Patent GB-1134684-A (GB)
Title: Improvements in the manufacture of a sheet of thermoplastic fibres for example glassfibres
IPC: D04H1/72
Filed: 1966-01-20
Abstract: 1,134,684. Forming fibre sheets; fibrous fabrics. COMPAGNIE DE SAINT-GOBAIN. 20 Jan., 1966 [21 Jan., 1965], No. 2646/66 Headings D1F, DIN and D1R. A sheet is made from filaments of thermoplastic material by conducting a group of substantially parallel filaments 3 through a zone of low pressure to bring the filaments in the form of fibres into contact with an attenuating drum 4; conducting the fibres 3 through a zone of high pressure to apply them against the drum 4 to cause them to be entrained by the drum 4; detaching the fibres 3 from the drum 4 before they have made one revolution thereon, such detachment being caused by the action of a current of gas previously used for applying the filaments 3 against the drum 4; and regulating the width of the group of fibres 3 by modifying the width of the current of gas. As shown, glass filaments 3 are spun from nozzles 2 of a spinneret 1 and drawn onto the rotating drum 4 of axial length greater, preferably 60%, than that of the spinneret 1. Arcuate guides 5,6 having upturned edges 7,8 are movably mounted over part of the drum periphery. A nozzle 9 is mounted between the guides 5,6 and directs a current of gas between the guide 6 and the drum 4 to produce the low pressure zone between the guide 5 and the drum 4. An inclined rectangular deflector plate. 10 changes. the direction of the air so that fibres detach themselves from the drum 4 before contacting the lower edge of the plate 10. A flexible plate 11 adjacent the guide 6 cooperates with the plate 10 to accelerate the air carrying the fibres 3 and is adjustable towards and away from the plate 10. Lateral dampers (12), (13), Fig. 2 (not shown), are secured to the plate (11) by brackets (14) and are adjustable relatively thereto manually or mechanically. The distance between the dampers (12), (13) determines the width of the sheet of fibres (17), Figs. 3-5 (all not shown), formed on a guide 15 which may be provided with a conveyor belt above the plate 10. Side parts 16 of the guide 15 are adjustable according to the required sheet width which may be up to 20% greater than the axial length of the drum. To form a narrow band of fibres, Fig. 6 (not shown), the dampers (12), (13) are inclined to the plate (11). The latter embodiment may be used to reinforce a sheet already formed, or in the course of being formed, on a conveyor belt by conveying to it a narrow band of fibres essentially arranged in only one direction. In a modification, Fig. 7 (not shown), lateral air turbulence between the spinneret and the drum (4) is eliminated by a wall (20) having lateral plates (21) at an angle thereto extending to the inlet of a suction duct (22). The upper part (24) of the wall (20) is made of asbestos. In a further modification, Figs. 8 and 9 (both not shown), a pressure compensation chamber is formed between the spinneret (1) and the drum (4). The chamber comprises walls (30), (31), (32), (33). The wall (31) may be of glass and is removable or openable. Perforated shields or diaphragms (36), (37) divide the chamber into three zones. Openings (38) having shutters (39.) of adjustable inclination are provided in the central zone.