US3453355A - Process for pneumatically tearing and parting fiber flocks - Google Patents

Description

PROCESS FOR PNEUMATICALLY TEARING AND PARTING FIBER FLOCKS Filed March 18. 1966 B- RUDLOFF July 1, 1969 Sheet B. RUDLOFF July 1, 1969 PROCESS FOR PNEUMATICALLY TEARING AND PARTING FIBER FLOCKS Sheet 2 of2 Filed March 18, 1966 INVENTOR BERNARD RUDLOFF mubqmI ATTORNEY.

United States Patent Int. Cl. imb 1/04 US. Cl. 264-115 6 Claims ABSTRACT OF THE DISCLOSURE A process for pneumatically tearing flocks of fibres by feeding the flocks through a confined space or tube, and upon leaving the space or tube, the flocks are impinged upon by one or more high speed jets of air to part the fibre flocks. Various modes and directions of the air jets as well as applying a resin and forming a mat are set out.

The present invention relates to a process for pneumatically parting fiber flocks, and to the manner of carrying out this process, more especially for the continuous conventional manufacture of unwoven felts of textile webs.

All the techniques known and carried out hitherto for opening up fibre wads and separating and individualising them for their preparation for spinning are carried out manually or mechanically, the wads being held and retained at one fixed point, on the one hand, and the tearing or parting of the fibres ensuring their opening being effected by a lateral reciprocating or circular movement, on the other hand.

It is known that the manual operation has been replaced little by little by the action of mechanical elements, feed tables presser cylinders, combs for the retention of the fibres and rotating cylinders or drums equipped with teeth and pins or combs with lateral movement for tearing into or parting of fibres.

Thus the opening up of wads of textile fibres and their separation are carried out nowadays mechanically and progressively by means of the conventional apparatuses such as beaters, cards, combers which ensure the' retention of'the fibres presented by a supply device tothe second group of machines, constituting the elements for tearing into fibres which are given either a rotational movement, as card breakers, card drums, comber heaters, or a lateral movement, as intersecting combs.

Now for certain manufacturing processes, and especially for the production of unwoven material, this fibreseparating system, being, a mechanical system, cannot give complete satisfaction 'by reason of the breakages of the fibres, by reason of being poorly adapted to the working of very short fibres, by reason of the limitation of the tangential speed of beaters equipped with pins or teeth which hardly permits of increasing the production of unwoven fleeces, the quality of which moreover depends upon good distribution of the fibres, perfect regularity of which these machines cannot ensure, and their coating with synthetic binders, whether liquid or in dry powder form, which is a function of the degree of separation of the fibres.

With the purpose of remedying these requirements in the manufacture of unwoven materials, the present invention proposes to replace the second group of mechanical elements by a pneumatic device for tearing into fibres with regulable pressure which is particularly adapted to the work of opening up flocks of any origins, without distinction of fineness, flexibility of fibre length, which can be of one single kind or short or can be mixed.

Thus it is one object of the present invention to provide a process for opening up and tearing into fibres textiles of any kind in flock form, designed more especially for the .production of unwoven materials, consisting essentially in causing air jets to act violently upon the cushions of fibres in flock form presented at the outlet of the supply device, in directions judiciously selected to effect, by introduction of air under regulable pressure into the flock, the tearing into fibres of these cushions, causing the fibres to fly individually as they are liberated from the engagement of the supply device.

It will be understood that by virtue of this pneumatic action, which acts upon flocks of fibres with a much higher speed while controlling the fibres, all risk of breakage being avoided and completely eliminated, the production of unwoven fleeces is much higher than that possible with the prior known processes. The variable pressure of the. air jets permits higher jet speeds than the tangential speeds of rotatable mechanical elements.

However the present process which permits opening up all textile flocks of any origin, without distinction as to the fineness, flexibility or length of the fibres. The process in particular permits the working of short fibres, for example 1 mm. in length. This obviously is of great technical interest and at the same time represents significant economical and rational progress in comparison with the most recent techniques.

Moreover it is important to point out that the process permits, by reason of the very high degree of separation of the fibres, fixing the fibres and distributing them with very great regularity on a conveyor belt, and enables coating by the synthetic binders utilised.

It is another object of the present invention to provide the carrying out of the process in the continuous manufacture of unwoven textile felts or webs by means of a system for opening up the textile fibres in flock form and their coating by' synthetic resins which are liquid, or in powder form, followed by polymerisation by baking, with possible incorporation of mineral or other charges and fire-proofing, including reinforcement with strands.

FIGURE 1 is a side elevation of the pneumatic device for opening up or parting of fibres, mounted at the end of a feed table;

FIG. 2 is a similar view, the supply of the fibre flocks being effected by an Archimedean screw;

FIG. 3 is a similar view, flocks being taken between two fluted cylinders;

FIG. 4 is a similar view, more especially for long fibres; and

FIG. 5 is a side elevation of the entire assembly for the continuous manufacture of unwoven fleeces or felts which can comprise one of the systems for pneumatic opening of the fibres according to FIGS. 1, 2, 3 or 4.

Referring now to the drawings, according to the present invention, the opening up of flocks of textile fibres and their separation are effected progressively by means of a pneumatic system replacing the conventional mechanical elements for tearing apart, having lateral or rotating movement, in which pneumatic system air jets act upon the flocks, the controllable air pressure being intro- 3 duced into the flocks, to cause the fibres to fly individually as they are liberated from the retention of the supply device.

In the drawings, as shown in FIG. 1, the pneumatic system comprises two parallel, juxtaposed and staggered air jets, acting vertically one against the other, which act upon the cushion of fibre flock 2 sliding over the fixed feed table 3 and delivered by the regulable-pressure fluted feed cylinder 1.

The flock is presented to a first pneumatic jet 4 which projects the liberated fibers downwards where they encounter the jet 5 which drives them upwards again.

The feed table 3 is of a special form. Its nose 3' is of concave, in-curved form in order to lay out the flock delivered by the cylinder 1 of the table 3 under the action of the jet 4 in the form of a tuft. This curvature has the purpose of deviating the jet 4 with the fibres which it detaches from the tuft on to the jet 5, which completes the opening up of the flock not yet opened and torn into fibres by the jet 4. The spacings 6 and 6 of the jets are adjustable by any conventional means.

By way of a variant, FIG. '2, when the flock is supplied by an Archimedean screw 7 within a tube 8, a nozzle 9 projects a jet of air under a pressure of 7 to 6 kg. violently on to the flock of fibres presented at the exit of the tube 8 at 10. A second jet of air under pressure issues from the tube 8 through the end piece 11 by way of the aperture 12 of an adjustable section. This second air jet, with adjustable pressure and delivery quantity, liberated at 12, projects the opened fibres forward as they are supplied by the screw 7.

According to still another variant, FIG. 3, the flock 2 supplied by the conveyor belt 13 beneath the equalising cylinder 14 is taken between the two feed cylinders 15 and 16, the upper cylinder being adjustable in pressure upon the lower cylinder. These two cylinders form the point of retention of the fibre flock which is opened out at the exit therefrom by the air jet issuing from the adjustable nozzle 17. The fibres thus separated under the action of the air jet fly ofl and are directed towards elements which subject the fibres to further treatment.

FIG. 4 shows another form of embodiment intended more especially for the pneumatic opening up of long fibres of 60 to 100 mm. mixed according to the need with short fibres of irregular lengths of from 5 to 50 mm. The flock of fibres 2 passing beneath the equalising cylinder 14 is brought by the conveyor belt 13 on to the feed table 3 having a concave, in-curved nose 3, and beneath the fluted feed cylinder 1 of regulable pressure, which feeds it and presents it to a cylinder 18 equipped with saw teeth, which rotates clockwise as indicated by the arrow 20, and mechanically tear the flock into fibres. The fibres thus opened up remain hooked in the toothing. A jet of air 19 under adjustable pressure and of very high tangential speed acts circumferentially on the cylinder 18 and causes the fibres to fly towards elements which later separate the fibres.

The incorporation of one or other of the forms of embodiment of the pneumatic system for opening up and tearing into or parting of fibres the flock of textile fibres in the installation effecting the continuous manufacture of unwoven textile felts or fleeces is illustrated by in FIG. 5.

This installation, which comprises a series of elements successively carrying out the manufacturing operations, comprises a charging device 22, into which the textile fibres are conducted by a pneumatic conduit 21, which charging device is composed essentially of an endless conveyor belt 23, the apron of which is equipped with pins 23, which in its ascending movement entrains clumps of fibres the quantity of which is determined by a con trolling roller 24, the distance of which from the apron is adjustable.

The fibres fall in tufts on to a horizontal endless conveyor belt 25 which carries them towards the position A where one of the pneumatic opening systems as described in FIGS. 1, 2, 3 and 4 is installed, whence they are brought by projection into a chamber 26, where the intimate mixing of fibres and resin is effected.

The fibres are blown into this chamber 26 by an air current 27, the direction of which is adjustable by means of direction-regulating devices 28, and the quantity delivered of which is controllable by means of a throttle 29. The open fibres are sucked on to the conveyor belt 30 by means of a suction box 31 fixed beneath the belt 30. The fibres are progressively superimposed and before their engagement between the belts 30 and 32, the device 33 of regulable height permits of their equalisation. This device 33 is in the form of a shoe and is provided with a nozzle through which a controllable air jet drives the fibres accumulating before it.

When using liquid resin, it can be introduced into the fibres by the air jets 4 and 5 of the pneumatic opening system according to FIG. 1. However by way of variant, at 34 in the chamber 26 there are provided nozzles introducing a mist of very finely atomised liquid resins into the chamber, which resins coat the fibres while they fly in the eddy which holds them for a certain time in suspension in the air, which time is adjustable by means of the circuit 35 mounted on the box 31 which places the chamber 26 under suction, by withdrawing a portion of air current 27.

'By means of the mechanical distributor 36 it is also possible to introduce mineral charges, such as barium sulphate, asbestos or others, which may or may not be mixed with synthetic resins in very fine powder form, into the eddy of fibres in the chamber 26.

An external air entry is provided in the top of the chamber 2 6 with adjustable flaps 37.

As the resin-coated fibres accumulate on the conveyor belt 30, a second conveyor belt 32 of adjustable height takes the fibre-resin mixture which is thus fed into the tunnel 38 for polymerisation. By means of belts 32 and 30 it is possible to form regular, more or less dense mats or cushions of fibres, with strictly flat surfaces.

The air current 27 can be heated in order to pre-heat the fibre-resin mixture.

A current of hot air is introduced by means of fans 39 into the polymerisation tunnel 38. This current passes through the fleece and furthermore can be directed either from the top downwards or from the bottom upwards or alternately in both directions, according to the nature, thickness and constituents of the finished product to be obtained. For the same reason, conventional speed-variation means (not shown) permits varying the speed of the endless belts 30 and 32.

At the exit from the tunnel 38 the unwoven felt is either wound on a spindle or it passes into a guillotine 40 which cuts it in sheets of desired length. It can also be cut into belts, the width of which is adjustable.

I claim:

1. A process for pneumatically parting fibre flocks comprising (a) feeding said flocks into and out of a confined space, and (b) impinging upon said fiber flocks emerging from said confined space at least a pair of high speed air jets flowing in different directions to thereby cause parting of said fibre flocks.

2. The process of claim 1 including coating said parted fiber flocks with synthetic resins.

3. The process of claim 2 in which said coating is applied as a liquid resin in mist form.

4. The process of claim 1 wherein said air jets have adjustable pressure thereto and-said jets being aligned in a parallel direction, but offset relative to each other and flowing generally against each other.

5. A process of pneumatically parting and tearing fibr flocks comprising (a) feeding said fiber flocks through a tube by rotating a screw therein, and (b) impinging upon said fibre flocks leaving said tube an air jet axially aligned with said tube to cause pneumatic parting and tearing of said fibre flocks.

6. A process for tearing and pneumatically parting fib-re flocks comprising (a) feeding said fibre flocks into and out of a confined space, (b) rotating against said fiber flocks emerging from said confined space a sawtoothed cylinder in which said fibre flocks are booked in the toothing thereof, and -(c) impinging tangentially in the rotational direction of said cylinder and air jet of controllable pressure and flow to cause tearing and pneumatic parting of said fibre flocks.

References Cited UNITED STATES PATENTS 2,152,901 4/1939 Manning 264-115 2,619,151 11/1952 Sheidley 264-115 5 3,081,207 3/1963 Fox 264-121 3,157,440 11/1964 Hijiya et al. 302-28 ROBERT F. WHITE, Primary Examiner.

10 J. R. HALL, Assistant Examiner.

US. Cl. X.R. 26412l

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