IT8149169A1 - Improvements in elastic bandages obtained by knitting - Google Patents

Description

?the improvement of elastic bandages, obtained by knitting?

- SUMMARY_

The subject of the invention is a porous elastic bandage made by knitting and having a low weight, which has a warp consisting of a series of textured threads, knitted in a simple chain stitch and a series of -of?textured?floating?threads,.both.series_being-held-together_by_two_sets??of_non-elastic_weft_threads._The_weft_threads_are_used_in_a_regular_and_repeated_configuration_across_the_width_of_the_bandage_and_are_interlaced_with_the_loops_of_the_threads_of_the_simple_chain_stitch,_one_set_of_weft_threads_passing_under_the_floating_threads_and_the_other_under_the_floating_threads_without_being_interlaced_with_them.-

-DESCRIPTIONS!

Elastic bandages have been made in the past by weaving on narrow or ribbon looms, the retractive and supporting force being provided by special warp threads. Earlier bandages employed twisted cotton warp threads, but the use of cotton warp threads has been supplanted to a considerable extent by the use of elastomeric warp threads, initially made from extruded or cut rubber, but more commonly from artificial elastomeric polymers. Such elastomeric warp threads are usually used in -faces with a layer of non-elastomeric filaments.

Such bandages, although effective in use, have the disadvantage of being relatively thin. They are produced individually, on a narrow loom, using expensive, wound elastomeric threads, with relatively slow production speeds intrinsically present in the weaving process. In an attempt to avoid imitations of the weaving process, the aim was to produce knitted elastic bandages.

? Most of the. "woven bandages that have been proposed use silicate yarns as part of the warp structure and usually use very heavy weft yarns to prevent the bandage from twisting when stretched. They are relatively heavy, having an average weight of between 204 and 408 grams per square meter, and because of their compact, rigid structure, they are warm and uncomfortable to wear. _ . ?j- She is a U.S. patent holder. I...4-?.173??-131 ?_ - -the-production-of-a-light-elastic-bandage-has-been-described-in-which-the-warp-threads-consist-of-a-series-of-false-twist-threads,-formed-in-chains-of-stitch-loops,-each-of-these-threads-having-incorporated-a-second-false-twist-thread-with-a-twist-in-the-opposite-direction!

-X-weft threads_are_used_through_the_warp_thread_in_varied_and_recurring_configurations_through_the_warp_threads,_in_such_a_way_that_the_overlapping_layers_of_the_bandage_adhere_to_each_other_in_relatively_non_movable_relation,

-Wraps of this nature, although eminently satisfactory for use, are relatively complex in manufacture due to the lack of the ability to form each warp thread into a simple chain stitch configuration, with a second warp thread incorporated into the fabric and with the intricate configuration of the warp threads. -The present invention provides a warp-knitted elastic yarn which comprises a series of parallel, textured warp threads formed into loops of simple chain stitches, a series of floating, textured threads which extend parallel to the said series of warp threads but are not connected to them, and two series

a regular, repetitive configuration across the width of the bandage, the weft threads being interlaced with the loops of at least some of the warp threads worked with a simple chain stitch, and one set of weft threads passes above one while the other passes below the floating threads without being interlaced with them. The elasticity of the bandage according to the invention is provided by the intrinsic characteristics of elongation and recovery of the properties. -priet?-initial or-recovery-of-textured-warp-threads.?These?threads?are-continuous-filament-threads-to-which-greater-volume-and-softness-has-been-imparted,-together-with-recoverable-stretch-thanks-to-the-thread-introduction-of-crimps-curls,-serpentine-and-undulations-for-false-twisting. Such threads-are?commercially-produced-with-well-known-processes-and,-when-the-filamentous-material-is-of-a-moplastic-nature,-as-in-the-case-of-nylon-or-polyester,-a-heat-hardening-stage-uses-procedures.? _to._of false__twisting..!or__stretching.a the _wrinkled_confi-.guration_of_the_filq_r8lativamenia permansu-

tQe.

1_ The yarn can be twisted in a clockwise direction or in a counterclockwise direction, in the process of false twisting to produce the so-called threads, with a clockwise or counterclockwise twist.

In most light weight bandages, it is desirable to have a substantially balanced number of S- and Z-twist yarns in the warp to minimize the tendency of the bandage to twist when unrolled. To minimize the tendency of the bandage according to the present invention to curl or curl, it is preferable that there be a substantial equality in the torque distributed by the S-twist yarns and the Z-twist yarns. ornano.1 .'.total warp,of the .bandage._

This result can be achieved in various ways, as will be explained in more detail below.

The preferred embodiment of the knitted elastic bandage according to the present invention is illustrated in the accompanying drawings, in which: - Figure 1 represents an enlarged isometric view of a repetition of the basic structure of the bandage

Figure 2 represents an enlarged-scale cross-section of a false-twist L-shaped warp thread;

-- figure -3-schematically represents-the1 | -paths-of-the-warp-threads-and-of-a-series-of-weft-threads-in-the-segment-of-the-wrap-represented? -in-figure?1;- 1- - --figure-4-represents-the-paths-of-warp? -two-the-series-of-weft-threads-that-interlace-with-a-warp-thread; -and?- - - ??

-figure-5 shows in detail in? { -magnified-the-interlacing-of-^.both-sets-of-weft-threads-with-a-warp-thread-formed-in-a-simple-chain-stitch*. Figure -1?represents-a-repetition-of-a-bandage-10-comprising-two-sets-of-warp-threads?12-and-M,-both-of-which?are-of-a-textured-nature-and-susceptible-to-elongation. Each < -! -thread-1-2-?-formed-in-a-series-of-chain-stitch-loops? -the -simple-chain-as-represented-in-figure-5-and-two-elastic-weft-threads-16-and-18-are-incorporated-in-each-of-its-loops,-as-indicated-in-20.-Each-thread-14-is-a-floating-thread-which-simply-passes-between-the-weft-threads-16-and-18-and-is-not-knitted-with-the-other-threads-of-the-bandage.-The floating-threads- . -they -provide -stability -to -the -bandage -and -increase -the -coverage -factor-(in -other-words-the-number-of-threads-per-inch-equal-to-2.54-cm-divided-by-the-square-radius-of-the-thread-size): -The -preferred-range-of-coiftinated-threads-of-the-simple-and-floating-chain-stitch-is-between-20-8-40-threads-pa;

polyicej?equal-to-2.54-cm-and?these-threads-preferably-when-a-size-in-the-range-between-70-denier-? and?230-denier

Both the threads of the simple chain stitch 42 and the floating threads 14 can have mixed S twist and Z twist. They are not necessarily drawn in strict alternation, since a bundle of S-type threads and a bundle of Z-type threads can be interwoven randomly to provide a stable, torque-free bandage, provided that the number of threads of each twist type is substantially equal. Furthermore, it is not essential that there is a be an equal number of floating threads and simple chain stitch threads alternating across the width of the bandage. Since the main function of the floating threads is to impart stability and weight to the bandage, the ratio between

?the?threads...of...the_chain_stitch,_simple...and_the_threadsQut-!

,tusn.ti__can?...vary.from.a.limit.of.two.or.more?to.one_ _.and_a_limit_of_one_or_two.or.more?,_depending_on_the_size.of_the-wires._

Alternatively ..a more convenient._.proceed?__ |

balancing_method_of_the_threads_with_twisting__S _e.

i

dei_fil1._con_tor_citura_Z...c.onsiste_neli laavere

_jjthreads_.of .single_chain_stitch_warp_of_one_type_of_twist_and_.all_floating_threads._of_the_type.

?

!opposite.of.twisting.--This-? ...procedure when_there_are_approximately_equal_numbers_of_threads..of_simple_chain_stitch_and_of_floating_threads,.with_similar_degrees_of?twisting..

-While in figure 1 you thread the weft_l6___.

48-are.represented.,as incorporated in 20 in the 1

j i -?rigei-of..-all-.i_?ili-42-de2_ simple._chain._stitch * [ -what?-is_not_?-essential.._The _main_function? -of-the-weft-threads,:.apart._.from..the..maintenance..of??the?warp.threads. _in_an...integrated_structure,-consists-in-jproving transverse stability_and resistance.to shrinkage of the bandage when subjected .to .stretching!--will vary .with .the_size_and .number .of .the .weft .threads, .which .are..prefsribly..opto .threads .of .the_size .between .JQ/1_ 030/1? with . |*40-to-20-weft-threads.for..each-police, equal to 2, 3, 4, cm,-of-length-,of-the-bandage,_ __ ! __ _ The_weft_threads.are.extended.in.a.regular.row.repeatedly.across.the_width_l_of_the_bandage,_each_weft_thread.preferably_extending_over_5_to_9_warp_threads._

_ :_ As shown in figure 2, each warp thread is a false weft thread 22 with textured filaments 24. Figure 3 shows schematically the way in which the weft threads 16 are incorporated into the loops of the warp threads 42. Figure 4 illustrates the interlacing of both weft threads 16 and 48 with the warp threads 1-2 and 2&.

-The 3i?bandages ..can?_be...produced on a crochet machine ..using-three.-thread-guide-bars-for-repetitive-operation,-in-a-vertical-plane-perpendicular-to-the-horizontal-needles-of-the-machine. -Two of the bars are moved across the width of the bandage to insert the 46 and 18 weft threads of 20/1 cotton, and the third bar is used to insert the 14 floating textured threads, which have a count of approximately 1.40 denier, textured with a type 2 twist and heat-hardened nylon. The 12 threads of the single drop stitch are of approximately 1.5 denier, with a type 5 twist. CPine represented_in_ _:figure-1,.._;there.are_five_those_threads_with_simple_chain_stitch.. .and-.four..floating_threads_for_an_entire_repetition_of_the_configuration'..The_configuration.,of_the_threads..distract_it? the one represented in the figures 1 is 3 in all the cotton weft threads 16 and 18 are interlaced with each of the warp threads 11 of the simple chain stitch, but they simply pass above and below the floating threads 44, without being interlaced, with them: __V?__.are .weft ends.per.police.of.length_of_the_bend-

JRoich?_the..Jb.endage.f__cos?_cQme__format

on the machine, ...presents a certain amount of stress due to the tensions applied to the various threads: during the treatment, it was conditioned by being exposed to humid steam at a temperature of 80°C for approximately two minutes, twice as long as it was dried. The weight of the reclassified, dried bandage is 140 grams per square meter; the finished bandage has a porosity to air of more than of--?00 cubic feet,-equal to 19.8 cubic meters,--of air, per square foot, equal to 100 square meters per minute,--under a pressure of?0.5 inches equal to 1.27 cm, with the test carried out--on--a Frazier air permeability apparatus. At 100^b of elongation,--the bandage has nine strands--or strands--of weft per inch,--equal to?2r.54 cm.? H--weft coverage factor;--

and therefore of 2 (9/square root of the yarn title 20). This is a very low coverage factor, characteristic of open mesh structures. Together with the dispersed and downy configuration of the textured warp yarns, this ensures breathability and comfort of use that are not found in conventional elastic bandages. In addition to being light in weight and comfortable to wear, the bandage according to the invention is absorbent and can be washed and sterilized without degradation, since it does not contain rubber? or "synthetic elastomeric material, it can be used in cases where elastomeric threads in contact with the skin give rise to allergic reactions;

Those who are experts in the field will be able to appreciate the "chef" "differently from the production of beii

JRIVETIDICATIONS.

-1.-Steastic bandage, knitted, bold,-..which.comprises.a.series.of.parallel.textured.warp.threads.formed.in.lavender.loops.with.a.simple.chain.stitch,.a.series.of.floating.textured.threads,,which.extend.narratively.to.the.said.series.of.warp.threads.but.are.not.connected.to.them,and,two.series.of.transfer.threads; inelastic yarns which are unfolded in a regular and repetitive configuration across the width of the band, the weft yarns being interlaced with the loops of at least some of the warp yarns of the simple chain stitch, and one set of weft yarns passes over and the other passes under the floating yarns without them being interleaved with each other. 2. A band according to claim 1, wherein the number of warp yarns of the simple chain stitch is substantially equal to the number of floating threads. 3. Bandage according to claim 2, wherein the single chain stitch threads and the floating threads alternate across the width of the bandage.

- -4.-Bandage according to claim 1, wherein the total number of warp threads of the a-o-a-stitch in the simple knit and of the floating threads contains a substantially equal number of S-type twist threads and 2-type twist threads. - - 5.-Bandage according to claim 2, wherein the floating threads and the a-o-a ...

6.- Bandage according to claim 1 wherein the weft threads are interlaced with the embroideries of all the threads of the simple chain stitch.

- 7v - Bandage according to claim 1, wherein the textured warp threads are made of heat-hardened thermoplastic material.

8.-Wrap according to claim 5, wherein the series of weft threads are spread out over ten to nine warp threads,

_9?-Bandage according to claim J, substantially -as previously described .with _ -reference. to the attached drawings. _