US3791745A

US3791745A - Spectrophotometer attachment for testing yarn dyeing qualities

Info

Publication number: US3791745A
Application number: US00318218A
Authority: US
Inventors: Henry R Mac
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1972-12-26
Filing date: 1972-12-26
Publication date: 1974-02-12
Anticipated expiration: 1991-02-12

Abstract

Dyeing qualities of yarns from different packages of yarn which are intended to be identical are tested by knitting a sleeve having longitudinal segments formed of the yarns to be tested and at least one segment formed of a yarn known to have the desired dyeing characteristics. The knitted sleeve is then dyed and it is found that some or all of the segments have accepted the dye to a different extent than the segment or segments knitted of the yarn having the desired dyeing characteristic. This application discloses an apparatus facilitating the checking by means of a spectrophotometer the depth of shade of the different longitudinal segments of the dyed knitted sleeve, whereby the yarns may be objectively classified as to dyeability.

Description

United States Patent 191 MacHenry SPECTROPI-IOTOMETER ATTACHMENT FOR TESTING YARN DYEING QUALITIES [75] Inventor: Richard MacIIenry, Prospect Park,

[52] U.S. Cl 356/244, 356/96, 356/245, 356/195, 356/173 [51] Int. Cl G01j 3/46, GOlj 3/02 [58] Field of Search..... 356/96, 173, 244, 245, 246; 250/226 [56] References Cited UNITED STATES PATENTS 6/1972 Horer et a]. 356/244 OTHER PUBLICATIONS Matthews, Jr., American Dyestuff Reporter, July 29, 1968, pp. 30-36.

451 Feb. 12, 1974 Primary Examiner-Ronald L. Wibert Assistant Examiner-R. J. Webster Attorney, Agent, or Firm-Thomas R. OMalley et al.

[5 7] ABSTRACT Dyeing qualities of yarns from different packages of yarn which are intended to be identical are tested by knitting a sleeve having longitudinal segments formed of the yarns to be tested and at least one segment formed .of a yarn known to have the desired dyeing characteristics. The knitted sleeve is then dyed and it is found that some or all of the segments have accepted the dye to a different extent than the segment or segments knitted of the yarn having the desired dyeing characteristic. This application discloses an apparatus facilitating the checking by means of a spectrophotometer the depth of shade of the different longitudinal segments of the dyed knitted sleeve, whereby the yarns may be objectively classified as to dyeability.

5 Claims, 7 Drawing Figures SPECTROPHOTOMETER ATTACHMENT FOR TESTING YARN DYEING QUALITIES This invention relates to apparatus for testing the dyeing characteristics of yarns forming segments of a dyed sleeve, the segments of which are knitted of yarns from different packages and more particularly to an improved arrangement for facilitating the presentation of the various segments to the sample sensing station or scanning window of a spectrophotometer. In its more basic aspect, the invention relates to an improved means for classifying yarns as to dye acceptability.

Certain types of man-made fibers, polyester fibers being especially notable, are very sensitive as to dye acceptability. For example, yarns from two packages of yarn manufactured side-by-side will frequently dye to a slightly different or even greatly different shade when subjected to identical dyeing procedures. There are many factors that affect the dyeability and some of these factors are difficult to precisely control. For example, manufacture of continuous filament polyester yarn includes a stretching or drawing operation carried out while the yarn is passing over a heated plate. Both the amount of draw and the temperature, as well as the speed, affect the dye receptivity of the yarn, as do other steps in the manufacturing operation. This invention is not concerned with the reasons why supposedly identical yarns do not dye the same, but this phenomenon is merely pointed out to explain the background of the invention.

Prior to the present invention, it was the practice of at least some manufacturers of continuous filament polyester yarns to classify the different packages as to dyeability by knitting sleeves having a plurality of segments, every third one of which was formed of yarn known to have the desired dye receptivity and the other segments of which were formed of yarns from different packages. These sleeves were knitted in great quantity so that a small amount of yarn from every package manufactured was used to form a sleeve segment adjacent a segment formed of the control or standard yarn of known dyeability. Each segment of each sleeve was identified as coming from .a particular package. The sleeves were dyed, usually with a single component dye, e.g., blue, and stretched over a simple form. An inspector then compared each segment formed of yarn being tested with the control segment adjacent thereto and noted whether the test segment was a deeper or less deep shade than the control segment. The yarns were then classified in accordance with the subjective judgment of the inspector in various ways differing probably from manufacturer to manufacturer. For example, the yarn could be classified as of acceptable quality for dyeing if judged to be fairly close in shade to thecontrol, whether lighter or darker, or classified as suitable only for use in undyed fabric if judged to be too far different in shade from the control. The yarns could, of course, be divided into more than two categories, if desired. At any rate, the classification was strictly subjective and could of course depend upon the particular inspector and was not necessarily consistent even with a given inspector. Furthermore, every third segment of each sleeve was formed of the control or standard yarn, thus necessitating the use of a substantial amount of the control yarn and requiring a substantial amount of time in knitting duplicating segments of the sleeves.

The present invention involves the use of a knitted sleeve as described above except that only one sleeve segment need be formed of the yarn known to have the desired dye receptivity, thus requiring considerably less time and using considerably less yarn than with the prior art procedure where every third segment of the sleeve is formed of the same control yarn. The present invention also involves an objective test for comparing the depth of shade of the various sleeve segments with depth of shade of the segment formed of the control yarn whereby the yarns may be accurately classified, either into two groups as properly dyeable or not properly dyeable or into several groups each containing yarns that accept dye at substantially the same level.

It is an object of this invention to provide an improved means for facilitating the inspection and numerical classification by a spectrophotometer of the dye receptivity of yarns forming segments of a dyed knitted sleeve.

.Other and further objects, features and advantages of the invention will become apparent as the description of a preferred embodiment thereof proceeds.

Referring now to the drawing:

FIG. 1 is a front elevational view of the apparatus;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a sectional view taken along the line IIIIII of FIG. 1 with certain parts shown in full to facilitate illustration;

FIG. 4 is a plan view of an unwinding means forming one element of the invention;

FIG. 5 is a section taken along the line V-V of FIG.

FIG. 6 is a diagrammatic view of a knitted sleeve of the type to be tested or inspected; and

FIG. 7 is an isometric view of a sleeve spreader forming part of the invention.

There are many specifically different spectrophotometers, the basic function of all of them being to numerically indicate the difference in color shade between a sample and a control or known specimen. The more sophisticated spectrophotometers are capable of comaring a sample with a pure white specimen and displaying or printing a numerical value indicative of the depth of shade of the sample. Since the present invention may include as one of its elements a spectrophotometer of any of a variety of known types, the instrument itself is not shown herein in detail and is indicated only generally at 10 and includes a housing having a front wall 12. For purposes of describing the invention, it will be assumed tht the spectrophotometer forming one element thereof is of the type that prints a numerical value on a tape each time a dyed segment of the knitted sleeve is presented to its'sample scanning window or sensing station. With this type of instrument, when the segment of the dyed sleeve knitted of the yarn known to have the desired dye receptivity is presented to the sample scanning window, a numeral is printed on the tape. If subsequent segments of the sleeve have dyed to a lighter or darker shade, a higher or lower numeral will be printed and having established a numerical range for as of the various segments this invention includes a spreader generally designated at 14 and shown particularly in FIG. 7 and presentlyto be fully described.

Referring now particularly to FIGS. 1 and 2, the housing of the spectrophotometer includes a top wall 16 of relatively thin metal to which is secured, by suitable bolts, screws or the like 18, a sturdy reinforcing plate 20. Positioned upon and secured to plate 20 is a block 22 having secured therein and extending therebeyond parallel to one another a pair of

rods

24 and 26. Slidably mounted on

rods

24 and 26 is a carriage generally designated 27 comprising a reel supporting yoke which in the specific embodiment shown consists of a horizontally extending member 28 secured to the upper ends of which through the intermediary of brackets 30 and 32 respectively are

members

34 and 36.

Members

34 and 36 have notches in their upper ends, only the notch 38 of member 34 being shown, to receive a spindle or core 40 on which is wound a roll 42 of the knitted sleeve to be tested. Secured to the lower face at the ends .of member 28 and extending perpendicular thereto are a pair of supports .44 and 46. Support 44 has suitably mounted therein

bearings

48 and 50 slidably embracing

rods

24 and 26 respectively. Support 46 has mounted therein a bearing 56 slidably embracing rod 24 and another bearing, now shown, embracing rod 26.

Thus, the carriage supporting the roll 42 is slidably mounted on the

rods

24 and 26.

The front wall 12 of the spectrophotometer has a sample scanning window 54 therein and secured to the front wall 12 at a point diametrically opposite the scanning window from carriage 27 is a sleeve unwinding means indicated generally at 55. In order to reinforce the wall 12 of the spectrophotometer and'better support the unwinding means a reinforcing plate 56 is secured to the wall. A member 58 is slidably mounted on plate 56 by means of a pair of flanged

rollers

60 and 62 which are rotatably mounted on plate 56 and extend through a slot 64 provided in member 58. Referring now particularly to FIGS. 4 and 5, member 58 has secured thereto an element 66 having a portion 68 partially underlying plate 56 and member 58 and providing a bearing for a spindle '70 (see FIG. 5) of a roller 72. Also secured to member 58 is an element 74 having a portion underlying plate 56 and member '58 providing a bearing for a spindle at the opposite end of roller 72. Element 66 has a portion 76 to which is swingably connected by means of a pin 78 an arm 80. The free end of arm 80 provides a bearing for a spindle 82 of a roller 84. Element 74 has a portion 86 to which is swingably connected by means of a pin 88 an arm 90 the free end of which provides a bearing for a spindle at the opposite end of roller 84. A threaded pin 92 extends through an enlarged bore 94 in arm 80 and is screwed into plate 58. A spring 96 surrounds pin 92 and bears at one end against arm 80 and at the other end against a head 98 of the pin whereby the arm is urged in a clockwise di rection as viewed in FIG. 5. A similar spring arrangement, generally indicated at 100 is provided for arm 90. Thus, roller 84 is urged toward engagement with roller 72. A knob 102 is operatively secured to roller 84 for selectively rotating the same and meshing

gears

104 and 106 are secured respectively to

spindles

70 and 82 whereby rotation of roller 84 is transmitted to roller 72. The surfaces of

rollers

72 and 84 do not quite contact but are held close enough by the springs to grip the knitted sleeve when it is positioned therebetween as presently to be described. To insure a good grip on the sleeve, the rolls are knurled or covered with rubber.

Referring now to FIGS. 1 and 2, secured by means of a bolt 1118 to the support member 44 of carriage 27 is an arm 110 to the outer end of which is secured the upper end of a shaft 112. The lower end of shaft 112 is secured to one arm of a bracket 114, the other arm of which is secured to the member 58 of the slidably mounted unwinding means 55. Shaft 112 constitutes a handle by means of which carriage 27 and unwinding means 55 may be moved back and forth as a unit.

The spectrophotometer normally has a manually operable sample holder for resiliently pressing the test sample against the sample scanning window and a similar holder for the standard or control specimen, the instrument having two scanning windows for simultaneous scanning of the control and sample specimens. The present invention includes some modification of the operation of the sample holder, as will now be described. A circular disk 1 16 has a pair of tabs 118, only one of which is shown in FIG. 3, which embrace a block to which they are connected for a limited amount of swivel movement by a pin 122. Block 120 is secured to a substantially triangular plate 124 which is hinged at 126 to a member 128 which is secured to the front plate 12 of the spectrophotometer and spaced therefrom by a spacer block 130. A coil spring 132 surrounding a portion of hinge 126 urges plate 124 in the direction to engage disk 116 against a frame member 134 provided around the scanning window 54 (see FIG. 3). Block 1211 has a pin 136 extending therefrom into an opening provided in one end of a member 138 and a suitable set screw or the like holds the pin 136 in engagement with member 138. At the other end, member 138 is connected through a suitable flexible linkage 140 to the armature of a solenoid 142. Upon energization of solenoid 142, hinge 126 becomes a fulcrum about which member 138 swings to lift disk 116 out of engagement with frame 134 thereby allowing a test specimen to be positioned between the disk and the frame.

The knitted sleeve itself forming the roll 42 is designated 144. Said sleeve has segments knitted of yarns from many different packages, a few of the segments being designated in FIGS. 1 and 6 as A, B, C, D, E and F. Let it be assumed that segment A is knitted of a yarn known to accept a certain type of dye to a desired extent and that the other segments are knitted of yarns presumably the same as that forming segment A. After the sleeve is fully formed, it is dyed in a manner such that each segment is subjected to the same treatment and for any of a number of reasons previously referred to it is found that at least some of the segments have dyed to a lighter or darker shade than segment A. The present invention makes practical theme of a spectrophotometer to accurately classify as to dyeability the yarns forming the various segments of the knitted sleeve.

In use, the sleeve 144 is wound onto spindle 40 to form the roll 42 and some of the sleeve is pulled from the roll and spreader 14 is inserted into it. As shown in FIG. 1, spreader 14 is wide enough to stretch the sleeve and remove any wrinkles. A portion of the sleeve below the spreader is then inserted between

rollers

72 and 84 of the unwinding means 55 which pinch the sleeve therebetween. Eccentrically mounted

guide rollers

146 and 148 are mounted on slide 58 of the unwinding means and serve to center the spreader which floats within the sleeve as the sleeve is subsequently unwound from the roll. As shown in FIG. 1, segment C of the sleeve is aligned with the sample scanning window 54 and it will be observed that carriage 27 and unwinding means 55 are positioned as far toward the right as their sliding action will permit thus bringing a part to the left of the centerline of the sleeve into alignment with the sample scanning window 54. In FIG. 6, that part of the sleeve shown in FIG. 1 as aligned with the scanning window is indicated by a circle designated 150. Even a sleeve segment knitted of a single yarn may not dye absolutely uniformly and therefore this invention provides the means for readily taking two readings from each segment. After taking the reading with the sleeve positioned as shown in FIG. 1, the operator energizes solenoid 142 to lift the holder 116 from the sleeve and then moves handle 1 12 toward the left to slide carriage 27 and unwinding means 55 to the left to thereby align a portion indicated by a circle 152 in FIG. 6 with the scanning window 54. Solenoid 142 is then deenergized to permit holder 116 to press the sleeve against the scanning window and a reading is then taken of the depth of shade of sleeve portion 152. The readings for

portions

150 and 152 are averaged to give a number used for classifying the yarn of segment C. The operator then uses knob 102 to rotate pinch rolls 72 and 84 and draw a portion 154 of sleeve segment D into alignment with scanning window 54. It is not necessary to lift holder disk 116 during this movement of the sleeve. After taking a reading for portion 154 the operator uses handle 112 to restore carriage 27 and unwinding means 55 to the positionshown in FIG. 1 to thus align a portion of the sleeve indicated in FIG. 6 by circle 156 with the scanning window. As will readily be understood, the foregoing procedure is repeated for each segment of the knitted sleeve. At some point in the operation, readings are of course taken from segment A of the sleeve, this being the segment knitted of the yarn known to have the desired dyeing characteristics.

Spreader 14 is relatively thin and consists of

parallel sections

158 and 160 offset from one another whereby section 158 rests against the front wall 12 of the spectrophotometer (except being separated therefrom by the sleeve 144) and the portion 160 is aligned with the space between

rollers

72 and 84 of the unwinding means 55. It hasbeen found that the spectrophotometer gives most accurate readings when the knitted sample is doubled so that light is reflected from two layers of material and therefore spreader 14 is provided with an opening 162 aligned with scanning window 54. From FIG. 3, it will be seen that holder 116 presses two layers of the sleeve against the scanning window, one layer being pressed through opening 162 of the spreader.

Having thus described a preferred embodiment of the invention, what is claimed is:

1. Apparatus for testing dyeing qualities of segments of a dyed sleeve knitted of yarns from different packages for use with a spectrophotometer having a scanning window, comprising a reel mounted on one side of the scanning window for supporting a rolled up dyed knitted sleeve having segments knitted of yarns from different packages, unwinding means located diametrically opposite the scanning window from said reel for unwinding the sleeve from the reel and moving it past the scanning window, a spreader floatingly positioned within the sleeve to stretch the sleeve transversely to avoid wrinkles in line with the scanning window, and means for urging the spreader against the scanning window.

2. The apparatus set forth in claim 1 wherein said spreader is a flat plate having an opening therethrough in alignment with the scanning window whereby the light source of the spectrophotometer is able to strike two layers of the knitted sleeve.

3. The apparatus set forth in claim 1 wherein said unwinding means comprises a pair of rolls for squeezing the knitted sleeve, means for yieldably urging said rolls toward one another, and manually operable means for rotating at least one of said rolls whereby the sleeve may be advanced to selectively align the various segments thereof with the scanning window.

4. The apparatus set forth in claim 3 wherein said reel and said unwinding means are mounted for parallel movement in a direction to move a knitted sleeve extending therebetween transversely of the sleeve to align

Claims

4. The apparatus set forth in claim 3 wherein said reel and said unwinding means are mounted for parallel movement in a direction to move a knitted sleeve extending therebetween transversely of the sleeve to align different areas of each segment thereof with the scanning window, and means interconnecting said reel and said unwinding means for movement as a unit.

5. The apparatus set forth in claim 4 wherein said last mentioned means comprises a Manually operable handle.