US2839909A

US2839909A - Knitted fabric

Info

Publication number: US2839909A
Authority: US
Inventors: John E Morgan
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-05-16
Filing date: 1957-05-16
Publication date: 1958-06-24
Anticipated expiration: 1975-06-24

Description

June 24, 1958 J. E. MORGAN KNITTED FABRIC F iled May 16, 1957 3 Sheets-Sheet 1 H CKKKTTTKK CKKKTTTKK TTKKKKKT TTKKKKKT KKKTTTKK CKKKTTTK .DTTKKKKKT DTTKK KKT 23 5678 FIG.5

INVENTOR N .A. G R O T M mu E. M M Mm E M D m .US v T W R. m M R LD N DT C Wu S E m m G F m. y m m MTH m CTT s M Dm W E x M m a S E N D N T E X L T Mm mm m w w R K D D A-TTORNEY N -O -l -NUMBER OF KNIT COURSES June 24, 1958 J. E. MORGAN 2,839,909

KNITTED FABRIC Filed May 16, 1957 v 3 Sheets-Sheet 2 FIG. 3

D D C C D D C C 20 2| 20 2| 26 I 25 Z6 Z5 INVENTQR JOHN E MORGAN ATTORNEY June 24, 1958 J MORGAN 2,839,909

KNITTED FABRIC Filed May 16, 1957 5 Sheets-Sheet 3 JOHN E MORGAN Mow,

. needle banks.

United States Patent The present invention relates to the knitting of airentrapping fabrics which are suited for use in the production of garments such as underwear and which, be-

cause of the cellular configuration or shape of the fabric is particularly adapted to provide warmth. The invention includes the treatment of the knitted product to enhance its hand and softness and also its Warmth retaining character. The invention also includes the new heat insulating fabric which is produced by the invention, both before and after treatment thereof to enhance the softness and heat insulating quality thereof.

The invention is particularly directed to the production of light weight knitted fabrics which are not irritating to the skin of the wearer and which have a multitude of air-entrapping cells formed therein, these cells being retained to continue the insulating excellence of the fabric dispite prolonged wear.

In accordance with the present invention, a fabric is knitted upon a rib knitting machine having opposed Preferably, the needles are independently mounted on each of the needle banks in groups with the groups of needles on each of the needle banks being positioned between the groups of needles on the opposed needle bank.

The rib knitting machine under consideration is operated by producing tuck stitches on one of the needle banks while the needles of the opposite needle bank are knitting in conventional fashion. After this is done for a plurality of courses, the operation of the machine is reversed and the needles which produced tuck stitches are cauesd to knit in conventional fashion while the needles which formerly knitted in conventional fashion are caused to produce tuck stitches. This latter operation is also performed for a plurality of courses. The operation of the machine is thus switched back and forth so that the pattern of knitting is reversed every several courses.

It will be understood that when tuck stitches are produced, that the needles are projected insufficiently to cast-off the yarn loops thereon and that the number of yarn loops in the hook of the needle increases with each successive pass of a yarn feed, e. g., with each successive course of knitting. When the needles of one of the needle banks which have been moved through several courses of tuck stitches are finally knitted in conventional fashion, all of the yarn loops carried by the needle at the time are simultaneously knitted off. Since a rib knitting machine is used so that there are opposed needle banks, and because the operation is periodically reversed, the knitting off of a plurality of yarn loops is performed alternately by the needles of each of the opposing needle banks. 7

As will be appreciated, each successive knitting off of a plurality of yarn loops is effected in the opposite direction (an inherent characteristic of the use of opposed needle banks as in rib knitting). The yarn loops which are knitted off as a result of the tuck stitches extend transversely across the knitted product between intended to illustrate the invention as 2,839,909 Patented June 24, 1958 ICC longitudinally extending ribs and overlie longitudinally extending troughs of valleys. The longitudinal ribs form the sides of the air-entrapping cells and the tuck stitches form the bottom and top walls of these cells. When the fabric is turned inside out, the troughs or valleys become the longitudinal ribs for the back side of the fabric and the longitudinal valleys of the front side become the ribs. The tuck stitches from the other needlebank form the bottom and top walls of the cells on the back side of the fabric. 7

It is to be particularly noted that the opposed'needles are arranged in groups andare not constituted, in accordance with preferred practice of the invention, by single needles disposed between adjacent needles of the opposite needle bank. This is of importance because when the tuck stitches are formed by adjacent needles on the same needle bank, only a limited length of yarn is used and when these tuck stitches are knitted off the loops so formed are stretched between adjacent longitudinal ribs and function to draw these ribs together at spaced apart points along the length thereof. This serves to accentuate the cellular construction which is produced. At the same time, the tuck strands underlie the ribs and function to brace and maintain the height of these ribs when the fabric is stretched or subjected to prolonged wear.

A feature of the invention is the manner in which the knitted cellular fabrics of the invention are treated, not only to cleanse the fabric, but to nap itin a manner which facilitates the entrapment of air within the: cells of the fabric.

As will be seen more fully hereinafter, the knitted fabrics of the invention define cells the walls-of which are of varying height. More particularly,-there are side Walls constituted by longitudinally extending knitted ribs and transverse ridges which constitute the top and bottom walls of each cell. These transverse ridges are constituted by superposed tuck'strands which are of lesser height than the longitudinal ribs. In accordance with th e invention, the yarns comprise fibrillatable fibers and the knitted fabric is treated to raise a nap the fibrillations of which extend in all directions from the crests of the ribs and from the outer tuck strands to enhance; the ability of the cells which are knitted to entrap air. Since the outer tuck strands are lower than the longitudinalribs, there is provided fibrillations at two different levels.

The treating procedure broadly involves cleaning or scouring the knitted product as by passing the fabric through an aqueous bath containing a detergent or solvent for the grease, size or other foreign substances which may be present, drying the fabric while preferably tum.- bling the same so that the dried fibers are not all aligned and then napping the surfaces of the drum-dried fabric to fibrillate the yarns or strands at the crests of the longitudinal ridges and at the outer surface of the outer tuck strands.

The invention will now be more fully. described in conjunction with the accompanying drawings which are applied to a 2 X 2 rib knitting machine. i

Fig. l'is a diagrammatic view illustratinga portion of a circular knitting machine having a pair of opposed I needle'banks, e. g., a cylinder anda dial, and showing the positioning of the needles for 2 x 2 rib knitting.

Fig. 2 is a chart indicating the operation of the dial and cylinder needles in successive knitting courses, this knitting sequence of Fig. 2, the view being on a greatly enlarged scale so that the knitted structure which is produced can be more easily understood.

Fig. 4 is a photograph of the knitted product, the photograph representing an enlargement of 16 times.

Fig. 5 is a schematic view of flow-sheet character illustrating the sequence of treatment to which the knitted product of Fig. 4 is subjected for the:purpo'se "ofyen Fig. 6 is a photograph, similar to Fig. 4, ai1d showing the knitted product after treatment as indicated in Fig. 5.

Referring to Fig. 1, it will be seen that there is employed in accordance with the invention a rib knitting machine having a pair of'opposed needle banks. Since the invention is particularly adapted for application to circular knitting machines one of the needle banks is identified by the letter C to indicate that it is the cylinder of a circular knitting machine and .the other needle bank is identifiedby the letterD to indicate that it is the dial of a circular knitting machine.

It is desired to immediately make it clear that the invention is-not limited to circular or even to continuous knitting ;so long as there are opposed needle banks. Normally there will be two needle banks in accordance with the inventionbut this does not exclude the presence of additional needle banks so long as'alternate groups of opposed needles are positioned to knit o. in opposite directions. The invention can even be performed with machines such as links and links machines in which the needles may -be operated from either of two aligned needle beds (usually axially spaced apart cylinders) so long as alternate groups of needles are operated to knit off" in oppositedirections. V

It will be observed that the needles 10 of the cylinder C are arranged in pairs. In brief, the cylinder C does not have a full complementof needles (or if it does some of the needles must be held inoperative). At the same time, the needles 11 of the dial D are also arranged in pairs. It will be observed that each pair of cylinder needles 10 are disposed between each pair of dial needles 11 and vice versa. This is a 2 x 2 rib knit needle position.- -Fig. 1 also indicates the presence of combing 12 so that the

needles

10 and 11 willhave something to draw against'when knitting is performed in conven-. tional manner. a

The use of pa rs of opposed needles is preferred but is not essential to the invention. When each group of opposed needles is constituted by three adjacent needles (a 3 x 3 rib knit needle positioningLthen the'ribs and valleys will be wider. The'opposed groups-of needles need not have the same number of needles and a 2 x 3 or a 2 x 4 or a 3 x 4 rib knit needle positioning may be employed. It is even withinthe scope of the invention to employ a l X 1 10i 1 x2 rib knit needle positioning butthc cell formation is not nearly as deep and 'as well defined.. It is stressed that the 2 x 2 rib knit needle positioning which is preferred is uniquely superior in providing superior cell'forrnation and consequent-air entrapment and this is so with particular emphasiswhen the. 2 2 positioning is compared with a "l x 1 orfeven a 116i 21p ositioning.

. Fig.2 shows a preferrediknitting sequence .in laccor dance'wlth'the'invention. It will be observed that in general, when the dial needles are; knitting conventionally,

that the cylinder needles produce tuckfs'titches,and vice versa; It will also be observed that "the 7 dial needles knit conventionalstitches' for a "plura'lityo'f consecutive courses and. then knit tuck stitc'lies for apluralityoficonsecutlve courses. i

'In the preferred sequence of FigL Z Qthe 'neEdles knit five 1 conventional stitches {and then "three-tuck; stitches.

is knitted by the needles of one of the needle banks is performed at the same time that the needles of the other needle bank are performing their first conventional stitch. This constitutes preferred operation of the invention and leads to the production of a knitted product which'is of particularly uniformshape. However, the specific sequence of Fig. 2 is not essential to the invention although it does illustrate the best mode of practicing the invention as itis presently understood.

Referring specifically to Fig. 2, the vertical columns labeled D and C refer to individual needles on the dial and the cylinder respectively. The horizontal columns numbered 1, 2, 3, etc., identify consecutive knitting courses.

The letter K identifies a conventionally knit stitch in which the needle is projected sufficiently to cause the old yarn loop to move rearwardly for a sufiicicnt distance to open the needle latch and to be cast off upon the body of the needle to the rear of the opened latch. The needle is then normally partially retracted to move the yarn forwardly to partially close the latch (a tuck position) and fresh yarn is placed in the hook of the needle. The needle is then fully retracted within the needle bed to cause the oldyarn loop to be knitted off" the needle and to draw the new yarn loop to the extent desired.

It will be understood that the foregoing depicts typical conventional knitting and is presented as illustrative of the invention and not as limiting the same. If a plurality of old yarn loops are present on the needle at the beginning of the conventional knitting sequence, as the result of previous tuck stitches. then all of these old yarn loops will be simultaneously cast off during needle projection the needle projection is insufficient to cause the old yarn As will be evident; when{the-first coiiventional stitch-is knitted, four yarn loop's will be knnteasrr at the same time. Three of th'e yar n loopsffbrm tiiek strands -It will i lastly be "se e'n tha t tlie last cohv entiofial' stitch which loop or loops to be cast off to the rear of the latch. When the needle is then retracted, no yarn loop is knit off and the yarn loops accumulate within the hook portion of the needle. The needle may be fully rctracted or preferably only partially retracted to minimize drawing of the fresh yarn. It will be appreciated that any slack is taken up by the drawing action of the opposing needles of the opposite needle bank which knit conventionally while the needles of the other needle bank are producing tuck stitching.

The cammingneccssary for each of the foregoing operations is a matterof common and general knowledge in the art. The selection and timing of this camrning in the needle beds toaccomplish the sequence of knitting actions described in Fig. 2 is obvious and will not be described in detail here with the exception of a brief description to be presented hereinafter to show the siniplicity of the invention as adapted to circular machine operation with a plurality of yarn feeds.

With the 'foregoing'description in mind, the knitting sequence of Fig. 2 will beself-explanatory.

Referring to Fig. 3, the yarn loops knitted by the dial needles are shown at 24 the yarn loops knitted by the cylinder needles are shownat 21, and thc tuck strands are identified by the

numerals

22 and 23. The numeral 22 designates the tuck strands produced by the dial needles and the numeral 23 designates the tuck strands the back surface of the valleys 26.

Fig. 4, being a photomicrographg' is self-explanatory. Some of the yarn feeds carried black threads to facilitate identification of individual courses. The product pictured in Fig. 4 is a photograph of the same productdiagrammaticallys'hown in Fig. 3 and the identifying nu-' merals have the same meaning. 7

Fig. 5 is a flow-sheet of fabric treatment in accordance with the invention and this flow-sheet is self-explanatory. The flow-sheet schematically illustrates the specific treatment utilized in the specific illustration of the invention which will be presented hereinafter.

Fig. 6 is a photomicrograph of the cleaned, dried and napped product produced by the treatment indicated in Fig. 5. The numeral 27 indicates the nap on the ribs 25 and the numeral 28 indicates the nap on the outer tuck strand.

Example The invention will now be illustrated in its presently preferred form employing a knitting machine of the circular type having a single cylinder and a single dial each of which is provided with 12 needle slots per linear inch. The cylinder needles are 36 gauge and the dial needles are 24 gauge.

The yarn used is a number 12 single yarn consisting of cotton. Reed #1 (the middle dial tuck) has one end of 8 single yarn thereby raising the height of the cell walls, feeds #2 to 7 inclusive use 12 single yarn. Mixtures of cotton with other fibers both natural and syn- .thetic may also be employed with success.

The needle arrangement used is the 2 x 2 needle positioning shown in Fig. 1 and the knitting sequence followed is the specific sequence indicated in Fig. 2.

The circular knitting machine is provided with 8 yarn feeds which are equally spaced around the periphery of the machine. Each yarn feed supplies yarn-to both the dial and the cylinder needles. Considering the yarn feeds as being numbered 1 -8 consecutively, and'with the understanding that the yarn feeds circle the machine with the cams for the dial and cylinder needles while the cylinder and-dial are stationary, the cams are constructed as follows: i

- The dial cams opposite yarn feeds 1, 2, and 8 are configurated to move the needles which they pass through a tuck stitch sequence as previously described in detail. The dial earns opposite yarn feeds3, 4, 5, and 6 are configurated to move the needles which they pass through a conventional knitting sequence as has also been previously described in detail.

The cylinder cams opposite yarn feeds 1, 2, 3, 7, and 8 are configurated to move the needles which they pass through a conventional knitting sequence and the cylinder cams opposite yarn feeds 4, 5, and 6 are configurated to move the needles which they pass through a tuck stitch sequence.

As will now be appreciated, a conventional circular rib knitting machine has been made to pursue continuously and without change in speed or operation the knitting sequence of Fig. 2 by the simple expedient of selecting and positioning the needle operating cams.

It has been found that the application of a heavy tension on the fabric produced is beneficial in achieving fully satisfactory machine operation.

The fabric produced is then passed throughascouring bath for the purpose of removing all foreign matter such as dirt, oil, paraffin, etc. A suitable scouring bath which may be at the boiling point during scouring has the following composition:

In place of the detergent specified above, any of the common detergents anionic, cationic or non-ionic can be used. The detergent may be of the common anionic type .such as sodium lauryl sulfate, dioctyl sodium sulfosuc- Parts by weight cinate, sodium oleate, and sodium or potassium salt of keryl benzene sulfonate (kerylrepresents a kerosene fraction of'from C-12 to C-18 carbon length used in alkylating benzene), the sodium or potassium salt of 0-12 to Cl8 alkyl naphthalene sulfonate, the alkali metal salt of sulfonated castor oil, etc.

Suitable cationic detergents are amine and quaternary ammonium salts containing hydrocarbon chains of 12 or more carbons, such as Triton X-400. Cetyldimethylammonium acetate is also suitable.

The amine salt is preferably one which is wholly aliphatic in nature and secondary as well as tertiary amine salts are particularly effective. Such specific salts as saugryl dimethyl amine hydrochloride, oleyl dimethyl amine sulfate and stearyl methyl amine sulfate are all suitable.

Non-ionic detergents can also be employed, such materials including glyceryl monolaurate, a sorbitol monooleate, sorbitol monostearate, and ethylene oxide condensation products of each of these aforementioned hydroxy esters in which from one to all the hydroxy groups are condensedwith one mole of ethyl hydroxy in the presence of an alkaline catalyst.

The scoured fabric is then mangled to extract liquid from the same and dried on a conventional loop dryer.

The dried fabric is then napped or fleeced lightly first on one side and then on the other side (the circular knitted fabric is turned inside out).

Rewet with water and then dry again in a fabric tumbling drum dryer. The dried fabric was then finished by calendering on a Tube-Tex Tensionless Calender which is described in Textile Industries, April 1952.

The napping operation was performed on a Universal Napper Grinder which is described in booket N-69 published by the Davis & Furber Machine Company of North Andover, Mass. Another napping machine which can be used effectively is the 20 Roll Geared Double Action Napper described in Davis & Furber Bulletin N-66A.

If desired, the finished product may be run through mechanical shrinkage equipment after washing at any desired temperature.

The heat insulating cellular knitted fabrics of the invention are of outstanding utility where extreme warmth coupled with'light weight are desired. These fabrics are, therefore, particularly adapted for underwear intended for arctic use. However, the utility of the knitted fabrics of the invention is not limited in this regard and these fabrics can also serve as the basis for sweaters, dresses and other articles of knitted outerwear.

The invention has been described to illustrate the con tinuous production ,of what might be considered to constitute yard goods. The invention is not limited in this regard since many variations can bemade without de-' parting from the invention as it has been described. Thus, for example, the invention can be performed in such manner as to provide rib knitted culf portions.

If these cufi portions are desired, it isonly necessary to remove the tuck forming cams from the cylinder and modifications of the invention lie within the skill of the art and are intended to be encompassed by the'claims which follow.

I claim:

l. A heat insulating knitted fabric comprising a rib knitted fabric having longitudinally extending alternate ribs and valleys on both sides thereof and longitudinally 7 spaced apart laterally extending groups of adjacent tuck strands overlying the valleys and underlying the ribs of said fabric, said ribs forming the side walls of air-entrapping cells the top and bottom walls of which are constituted by said tuck strands.

2. A heat insulating knitted fabric as recited in claim 1 in which said tuck strands rise to a height which is less than the height of the crests of th'e'adjacent ribs and in which said tuck strands extend across at least two conventionally knitted yarn loops.

3. -A'he"at insulating knitted fabric as recited in claim 1 in which said knitted fabric comprises fibrillatible yarn and said fabric is napped to provide fibrillations extending from the surface of said ribs and said tuck strands.

4. A heat insulating knitted fabric as recited in claim 1 in which the tuck strands on opposite sides of said fabric are staggeredalong thelength of said fabric.

5. A method of forming a heat insulating knitted fabric having air-entrapping cells on both sides thereof comprising knitting on a 'rib knitting machine having opposed needle banks a first plurality of courses with the needles of 'one of the .needle banks being operated to produce conventional knit stitches and with the needles of the opposed needle bank being operated to produce tuck stitches and then reversing the sequence to knit a plurality o f courses with the needles of. said first named needle bank being operated to produce tuck stitches while the needles of said "opposed needle bank are operated to produce conventional knit stitches.

"6. A method of forming a heat insulating knitted fabric having air-entrapping cells on both sides thereof on a rib knitting machine'having opposed needle banks comprising, providing said needle banks with spaced apart groupsof needles, said groups of needles oneach of said needle banks being positioned between groups of needles on the, other of said needle banks, knitting a first plurality of courses with the needles of one of knit stitches and alternately repeating said first plurality of courses and said second plurality of courses.

11. A method of continuously forming a heat insulating knitted fabric as recited in claim 10 in which all of the needles areoperated to produce conventional knit stitches for at least asingle course after said first plurality of courses and after said second plurality of courses.

12. A method-of-continuously forming a heat insulating knitted fabric as recited in claim '11 in which said first and said second plurality of courses are each constituted by three consecutive courses and a single course in which all of the needles are operated to produce conventional knit stitches after each of said plurality of courses.

13. A method of forming a heat insulating knitted fabric having air-entrapping cells on both sides thereof on a rib knitting machinehaving opposed needle banks comprising, providing, said opposed needle banks with independently mounted 'knittingneedles positioned in 2 X '2 rib knitting position, knitting three courses with the needles of one of the needle banks being operated to produce conventiona'lk'nit stitches and with the needles of the opposed needle bank being operated to produce tuck stitches, then knitting a single course of conventional knit stitches with the needles of both of said needle banks, then knitting threeflcourses with the needles of said first-named needle bank being operated to produce tuck stitches while the needles of said opposed needle bank are operated to produce conventional knit stitches, then knitting a single course of conventional knit stitches with the needles of both of said needle banks and then repeating the above set forth series of operations.

14. -A method 10f forming a heat insulating knitted fabric having air-e'ntrapping cells on both sides thereof comprising knitting with fibrillatible yarn arib knitted fabrc having longiudinally extending alternate ribs and valleys on both sides thereof and longitudinally spaced the needle'banks being operated to'pro'duce conventional are operated to produce conventional knit stitches for i at leasta." single courseafter said first plurality of courses and after 'said secondplurality of courses. 9 "8.A method of forming a heat insulating knitted fabric as recited in clairn 6i n which the needles of said needle banks are positioned'toflassume a 2 x 2 rib knit position. I I

9. A method forming arheat insulating knitted fabric as recitedin claim 7 in which the needles of said needle banks are positionedtoassume Ca 2 x 2 rib knit position.

10. A method of continuously forming a heat insulat- A ing fabric having air-entrapping cells on both sides thereof on a circular rib knitting machine having a dial and a cylinder provided withjndependently mounted groups of-knitting needles, said. groups of needleson said dial f l j ldv yli b n'gpositioned between one another, knittinga'first plurality of courses withthe needles of said dial being operated to produce conventional knit stitches and with'thenee'dles'of said cylinder being op- -erated toproduce tuck stitchesand then knitting a sec- 'on'd"plurality ofcourses with theneedles of said dial,

being operated to produce tuck stitches while the needles of said cylinder are ..-,operated to produce conventional apart laterally extending groups of adjacent tuck strands overlying the valleys and underlying the ribs of said fabric, said ribsforming the side walls of air-entrapping cells thetop and bottom walls of which are constituted said tuck strands scourin'g the knitted fabric, drying the scoured fabric'and then napping said dried fabric.

15. A method of forming 'a heat insulating knitted fabric as recited in claim 14 in which said scouring is performed by passing the knitted fabric through an aqueous bath containing a detergent to remove dirt, grease and" similar 'foreign' material.

16. A method of forming a heat insulating knitted fabric as recited in claim 14 in which said tuck strands rise to a height which is less than the height of the crests of the adjacent'ribs and said napping operation produces fibrillations at two different levels and in which said tuckstrands extend across at least two conventionally knitted yarn loops.

17. A method 'of forming a heat insulating knitted fabric-as recited-in vclaim 14in which both faces of said dried fabric are napped.

18. A method forming a heat insulating knitted fabric as recitedin claim 14 inwhich said scoured knitted fabric is dried while said fabric is tumbled.

References-Cited in the file of this patent UNITED STATES PATENTS r 714,602 GreatiBritain Sept. 1,