| 摘要 |
1,095,705. Sheeting P.V.C. SOMMER S.A. Dec. 17, 1964 [Dec. 18, 1963], No. 51336/64. Heading B5A. In the manufacture of gelled plastic sheets or plates, an unsupported layer of uncured polyvinyl chloride plastisol paste is deposited by means of a feeding device on to a rotary internally heated roll on which the layer is gelled while it is at its final dimensions. As illustrated in Fig. 1, the feeding device comprises a doctor 1 which spreads uncured plastisol paste 5 on to rotary roll 3 at peripheral position A to form a layer 4 which, after gelling, is removed from the roll at peripheral position B by auxiliary roll 9 to give sheet 10. To prevent pregelling of the plastisol paste, the doctor may be cooled, for example by circulation of cold water through cavity 2 formed therein. As illustrated in Fig. 2 (not shown), the feeding device comprises a single roll, whch may be internally cooled, acting as a rotary doctor; as illustrated in Fig. 3, the feeding device comprises two rolls 7 and 8, each of which may be internally cooled, rotating in opposite directions and together acting as a calender. The rotary internally heated roll preferably is heated to a temperature between 160‹ and 197‹ C., for example by means described in Specification 1,026,753. The layer may pass over at least one further rotary internally heated roll disposed after the rotary internally heated roll receiving the uncured plastisol layer; as illustrated in Fig. 4 (not shown), the layer passes around and in contact with a major portion of the periphery of each of a receiving roll and two further rolls before being removed by an auxiliary roll. The sheet or plate may be either formed, for example, with a hollow pattern, drawing or ornamental design, which subsequently is filled by an additional coating, or lined with a bedizened polyvinyl chloride sheet or film which is to constitute the wearing layer of the article when used as a lining. |
