US3419451A - Method and apparatus for making multicomponent nonwoven fabric - Google Patents

Description

Dec. 31, 1968 E. BOBKOWICZ I 3,419,451

METHOD AND APPARATUS FOR MAKING MULTICOMPONENT NONWOVEN FABRIC Filed April 23, 1965 O II I 2/ W W 6 a we Bl I 6 L \\VI;: ;ir -9 10,21 l8 I9 20 C) O Q F/GQ/ l 20 F [G 2 INVENTOR.

EMILIAN BOBKOWICZ United States Patent 3,419,451 METHOD AND APPARATUS FOR MAKING MULTICOMPONENT NONWOVEN FABRIC Emilian Bobkowicz, 1155 Dorchester Blvd., W. Suite 905, Montreal 2, Quebec, Canada Filed Apr. 23, 1965, Ser. No. 450,444 14 Claims. (Cl. 156-161) ABSTRACT OF THE DISCLOSURE Multicomponent nonwoven fabric is produced by extruding from a die a curtain of warp resin filaments which are then stretched to provide molecular orientation, s multaneously helically and continuously winding by means of a rotating frame a plurality of weft yarns around these warp filaments, which weft yarns, in order to achieve regular spacing, first pass in the notches of serrated strips running along the edges of said curtain of warp filaments, and lamination and consolidation of the obtained warp-Weft construction are effected by a pair of pick-up pressure rolls which are driven at a higher speed than the extrusion rate of the warp filaments and thus also accomplish the stretching and resulting molecular orientation of the latter.

This invention relates to improvements in the manufacture of nonwoven textile webs.

More particularly, it relates to a novel method and apparatus for making multicomponent nonwoven fabrics through lamination and consolidation of a curtain of extruded and oriented resinous warp filaments contacted with suitable weft yarns helically wound around said curtain and, possibly, with additional superimposed webs of staple fibers.

In the hitherto known methods for the manufacture of non-woven fabrics it was necessary to apply a thermoplastic bonding agent in solvent, solution, powder or staple fiber form. This resulted in the requirement that the material be dried and the resin, serving as the bonding agent, be heat-softened and then cured or coagulated by cooling, before the final lamination and consolidation of the nonwoven web could take place. Consequently, these production methods are rather laborious, complex and relatively slow, and involve economical as well as technological limitations.

Applicants Canadian Patent No. 684,091 of Apr. 14, 1964, discloses an improved method and apparatus for producing nonwoven textile webs. It eliminates some of the drawbacks of conventional processes mentioned above. However, according to this patent it is still necessary that the yarns which constitute the warp layer and which may or may not comprise a thermoplastic bonding agent, be separately prefabricated.

Also, according to said patent, the web formed of superimposed warp and weft yarns must be heated to activate the bonding agent, before it can be consolidated and laminated.

The first requirement that the warp yarns be prefabricated is rather inconvenient because it necessitates a separate production set-up equipped to manufacture warp yarns intended to be used in the process. This also increases the cost of the resulting fabric.

The second requirement of applying heat to the warp and weft yarns also has its disadvantages since special care must be taken not to dam-age by heat the staple fibers in said yarns. Moreover, this constitutes a limiting factor in respect of the selection of the thermoplastic bonding agents; only those which have a lower melting point than the employed staple fibers can be used.

3,419,451 Patented Dec. 31, 1968 The present invention eliminates the above mentioned inconveniences and limitations and enables to produce nonwoven fabrics in one step, without using separately maufactured warp yarns and without applying heat prior to lamination and consolidation.

It is therefore an object of the instant invention to provide a method and an apparatus for making nonwoven webs in a simple and eflicient manner without using prefabricated warp yarns.

A further object of the invention is to provide a one step method and apparatus for manufacturing nonwoven fabrics without application of heat to the warps and Wefts prior to their lamination and consolidation.

A still further object of the invention is to provide a method of making nonwoven textile webs wherein any extrudable resin may be employed to form the warp layer.

Other objects and advantages of the invention will be apparent from the following more detailed description of the invention,

In general terms, this invention is an improvement of that disclosed and claimed in applicants Canadian Patent No. 684,091 mentioned above. However, instead of using prefabricated warp yarns, there is now employed a layer or curtain of directly extruded and oriented warp filaments. While still tacky, these filaments are brought into contact with weft yarns which are helically and continuously wound around them so as to form a weft layer. The obtained composite web is consolidated and laminated by a pair of pressure rolls which are preferably cooled. The rolls are also driven at a higher speed than the rate of resin extrusion in order to achieve the desired axial orientation of the extruded filaments.

To ensure proper spacing and controlled forwarding of the weft yarn layer, in step with the inner filament warp layer, a prefabricated continuous strip of material, serrated on its outer edge, is conveyed on each side of the Warp layer. In this Way, the weft yarns enter into the consecutive notches of the serrated strips, while being wound around the warp layer, and are thereby evenly distributed and forwarded towards the cooled laminating rolls. The entire combination, including the serrated strips, is then compressed and consolidated by said rolls into a ready nonwoven fabric wherein the serrated strips form a strong inside-bonded side-edge.

In addition, one or two fiberwebs with parallel or randomly arranged fibers may be superimposed upon the warp-weft construction prior to its lamination and consolidation and while the warp filaments are still in plastic condition. The obtained composite web is then passed through the nip of cooled pressure rolls where the material is consolidated by compression and coagulation into a multicomponent nonwoven fabric comprising a strong inside layer of warp and weft yarns and an outside texturizing layer of a web of staple fibers.

Summarizing, therefore, the method of the instant invention comprises:

extruding a curtain of resinous warp filaments;

stretching said filaments to cause proper orientation of the resin molecules;

helically winding around said curtain of warp filaments a layer of properly spaced weft yarns so that the latter will contact said filaments while they are still in plastic condition;

if desired, superimposing upon the obtained warp-weft construction, on at least one side thereof, a web of staple fibers; and

laminating and consolidating the so produced multicomponent structure.

The apparatus, object of the instant invention, comprises a combination adapted to carry out the above described method.

Thus, it may comprise: an extruder for extruding a curtain of resinous warp filaments; a pair of pressure rolls positioned below said extruder and adapted to take-up, compress and consolidate the composite structure of which the extruded warp filaments form the middle layer; means for driving said rolls at a higher speed than the rate of filament extrusion to cause proper orientation of the filament resin molecules; means on both sides of the extruder for forwarding strips of material with serrated outer edges at each side of the filament curtain; and means for helically winding around said warp filaments and serrated strips a plurality of weft yarns so that they will enter into the consecutive notches of the serrated strips and thereby Will be evenly spaced and forwarded, together with the filament warp yarns, towards the consolidating pressure rolls.

Moreover, there may be provided, on at least one side of the pressure rolls, means for forwarding a staple fiberweb towards the nip of said rolls so that it will superimpose the original warp-weft construction and will be laminated and consolidated therewith.

Finally, there will usually be provided means for cooling the pressure rolls to enhance the coagulation of the resinous material during the compression operation.

Essentially, however, the apparatus will comprise, in combination:

means for extruding a curtain of resinous warp filaments downwardly along a constructional path;

weft layer means close to said constructional path for helically winding a plurality of continuous and proper- 1y spaced weft yarns around said warp yarn curtain, to form a multicomponent warp-weft construction;

if desired, means for superimposing upon said warp-weft construction, on at least one side thereof, a web of stable fibers; and

a pair of pick-up pressure rolls at the bottom of said constructional path, driven at a higher speed than the extrusion rate of the warp filaments so as to stretch said filaments in order to cause proper orientation of the resin molecules, said rolls also being adapted to laminate and consolidate the obtained nonwoven construction.

The invention will now be described in greater detail with reference to the appended drawings in which:

FIG. 1 is a vertical side view of the apparatus according to the present invention with some parts shown in section;

FIG. 2 is a vertical front view of the lower portion of the apparatus according to this invention with some portions also shown in section; and

FIG. 3 is a section view through line BB of FIG. 1.

As shown in the drawings, there is provided according to the invention an extrusion apparatus having an extrusion barrel 1 projecting through the upper portion of a circular frame 2 which is rotatably mounted by means of bearings 4 on a frame 3 and driven by pulley 5. This circular frame 2 has at its lower end a plurality of compartments for carrying a plurality of yarn packages 6 pivotally mounted on shafts 7.

The extrusion die 13, at the bottom of barrel 1, comprises a plurality of aligned orifices 14 (see FIG. 3) through which the warp filament yarns 15 are extruded, between downwardly extending plates 11 and 12, towards pick-up laminating rolls 16 and 17.

At the same time, serrated strips 21 are unwound from supply rolls 22 and are guided through channels 23 on both sides of the extruder barrel 1 and then through channels 24 and 25 on both sides of the extruder head 13. These strips are thus conveyed at each side of the extruded filament curtain towards the pick-up laminating rolls 16 and 17.

Moreover, while frame 2 is rotated, the yarn ends from packages 6 are threaded through holes 8 and assembled in a yarn spacing and laying member 139 Which they are helically wound around the plates 11 and 12 bound by the serrated strips 21, in such a manner that the resulting weft yarns 10 enter into the subsequent notches of said strips 21 and form a regularly spaced weft yarn layer around the curtain of extruded warp filaments 15.

The so formed construction may be laminated as such or additionally superimposed with fiber webs 18 and/or 19 and then subjected to pressure and cooling by passage through rolls 16 and 17 which are preferably chilled from the inside. The obtained finished multicomponent nonwoven fabric 20 can be wound on a commercial fabric roll 26 of suitable size.

The apparatus of the invention therefore comprises: an extruder with an extrusion barrel 1 and an extrusion die 13 adapted to extrude a curtain of filaments 15; a pair of plates 11, 12 positioned about said extrusion die, extending downwardly thereof and having guiding channels 24, 25 for the serrated strips 22, said plates being so shaped as to enable winding of weft yarns 10 around their edges and to hold said weft yarns in position until they are picked-up by pressure rolls 16 and 17; supply rolls 22 and guiding channels 23 at each side of the extrusion barrel 1 for conveying the serrated strips 21 before they enter the guiding channels 24, 25; a rotatable frame 2 around said extruder with compartments carrying a plurrality of yarn packages 6 pivotally mounted on shafts 7 and a spacing and laying member 9 for forming a properly spaced layer of weft yarns 10 helically wound around the side edges of the plates 11 and 12 as well as around the serrated strips 21 and the curtain of warp filaments 15; and a pair of pressure rolls 16, 17 for laminating and consolidating the formed warp-weft structure, bound by the serrated strips 21, to form a nonwoven fabric.

The apparatus may also comprise means (not shown) for superimposing upon this initial structure a pair of fibrous webs 18 and 19 of any desired quality and design just prior to lamination and consolidation by rolls 16, 17.

Finally, the apparatus will also be provided with means for driving and rotating frame 2; means for chilling the rolls 16, 17; means for driving said rolls 16, 17 at a higher speed than the extrusion rate of filaments 15; an output roller 26; as well as any other instrument or device required for a good performance or control of said apparatus.

The operation of the apparatus enables to carry out the novel method of the instant invention and comprises; extruding through the aligned orifices 14 of the extrusion die 13 a curtain of warp filaments 15; picking-up these filaments by the rolls 16, 17 which are driven at such a speed as to effect on said filaments a substantial drawing action to cause an adequate orientation of the resin molecules; at the same time conveying through channels 23 and 24, 25 the serrated strips 21 and leading them, one at each side of the filament curtain, towards said pressure rolls 16, 17 by which they are picked-up and laminated together with the filaments 15; helically winding and properly spacing weft yarns 10 around the curtain of filaments 15 through the use of the rotating frame 2, the spacing and laying member 9, the plates 11 and 12 and the serrated strips 21; and laminating as well as consolidating the whole combination by cooled pressure rolls 16, 17, if desired, together with superimposed fibrous webs 18 and/or 19.

Although any extrudable resin may be used for the warp filaments 15, it is preferred to utilize thermoplastic materials for this purpose.

Furthermore, it is preferable to use thermoplastic serrated strips 21.

As weft yarns 10, it is preferred to employ staple fiber yarns.

Finally, the fi'berwebs 18 and 19 may be made of any suitable staple fibers with parallel or random arrangement of the fibers.

As is evident from the above, the invention enables to produce nonwoven webs in a simple and efficient manner, with any desired fibrous texture and Without use of prefabricated warp yarns or application of heat for activating the bonding agent.

The resulting material may therefore be very similar to the usual woven fabric; but the expensive weaving operation has, of course, been eliminated. This substantially reduces the cost of the finished product.

It should also be understood that the invention is not limited to the specifically described and illustrated embodiments and many modifications evident to those skilled in the art can be carried out without departing from the spirit and scope of the invention as defined in the following claims.

I claim:

1. Method for making a multicomponent nonwoven fabric comprising:

(a) extruding from a suitable extrusion die, provided with a plurality of aligned orifices, a curtain of warp resin filaments;

(b) stretching said filaments to cause proper orientation of the resin molecules;

(c) conveying a narrow strip with a serrated outer edge at each side of the curtain of warp filaments;

(d) helically and continuously winding around said curtain of warp filaments, bound by the serrated strips, a layer of weft yarns originating from a plurality of yarn packages rotatably mounted about the extrusion die, so that said weft yarns will contact said warp filaments while they are still in plastic condition;

(e) simultaneously spacing said weft yarns so that they will enter into consecutive notches of the serrated strips; and

(f) laminating and consolidating the obtained construction by passing it through a pair of cooled pressure rolls.

2. Method according to claim 1, in which prior to lamination and consolidation, and while the warp filaments are still in plastic condition, the construction is superimposed, on at least one side thereof, with a staple fiber web, whereby a multicomponent nonwoven fabric with an even fibrous texture on at least one side thereof is obtained.

3. Method according to claim 1, in which the Warp filaments are made of a. thermoplastic resin.

4. Method according to claim 1, in which stretching of the warp filaments is caused by driving the pressure rolls at a higher speed than the rate of filament extrusion.

5. Method according to claim 1, in which the serrated strips are made of thermoplastic material.

6. Method according to claim 1, in which the weft yarns are staple fiber yarns.

7. Method according to claim 1, in which the weft yarns are filament yarns.

8. Apparatus for making a multicomponent nonwoven fabric comprising in combination:

(a) means for extruding a curtain of resinous warp filaments along a constructional path;

(b) weft layer means close to said constructional path for helically winding a plurality of continuous and properly spaced weft yarns around said warp curtain to form a multicomponent warp-weft construction; and

(c) a pair of pick-up pressure rolls at the end of said path, driven at a higher speed than the extrusion rate of warp filaments so as to stretch said filaments in order to cause proper orientation of the resin molecules, said rolls also being adapted to laminate and consolidate the nonwoven construction.

9. Apparatus for making a multicomponent nonwoven fabric comprising in combination:

(a) an extruder with an extrusion die provided with a plurality of aligned orifices and adapted to extrude a curtain of warp filaments;

(b) a frame rotatable about said extruder and containing a plurality of Weft yarn supply packages, and means for rotating said frame;

(c) means for conveying a narrow strip with a serrated outer edge at each side of the curtain of warp filaments;

(d) a spacing and laying member cooperating with said frame and adapted to lay a plurality of Weft yarns, originating from the weft yarn supply packages, in a properly spaced relationship and so that they will be helically wound around the curtain of warp filaments, bound by the serrated strips, when the frame is rotated, to form a multicomponent warp-weft construction;

(e) a pair of pick-up pressure rolls positioned below the extruder die and adapted to laminate and consolidate said warp-weft construction; and

(f) means for driving said pressure rolls at a desired higher speed than the rate of extrusion of the warp filaments so as to stretch the warp filaments and cause proper orientation of the resin molecules.

10. Apparatus according to claim 9, in which the extrusion die is provided with two extending plates having a guiding channel at each side for each serrated strip, said plates being adapted to provide adequate support for and to help proper forward movement of the helically wound weft yarns.

11. Apparatus according to claim 8, further comprising means for superimposing upon the warp-weft construction, on at least one side thereof, a web of staple fibers. 12. Apparatus according to claim 8, further comprising means for cooling the pick-up pressure rolls.

13. Apparatus according to claim 9, further comprising means for superimposing upon the warp-weft construction, on at least one side thereof, a Web of staple fibers.

14. Apparatus according to claim 9, further comprising means for cooling the pick-up pressure rolls.

References Cited UNITED STATES PATENTS 3,041,230 6/1962 Diehl 156172 2,847,056 8/1958 Vanlaer 156-172 XR 3,031,360 4/1962 Currier 156-167 FOREIGN PATENTS 880,236 10/ 1961 Great Britain.

PHILIP DIER, Primary Examiner.

US. Cl. X.R.

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