US3037248A - Apparatus for forming fibrous materials into a web - Google Patents

Description

June 5, 1962 E. CALLAGHAN 3,037,248

APPARATUS FOR FORMING FIBROUS MATERIALS INTO A WEB 2 Shegts-Sheet 1 Filed Aug.

INVENTQR 445527 [bl me 6444mm ATTORNEY June 5, 1962 Filed Aug. 10, 1959 A. E. CALLAGHAN 3,037,248 APPARATUS FOR FORMING FIBROUS MATERIALS INTO A WEB 2 SheetsSheet 2 INVENTOR ALBERT Eon Aw CALL/JGHAN QM Jim ATTORNEY United States Patent C) London, England Filed Aug. 10, 1959, Ser. No. 832,854 2 Claims. (Cl. 19-156) This invention relates to apparatus for forming fibrous materials into a web.

According to the invention, the apparatus for forming fibrous materials into a web comprises upper and lower condenser rolls disposed in nipping relation one above the other and each having a gas-pervious peripheral surface, a casing in which the rolls are mounted, a blower, ducting leading from the blower to part of the casing adjacent to the entry of the nip between the rolls, means defining portions of the peripheral surfaces of the rolls before the nip which are open to the ducting, means for delivering fibrous material into the ducting to be carried by the blower blast to said surface portions of the rolls which retain the material while the blast passes to the roll interiors, and adjustable resilient means supporting the upper roll to be rotatable about an axis movable in a plane containing the axis of the lower roll so that in use the weight of the upper roll is partially counterbalanced by said resilient supporting means.

The apparatus of the invention will be now more particularly described with reference to the accompanying drawings in which:

FIGURE 1 is a somewhat diagrammatic view of an embodiment of the invention, and

FIGURE 2 is a detail view of the roll-mounting arrangement of a slightly modified construction.

The apparatus shown in FIGURE 1 comprises a blower 1 in the form of a centrifugal fan having a rotor 2. From the peripheral outlet of the blower, ducting 4 reads generally horizontally from the blower casing 3 to a casing 5 for a pair of rolls 6, 7, each of which has a gas-pervious peripheral surface (the rolls 6 and 7 are hereinafter termed condenser rolls). The ducting 4 has an inlet opening on its upper side for fibres to be treated by the rolls 6, 7. This inlet opening is the outlet from a rotary opening machine 9 having an opener drum 10 and shroud 11. Fibres are supplied to the machine 9 in a raw form requiring an opening operation to produce fibrous material suitable for condensation on the rolls 6 and 7.

The ducting 4 is of rectangular cross-section and tapers from the blower outlet to a part 8 of smaller crosssection extending to the near edge of the outlet from the machine 9. From the far edge of the outlet, the upper wall 12 of the ducting 4 is inclined downwardly at a slightly angle to the casing 5. The lower wall 13 of the ducting has a humped shape similar to the upper surface of an aerofoil. Thus, the ducting 4, between the machine 9 and the casing 5, first gradually narrows and then opens out steeply.

One of the condenser rolls 6 lies about centrally below, though spaced from, the junction of the upper wall 12 of the ducting 4 with the casing 5. The steeper part of the wall 13 of the ducting 4 curves into the casing 5 beside, and slightly spaced from, the upper part of the roll 6. The other condenser roll 7 is disposed above and partly forward of the roll 6, a line through the axes of the two rolls being inclined at about 50 to the horizontal.

The casing 5 for the condenser rolls includes a hood 5a which enclose the upper part of the roll 7. The casing 5 also includes a hood 5b disposed below the lower lice roll 6 and enclosing the lower part of that roll. These hoods 5a, 5b are for leading away blower blast air from the interiors of the rolls 6, 7 and are connected to return circuit ducting 13' leading back to the entry of the blower 1.

The opening machine is constructed for feed of the material to be treated to take place between two pairs of feed rolls, respectively 14 and 15, mounted as a set disposed directly above the opener drum 10. The drum has a spiked periphery which, in some cases, may be fitted with slats to reduce the effective length of the spikes. The lower pair 15 of the feed rolls is arranged in an opening in the upper part of the shroud 11 of the drum 10. The upper pair 14 of feed rolls are of larger diameter than, and are arranged directly above, the first pair 115 in a casing part 16. This casing part 16 has a short hopper 17 at the top to which the material to be opened is fed by an endless feed belt v18. A slatted roller 19 is fitted above the mouth of the hopper 17 adjacent to the delivery end of the feed belt 18 to assist charging of the hopper.

The shroud 11 of the spiked drum 10 forms a casing for the latter and curves concentrically about the drum. At one side 11a, the shroud curves from the bottom of the feed roll casing part 16 to the near edge of the opener outlet. On the other side 1111, the shroud curves from the bottom of the casing part 16 to the far edge of the opener outlet. The shroud 11 is made so that the radius of the curved rear part :11a is larger than that of the curved front part 11b, the latter lying relatively close to the tips of the spikes on the drum 10. The drum 10 suitably has shrouded ends and may be driven in either direction.

It is important to define the portions of the peripheral surfaces of the condenser rolls 6, 7 on which fibres are to be deposited. in FIGURE 1, projecting felt seals 21 are provided at the junctions between the upper and lower walls 12, 13 of the ducting 4 with the casing 5. The seals 21 present their free edges to the peripheral surfaces of the two condenser rolls 6, 7, and that portion of the surface of each roll which extends from the free edge of the respective seal 21 to the nip of the rolls 6, 7 constitutes the surface portion onto which the fibres will be deposited from the blower blast. 0n the other side of the rolls is and endless take-away belt 22 supported on rollers 23 and 24, the former of which is adjacent the nip of the condenser rolls 6, 7. Between this one roller 23 and the lower condenser roll 6 is another felt seal 25 mounted on one side of the lower hood 5b with its free oppositely facing edges presented respectively to the roller 23 and to the roll 6. Also, at the corresponding side of the hood 5a is a further felt seal 26.

On the entry side of the condenser rolls 6, 7, the seals 21 determine the portions of the peripheral surfaces of the rolls lying before and up to the nip of the rolls onto which the fibres are deposited. On the exit side of the rolls 6, 7, seals 25, 26 are set substantially to allow effective take-up of the web discharged from the rolls 6, 7 by the take-away belt 22.

The modified machine of FIGURE 2 is generally similar to the machine already described, the main difference being that the upper roll 7 is resiliently mounted directly above the roll 6. As before, the rolls are provided with hoods of which only the upper one 5a is shown in FIGURE 2 and the hoods are provided with seals of which only the upper pair 21, 26 is shown.

The lower roll 6 is rotatably mounted in a fixed hearing pedestal 30 whereas the roll 7 is rotatably mounted in a bearing block 31 which can slide freely between fixed vertical guide rails 32. The stub shafts 33, 34 of the 3 rolls 6, 7 respectively are connected by caliper arms 35 which are pivotally interconnected in diamond linkages with one pair of diagonally opposite corners pivotally mounted about the shafts 33 and 34. Thus the caliper arrangement enables the upper roll 7 to float in the vertical direction while resting on the web of fibres in the nip between the rolls. The other pair of diagonally opposite corners of each linkage are connected by a spring-loaded device 36 provided with a thumb-nut adjustment 37. This device 36 acts to counterbalance some of the weight of the upper roll 7 and hence decreases the pressure of the latter on the web of fibres.

Both rolls are of the same diameter and comprise an outer cylindrical shell formed from perforated sheet metal fixed to annular end plates 38 which are mounted on the stub shafts 33, 34, the latter as shown being hollow. A baffle plate 39 is mounted within each of the rolls 6, 7 to shroud a rear arcuate portion of the inner eriphery thereof. Each baffle plate 39 is mounted, as illustrated in FZGURE 2 only for the upper roll 7, on ribs 40 welded to a central shaft 41 which is rotatably mounted in the hollow stub shafts 33 or 34. The shafts 41 each project at one end at which they are connected to adjustment levers such as 42, which are locked in position by set screws such as 43.

The bafiie plates 39 shroud the peripheral portions of the rolls 6, 7 between the nip of the rolls and the seals 25 and 26 respectively to isolate the suction within the rolls from atmosphere at the rear of the latter.

Pulleys 44 are mounted on the stub shafts 33, 34 at one end of the rolls 6, 7 and a common driving belt 45 engages these pulleys and is also guided around fixed guide pulleys 46. This arrangement provides a common drive for the two rolls 6, 7 which allows relative movement of the rolls without interrupting the drive.

In the operation of both arrangements, fibrous material fed by way of the feed rolls 14, 15 to the opening machine 9 is treated by the spiked drum 10 in such a way that the material is broken up and separated largely into individual fibres which are delivered from the opener outlet and taken up in the blast of air from the blower 1. The constriction of the blower ducting at 8 towards the near edge of such outlet imparts increased velocity to the blast. Beyond that edge, the opener outlet extends through an angular extent of some 60 to 70 up to the upper wall 12 of the blower ducting 4 so that there is a region of increased cross-section in the ducting 4 adjacent to the fibre inlet thereto. This increased cross-section allows the blast to slow down sufficiently and to take up the opened fibres in a substantially evenly distributed condition. The velocity of the blast then gradually increases in the constriction of the ducting 4 over the humped part of the lower wall 13 thereof, so as to assist in drawing away the fibres from the opener outlet. The fibres pass over the aerofoil-shaped humping and are then deposited on the peripheral portions of the rolls 6 and 7 between the seals 21 and the nip between the rolls. In the meantime the suction set up in the hoods a, 5b owing to their connection through the return ducting 13 leading to the fan inlet withdraws air from the interiors of the condenser rolls 6, 7 while assisting the deposit of the fibres on said peripheral portions of the rolls.

By depositing an even layer of the fibres on said portions which are presented to the fibres delivered by the blower blast, the fibres can be effectively intermingled as they pass through the nip between the two rolls. At this stage, the deposited fibres are given a slight compression, but there is a natural recovery of the fibres on ejection from the nip when the fibres possess a natural resilience.

It will be understood that by increasing or decreasing the pressure and velocity of the blower blast, heavier or lighter cohesion of the fibres is possible, as the case may be.

With the arrangement of FIGURE 2, in which the upper condenser roll 7 floats vertically while resting on the web of fibres in the nip between the rolls 6, 7, the peripheral speed of the rolls controls the build up of material being processed thus controlling the ultimate thickness of the web or padding being formed.

Owing to the introduction of suction within the hoods 5a and 5b at a region surrounding the top part of the upper condenser roll 7 and the region surrounding the bottom part of the lower condenser roll 6, any unpleasant dust present will tend to be eliminated, the dust being sucked through the condenser rolls 6, 7 to the intake of the fan 1.

It has been noted that most animal fibres have a tendency to felt naturally when approaching one another and this, added to the separation of the initial fibres and a mechanical joining which takes place at least of some of the fibres at the nip of the condenser rolls 6, 7, enhances the lateral and longitudinal strength of the end product. It can also be said, in taking a given weight of initial fibrous material, that by separating the individual fibres in that weight and controlling the fibres in the manner aforesaid in their flight to the circumference of the condenser rolls, a considerable joining of the fibres is apparent in the end product which gives desirable cross and lengthwise strengths to webs made up from such end product.

The product emerging from the condenser rolls 6, 7 is removed by the delivery belt 22 and is a material which can be used as padding or stufiing or may be subjected to further treatment to produce non-woven webs, carpet underfelt, heat-insulating material and other useful products.

The apparatus of the invention is advantageous in the treatment of mineral and animal fibrous materials or fibres of, for example, asbestos and leather. It is also useful for the treatment of vegetable and synthetic fibrous materials and fibres of, for example, paper, wool, flax, cotton, jute, coir, cellulose acetate and rayon.

I claim:

1. Apparatus for forming fibrous materials into a web comprising upper and lower condenser rolls disposed in nipping relation one above the other and each having a gas-pervious peripheral surface, a casing in which the rolls are mounted, a blower, ducting leading from the blower to part of the casing adjacent to the entry of the nip between the rolls, means defining portions of the peripheral surfaces of the rolls before the nip which are open to the ducting, means for delivering fibrous material into the ducting to be carried by the blower blast to said surface portions of the rolls which retain the material while the blast passes to the roll interiors, and adjustable resilient means supporting the upper roll to be rotatable about an axis movable in a plane containing the axis of the lower roll so that in use the weight of the upper roll is partially counterbalanced by said resilient supporting means.

2. Apparatus for forming fibrous materials into a web comprising upper and lower condenser rolls disposed in nipping relation one above the other and each having a gas-pervious peripheral surface, a casing in which the rolls are mounted, a blower, ducting leading from the blower to part of the casing adjacent to the entry of the nip between the rolls, means defining portions of the peripheral surfaces of the rolls before the nip which are open to the ducting, means for delivering fibrous material into the ducting to be carried by the blower blast to said surface portions of the rolls which retain the material while the blast passes to the roll interiors, stub shafts on which the rolls are mounted, a pivoted link system interposed between the stub shafts of the rolls at each end thereof, each link system comprising two pairs of calliper arms arranged in diamond formation with one pair of diagonally opposite corners being connected to the stub References Cited in the file of this patent UNITED STATES PATENTS Lummus Sept. 28, 1880 Sewell July 10, 1883 Harney Dec. 1, 1931 10 6 Thomas May 22, 1934 Aldrich July 13, 1937 Buresh et a1 Ian. 25, 1955 Kozrna Oct. 7, 1958 Buresh et a1 Mar. 10, 1959 FOREIGN PATENTS Canada June 10, 1958 Great Britain June 15, 1938 Great Britain May 7, 1947

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