GB657293A - A method and apparatus for forming ribbons of glass and similar plastic material - Google Patents

Abstract

<PICT:0657293/IV (a)/1> <PICT:0657293/IV (a)/2> <PICT:0657293/IV (a)/3> <PICT:0657293/IV (a)/4> A ribbon of organic thermoplastic or thermosetting material is made, the ribbon being thicker than is desired in the finished form, and is then passed between opposed cooling members which vibrate rapidly to and from each other and reduce the thickness of the ribbon. Fig. 1 shows an apparatus comprising a tank 10 from which a ribbon of thermoplastic material 14 is drawn by rollers 15, the ribbon being flattened, whilst it is setting, by rapidly-reciprocating hollow cooled platens 16. The platens are carried by sliding brackets 20 which are reciprocated by cranked shafts 22. In another arrangement (Fig. 4, not shown) the feed is vertically downwardly from the tank and the ribbon, after having been pressed between vertically-arranged cooled reciprocating platens, is bent around a roll and carried away horizontally. Fig. 5 shows two curved platens, the platen 51 being stationary and the platen 50 being reciprocated by an eccentric 55; or both of these platens may reciprocate. If the material to be sheeted is thermosetting, the platens are heated. The platens may be of thin metal reinforced internally by struts. The Specification as open to inspection under Sect. 91 describes also the production of sheets, and states that continuous prisms may be formed on one face of the ribbon by using a platen 441, Fig. 7 (Cancelled), having a suitably-shaped forming surface 46; and that the arrangement shown in Fig. 5 (Cancelled) may be used, in which molten material 38 passes under a control gate 39, between sheeting rolls 41, 42, over rolls 43 and between horizontally-arranged reciprocating platens 44, 441. This subject-matter does not appear in the Specification as accepted.