US2575781A

US2575781A - Method of crimping textile fibers

Info

Publication number: US2575781A
Application number: US121440A
Authority: US
Inventors: Joseph L Barach
Original assignee: ALEXANDER SMITH Inc
Current assignee: ALEXANDER SMITH Inc
Priority date: 1949-10-14
Filing date: 1949-10-14
Publication date: 1951-11-20
Anticipated expiration: 1968-11-20
Also published as: NL164588B

Description

Nov. 20, 1951 J. l.. BARACH METHOD OF CRIMPING TEXTILE FIERS `Filed Oct. 14, 1949 Nm mln; m Wm. j m vm mw n 5 m E y ux S WIM 2:. :am m A d mw mw Nw ww mw Wm b. mw Q ww -H N uw NM mw TTOP/VEY Patented Nov. 20, 1951 METHOD CRIMPING TEXTILE FIBERS Joseph L. Barach, Montclair, N. J., assignor to Alexander Smith, Incorporated, a corporation of New York Application October 14, 1949, Serial No. 121,440

This invention relates to a method for crimping textile fibers, and more particularly to a method for imparting a controlled crimp to wool and other naturally resilient fibers having similar characteristics.

An object of the invention is to provide a novel and improved method for producing a fiber characterized by a predominant sharp, angular bend or crimp with the portions between bends substantially straight.

Another object is to provide a, crimping method which is readily controllable for producing a uniformly crimped product.

Another object is to provide a method for pretreating the fibers prior to crimping for improving their crimp characteristics.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

' In one form of crimping apparatus the crimp is produced mechanically by feeding the pretreated iibers in the form of a slubbing between feed rolls into a crimping chamber which is maintained full of fibers under a predetermined back pressure. As the fibers are forcedfinto the crimping chamber, they are laid in a zig-zag form and are pressed to form sharp angular bends or crimps with intervening straight portions, the

- length of which depends upon several factors,

such as the characteristics of the fibers and .the pressure, temperature, and moisture conditions to which the fibers are subjected.

The crimp is set by treatment in a setting chamber with a setting agent under controlled conditions of time, temperature, moisture and pH in the range below which the natural resilience of the fibers resists deformation and above which degradation occurs, the relationship being such that the fibers are brought to the plastic condition necessary for the formation of a permanent crimp.

In accordance with the present invention the slubbing is pretreated for softening and heating the fibers before introducing them into the crimping chambery Such pretreatment may comprise subjecting the fibers to hot water, chemicals or steam under conditions to introduce moisture, produce swelling and softening andv raise the temperature to a point sufficiently high to presoften the fibers and condition them for crimping.

This pretreatment has been found to result in a higher crimp frequency (more crimps per inch) a lower crimp amplitude, and a more uniform crimp throughoutthe cross section of the slub- 4 Claims. (Cl. 19-66) bing than that produced under the same crimping and setting conditions, but Without the pretreatment.

The novel features which are characteristic of this invention will be better understood by referring to the following description, taken in connection with the accompanying drawings in which a specific form of crimping apparatus has been set forth for purposes of illustration.

In the drawings:

Fig. 1 is'a vertical section through an apparatus for carrying outthe present process; and

Fig. 2 is a detail view of a different form of pretreating apparatus. i

Referring to the drawings more In detail, the crimper is shown as comprising a frame `IU carrying a pair of feed rolls II and I2 and drive shaft I3. The shaft I3 is journalled in the frame I0 and carries a pinion I5 and a sprocket I4 which is driven by a suitable power source, not shown. The feed roll II is keyed to a shaft I6 journalled in the frame IIJ and carrying a gear Il meshing with the pinion I5. The feed roll I2 is keyed to a shaft journalled in bearing blocks 2I which are slidable in the frame I0. The roll |12 is held in pressure engagement with the material fed between the rolls by springs 22 seated around threaded rods 23 which bear against the bearing blocks ZI. Tr rods 23 exte d through a bracket 24 attached to the frame I0 and carry nuts 25 and adjusting knobs 26. The nuts 25 are held against rotation by the frame III. The springs 22 are seated between the nuts 25 and the bracket 24 and their tension may be adjusted by means of the knobs 26.

The shaft 20 carries a gear 3U meshing with the gear I-8. The gears IB and have teeth of sufhcient depth to remain in mesh throughout the normal range of sliding movement of the shaft 2D during the operation of the crimper.

Positioned below the rolls II and I2 is a vertical tube 33 having a tapered bore 34,. forming a setting chamber. The tube 33 is attached t0 a. saddle 35 having a tapered central bore 33 forming a crimping chamber and having a curved upper surface 31 conforming to the bight of the rolls II and I2 and machined to have a slight running clearance from the surfaces of the rolls.

. The saddle 35 is attached to the frame In and has a plurality of radial passages 42 for the injection of the setting agent into the crimping chamber. The radial passages 42 communicate with an annular passage 43 in the saddle 35 which is closed bya collar 44 to form an inlet manifold. The

y setting agent is supplied to the annular passagev Il by a pipe II registering with a port 48 in said collar and connected to a header 62. A valve 41 controls the flow of setting agent through the pipe 45. A plurality of annular manifolds '60 are disposed around the tube 33 at spaced points along its axis and are connected with the bore 34 by rows of ports BI which are spaced around the periphery of the tube. The manifolds are connected to the header 62 by individual pipes 83, each controlled by a valve 64. The header 62 communicates with a supply pipe 65 through which the setting agent is introduced.

At its 'lwerl end the tube $3 carries a flanged extension 50 to which a door 52 is hinged by hinge 53 and is held closed against the tapered end 54 of the extension 5D by a weight -55 attached to an arm 56 secured to the door.

The pretreating apparatus shown in Fig. l comprises a tank 'I0 containing the pretreating liquid 'II such as water or a chemical softening agent such as thioglycolic acid. The liquid 'II is heated by steam which may be introduced directly by a perforated steam pipe 'I3 or by a heating coil if desired. The fibers to be treated are passed in the form of a condensed tow or slubbing 'Il between feed rolls I5 into the liquid 'II in the tank '|0.and are withdrawn between feed rolls 16 and passed over a roll y5'! to the crimping rolls I I and I2. The feed rolls 'I6 squeeze the excess moisture from the slubbing and are adjusted in accordance with the desired moisture content of the slubbing fed to the crimping chamber. The feed rolls 'I5 and 'I6 are operated at a rate to produce the desired time of treatment in the liquid 1I.

In the embodiment of Fig. 2 the slubbing 14 is fed by feed rolls 80 and 8| through a chamber -82 to which steam is supplied from steam pipe 83. The direction of feed of the slubbing is counter to the steam and any excess condensed moisture drains out of the end of the chamber. In this form the time of treatment is determined by the rate of the feed rolls and temperature is determined by the condition and quantity of the steam. The slubbing 'I4 is fed from the chamber 81 over the roll 51 to the crimping chamber as in Fis'. l.

In operation the raw wool is first opened, scoured, for example with soap and soda, ash in several stages, then washed and dried in the usual manner to form a stock wool. This scoured stock wool is fed to a web-forming device such as a card and condensed into a rope 14 which is fed to the pretreating tank 'I0 of Fig. l or to the chamber 82 of Fig. 2, from which it is fed over the guide roll 51 to the feed rolls II and I2 as a sliver or slubbing. The pretreating tank 10 may contain water or a chemical setting agent such as thioglycolic acid which is heated to the desired temperature, for example 212 F. by the steam pipe 13. The time of treatment is such as to cause the desired amount of moisture to be absorbed within the fibers, for example from 20% to 30%, for swelling and softening and to be uniformly heated to a temperature approximating that of the bath.

In the form of apparatus shown in Fig. 2 the fibers are subjected to steam, preferably saturated steam under conditions to absorb the desired amount of moisture and to be heated as above stated. The pH may also be controlled to facilitate the swelling and softening of the fibers.

In either case, the pretreated fibers are then stuffed by the feed rolls I I and I 2 into the crimping chamber and through the setting chamber 4 and are forced out of the bottom of the setting chamber against the pressure exerted by the discharge door 52. The fibers are held in the crimping and setting chambers by the door until they have been packed sufliciently to force the door slightly open against the force of the weight Il. 'I'he back pressure of the packed fibers causes the fibers being forced against the packed fibers by the feed rolls to be folded over in zig-zag crimps. the spacing of which depends upon the nature of the fibers, the pretreatment. and the back pressure.

The setting agent which may comprise superheated water, steam, or a chemical is introduced through the pipe 65, header 62, and passages 42 and 6I into the mass of packed fibers. Such chemical setting agents as thioglycolic acid and its salts, such as calcium or sodium thioglycolate, formaldehyde, a sulfoxylate formaldehyde. such as or sodium, and the like, may be used.

The distribution of the setting agent along the crimping and setting chambers is controlled by adjustment of the valves 41 and 64. The distribution is selected to maintain the mass of fibers at the optimum conditions of moisture content and temperature during their entire time in the setting chamber. The setting agent may be heated to a temperature between 212 F. and 275 F. Steam or superheated water at a pressure of l5 pounds per square inch and at a corresponding temperature is preferred.

The density of the mass of fibers is sufficient to maintain the setting agent under pressure while its heat is being transferred to the fibers.4 The quantity of setting agent introduced is controlled in accordance with the desired temperature and moisture content of the fibers. Any excess of water drains out of the bottom of the chamber.

The back pressure at the entrance of the crimping chamber affects the size of the crimp, a higher pressure causing a finer crimp (more crimps per inch) and vice versa. For equilibrium conditions of moisture content and pH, the setting time varies inversely with the temperature.

'I'he quantity and distribution of the setting agent should be selected to cause the fibers to reach rapidly the desired temperature and moisture content and to maintain these conditions during their entire passage through the chambers. The fibers are thus crimped uniformly and under accurately controlled conditions of time, temperature and moisture.

'I'he crimped fibers emerge from the crimper in the form of a very condensed tow or rope, which is easilyopened and separated. It may then be dried, carded and spun in the usual manner.

The fiber thus crimped is characterized by sharp angular bends or crimps which may or may not be uniformly spaced, but are separated by relatively straight lengths of fiber. It may be spun into yarn and skein dyed or may be pickedandstock dyed in the usual manner.

It is evident that changes and modifications may be made without departing from the scope of the invention.

What is claimed is:

1. The method of imparting an artificial crimp to textile fibers, which comprises passing said fibers through a zone containing a heated fluid and moisture, maintaining the fibers in said zone for a time to presoften the fibers for crimping, gripping said fibers between closely spaced conveyor surfaces discharging into a substantially closed zone, and forcing the gripped fibers into said zone against the pressure of a mass of fibers held compacted under pressure in saidzone, said pressure being adapted to cause the fibers to be progressively folded over and crimped as they are delivered from said conveyor surfaces, holding the mass of crimped fibers compacted under a substantially constant pressure to retain the crimp therein, introducing a setting agent under pressure into said zone, treating the mass while thus compacted with said" setting agent under conditions to produce a permanent set of said crimp in said fibers, and withdrawing the crimped fibers from said zone.

2. The method set forth in claim 1 in which the fibers are pretreated with hot water for a time to cause the fibers to absorb within the fibers about 2O to 30% of their weight of water.

3. The method set forth in claim 1 in which the bers are pretreated with steam for a time to cause the fibers to absorb within the fibers about 20% to 30% of their weight of moisture.

6 4. The method set forth in claim 1 in which the fibers are pretreated with a thioglycolic acid for a time to cause the bers to absorb within the fibers about 20% to 30% of their weight of moisture.

JOSEPH L. BARACH.

REFERENCES CITED The following references are of record. in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,300,791 Lodge Nov. 3, 1942I 2,321,757 Lodge June ll5, 1943 2,435,891 Lodge Feb. 1.0, 1948 2,505,618 Hammerle Apr. 25, 1950 2,514,557 Pfau July 11, 1950

Claims

1. THE METHOD OF IMPARTING AN ARTIFICIAL CRIMP TO TEXTILE FIBERS, WHICH COMPRISE SPASSING SAID FIBERS THROUGH A ZONE CONTAINING A HEATED FLUID AND MOISTURE, MAINTAINING THE FIBERS IN SAID ZONE FOR A TIME TO PRESOFTEN THE FIBERS FOR CRIMPING, GRIPPING SAID FIBERS BETWEEN CLOSELY SPACED CONVEYOR SURFACES DISCHARGING INTO A SUBSTANTIALLY CLOSED ZONE, AND FORCING THE GRIPPED FIBERS INTO SAID ZONE AGAINST THE PRESSURE OF A MASS OF FIBERS HELD COMPACTED UNDER PRESSURE IN SAID ZONE, SAID PRESSURE BEING ADAPTED TO CAUSE THE FIBERS TO BE PROGRESSIVELY FOLDED OVER AND CRIMPED AS THEY ARE DELIVERED FROM SAID CONVEYOR SURFACES, HOLDING THE MASS OF CRIMPED FIBERS COMPACTED UNDER A SUBSTANTIALLY CONSTANT PRESSURE TO RETAIN THE CRIMP THEREIN, INTRODUCISNG A SETTING AGENT THE PRESSURE INTO SAID ZONE, TREATING THE MASS WHILE THUS COMPACTED WITH SAID SETTING AGENT UNDER CONDITIONS TO PRODUCE A PERMANENT SET OF SAID CRIMP IN SAID FIBERS, AND WITHDRAWING THE CRIMPED FIBERS FROM SAID ZONE.