US3568278A

US3568278A - Method of drawing and crimping yarn

Info

Publication number: US3568278A
Application number: US15243A
Authority: US
Inventors: Denis Albert Edward Mattingly
Original assignee: Klinger Manufacturing Co Ltd
Current assignee: Klinger Manufacturing Co Ltd
Priority date: 1967-01-28
Filing date: 1970-02-27
Publication date: 1971-03-09
Anticipated expiration: 1988-03-09
Also published as: GB1213151A; NL6801222A; FR1566301A

Abstract

UNDRAWN OR PARTIALLY DRAWN YARN IS CRIMPED AND DRAWN OR MORE FULLY DRAWN BY KNITTING THE UNDRAWN OR PARTICALLY DRAWN YARN INTO A BODY OF STITCHES, STRETCHING THE BODY OF STITCHES SO AS TO DRAWN THE YARN AND SETTING THE YARN WHILE IT IS IN THE CONFIGURATION OF THE STRETCHEDSTICHES. THE BODY MAY BE A CHAIN OF STITCHES WHICH IS CONTINUOUSLY NITTED, FED INTO THE DRAWING AND SETTING ZONE AND THEN UNRAVELLED FROM ITS LEADING END.

Description

v March 9, 1911 D. A E. MATTINGLY METHOD OF DRAWING AND GRIMPING YARN 2 Sheets-Sheet 1 Original Filed Jan. 29, 1968 ,nr i o March 1 D. A. E. MATTINGLY 3,568,278

METHOD OF DRAWING AND CRIMPING YARN Original Filed Jan. 29, 1968 2 Sheets-Sheet ,2

United States Patent 3,568,278 METHOD OF DRAWING AND CRIMPING YARN Denis Albert Edward Mattingly, London, England, as-

signor to The Klinger Manufacturing Company Limited, London, England Continuation oil-application Ser. No. 701,248, Jan. 29, 1968. This application Feb. 27, 1970, Ser. No. 15,243 Claims priority,-application Great Britain, Jan. 28, 1967, 4,316/67 Int. Cl. D04b 19/00 US. Cl. 28-72.16 Claims ABSTRACT OF THE DISCLOSURE Undrawn or partially drawn yarn is crimped and drawn or more fully drawn by knitting the undrawn or partially drawn yarn intoa body of stitches, stretching the body of stitches so as to drawn the yarn and setting the yarn while it is in the configuration of the stretched stitches. The body may be a chain of stitches which is continuous- 1y knitted, fed into the drawing and setting zone and then unravelled from its leading end.

This is a continuation of application Ser. No. 701,248 filed Ian. 29, 1968 and now abandoned.

The invention relates to crimping yarn, and more particularly to crimping thermoplastic yarn or yarn having a thermoplastic component.

According to one aspect of the invention there is provided a method of producing crimped yarn comprising the steps of forming undrawn or partially drawn yarn into a body of yarn having a stitched configuration, stretching the body to draw the yarn, setting bends in the yarn while the body is stretched, and then unravelling the crimped yarn from the body.

Preferably, the step of drawing the yarn takes place while the yarn is in a heated condition. This drawing may or may not draw the yarn to its fullest extent.

The step of stretching the body may be achieved by underfeeding the body into theheating Zone.

The body may be in the form of a chain of looped stitches. Alternatively, the body may be in the form of a knitted fabric comprising a plurality of rows each made up of a plurality of stitches.

The stitched configuration of the body may be such that'the stitches can be unravelled from the leading end of the body and the method operated as a continuous process.

According to another aspect of the invention there is provided apparatus for producing crimped yarn comprising stitch forming means for forming undrawn yarn into a body of yarn having a stitched configuration, means for stretching the body of yarn in the stitched configuration to draw the yarn, heating means arranged to heat the body of yarn while the body is in a stretched condition and means for unravelling the crimped yarn.

The stitch forming means may comprise a single needle, such as a latched, bearded or hooked needle, or may comprise a knitting machine including a plurality of needles.

The invention will now be described by way of example with reference to the accompanying diagrammatic drawing in which:

FIG. 1 shows a general perspective view of a yarn crimping apparatus;

FIG. 2 is an elevation of the opposite side of a part I of the apparatus of FIG. 1;

FIG. 3 is a plan view of part of the apparatus shown in FIG. 2; and

FIG. 4 shows part of a chain of looped stitches.

Referringv now to the drawings, the basic features of the apparatus are, reading progressively along the yarn path'indicated by the chain dotted line in FIG. 1, a yarn supply bobbin 1, a knitting station. 2, feed rollers 3 and 4, a heater 5, feed rollers '6 and 7, feed rollers 8- and 9, and a crimped yarn take-up bobbin 10.

The apparatus is mounted in a fixed frameworkwhich is omitted from the drawing for simplicity. Several separate units can be arranged on a single elongated framework.

Referring to FIG. 1 in more detail, undrawn yarn 11 passes from the supply bobbin -1 around a hysteresis tensioner 14 at the knitting station 2.

The knitting station comprises a needle 17, one end of which is provided with a hook and'the other end of which is screwed into a crank shaft 18 and secured by a locknut, the needle and the crank shaft forming asubstantially straight line. The crank shaft 18 is slidably mounted intermediate its ends in a journal bearing-18A which is mounted on a block 19 for pivotal movement about an axis transverse to the crank shaft. 'A pulley 21 mounted on a shaft is driven by an electric motor 22 via a belt 23 passing around a pulley on the spindle of the motor 22. A crank wheel 24 is mounted on'sa'id shaft on the opposite side of the block 19 to the pulley'21. The end of the crank shaft 18, remote from the needle is pivotally mounted on the wheel 24 by means of a pin 15 so that on rotation of the wheel 24 the crankshaft is reciprocated and at the same time rocked about the pivotal axis of the journal bearing 18A and the hooked end of the needle moves in an endless path. Attached to the end of the block 19 is a yarn guide assembly including anapertured bracket 16 through which the needle moves and on which yarn guides 17A and 17B are mounted at either side of the hooked needle 17 so as to guide yarn transversely across the path of movement of the book of the needle.

Yarn isfed to the knitting station via the .tensioner 14, passes through one turn around the needle and leaves the knitting station in the form of a continuous chain 12 of looped stitches.

The stitching operation is self-starting in'that once the .yarn is threaded through the guides 17A and '17B, the needle. automatically picks-up the yarn and: commences to form stitches in the yarn. It is usually required that the first stitch is formed by manually operating'the crank mechanism while pulling the yarn through the guide 17A. In order to form the first stitch the tension in the yarn at the guide 17A is required to be greater than for usual operation.

With the stitching operation already commenced and stitches formed in the yarn being drawn away from the needle, and the needle near its extreme rearward position (in relation to the crank mechanism as seen in FIG. 1) the needle begins to move forward and upward simultaneously so that the end of the needle-lifts over the stitches already formed to its extreme forward position, and the stitches are now held on the needle-by a loop of yarn: on the shank of the needle. The needle continues from this position, as it describes an endless path of generally eggshape, to move downwards as it moves rearward so that the yarn being fed from the guide 26 enters behind the hook of the needle.

The needle continues rearwards tnd the yarn which was engaged by the hook is drawn through the loop-on the shank of the needle. This loop has now moved forward along the shank of the needle and over the hook. As the needle continues rearward the loop moves beyond the end of the needle and is cast-off so forming a next stitch in the yarn. The needle will then be at its extreme rearward position again, thus completing a stitching cycle.

The chain of looped stitches formed by the knitting station is passed through a ceramic guide 34 to the rubber surfaced roller 3. The roller 3 is urged into contact with the roller 4 by means of a spring 38.

The roller 4 is mounted on an axle 41which carries a driving pulley 44 and is driven by the motor 22 via a belt 45, a pulley 46, a pulley 47 and a belt 48.

The rollers 3 and 4 positively feed the chain 12 through the guide 34 over a guide 50 and into engagement with a heater 5. j

The heater 5 is an electrically heated device which is heated by electric resistance wires (not shown). The temperature of the heater is thermostatically controlled and an adjusting switch 53 is provided for adjusting the temperature of the device. Two grooves 55 and 56 are arranged along the length of heater so that the chain of stitches 12 passes down groove 56 in contact with the heater around a guide 57 and then up the groove 55.

After leaving the heater 5, the chain of stitches passes through the atmosphere for a suflicient distance to cool and then passes over a smooth steel rod 40 to the rubber surface roller 6 which is urged by spring means (not shown) against the roller 7. The roller 7 is attached to a driving pulley 59 driven by the motor 22 via a belt 61, shaft 72, pulley 47 and belt 48.

Thechain 12 is wound a number of times around the rubber covered roller 6 and an adjacent yarn separating guide 62, so that the rollers 6 and 7 nip the chain between them. Immediately after passing between the rollers 6 and 7 the chain of stitches is unravelled by pulling the yarn from the chain and the unravelled yarn engages a motor cut-out device 63, which is intended to stop the motor 22 should the yarn break, or should the tension in the yarn exceed a predetermined limit. The unravelled yarn then passes around a ceramic guide 64 and through the nip between the rubber surface roller 8 and the roller 9 which are urged together by a spring (not shown) and to be set in the yarn to form a series of crimps along the which pull the unravelled yarn from the chain of stitches;

axle 41 driven by the motor 22 via pulley 44, belt 45,

pulley 46, pulley 47 and belt 48.

The crimped yarn 13 is fed through a ceramic guide 65- to a yarn traverse guide 66 carried by a reciprocatory Wire forming part of a traverse mechanism and then wound on to take-up bobbin 10, which is driven by a cork surfaced roller 71. The roller 71 is driven by the motor 22 via pulley 59, belt 61, shaft 72, pulley 47 and belt 48.

In operation, the undrawn yarn 11 is formed into a chain of looped stitches of the form illustrated in FIG. 4 atthe knitting station. The tension in the yarn is controlled by the hysteresis tensioner 14. If the tension is too low, the needle 17 is no longer able to form the chain of stitches. If the tension is too high, the chain moving away from the knitting station tends to pull the undrawn yarn through the knitting station so that fewer stitches are formed per unit length of the undrawn yarn. Also, when the tension is high the action of the needle'17 can tend to stretch the undrawn yarn and at least partially draw the yarn at the knitting station.

The tension is adjusted so that the maximum number of stitches are properly formed in the yarn for a given ratio of the reciprocatory speed of the needle 17 and the throughput speed of the yarn and so that very little, if any, drawing takes place at the knitting station.

The chain of looped stitches 12 is fed over the heater by the rollers 3 and 4 and the rollers 6 and 7. The peripheral speed of the rollers 6 and 7 is arranged to be greater than the peripheral speed of the rollers 3 and This causes the chain of looped stitches to be stretched so causing the stitches to elongate to several times their original length and at the same time causing the yarn in the stitches to be drawn.

length of the yarn.

Heat may be required to enable the yarn to be drawn as well as to enable crimps to be set in the yarn. The temperature of the heater is varied depending on whether or not heat is specifically required for drawing the yarn and depending on the actual composition and denier of the yarn.

The yarn path between the heater and the rollers 6 and 7 is arranged to be sufliciently long to allow the yarn to cool while the chain of stitches is maintained in the stretched configuration.

After leaving the rollers 6 and 7, thelooped stitches are unravelled from the leading end of the chain. This is achieved by arranging the peripheral speed of the rollers 8 and 9 to be greater than the peripheral speed of the rollers 6 and 7 in a predetermined ratio. The ratio is chosen so that the unravelling point remains intermediate the rollers 6 and 7 and the rollers 8 and 9 as the yarn passes through the apparatus.

The crimped yarn 13 which leaves the rollers ,8 and 9 is wound onto the take-up bobbin 10. The crimped yarn is substantially uniformly crimped, in the form of a series of uniform waves of V-like shape.

I have found that yarn drawn while in a stitched configuration and heat set in the manner described produces crimped yarn which can be made up into fabric and satisfactorily dyed inthe usual way.

In one example, undrawn nylon 6 (450 denier, 48 filament) yarn was crimped in the manner described above. The peripheral speed of the rollers 6 and7 was three times greater than the peripheral speed of the rollers 3 and 4. The heater temperature was C. The peripheral speed of the rollers 8 and 9.was approximately three times that of the rollers 6 and 7, and the speed of the crimped yarn onto the take-up bobbin was 280 ft./m in. giving a small degree of overfeed on to the package.

It will be appreciated that the type of crimped yarn produced can be varied in several ways for any particular composition and denier of yarn. The draw ratio is readily adjustable and can, if desired, be intermittently or regularly adjusted to enable, a non-uniformly crimped yarn to be produced. The draw ratio is adjusted by altering the relative peripheral speeds of the rollers 3 and 4 and the rollers 6 and 7.

The frequency at which crimps occur in the crimped yarn is dependent on the stitch size formed in the undrawn yarn at the knitting station. The stitch size is .in creased during the drawing of the yarn by a predetermined amount dependent on the draw ratio. Preferably, the stitch size at the knitting station is kept very small so that the crimp frequency in the crimped yarn is fairly high.

Instead of forming a chain of stitches as described.

above, the undrawn yarn can be knitted into a length of fabric comprising a configuration of looped stitches. The length of fabric is then elongated to several times its length while heatedin order to draw the yarn in the looped stitches and set the, stitches in their stretched form to produce, when the fabric is unravelled, a crimped drawn or partly drawn yarn. I

In some .cases, particularly when crimping multifilament yarn, means may be provided to increase the three dimensional bulkiness of the crimped yarn produced. Such means may comprise a sharp edge device or an air blast device arranged to engage or act upon the yarn after it has been unravelled from the chain and before it is wound on to the package It] and separate the filaments of the yarn to a certain extent.

What is claimed is:

1. A method of drawing and crimping yarn, comprising continuously and on the run carrying out the following sequence of steps:

(a) forming a drawable yarn into a chain of stitches each of at least some of which comprises a segment of yarn passing around the segment of yarn of another stitch;

(b) feeding said chain to a drawing and setting zone at a first rate;

() passing the chain through the drawing and setting zone;

(d) positively withdrawing said chain from the drawing and setting zone at a second rate, said second rate being greater than the first rate whereby the yarn is drawn and at least some of the segments of yarn passing around other segments of yarn are bent sharply around the other segments of yarn and the yarn is set in this configuration; and

(e) downstream from said positive withdrawing at said second rate positively driving said yarn at a third rate, said third rate being sufficiently greater than said second rate to cause unravelling of the thusly crimped yarn from the leading end of said chain between the point of said withdrawing at said second rate and the point of said driving at said third rate.

2. A method according to claim 1, in which the ratio of said second rate to said first rate is set to equal the desired draw ratio.

3. A method according to claim 1, in which the yarn is heated while being drawn.

4. A method according to claim 3, in which the heated yarn is permitted to cool while drawn.

5. A method according to claim 1, in which each of the stitches of the chain formed in step (21) comprises a segment of yarn passing around the segment of yarn of another stitch and in step (d) each of the segments of yarn passing around other segments of yarn are bent sharply arouno the other segments of yarn and the yarn is set in this configuration.

References Cited ROBERT R. MACKEY, Primary Examiner US. Cl. X.R.