US 3022813 A
Description (OCR text may contain errors)
Feb. 27, 1962 B. M. GLOVER 3,022,813- METHOD MAKI NG BONDED NON-WOVEN FAB FROM TEXTILE FIBERS Filed. July 24, 1958 t 5 M I? i y 4 4x w'ehvar iajlumm ll 1J4 Glor 57 im/Jug A fl-owre United States Patent 3,022,813 METHOD OF MAKING BONDED NON=WOVEN FABRIC FROM TEXTILE FIBERS" Benjamin Marshall Glover, Ashgarth, Bruntcliife Road, Morley, near Leeds, England Filed July 24, 1953, Scr. No. 750,730 Claims priority, application Great Britain July 25, 1957 2 Claims. (Cl. 156-148) In the normal course of production of many types of textile materials made of wool, cotton or any kind of hair or fibrous material or of any combination of such materials, it is common practice topass such material at an early stage in its preparation through a scribbling machine or random webber from which the fibrous material finally emerges in the form of a very thin web of such material, in many cases little thicker than a spiders web, and extending to the full width of the machine.
This web or layer of loose hairs or fibers is continuous and can, if so desired, by the use of a folding device such as a Blamires Feed or similar means, be built up by laying one layer upon another to any desired thickness, and if, as in the case of the Blamires Feed, the platform upon which the build-up takes place is composed of an endless lattice which is caused to rotate slowly in a direction away from the machine the built-up layers or sliver, as it is by this time known, can be of any desired length.
One object of this invention is to produce a non-woven fabric in which a number of web-like layers of fibres are bonded together with their fibres well intermingled but wherein the nature of the resultant fabric can be varied in its physical characteristics by suitably controlling a number of factors involved in the process of production.
In particular it is an object of the invention to produce such a fabric by a process which enables the built-up layers of the sliver to be well bonded together by means of displaced fibers as well as by partial impregnation of the sliver with a bonding agent of the kind hereinafter referred to whilst excluding this agent from the top and bottom layers of the fabric, thus producing a strongly bonded fabric which can still retain its fibrous or hairy exterior.
In the process used according to the present invention, prior to or during the build-up, just the intermediate layers of loose hairs or fibres are sprayed with a plastic bonding agent and the assembly of built-up layers is faced on both sides with unbonded and unimpregnated outer layers and is passed through a fibre intermingling machine and then subjected to treatment for the purpose of setting, gelling or vulcanizing the bonding agent, according to the nature of the latter. It will therefore be seen that after the intermediate layers are built up by folding and are sprayed with aqueous bonding agent, unbonded and unimpregnated layers of slivers are provided on the opposite faces of the intermediate layers and the assembly is ready for the needling operation.
An aqueous solution of rubber latex would be a suitable bonding material but other thermo-plastic and synthetic materials may be used, for example, that known as Butadiene Acrylonitrile synthetic rubber, such material being well known for the purpose in view and requiring no further description.
As the partially impregnated sliver of built-up layers moves from the point where it is built up it immediately passes through the fibre intermingling machine, a machine which might be compared in action with a multiple needle sewing machine having a head and a foot, the latter compressing the sliver upon a recticulated base plate and both the head and foot being caused to move up and down at high speed, but unlike the sewing machine which makes use of needles, the head in this case holds one or more 3,022,813 Patented Feb. 27, 1962 sewing machine needles, the thickness varying according.
to the strength and density of the hairs or fibres which make up the sliver. They are smooth-sided and without the laterally projecting barbs usually associated with the needles of needle-punching machines, but at the lower extremity of each plunger instead of a single point there is a fork of inverted U, or like shape, each limb of which isbrought to a smooth point. Preferably up opposing sides of the plunger from the base of the inverted U run two longitudinal grooves the function of which is as follows: It will readily be seen that each time the head of the intermingling machine is caused to rise and fall and the plungers pass through the partially impregnated sliver, a number of the horizontally laid fibres contained in the sliver will be caught in the inverted U at the base of each plunger and carried in the grooves up the sides of each plunger through the sliver in a more or less perpendicular position.
In this manner substantially the whole of the hairs or fibres which comprise the different layers originally built up into the laminated sliver are intermingled one with another. Any possibility of delamination, which is not unknown in ordinary bonded fabrics, is completely eliminated and a considerable degree of strength is at the same time added, which in turn allows for a reduction in the quantity of bonding material required as compared to that used in the normal bonded fabrics, which usually relies for its entire strength upon the amount of bonding agent used.
Finally the material is passed through the driers and/ or around heated rollers in order to dry out the moisture in the bonding agent or agents and by doing so causes it to set or gel and thereby hold the intermingled fibres permanently in position. Should natural or synthetic rubber latex be the bonding agent used, a vulcanizing chamber would be brought into operation at this stage.
By the use of this process a very considerable range of fabrics can be produced, varying from thick board-like or thin paper-like fabrics, to soft handling fleecy, blanket type materials, such variations being brought about by the type of material used in the sliver, the thickness of the sliver, the amounts of bonding agent used, the speed of the intermingler and finally the pressure applied, in the first place by the foot of the intermingler and later during the final drying out of the moisture contents of the bonding agent.
In order that the invention may be more clearly understood and readily carried into effect the same will now be more fully described with reference to and by the aid of the accompanying drawings, which illustrate in a purely diagrammatic form the process according to the invention and a suitable means for carrying it into effect. In such drawings:
FIGURE 1 illustrates how the web of fibres can be layered by a folding device, sprayed with the bonding agent, passed through an intermingling machine, and then treated to dry and set the bonding agent.
FIGURES 2 and 3 are detail views of one of the plungers used in the intermingling machine. FIGURE 3 being a section taken on the line IIIIII in FIGURE 2;
FIGURE 4 is a detail in side elevation of the plungers, presser foot and base plate of the intermingling machine.
Referring to these drawings the web w of fibres coming from the scribbling or other web producing machine (not shown) is laid in layers to produce a sliver s by the lattices of a folding device indicated generally at f of substantially known kind, the lattice f reciprocating lengthwise of the web whilst the lattice f only travels at right angles thereto to carry the sliver of built-up layers to the feed means of the intermingling machineindicated generally at i. "A spray pipe p to whic h the bonding agent (an aqueous solution of rubber. latex) is sup-1 plied in any suitable manner is supported above the web being laid in lattice and is reciprocated with lattice i so as to spray each succeeding layer across the width of the sliver for covering with the unbonded layers of sliver on opposite sides of the sprayed layers. This spraying is thereby so arranged so that no bonding medium is deposited upon the top or bottom layers of the assembled layers.
The intermingling machine i includes a baseplate 1 over which the sliver of built-up and sprayed layers is led, a presser foot 2 spanning the sliver and arranged to be raised and lowered to compress the sliver against the base plate, and a head 3 carrying a series of plungers 4. These plungers are closely spaced and span the sliver, two rows being indicated with those in one row staggered relative to those in the other row to give efiective coverage of the whole width of the sliver. The presser foot and the base plate are both perforated with holes 2* and 1 respectively to allow the plungers to pass through.
One of the plungers or needles 4 is shown in FIG- URES 2 and 3 and consists of a thin rod with its lower end shaped to an inverted U and well rounded on all edges so as to be capable of engaging fibres and carrying portions of them down through lower layers of the sliver smoothly to produce the intermingling of the fibres. Longitudinal grooves 4 in the smooth sides of the plunger accommodate the fibres when being pushed down and so reduce the openings punched in the sliver to the size of the plungers, these openings closing as the plungers are withdrawn. As there are no barbs or other projections on the sides of the plungers their withdrawal does not disturb the already intermingled fibres.
Any suitable means may be used for supporting and operating the reciprocating head and presser foot but these two members will be actuated in timed relationship to one another so that the plungers pass down into the sliver before the foot compresses it and so that they withdraw from the sliver before the foot rises so that the foot prevents the sliver from being lifted and disturbed. The action of the plungers is so rapid (e.g. a thousand strokes a minute) that the sliver can move continuously through the intermingling machine.
The fabric is then dried by being passed around a series of heated cylinders indicated generally at d and is then passed through a vulcanizing apparatus indicated generally at v to complete the treatment. In some cases the drying stage may not be necessary where vulcanizing is carried out, and in others vulcanizing will not be necessary where the bonding agent is not rubber or its substitute.
1. A method of manufacturing a bonded, non-woven assembly of layers of textile fibers to form a unitary, multiply non-woven fabric having a fibrous hairy exterior on both outer surfaces, comprising forming a continuous web of sliver from said textile fibers, folding said web on itself by alternating movement to build up a plurality of sliver layers, constituting the intermediate layers of said assembly, spraying the layers forming the intermediate layers during said folding step with a bonding agent, facing the opposite sides of said intermediate layers with a web formed of unbonded and unlmpregnated sliver, needling the assembly of outer unbonded facing layers and the intermediate bonded layers with a plurality of smooth sided, thin needles each formed with longitudinal grooves on opposite sides extending to the tip thereof and terminating in an inverted U at the end of the groove at the needle tip, the reciprocating movement of the needles intermingling the horizontally laid fibers in the sliver layers by catching the fibers in the inverted U and carrying them into adjacent layers, and thereafter drying the assembly to set the bonding agent.
2. A method as claimed in claim 1 wherein said bonding agent is aqueous rubber latex.
References Cited in the file of this patent UNITED STATES PATENTS 1,978,620 Brewster Oct. 30, 1934 2,142,566 Lehman Jan. 3, 1939 2,331,321 Heaton Oct. 12, 1943 2,339,431 Slayter Jan. 18, 1944 2,381,184 Ripley Aug. 7, 1945 2,429,486 Reinhardt Oct. 21, 1947 2,557,668 Lincoln June 19, 1951 2,616,482 Barnes Nov. 4, 1952 2,713,016 Weiss July 12, 1955 2,723,707 Erbe Nov. 15, 1955