摘要 |
<p>Moulding/tempering of glass sheets of less than equilibrium thickness i.e. the thickness to which it will spread under the sole influence of its surface tension and gravity on a non-wetted surface, by (a) periodically introducing a suitable volume of molten glass into the cavity of a mould, not wetted by molten glass and with dimensions and shape as required for the finished sheet and which is placed in an enclosure heated to the temp. of molten glass, (b) modifying the shape of this volume of glass by a forming tool so that it covers the bottom of the mould and is in continuous contact with the surrounding lateral surfaces, in such a way as to create a pre-form, thinner in its central zone and thicker in its marginal zones than the molten sheet to be produced, (c) simultaneously withdrawing the forming tool and establishing a gas pressure above the liquid glass pre-form above atmospheric and such that the sheet of motel glass can be in equilibrium while covering the bottom of the mould, (d) hardening (solidifying) the molten glass sheet to fix its thickness and finally transferring the hardened sheet to another compartment in which it is energetically cooled to ensure that it is tempered.</p> |
