Patent GB-1332081-A (GB)
Title: Method and apparatus for manufacturing webs or sheets of synthetic material from strips joined together along their edges
Inventor: BLOSE W
IPC: B29C48/00
Filed: 1971-07-21
Abstract: 1332081 Moulding films and sheet material; seaming; laminates WEILL & REINEKE GmbH 21 July 1971 [7 Aug 1970] 34093/71 Headings B5A B5B B5N and B5K A strip of material in a plastic condition, e.g. P.V.C. or uncured rubber material, is deposited on to a support surface from depositing means which reciprocatingly transverses across the surface in a direction transversely of that in which the support surface is incrementally unidirectionally displaced, intermediate each depositing transverse, so that the strip is successively deposited along the length of the support in contact at abutting or overlapping adjacent edges at which joining is effected to form a continuous sheet, e.g. by bonding by adhesive, or by fusion of material in a hot plastic condition. The depositing means may comprise a carrier for a reel of unvulcanized rubber. Deposition may be effected during movement of the depositing means in only one of its directions of transverse but, in the described embodiment, is effected on a conveyer belt, or on a rotary drum 4, parallel to the axis thereof, from the die 2 of an extruder 1 which deposits a hot, plastic P.V.C. strip during both directions of its transversing movement effected, against positionally adjustable stops, along rails 3. Joining of the overlapping strip edge on the drum 4 is effected by a pressure roller 7 carried on each side of the die 2, and extrusion may be halted at each end of the transverse during advancing rotation of the drum 4 on support rollers 5. The surface of the drum 4 on which the strip is to be laid is heated by gas burners 11, and the deposited strip is maintained hot or further heated on the drum 4 by radiators 12. A screen 15 prevents the access of hot air to a region in which cooling is effected, by means 16 blowing cold air or spraying cold water against the drum 4, which may also be provided internally with cooling means. The rounded strip edges arising from the changing transverse of the extruder 1 are trimmed by a rotating cutter 17 and the sheet removed from the drum 1 may then be levelled at its edge by a milling device 19 and/or may be perforated by a punching device 20 and cut by a saw 21. In the Fig. 3 embodiment, the strip 6, which is deposited from the die 31, is also provided adjacent its overlapping edge with a profile strip 25 extruded from a further orifice 26 of the die 31, the strip 25 and the overlapping edge being profiled, e.g. to dovetail configuration and joined by pressure from a shoe 27 which is carried by the die at 30 and which may also be simultaneously displaceable transversely of the direction of die movement to profile accordingly. The process may be used to coat a woven web; the device 14 of Fig. 1 may comprise rollers for profiling the surface of the sheet, or a device for laminating a web to the sheet, or for attaching a fleece surface, or bristles, to the sheet. The sheet may be of varying thickness effected by variation of the ratio between extrusion and traversing speed, and the thickness may be varied along each deposited strip length. The sheet may also be configured by profiling of the support surface on which it is deposited.