US2957224A - Apparatus for helically crimping thermoplastic threads - Google Patents

Description

J. BILLION Oct. 25, 1960 APPARATUS FOR HELICALLY CRIMPING THERMOPLASTIC THREADS Original Filed Feb. 17, 1954 INVENTORJ #44055 15/11 /0/1 ATTORNEYS.

APPARATUS FOR HELICALLY CRIMPING THERMOPLASTKC THREADS Jacques Billion, 21 Rue Puits Gaillot, Lyon, France Original application Feb. 17, 1954, Ser. No. 410,9625,

now Patent No. 2,881,504, dated Apr. 14, 1959. D1- vided and this application Oct. 5, 1955, Ser. .No. 538,646

Claims priority, application France Feb. '24, 1953 1 Claim. (Cl. 28-1) The present invention relates to apparatus for imparting a helical crimp or deformation to thermoplastic threads to increase the flufliness of the threads themselves and of fabrics woven therefrom.

This application is a division of my copending-application, Serial No. 410,968, filed on February 17, 1954, now US. Patent No. 2,881,504, for a Process for Crimping Textile Threads.

When textile threads in general, and threads with continuous fibers in particular, are made up into textile articles by knitting, weaving or the like, they have the disadvantage of being relatively flat, without firmness, and inelastic.

For this reason various attempts have been made in very many applications to improve this state of affairs and to impart more elasticity, bulkiness or fiufliness and firmness to such threads, and consequently to the fabrics or other articles made therefrom.

This result is usually obtained by imparting to the threads a high twist, of the order of 2,000 to 3,000 turns per metre, for example.

These high twist threads are known as crepe threads.

But, although this creping or high twist process can easily be carried out with certain threads, such as: silk, viscose rayon or wool, and gives good results, it cannot on the other hand be employed in normal working conditions with certain other threads such as those of acetate rayon or those having a superpolyamidic base. It is said that these threads do not become creped.

In order to achieve a crepe state, attempts have been made to crepe the thread by a twist imparted in specific conditions, or without overtwisting it, by giving it a sinusoidal or helical configuration.

It is obvious that the helical shape or configuration, similar to that of a cork-screw or a screw, deforms the thread in three dimensions and gives better results than the sinusoidal form, which deforms the thread only in a plane or in two dimensions.

Various processes have been proposed for obtaining threads with a helical crimp, but they are expensive and have never had advantageous practical results.

The apparatus according to the present invention has as its object to impart a helical crimped configuration to threads and to the filaments of which they are composed, in order that the textile articles which are produced from such helically crimped threads will have, amongst other things, a greater elasticity, a more resilient feel, a more flattering and duller appearance, more bulkiness, and improved heat-insulating properties.

The process consists in winding a short longitudinal portion of the thread to be deformed effectively freely longitudinally movably at least once around a guide or support, in drawing it by one end while maintaining it thus wound, and in fixing the helical deformation produced by said winding while said deformation is being produced progressively throughout the length of the thread.

atent Q Patented Oct. 25, 1960 The accompanying diagrammatic drawings illustrate, by 'way of example, apparatus for carrying said process into :effect:

Fig. l is a perspective view of a thread which has been subjected to this process;

Fig. 2 shows a constructional form of apparatus for producing the deformation;

Fig. 3 is a perspective view of an alternative threadfeeding apparatus.

In :the .illustration of Fig. 2, a 70 denier thread 2 having .a base of polyesters, formed of 36 filaments and having a twist of 30 turns per metre, is taken from a spinning bobbin 3.

The thread is drawn off this bobbin, passed over a grid-type .or other tensioning means 4 in order to give it va uniform tension, then it is wound 40 times around a .small metal shaft 5 which is 6 cm. long and which is preferably grooved helically over 4 cm. of its length up to 1 cm. from each end by a groove 6 in the form of a screw-thread or regular helix of 39 turns.

.At each rotation of the shaft the groove is advanced by 1 mm. This groove is U-shaped and is /2 mm. wide and 1 mm. deep. The diameter of the shaft is 3 mm.

For initially placing the thread 2 in the groove 6, the shaft 5 may revolve freely on its two end portions, which are mounted in two small bearings.

The small bearings are carried by the end walls 7 of a housing connected to a heating plate 8 which is maintained at sufiicient temperature to enable the shaft around which the thread is wound to be kept at a temperature of C.

After passing slidingly along the bottom of the groove 6, and in so doing turning 39 times around the shaft 5, the thread 2 is preferably drawn at a constant speed of 12 meters per minute by the pulling roller mechanism of a thread-feeding device such as that of Fig. 3 later described herein, and is then received with reduced tension on a final support element 13.

In order to wind the thread to which a helical configuration is to be imparted, an easy method consists in subjecting it to a tractive stress by the support (tube, reel, bobbin on which the treated thread is wound after the operation (as shown in Fig. 2); in this case the support from which the thread is taken should preferably oppose this tractive stress with as constant as possible a force, but should not be driven itself.

This method, however, has the disadvantage that the thread arrives at and is wound on its support under considerable tension, so that the pressure of the thread turns one against the other partially destroys the desired helical deformation which has just been imparted to the thread. In order to remedy this, it is proposed that the thread should be passed, after the permanent fixing of the deformation, over the rollers of a thread-feeding device (Fig. 3).

This thread-feeding device may be of standard type, such as those used for feeding the thread in doubling twisting frames. It may consist of one or more rollers 10 and 11 revolving at a predetermined constant speed, and on which the thread 2 executes a sufficient number of turns for it to be driven at the peripheral speed of the rollers without the possibility of slipping or with very slight and constant slipping.

When it issues from the thread-feeding device the thread is received and wound onto the support 13 without any appreciable tension.

It has been observed that in order to carry out the process it was necessary to fix the deformations imparted to the thread by its twisted position while such deformations were actually being produced.

The temperature should be as high as possible Without risking any deterioration or injury of the textile fibres.

The speed at which the thread will be pulled and the fixed easily, and more particularly to thermoplastic 3 ,threads.

The thread subjected to this process may be an untwisted thread or a thread with negligible twist, for example, the twist received by the thread during spinning, but it may also have previously undergone a twisting, even a considerable twisting. It may also be a doubled thread, composed of threads of difierent size or nature as the case may be.

As will be obvious, the invention is not limited to the possible embodiments which have been described in some detail hereinbefore, but it includes all other embodiments Within the scope of the claims for carrying this method of deformation into efiect.

I claim:

Apparatus for imparting a helical deformation to a thermoplastic thread, said apparatus comprising a freely rotatable cylindrical guide member having an external helical groove formed therein coaxially therewith, said external groove being adapted to receive a short longitudinal portion of said thread freely slidably therein whereby said portion of said thread is maintained in a helical configuration during passage along said groove, pulling means for drawing said thread progressively over said guide member through said groove whereby said cylindrical guide member is rotated, tensioning'means disposed ahead of said guide member for imparting a substantially constant tension tosaid thread prior to and during its passage through said groove, and heating means disposed in proximity to said groove for heating said thread during the course of its passage over said guide member.

References Cited in the file of this patent UNITED STATES PATENTS 1,625,983 Carter Apr. 26, 1927 2,216,142 Taylor et al. Oct. 1, 1940 2,244,832 Finlayson et al. June 10, 1941 2,319,077 McNally et'al May 11, 1943 2,393,058 Pierce et al. Jan. 15, 1946 2,475,922 Stockly July 12, 1949 2,797,529 Mohr et al July 2, 1957 FOREIGN PATENTS a 501,201 Great Britain Feb. 23, 1939

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