| 摘要 |
<p>1397652 Composite films LA CELLOPHANE 5 Jan 1973 [11 Jan 1972 18 May 1972] 795/73 Heading B5B Apparatus for the production of composite films by co-extruding liquid film-forming compositions through a flat extrusion die comprises a chamber behind the die 1 and a cylindrical feed pipe 2 leading into the chamber in which feed pipe is fitted a flow regulating device comprising a partition 6 mounted on a member 7 so as to be freely rotatable about the axis of the pipe so enabling the angle between the plane of the partition and that of the die to be altered, and hence the angle of the plane of separation of the polymer compositions supplied via channels A and B. Fig. 6A (not shown) shows the partition (6) end-on. According to the orientation given to it, member (7) can be given any position between the two extremes shown in broken lines. Fig. 7 shows a device comprising two partitions 6 and provided with an extra feed channel C and Fig. 8 (not shown) a device with three partitions and two extra feed channels. The apparatus of Fig. 14 utilizes two of the flowregulating devices in series, each being independently rotatable so that each can be oriented both relative to the other and to the lips of the die, and so arranged that the flow from the upstream device may pass either into the middle region or into the side regions of the downstream device. This enables both laminated and juxtaposed films to be obtained, and films which may be laminated and over only part of their width or even not at all. Edge portions of a film may be made of lower grade polymer, or contain recovered waste material. Polymer melts B and C are supplied via side channels 12 and 13 and polymer melt A via a central channel 14 located in rotatable member 15. (For clarity the part of the device above the broken lines has been turned through 90 degrees so that channels 12 and 13 are seen in profile.) Alternatively, four polymer melts may be supplied using a device of the form of Fig. 8 (not shown). Threaded ring 27 connects this device to a similar device consisting of a cylindrical body 28 provided with partitions 19 which can be rotated inside cylindrical body 20, which is attached by threaded ring 24 to feed pipe 21 leading to the extrusion nozzle. A polymer melt D, intended to form the edges of the film, or alternatively two melts D and E, are supplied through side channels 22 and 23, and distribute themselves on either side of the composite melt of the polymers A, B and C.</p> |
