Patent GB-950638-A (GB)
Title: Process and apparatus for finishing fabric tube
IPC: D21F1/00
Filed: 1961-04-14
Abstract: 950, 638. Finishing fabrics; treating fabrics. FORMEX Ltd. April 14, 1961 [April 18, 1960], No.13490/61. Headings D1L and D1S. An endless band of fabric of synthetic material, e.g. nylon, is moved longitudinally thereof through an endless path, is stretched both longitudinally and transversely and is subjected to a further finishing treatment. The fabric is stretched longitudinally by rolls 10,12 either or both of which are driven and which are pivotable in a vertical plane at 24, 30 to facilitate threading the fabric therearound. The bearings 26, 28 of the roll 12 are supported on a carriage 32 comprising a U-shaped frame 60 connected by a web 58 to a driving portion 34 supported on rollers 36 which run on fixed rails 38,40. The portion 34 drives a shaft 44 having gears 50, 52 fixed thereto to mesh with racks 56, 54 respectively so that the roll 12 may be moved towards or away from the roll 10 on rotation of the shaft 44. The transverse stretching of the fabric is performed upon the lower reach 14b thereof by endless tenter chains 62, 64 mounted on supports 66, 68 having brackets 70, 72 depending therefrom to co-operate with threaded portions 74, 76 of interconnected shafts 78 rotatable by a motor (not shown) or a handwheel 81 to adjust the distance between the chains 62, 64. The chains are driven at a constant speed irrespective of the lateral position thereof and pass around idler sprockets 108,110 carried on extensions 104,106 pivoted on shafts 112,114. Each extension 104, 106 comprises an edge sensing device 126 including a hollow body 128 connected to a source of air. The edge 14c of the fabric causes a change in pressure within the body depending on the extent to which the edge overlaps an aperture 132 therein. The pressure change causes the extension 104 to pivot to maintain a constant relationship between the aperture 132 and the edge 14c. A plate 134 lifts the edge 14c to hold it clear of the tenter pins 82 which are travelling around the sprocket 108. A circular brush 133, Fig. 4 (not shown),then presses the edge 14c on to the pins 82. Each chain 62, 64 comprises a sprocket chain 142, Fig. 5, having a plate 144 secured to each link thereof and which carries the pins 82 which are slightly canted. An overhanging portion 154 of a retainer 146 prevents the plate 144 from tilting inwardly due to the fabric tension. Before the fabric passes between the chains 62, 64 it may be coated or impregnated, e.g. with synthetic resin by liquid applied by rollers 168,170 which may be driven from troughs 164,166 which are pivoted about shafts 156,158 to bring either one of the rollers into contact with the fabric. Alternatively, neither roller engages the fabric. The rollers may be replaced by a brush or spray. A powder or gas may be used to treat the fabric. Heaters 172, 174 are provided between, but beneath, the chains 62, 64 and are carried by a frame 176 adapted to be raised and lowered by at least one piston rod 178. In a modification, Fig. 7, the fabric is heated whilst it passes between the tenter chains by units 200,202 having outlets 204,206 which direct a uniform flow of the heating medium upwardly to hoods 210, 212 which receive the heated gas for recirculation thereof. A cooling unit 214 having a hood 218 is also provided. The units 200, 202, 214 may also be used to coat or impregnate the fabric with gas. To prevent the upper reach 14a of the fabric from sagging rolls 220 are provided. A fabric spreader positioned near the roll 10 comprises a roll 222 comprising a freely rotatable, flexible jacket 224 carried on a bowed bar 225 secured against rotation in bodies 226. The roll 222 is mounted on a stand 230 and adapted to be raised and lowered by rotation of a pinion (not shown) in a housing 224, the pinion meshing with rack teeth 238. The rolls 10,12 and chains 62, 64 are initially driven at a slow speed to facilitate inspection of the fabric as it passes over the roll 10. Initially the fabric is advanced through the apparatus with the rolls 10,12 so spaced that the path is less than the required finished length, to which length the path is adjusted after the fabric has been aligned. The fabric may be cut to the desired width whilst on the apparatus by a hot knife or rotary slitting blade to cut the edges consecutively or simultaneously and positioned between the last heater and the roll 12 or used against the surface of the roll 10 or roll 12. The apparatus may be used for the finishing of Fourdrinier cloths used in paper making machines.