GB762327A - Improvements relating to machines for forming random fibre webs - Google Patents

Abstract

762,327. Forming fibre webs. CURLATOR CORPORATION. Aug. 19, 1954 [March 10, 1954], No. 24171/54. Class 120 (1). A machine for forming a non-woven fibre web comprises a toothed rotor projecting into an air duct intersected by a movable foraminous condenser of the same width as the duct, a fan for effecting by suction air flow between the rotor and the condenser, means for conveying air from the pressure side of the fan to the rotor, a plurality of partitions disposed in the duct ahead of the rotor for dividing the duct into a plurality of channels and means in each channel for controlling the speed of air flow therethrough to control the thickness of deposit of fibres across the width of the condenser. In one embodiment Figs. 1, 2, a duct 267 is divided transversely into eight channels by thin plates 320, the flow of air in each channel being controlled by an adjustable venturi device formed by a fixed sheet 321 and an adjustable sheet 323. Duct 267 is connected at the lower end to the pressure side of a variable speed fan 222 and at the upper end to a duct 269 leading past a saw-toothed lickerin 155 to a rotary foraminous condenser 165. In this embodiment, fibre is fed in sheet form to lickerin 155 by a hopper feeder 20 comprising a slatted floor conveyer 27, a pinned elevating conveyer 40 and a pinned stripping apron 50. Fibre in the hopper is shielded from apron 50 by a plate 127. Conveyer 27 is driven intermittently from conveyer 40, at a variable relative speed, by means of an eccentric, variable crank and one way clutch mechanism. Fibre is doffed from conveyer 40 by suction from a rotor foraminous condenser 85 connected to a fan 70, the air flow being controlled by a damper 135. Fibre is formed into a web between condenser 85 and rollers 101 to 106 of which 101 to 104 are driven and 105 and 106 are idlers ; the web is fed downwardly between rollers 103, 104 on to a feed plate 130 whence it is fed by a feed roller 152 to lickerin 155. Fibre is doffed from the lickerin by the air stream in duct 269 as it passes at high speed between the lickerin and an inverted V-shaped member 305, which can be removed for cleaning. The lower surface of duct 269 on the feed side of the lickerin is freed from dust &c. by compressed air from a tube 335, Fig. 2. The upper surface of duct 269 on the delivery side of lickerin 155 comprises an adjustable sheet 275 of transparent plastic which tightly engages, adjacent the lickerin, a doffing bar 298 which can be manually rotated to avoid collection of fibre thereon. The condenser consists of an outer fine wire screen 166, Fig. 7, for web formation and an inner, coarse mesh, heavy wire screen 167 for supporting purposes. The ends of the two screens are connected to internal gear rings driven by pinions on a shaft 172. Upper and lower spacers 180, 181 provide a duct through the condenser, spacer 181 having a catcher 200 to catch any fibres drawn through the condenser screen. Removable end plates provide access to the inside of the condenser. Condenser 85 is constructed similarly to condenser 165. From condenser 165 ducts 261, 260 lead back to fan 222, providing a closed recirculating system. The web formed on condenser 165 passes beneath a roller 215, driven at a slightly higher peripheral speed than the condenser, and is delivered on a conveyer 340. In another embodiment, Fig. 15, air from condenser 165 passes into a chamber 352 and is delivered under pressure by two fans 355 into a duct 376 leading into an expansion chamber 351 ; the upper part of chamber 351, leading to the lickerin, is divided transversely by plates 380 into passages controlled by sheets 382. A door 385 in chamber 351 permits removal of dirt which settles therein. The V-shaped duct member of the previous embodiment is replaced by a tube 360 which is rotatable or removable for cleaning.