Saint-gobain Vitrage International

Dany-Ange Plebani

Denis Mathivat

Philippe Boutier

Jean-Marc Petit-Collin

Christophe Machura

Jean-Marc Petitcollin

Philippe Girard

Plastic sheets of good optical quality suitable for use in the glazings of automotive vehicles, eye glasses etc., are made by depositing a hardenable liquid mass upon a taut moving ribbon of plastic which has been pretreated by tensioning and heating to remove wrinkles and creases which otherwise would render optically unsatisfactory the sheet formed on the ribbon upon hardening of the liquid mass. The temperature range within which the pretreatment should be conducted is 60.degree.-100.degree. C., with 70.degree.-90.degree. C. being preferred; the tension applied in the pretreatment should be a dekanewton or more per square millimeter, preferably 1.5-7.5 dekanewtons per mm.sup.2 ; and the time of pretreatment is at least a minute and preferably 5 or more minutes. The lateral tension is preferably applied by means of pairs of opposed idler rollers positioned along the opposite side edges of the moving ribbon and biased toward each other to pinch the ribbon between them, with their axes angled outwardly by a few degrees from a direction normal to the direction of travel of the ribbon. The pretreatment heating is preferably applied in two successive ovens providing successive temperatures of about 70.degree. and 90.degree. C., respectively.

Method for the manufacture of plastic sheets of good optical quality

The invention relates to a production line for curved panes, in which the panes of glass are heated, brought in a horizontal position into a curving station where they are taken over by curving tools, and then finally conveyed into a quenching station, the stages of quenching and of entry of the glass into the curving station being at different heights.

Method and apparatus for producing curved panes having a two-level

The invention relates to a production line for curved panes, in which the panes of glass are heated, brought in a horizontal position into a curving station where they are taken over by curving tools, and then finally conveyed into a quenching station, the stages of quenching and of entry of the glass into the curving station being at different heights. Defective glass sheets are removable from the production line intermediate the curving station and the quenching station by cracking with an atomized fluid jet and subsequent crushing.

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Thourotte, France

Dany-Ange Plebani