JPS6285041A - Lightly bonded polyamide yarn and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generally relates to improved polyamide multifilament yarns, and more particularly, the present invention relates to improved polyamide multifilament yarns, and more particularly, the present invention relates to improved polyamide multifilament yarns.
The present invention relates to a polyamide yarn for use in cut-and-gile carpets that does not require twisting, and a method for making such yarn.

Cut Nog Illumination on the Knee Carpet!
Two or more bulky continuous filament nylon yarns used as yarns are typically ply-twisted together and then plied together while traveling in a relaxed state on a moving belt through an enclosure where saturated water vapor under pressure permeates the yarns. Heat fixed. This treatment fixes the yarn in a twisted configuration so that the yarn retains a significant degree of twist and gives a tight appearance after tufting, cutting, dyeing and use.

The appearance of a columnar tact shaft with a dense, well-divided tuft tip is such that the appearance of clustered tacts is undesirable. In contrast to velour carpets, they are less desirable for cutting and covering purposes.

Yarns that are not sufficiently twisted or heat set lose their twist so that the filaments of one tuft become intertwined with the filaments of the other, giving a matte appearance.

However, both ply-twisting and heat setting are time consuming and expensive operations.

Yarns that meet the same performance metrics as ply-twisted heat set yarns without the need for twisting would be highly desirable.

A multifilament polyamide yarn that does not require ply-twisting and is particularly suitable for use as a gill in cut twill fabrics, including carpet and upholstery fabrics, as it does not spread out or matt. The product has now been found. . The yarn consists of filaments ranging from about 5 to 40 denier per filament with an oriented window portion and a deoriented skin portion, and has a skin deorientation index (5kin Dsorien,
ttxtionIndex) is approximately 0.1”!
d-1'll upper f, 601. < is less than about 0.5, and the thickness of the deorientated skin portion is between 0.4 and 3.
It is characterized by being 0 micrometer. The filaments may be crimped in any known manner, but the crimping is preferably random in frequency, direction and width. This multifilament yarn has a bending stiffness ratio (bgntiin
gravity ratio ) (R/R(, f
7n) without adhesive or sizing agent, about 20~
200, preferably within the range of about 20-75, and the lateral separation distance (2 μm1 aport
It is characterized in that the diter tanct) is about 4, and the number of filaments is less than about 500, some of which are loosely bonded to each other. Yarns with a bending stiffness ratio of 20 to 75 are generally suitable for residential carpets, and yarns with 70=200 can be used for heavy friction equipment.

The yarn bundle can be substantially free of true yarn twist. This does not exclude accidental twisting during the handling of the yarn bundle, such as when the yarn bundle is removed over the end from a stationary four-way shaft, such as from a winding rack, in the conventional manner. do not have.

True twist is 3 cr! Yarn bundles with no more than about 1 turn per L are considered and considered to be substantially untwisted.

It is believed that the improved properties arise partly from the deorientation of the polymer molecules in the outer region of the filament skin and partly from the light bonding between the filaments. Evidence of disorientation can be obtained by observing the difference in birefringence between the skin and the core, or by observing the general lack of anisotropy present in mechanically torn "skin" sections. can be obtained by Evidence of light bonding between the filaments can be observed by physically pulling the yarns apart by hand and also according to the method described in Example 5. It has been found that the yarns of the present invention are significantly stronger than yarns not subjected to the process of the invention, which is due to the bending stiffness of the yarn bundles measured as described herein. and the calculated stiffness of the same yarn bundle, in which the filaments can move completely freely relative to each other. Such toughness of the yarns of the invention makes it possible to withstand heat) l [and moisture treatment without the presence of adhesives or sizing agents, without the presence of adhesives or sizing agents, with the tightening effect of fitted inlet and outlet passages in the steam treatment chamber. brought about. The inlet passage has a diameter approximately the same as or less than the diameter of the yarn bundle, in which the yarn bundle is slightly compressed to provide a yarn bundle of surface-crimped filaments. It is truly surprising that the yarns of the products of the invention, which have tough properties, can exhibit a high degree of loftiness in the production of carpet finishes. The bending stiffness ratio is a measure of the degree of light bonding between filaments. At too low a bending stiffness ratio, there is too little bonding between the filaments in the yarn bundle and the carpet made from such yarn bundles spreads out giving a matte appearance. If the bending stiffness ratio is too high, there will be too many strong bonds, and the carpet made from the yarn bundle will be rough to the touch.
And the filaments are excessively fused.

The yarn bundle of the present invention is radially compressed while passing through the inlet and outlet passages of the steaming chamber, so that the filaments are compressed in the radial direction into filaments without such compression.
- than the properties of maki -i forces into tight alignment and the filaments are lightly bonded where they touch. Since the filament retains a substantial amount of its original crimp, these contact points are of limited area and the light bonding at the contact points results in later bending of the yarn during the tufting and carpeting process. virtually disappears when Nevertheless, the combination of light bonding and tighter alignment provides a desirable degree of toughness and cohesiveness to the products of the invention, without the expense of conventional gray twisting and heat setting. cut
Make it possible to use it on pets. A light bonding moment allows the bulk to be restored in the final carpet form.

The method of forming a light bond and tightness between the filaments of the inventive product is particularly advantageous when using unusually lofty delivery yarns. Such yarns would have large fillers, mendroops, extending from the yarn surface that could not be fed satisfactorily through the conventional yarn guideways and needles of standard fiber tufting machines. When such a yarn is operated in accordance with the present invention with the dimensions of the equipment adjusted to suit the product disclosed herein, the surface loops are sufficiently thin to feed the yarn satisfactorily through tufting. Compressed upwards, yet they are found to not fold and expand during carpet finishing to restore the desired bulk and texture.

The product is made by the following method. That is, one or more crimped multifilament polyamide yarns are fed under tension through a fitted inlet extending 5.1 cm or more in length and saturated with substantially no entrained water. A chamber of sufficient size and maintained at a high pressure equivalent to saturation at a particular excess of water vapor to allow water vapor to be applied and impinged against the axis of the yarn bundle, and for the filaments to spread out and be individually treated with water vapor. The bundle of yarns is heated for 150 msec or less, preferably about
The filament is exposed to water vapor for ~70 milliseconds and passed through an outlet that is as closely fitted as the inlet, preferably an outlet with a diameter of the same to about [17 times the diameter of the inlet, where the ratio of outlet to inlet tension is 1.1 to 1 ton or more and rolled up onto a package.

Referring to FIG. 1 (a schematic diagram of an apparatus for carrying out the method of the invention), one or more crimped continuous filament yarns 10 are taken from a supply package 12 and assembled into a yarn bundle 14 in a guide 16. The yarns are combined and directed through a steam treatment unit 18 in which the yarns are treated by impinging saturated steam at elevated pressure onto the yarns. Saturated steam is supplied from a source (not shown) and enters the steam treatment device 18 through the ξ eve 20. The treated yarn 22 is then sent through advance rolls 24 to a winding cage 26.

FIG. 2 shows a longitudinal cross-section of the steam treatment device 18 in FIG. 1, in which the yarn bundle 14 enters the inlet 28 and enters the chamber 5-2 through an elongated tube having a fitted passageway 30. There, a portion of the saturated steam moves from chamber 32 countercurrently to the direction of yarn movement and begins to heat yarn bundle 14. Once the yarn bundle enters chamber 52, it passes through orifice 64.
Saturated water vapor impinges on the chamber and the longitudinal axis of the yarn bundle, separating the filaments and heating them individually from all sides, after which the yarn exits the chamber 62 and exits via a fitted passageway 56. Pass through 58.

Passageway 30 should preferably have cylindrical holes of a sufficiently small diameter so that a substantial amount of water vapor does not escape from upstream inlet 28 under the particular operating conditions selected. On the other hand, it should not be so small that the friction between the yarn bundle and the inlet places too much tension on the yarn. The degree of crimp in the filaments, denier and number of filaments and other factors will influence the diameter chosen. Condensation of water vapor onto the incoming filament helps minimize leakage as at high yarn speeds.

The inner diameter of the chamber 52 in which the water vapor impinges on the yarn should be large enough to allow the filaments to spread apart and be treated with water vapor on all sides. Surprisingly, this inner diameter may in fact be smaller than the inner diameter of passageway 50 under certain operating modes. The tension on the filament is higher in the chamber than in the passageway 30 due to the increased drag between the yarn and the entrance wall as the yarn advances, and this tension combined with the increase in filament temperature causes the filament to Straighten temporarily. They thus occupy significantly less space than before and have much greater freedom of movement while being steamed.

The diameter of chamber 52 should not be so large that the yarn can avoid direct impingement of water vapor from orifice 54. Preferably, the maximum diameter of the chamber is about 1.5 times the diameter of passageway 50.

In chamber 50 the filament surface reaches its maximum temperature approaching that of water vapor. Water vapor td +d significantly lowers the melting point of the IJ amide yarn, molecularly deorients the surface or skin of the filaments and increases the "tack poiy" temperature at which the filaments form light bonds.
The limited penetration of water vapor prevents deorientation of the filament core, thus preserving desirable properties such as tenacity and the ability to recover crimp and bulk during carpet finishing. The skin that is deoriented is a small percentage of the total filament.

The steam-treated yarn then enters passageway 56, which can have the same or smaller internal diameter than passageway 50. Some leakage of downstream steam in this part of the device may be desirable. This is because the high velocity of water vapor flowing through the orifice 54 in order to adequately separate and treat the filaments requires a significantly higher water vapor delivery rate. Apart from leakage, a considerable amount of water vapor is carried downstream with the yarn. Therefore, the inner diameter of passageway 56 should be the same size as passageway 50, although the tension and temperature of the yarn will straighten the crimp and give the yarn a somewhat lower bulk than when it passes through inlet 28. I can do it. Alternatively, the inner diameter of the passage 56 is the same as that of the passage 60.
It can be about 0.7 times the inner diameter of.

The sealing effectiveness of the inlet and outlet passages depends on the combination of the diameters of both passages as compared to the diameter and length of the yarn. Very short passages would need to be very small to provide an adequate seal, but this would place too much tension on the yarn. For practical purposes, a length of 2 inches or more as measured from the water vapor impingement orifice 34 is preferred.

The outlet passage will preferably be longer than the inlet passage.

The ratio of yarn tension at the downstream outlet to yarn tension at the upstream inlet is useful for operational control. It is a la meter. It is a measure of the frictional drag imposed on the yarn during its passage through the steam treatment equipment over the course of a day. This ratio should be at least 11:1, as lower readings indicate insufficient sealing against water vapor leaks. Although there is no set upper limit, each product will have a preferred operating limit to avoid drawing out excessive crimp, bulk or tangles.

Water vapor dissipates from the yarn as it exits outlet 58 into atmospheric pressure. By rotating the winding twin cage or by increasing the distance between the steam treatment device 18 and the winding package, the yarn can be suitably cooled and dried. If forced cooling is required, it should be done in a manner that does not cause the filament to separate, for example by being treated with cooling air under confined conditions similar to those in outlet 5B and in contact with a heat sink.

It is important that the saturated steam supplied through the PI F20 is substantially free of entrained water, since the presence of liquid condensate is important for t? This is because it causes variations in the dye receptivity of the IJ amide yarn. For this purpose, one or more condensate separators 40 can be provided in the feed line leading to the pipe 20, and this line and the
The tube should be maintained at the desired temperature in a known manner, such as by wrapping an electrically heated wire 42 around the line or steam path.

When using yarns with different dyeability or different properties therein, the different components will not be affected in the same way by the operating conditions.

For example, low melting point filaments will deorient too much and melt, giving an undesirable rough and stiff product. The most favorable operating conditions for such products can be determined by experiment.

Preferred articles of the invention are made from two or more crimped yarns 10 having at least two different colors or dyes, wherein Nelson (Ngμ50) U.S. Pat. , 543.146, at least one, but not all, of the yarns are twisted together and then all of the yarns are entangled together.

Cut the above preferred products of the present invention! When fabricated, dyed and finished into fiber carpet, the additional bonding imparted to the yarns by radial compression in the outlet 38 brings the fibers into the inter-fiber position they existed during use and during operation. to maintain the fixed position. Therefore, the filaments of a given color remain substantially together giving the appearance of a distinct spot of color and a distinct tact of the section. Nelson's U.S. Patent No. 4. ! 143,1
The yarns described in No. 46 are particularly useful in operation according to the present invention. In yarns with too little or no light bond formation, the filaments of a given color can separate and intermingle with filaments of a different color, giving a dull and dull appearance.

The lateral pull-off test directly measures the lateral bundle cohesion of the yarn. Two hooks are placed at randomly selected points near the center of the yarn bundle to separate the yarn bundle into two groups of filaments. 'By a tensile test to measure separation drag, such as on an Instron 1 machine, the two hooks were placed at an angle of 90° to the yarn axis at 5 inches/min (12,7 cyn 1 min).
pull away at a speed of

The hooks pull the yarn apart until a force of 1 ind (4s4.9) is exerted, at which point the machine is stopped and the distance between the two hooks is measured and recorded. Measure 10 times and take the average as the pull value. The length of the test yarn should be at least 4 to 6 inches (10 to 15 cm) and randomly selected from the entire yarn cage.

Typically, in yarns consisting of two or more feed yarns, the component yarns are not differentiated and therefore placing the hooks at random locations in the yarn provides a satisfactory measure of east cohesion. If the component yarns are distinguishable, the hooks are such that when the fibers pass water vapor through at least two components, their outer regions are partially melted and deorientated, resulting in a skin/core structure. Evidence of deorientation is shown below with a refractive index of "1sr1"
．． This can be seen by observing the fiber in a core-matched refractive index liquid chosen to calibrate tt. n
, the fringes passing through the skin are shifted in the direction corresponding to a higher refractive index than the core. Conversely, when examining n, the fringe transition in the skin corresponds to a lower refractive index compared to the core. The difference in refractive index, or birefringence, of the skin is smaller than that of the core. Since birefringence reflects molecular orientation, the skin is deoriented.

Additional evidence of deoriented skin can be observed with polarized light microscopy. By carefully separating the two joined fibers, the skin can be inspected.

When viewed at a 45° position, most of the skin appears anisotropic between crossed polarizations.

SDI is an experimental measure of disorientation in the skin.

It is a value related to the difference in refractive index between the skin and the core for light polarized parallel to the fiber axis, which is modulated by the thickness of the skin.

It is inferred from observation of the fiber with a two-beam line (Laitz) transmission optical interference microscope set up in a fringe field fashion. Illumination is provided by a mercury arc lamp filtered to give a wavelength of 541 m. The fibers are manufactured by R & P, Cargill Laboratories, Inc.
atories.

Core-matched refractive index liquid (wavelength 589 1.2
Nominal expansion 500 in nominal value 1.572 at 5°C
Observed at double magnification. The procedure for calculating SDI requires measuring the fringe transition d in the skin in relation to the inter-fringe spacing, as shown in FIG. This is verified with the aid of an interferometric drum compensator and an eyepiece hair reticle. D is a mechanical constant and in this machine corresponds to 210.degree. 5 degree graduations on the drum scale for a wavelength of 54177L.

The sample is prepared as follows: a flat microscope slide is immersed in half with some fibers placed on top of both halves in the chosen solution. Place a cover slip over both slides. Place one slide pre-5 on the microscope stage and position the fiber in the field of view. Place the other plate without fibers in view on the reference stage of the suspension microscope. This is a standard method to ensure that the two beams of the interferometer have the same length path. The interferometer is adjusted so that a vertical fringe is in view and one fiber is oriented perpendicular to the fringe. The microscope analyzer is set to transmit light that oscillates 7 parallel to the fiber axis. The interferometer is adjusted to give the sharpest fringes.

Preliminary observations are necessary to select a liquid with a core-matching index of refraction. The choice of this liquid is determined by sequentially immersing the fibers in liquids of a series of refractive indices. The liquid compatible with the core is the liquid that produces minimal fringe transition inside the fiber. When measuring hollow fibers, ignore the area corresponding to the hollow part of the fiber.

A region of fibers is first selected where the fringe transitions in the skin are clearly delineated. For example, a hollow approximately square cross-section requires a suitable orientation with respect to the light beam.

A suitable position is such that the fiber is placed on one of its edges so that three voids are visible. This is illustrated in Figures 4a and 4h. If only two voids are observed, the fibers lie on one plane as shown in Figures 5a and 5b. In such cases, the 9 turns of the fringe in the skin are obscured by refraction effects and d cannot be measured. In the case of fibers with a star-shaped cross-section, such as Triroll Pal, measurements are taken from the protrusion whose skin is not covered by other protrusions. In the posture shown in Fig. 6, the measurement is made on the protrusion A.
protrusions B and C cannot be measured because their images are doubled.

To measure the drum compensator, rotate the drum compensator until the first turn of the fringe is positioned so that the background fringe is on the vertical line of the reticle; record the corresponding compensator reading. This turn is then translated until the area of the fringe where the displacement is greatest (i.e. in the skin) coincides with the vertical line; the reading of this new compensator is recorded. The absolute value of the difference between the two readings is d. The SDI is calculated as follows: 5DI = - The fibers of the invention have an SDI of at least 0.05.

Irohiro! The approximate thickness of the leather can be obtained by photographing the fibers at 500x magnification in the fringe field format. Skin thickness is measured from micrographs with a 4x magnification including a 5 (1W reticle scale) in 0.1α increments.・Zeiss) 500 times more magnified than others
Corrected from a mirror photo. The skin thickness is always less than 4 μm.

Bending Stiffness Ratio Bending Stiffness Ratio (R/R) Fi The bending stiffness fm of a yarn is measured (R) and the calculated stiffness (Rc
fm) (where the subscript stands for “complete freedom of movement” (C
The bending stiffness of a complete FrgetLon of yarn can be determined by a number of techniques, such as IDR, Neadham, Massachusetts, USA (IRR, Neadham, USA)
Ma! 1 tachusgttz.

Mitex MK■ (Mitg, x
J/Arm) bending tester. In this test, referring to Figure 7,
A yarn sample 60 approximately 2 inches (5,1α) in length is inserted onto block 65 between pins 61 and 62 provided between pin 64 and arm 66 as shown. Next, adjust the pin 64 installed on the micrometer 65 to
o into light contact with the arm 66 of the force transducer 67. The distance from pin 62 to arm 66 is 1 inch. Block 65 moves to bend the sample into an arc in which the curvature of the yarn (curvature -1/radius of curvature) gradually increases.

This deformation is achieved by the movement of block 65. The maximum curvature is 1.5 inches-1. The outputs of the force transducer and the block rotation transducer are fed to an X-Y recorder. Since the bending moment on the sample is equal to the force on the force transducer multiplied by the distance between pins 64 and 66 and the curvature is proportional to the rotation of the block, the plot of the output is the yarn moment - curvature Give a response.

The slope of the moment-curvature plot is equal to the stiffness of the sample and has units of Kerr length'. Before the measurements are taken, the machine determines the thickness O, OO'1 inserted instead of the yarn.
inch (0,0025cr+t), width 0.5 inch (
Corrected by measuring the inclination of a piece of stainless steel with a calculated stiffness of 1.27 g). The stiffness of the stainless steel correction piece is calculated by the following formula: Rc = wct
c3Ec/12 where Rc=rigidity ul of the correction piece, ,=width of the correction piece=α5 inch 1c=thickness of the correction piece=α001 inchEC=4! Positive piece nownr rate = 3 [1,000,000
psi Therefore: Rc = 1250 inches 1 bond.

Dividing the slope of the plot of the correction piece into the calculated stiffness of the correction piece gives the correction coefficient. The stiffness of any unknown yarn sample is equal to its slope times the correction factor.

Five yarn samples from each item are measured as above and the results are averaged to give the value of R.

The RcfmO value is calculated by multiplying the stiffness of the cylinder with the Young's modulus of the fibers by the number of fibers.

In terms of a combined "textile" and engineering units, the relationship can be written as follows: where: f = 3.02X10-" pounds, inches 2/(
Denier) (cc) Nf = number of filaments in the yarn (calculated from the ratio of yarn to filament denier) E1 = fiber modulus (I!/denier) Wf = filament linear density (denier) d, 1 = filament density (g/eC) Next, divide R by Rcf, 71 to give the bending rigidity for each item.

EXAMPLES Example 1 Various crimped multifilament yarns are intertwined in several ways and passed through a saturated steam treatment apparatus under the conditions shown in Table 1 below.

Feed yarn A is 1225 denier, 1 per filament
9 denier cationically dyeable jet-bulked continuous filament nylon 66 yarn, each filament having a generally square cross section with rounded edges and a continuous void near the can rim. It is. Yarn B is the same as Yarn A except that it can be lightly acid dyed. Yarn C is the same as Yarn A except that it can be darkly acid dyed, but in addition, it has conductive carbon in the window for antistatic purposes as described in U.S. Pat. No. 3,803.453. It has denier 5 filament yarn. Yarn D is a 17507'neel, 6.51 denier per filament nylon high bulk continuous filament yarn, each filament having six voids of pentagonal cross section. The process of intertwining with the jets follows the disclosure of the patents listed in Table 1.

The steam treatment device G has an inlet 28 having a passage 50 with a length of 8 inches (2 (L!+am)) and an inner diameter of 0.070 inches (α178 tan), and an inlet 28 with a length of 1.00 inches (2.54 mm) and an inner diameter of 0.07 mm. 062 inch (α157cm) diameter 52 and diameter 0
．． 0.46 inch (0,117 cIL) orifice 5
4, and 12 inches long (50,50111) with 0 inner diameter
．． It consists of an outlet 38 having a 0.070 yte (0.178 cm) O passage 36.

Steam treatment device H is similar to G, and the inner diameter of the carrier passage 50 and passage 56 is 0.052 inches (a1526IIL
). The temperature of the water vapor in the tube 20 is approximately 5 inches (7.6 cm) at the orifice 54 in the tube 20.
) measured by a thermocouple inserted upstream.

The temperature of the water vapor in the chamber 52 is determined by the device G having perforations inside the chamber.
The temperature is measured by a thermocouple inserted into the wall of the chamber 52 opposite the orifice 34.

The yarn properties are shown in Table 1. Item 2, which is not steam treated, shows the low flexural stiffness ratio characteristics of the untreated yarn and the filament skin is not modified. Item 5
% 6.10 and 11 indicate that although steam treated, the properties are below acceptable levels.

Item 12 has filament fusion within acceptable limits, while item 15 is so strongly fused that many of the filaments cannot be separated. Items 10 to 15 are nylon 66
Nylon 6 has a very low melting point.

The time that the yarn is exposed to steam is considered to be the total time that the yarn spends in the steam treatment device 18 of FIG. This is from the inlet 28 of the device to the outlet 58'j! , is determined by dividing the total length at , by the yarn speed.

No substantial amount of water vapor was observed escaping from the inlet during the test.

Example 2 The yarns of items 6-9 of Example 1 were cut into 1/8 inch (3,1
s Yukiyuki) Turn it into a carpet with r-zu and soshite 5/
16 inch (8 m) cut - tacked to 32 oz/yd" (j, 086 kg/ly/) at pile height and dyed under the same conditions. Item 6 exhibits some tuft characteristics. Item 9 has cohesive tufts with less intermixing of filaments and adjacent tufts, but the carpet is still soft and resilient without roughness.Items 7 and 8 are intermediate in tuft properties.

Example 5 Three strands of cationically dyeable feed yarn A were entangled with a copolymer with sodium tartrate having a lower melting point than yarns B and C, so that under similar conditions the filaments were Items 1.2.4 or 5-9 can be expected to bind to a greater degree. The yarns were processed at a range of temperatures and exhibited products ranging from insufficiently to excessively bonded. This is a more advanced test than Item 5.

It can be seen from the data in Table 2 that items 14-16 have flexural stiffness ratios of about 20 or less, and have skin thicknesses and orientation indices that are too small to accurately measure K.

Example 4 1/8 inch (518 m) yarn of items 14-24
r-? , tufted into carpet at 52 oz/yd" (1,086 yd/-) to a 5/16" (8 m) cut quill height and dyed under the same conditions. Item 1
Nos. 4 to 16 have less agglomeration within the tufts, and the filaments of each tuft spread out and mix with neighboring tufts, giving a uniform matte appearance. Items 17-22 exhibit a contiguous nature in which the filaments are less likely to intermingle with nearby tufts, yet the carpet is soft, non-rough and resilient. Items 23 and 24 are excessively fused at rough edges L2.

Example 5 This example shows that the filaments are lightly bonded. The yarn was examined in detail as follows.

To avoid disturbing the structure of the yarn, the yarn is embedded in an epoxy matrix before cutting into cross sections. K does this by placing the sample yarn into the mold. Pour epoxy around it and let it cure. The cured sample block is removed from the mold, shaped and cross-sectioned with a microtome. Photograph the cross section on a microscope slide at appropriate magnification.

Spray the coated mold lightly with mold release agent and line each recess with cellophane tape. double-sided masking tool f
([approximately 6 folded) small "pillow"(" piLL
oup'') at the end of each recess.

Before placing the yarn into the mold, prepare the yarn as follows. Tape both ends of the Habo 200111 yarn using small pieces of masking tape, attach clamps to both ends, and hang the yarn from the hook on the stand. Apply sufficient weight to the lower clamp to stretch out the crimp, but be careful not to stretch the yarn. Using an eye dropper, apply a few drops of clear acrylic lacquer at a time and run down the yarn.

Ten applications are applied approximately 5 minutes apart and the sample is then left to dry for approximately 2 hours.

The coated sample is placed in the recess of the mold on top of one of the pillows 1, so that the sample is below the surface of the mold but does not touch the bottom. Trim the excess yarn from it.

An epoxy resin that fills ~8 mold cavities is prepared by mixing the following: Magra: x, (M
etrgLa, z) Resin 658 Clear Epoxy Casting Resin (Acta Chemicals & Insulation)
Can A? Knee ffH1, 7g Margras (Mar, qL
az) Resin 659 Clear Epoxy Casting Resin (Acta Chemicals & Insulation)
Kanno guni g) a, ay mala set” (Maraza
t) Modified Soamine Curing Agent 558 (Acme Chemicals & Insulation)
Company) 25. (1) Stir the resin mixture gently for about 5 minutes without bubble formation. Stirring should be continued until the solution becomes clear.

This solution is then poured over each sample. Air bubbles can be removed by manipulating the sample with a pair of tweezers. If the sample sinks to the bottom of the mold or rises to the top, the yarn must be repositioned. The resin was incubated at room temperature for 16 hours (or at 65°C).
It can be cured in 5 hours).

After curing, the room temperature cured mold is placed on a heating table for about 15 minutes. The warm sample block can be removed from the mold by grasping the end of the cellophane tube. (The oven-cured samples are removed from the mold immediately after removal from the oven.) The sample blocks are cooled on a flat surface and the cellophane tubes are removed.

Each sample block is molded and then placed on a warming table for approximately 2 minutes to loosen the filament. The sample block is then mounted in a microtome (Rotary Model 820 - American Optical) and sections 7 microns thick are made. Discard the first few sections. Good sections (no knife blade marks or puncture marks for obvious air bubbles or filaments) are prepared using Primol®.
555 (ga=15) or mineral oil (roux 1.47)
) onto a thinly coated microscope slide. Examine the section under the microscope and, when satisfied, place a coverslip over the specimen. Take a photo with appropriate magnification.

After carpet processing (but before applying latex), the yarn from the carpet tuft is cut into cross sections as described above, but only in one or different directions. This is because the length of the yarn is very short (Habo 1
5fi), so it is not suspended and cannot be filled with clear acrylic lacquer. It is simply held in the center of the mold using a pillow of tape and not touching the top or bottom of the mold.

Cross-sectional photographs of the yarn before and after carpet processing show that the fusion point increases with increasing water vapor temperature and that the fusion point is lost after the carpet processing operation. Cohesion is determined by examining cross-sectional photographs for loss of the boundary section between two contacting filaments.

This is shown in Figure 8, which is a cross-sectional photograph of item 21 before processing. Item 21 has some fusing points remaining after carpet processing, and the amount of fusing points increases as the water vapor temperature increases between items 22 and 24.

Examples The examples in the examples show that above the temperature at which light bonds initially form, the amount and strength of bonds increases as the temperature of the water vapor increases.

Teff the length of yarn. 7 (Ttflo) Place it on a block made of tetrafluoroethylene resin.

Cut yarn sections approximately 5 nm in length by placing a razor blade on the block at a 50'' angle and pulling it twice across the yarn without disturbing the bonds between the filaments present in the cut yarn sections. Care should be taken to ensure that the sample section has average visually obvious bundle agglomeration.The sample section should also be cut out of the yarn in areas with average visually apparent bundle aggregation.
Should not be cut from the tightly tied yarn area as in. The section is thus cut from a yarn with substantially intact bonds between the filaments.

Water 150-
Place in a 250-glass beaker containing.

B. Brown Melsonken ar p- (B.

Braun-Sonic (BRAUN-5ONIC) 7510 manufactured by Braun MgLrwrggn AG)
A sonic eraser is immersed in the water and the sample is agitated for 5 minutes at approximately 400 watts. The separation of the sectioned yarn bundle into individual filaments is then observed.

5 Upon stirring, the yarn bundle is completely separated into individual filaments.

6 Upon stirring, the yarn bundle is completely separated into individual filaments.

7 Following agitation, the yarn bundle separates into two large parts: about 6 agglomerates of filaments and about 12-24 individual filaments.

8 The bundle remains intact except for about 15 filaments that have been separated.

9 The bundle remains intact except for about 5 filaments that have separated.

Table 2 14 5(A) U.S. Patent 4,059,873
9050.0354 G No water vapor No water vapor 37.47. F3155.2
131.5 3875.3#
157.9 156°0 3814.0#
161.1 13&2 3
840.0164.1 14'5.5 5B42.7
167.2 145.8 3899.9169.
9 149.2 3877.71
173.0 153.4 3856.8175.
9 156.3 5917.917&9 160.
1 3905.50.0550 1
1.8 164.4 5897.2

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus for carrying out the method of the invention. FIG. 2 is a longitudinal cross-sectional view taken along line 2--2 of FIG. FIG. 5 is a schematic drawing showing the fringe transition (frin, qg 5hift ) characterizing the skin-core orientation difference and skin thickness. This is an interference micrograph of . Figures 4b and 5b are schematic cross-sectional views of the filament locations from which the micrographs of Figures 4a and 5a were taken. FIG. 6 is a schematic cross-sectional view of a trilobal filament. FIG. 7 is a schematic drawing of an instrument for measuring the bending stiffness of yarn samples. No. 81 is a photograph of a cross section of the yarn of the present invention. In FIG. 1, 10...... crimped continuous two: Ilament yarn, 12...... Supply package. 14...... Yarn bundle, 16...
...Guide, 18...Steam treatment equipment. 1 other person FIG, 4B S, ≧drop, (B Gansu 111, +., +5 + Berinya 1
51. Engraving of thermal drawing (no changes in content) FIG, 8, ・ , ・′ ;・ 7 1 ′ Puff.゛ 、・ 、 r---7-'''～” T9 to Pot
′ ・ To ′ / ・ ・ 2.゛-' , 5 ・ +-' Procedural amendment (Ryu) October 29, 1985

Claims (1)

Claims: 1. A substantially untwisted multifilament polyamide yarn comprising a plurality of crimped filaments having an oriented core portion and a deoriented skin portion, the yarn comprising:
The yarn has a bending stiffness ratio (R/R_c_f_m) of approximately 20.
and less than about 200, the filaments having a skin disorientation index of greater than about 0.05. 2. The thickness of the deoriented skin portion of the filament is approximately 0.
The yarn of claim 1 further characterized in that the yarn is greater than 4 micrometers and less than about 4.0 micrometers. 3. The yarn of claim 2, wherein the number of filaments is less than about 500 and the denier per filament is greater than about 5 and less than about 40. 4. The yarn of claim 1, wherein the skin disorientation index is less than about 0.5. 5, R/R_c_f_m is greater than 20 and 75
3. A yarn according to claim 2, which is smaller than . 6. The yarn of claim 5 further characterized in that the lateral pull-off distance is greater than about 0.25 cm and less than about 10 cm. 7. The thickness of the deoriented skin part of the filament is 0.8
Yarn according to claim 6, which is larger than a micrometer and smaller than 1.5 micrometers. 8. Yarn according to claim 1, in which some of the filaments are loosely bonded. 9. The multifilament polyamide yarn has a twist of about 0.33 to 2.0 per cm.
Yarn as described in section. 10. A method of treating a crimped multifilament polyamide yarn bundle with saturated steam under tension, the method comprising: a) feeding the yarn bundle through a tightly fitted inlet; saturated steam supplied into the chamber for more than about 15 milliseconds and about 150 milliseconds.
impinging for a period of less than milliseconds, wherein the chamber is large enough for the filaments to spread out and be individually treated with steam, and c) passing the filaments through a tightly fitted outlet; A method for processing a crimped multifilament polyamide yarn bundle, comprising the steps of: 11. The method of claim 10, wherein the diameter of the outlet is greater than about 0.7 times the diameter of the inlet and less than about 1.0 times the diameter of the inlet. 12. The method of claim 11, wherein the diameter of the chamber is less than 1.5 times the diameter of the inlet. 13. The method of claim 12, wherein the ratio of outlet to inlet tension is greater than about 1.1 to 1. 14. The method according to claim 15, wherein the saturated steam does not substantially contain entrained water. 15. Claim 14, wherein the crimped multifilament polyamide yarn is substantially untwisted.
The method described in section. 16. The method of claim 11, wherein the internal diameter of the inlet passageway is sufficiently small that no substantial amount of water vapor escapes through the upstream inlet.