Textile material and manufacture

Abstract

A run-resistant textile material includes a knitted structure of warp threads on a backing layer of loose fibrous material.

Individual fibers are pulled out of the layer by notched knitting needles of a warp knitting machine and formed into loops together with, and underlying the chain switched stitched warp threads. The fiber loops whose ends are anchored in the backing layer protect the fabric from laddering when a single stitch is broken.

Description

The present invention relates to a textile material and to a method of producing same by using a warp knitting machine DRAWINGdrawingsewing operation-simulating warp knitting machine. The machine is equipped with a plurality of knitting needles 13 (of which only one is shown), each of which has a hook 25, similar to the hook of a crochet needle on its shank and, at the front end a sharp point 26, similar to the sharp end of a sewing needle. The point 26 is not within the longitudinal center axis of the needle 13 but is off center in the plane of the hook 25 toward the open side of the hook. The needle 13 is attached to a shaft 27 which is connected to a needle bar (not shown), whereby the needle is operatively connected to reciprocating means for movement in the direction of the arrow B.

A wire or strip slide 12, fastened to a holder 28, is connected to reciprocating means (not shown) and adapted to close the hook 25 of the needle 13 so as to retain knitting thread 24 in the bight of the hook. The slide 12 is movable in a groove 29 provided in the shank of the needle 13.

The operation of the knitting needle 13 is synchronized with that of an eye needle 14 to which the knitting thread 24 is fed from a spool 24a or another suitable feeding device. The eye needle 14, attached to a holder 31, is rotatable about the axis of the needle 13 at a predetermined rate of revolution, whereby the knitting thread 24 is introduced into the hook 25 of the needle 13.

Fibrous material 5, comprising a voluminous and bulky mass of randomly oriented and loosely packed natural or man-made fibers is brought into the operating zone of the needles 13, 14 between conveyor belts 30 31 30' running on pairs of rolls 22, 23. Guide sheets 20 and 21 bordering the sides of belts 30, 30' retain the fibrous material thereon. The conveyor belts 30, 30' define with the guide members 20, 21 a passage inclined at an angle of approximately 45 degrees relative to the operating plane of the needles 13, 14. The conveyor belts 30 and 30' are operatively connected to a motor M. In the operating zone the fibrous material 5 is supported laterally by, respectively a knock-offover cam 17 proximate to the needle 13, and a counter bar 15 proximate to the needle 14. The knock-offover cam 17 and the counter bar 15 are aligned substantially parallel to each other and extend perpendicularly to the longitudinal axis of the needles 13, 14. At its upper end the knock-offover cam 17 is bent and forms a support for the guide member 21 on which the major portion of the weight of the fibrous material 5 rests.

The cam 17 is attached to a base 33. The counter bar 15 is provided with a plurality of pins 16 which point downward and which are placed so that the knitting thread 24, guided through the eye of the needle 14, passes between them.

A detent or stemming device 18, positioned under the operating plane of the needles 13, 14, within the area defined by cam 17 and the pins 16, is adapted to restrict the passage area of the fibrous material 5 in the region of the needles. The stemming device 18 is attached to a base 32 and forms an arm which is shiftable (by means not shown) in a lateral direction between the knock-offover cam 17 and the counter bar 15 and pins 16, as well as vertically at a right angle to the lateral shift. The face 34 of the stemming device 18, which is remote from the fibrous material 5, has a slanted portion at its upper end which terminates in point 35 at the tip of the opposite face of the stopping device.

A rapid compression of the fibrous material 5 induced by a predetermined constriction of the passage subsequent the operating zone of the needles, causes the fibrous material to be confined in an area of substantially step-shaped cross-section. An abutment 19 mounted on the base 32 is designed to support the pins 16 against lateral deflections which tend to arise from the push of the needle 13 piercing the fibrous material in the direction of the needle 14.

According to the present invention the fibrous material 5 arrives at the operating zone of the needles 13, 14, at a moderate speed, induced partly by the forward motion of the conveyor belts 30, 30' and partly by gravity acting on the weight of the material moving on an inclined surface. In addition, the pull of the finished textile material 2, as it is removed from the machine in the direction of the arrow X, causes the strongly cohering fibrous material 5 to settle in the operating range of the needles 13, 14, at undiminished bulk and volume. Within the operating zone the material 5 is pierced by the needles 13 which, at their forward position, receive in the bight of their hooks 25 the knitting thread 24 guided through the eyes of the needles 14. In the area defined by the suitably adjusted stemming device 18, the counter bar 15 and the knock-offover cam 17 the fibrous material is compressed, so that a large quantity of closely packed fibers are presented to the needles on their return movement out of the fibrous material. Fibers caught in the bight of the hooks 25 during the retraction of the needles 13, are carried back together with the warp thread 24, and are secured by slides 12 which engage the needle hooks before the needles are withdrawn from the material 5. Subsequently the fibers and the thread 24 are formed simultaneously into loops, the fiber loops 4 underlying the warp thread loops 3, as shown in FIGS. 1 and 2. Depending on the coordination of the needles 13 and 14, different yarn systems may be produced, i.e. fringe stitches, tricot stitches and the like.

The introduction of the fibrous material 5 in a voluminous bulky condition into the region of the needles 13, 14, the large expanse occupied by the fibrous material in the operating zone, and its subsequent sharp compression assure the presence of a fiber loop 4 under each warp thread loop 3. If the prerequisite conditions do not exist, and if the fibrous material used as a weight of less than 400 g./m.², the largest portion of the warp thread loops 3 will lack underlying fiber loops 4. Since an interruption in the array of fiber loops increases the tendency toward "laddering," runs can be arrested in such textile materials only in isolated spots. By contrast, a sewing operation-simulating warp knitting machine, having a structure according to the invention, is well suited to produce run-resistant textile material of all usable weight categories, and particularly of light-weight material for outerwear.

Claims

1. A textile material comprising a base, said base including a plurality of loose fibers, a warp knitted yarn system constituted of parallel rows of interlocking loops piercing said base and forming stitches on the opposite side thereof to secure said yarn system on said base, and a plurality of discrete fiber loops intermediate said base and said yarn system, each of said fiber loops being formed of at least one of said loose fibers and having ends which are located within the base and a closed loop portion closely underlying and following the configuration of a respective loop of the warp knitted yarn system, each of the fiber loops thereby being paired with a respective loop of the warp knitted yarn system, each of the pairs of loops passing through a next adjacent one of the pair of loops in the same row.

2. A method of producing a textile material on a warp knitting machine comprising feeding a relatively voluminous web of loose fibers in a relatively uncompressed condition into the operating range of the reciprocating needles of the warp knitting machine, advancing the knitting needles into and through said web for perforation of the web and for positioning of the hooks at the far side of the web, inserting warp yarns into the hooks of said knitting needles at the far side of the web, retracting said knitting needles into the web thereby to insert loose fibers into the hooks of the knitting needles, closing said hooks of said needles after said insertion of loose fibers but prior to withdrawal of the needles from said mass, forming the inserted warp yarns together with the inserted fibers into warp knit stitches on the near side of the web, and immediately proximate the operating range of the needles on the far side of the needles in the direction of travel of the web compressing the web into a cross section in the direction of reciprocation of the needles pronouncedly smaller than the cross section of the web in said direction as it is fed to the operating zone.

3. A method as defined in claim 2 wherein said fibers are formed into loop-like structures.

4. A warp knitting machine, comprising warp knitting means including a row of reciprocable knitting needles having hooks, the paths of reciprocation of the hooks defining a knitting zone, a row of yarn guides parallel to the row of knitting needles, means for supplying a respective yarn to each of the yarn guides, said yarn guides being adapted to insert the yarn into the hooks of the knitting needles for the forming by the knitting needles of the yarn into chains of warp knit stitches, knock-over means proximate to said needles for knocking over the stitches formed by the needles, counter means substantially parallel to the knock-over means, the knock-over means and the counter means being positioned along the knitting zone traversely of the paths of reciprocation of the needles, means for conducting a base to and passing the base through the knitting zone between the knock-over means and the counter means, and means for compressing the base in the direction of reciprocation of the needles immediately after the knitting zone.

5. A warp knitting machine as defined in claim 4 in which said counter means includes a bar and a plurality of pins extending downwardly from said bar, the pins being so spaced relative to each other as to permit the yarns to be guided and the needles to reciprocate between adjacent ones of the pins.

6. A warp knitting machine as defined in claim 5 including an abutment mounted adjacent to said pins on the side thereof remote from the knock-over means to limit or prevent deflection of the pins in the direction of forward movement of the needles during forward movement of said needles through the base.

7. A warp knitting machine as defined in claim 4 wherein said conducting means comprises a endless conveyor belt angularly disposed relative to the direction of said needles and a pair of guide members positioned for receiving the base from the belt and delivering the base to the operating zone between the knock-over means and

the counter bar. 8. A warp knitting machine as defined in claim 4 in which including means for displacing the compressing means is displaceable laterally intermediate said knock-over means and said counter means and vertically toward and away from said knitting needles.