WO2018193296A1

WO2018193296A1 - Method of making a yarn, yarn and garnment

Info

Publication number: WO2018193296A1
Application number: PCT/IB2017/057699
Authority: WO
Inventors: Giuliano Gandossi
Original assignee: FILTES INTERNATIONAL S.r.l. CON SOCIO UNICO
Priority date: 2017-04-19
Filing date: 2017-12-06
Publication date: 2018-10-25
Also published as: EP3612670B1; EP3612670A1; IT201700042999A1; PL3612670T3; ES2887014T3

Abstract

Method of making a yarn (1) comprising the steps of: i) providing at least one core strand or filament (2); ii) providing at least one covering strand (4) having an original twisting in a first winding direction (R1); iii) winding the covering strand (4) around the core strand/ filament (2) in a second winding direction (R2), opposite to said first direction (R1). Step iii) comprises the sub-steps of: a) reducing, up to substantially eliminating, the original twisting of the covering strand (4) in order to increase the longitudinal length; and b) imprinting a forced twisting on the core strand/ filament (2) in the second winding direction (R2). The method further comprises a step of: iv) rotating the core strand/ filament (2) in the direction (R3) opposite to the second winding direction (R2), so as to free it at least partially from the forced twisting; wherein, in step iv), the covering strand (4) receives an induced twisting in the opposite direction (R3), which reduces the longitudinal length of the covering strand (4) and generates an anchoring tightness on the core strand/ filament (2).

Description

DESCRIPTION

"ME THOD OF MAKING A YARN , YARN AND GARNMENT "

[0001] The present invention relates to a method for making a yarn for protective fabrics, i.e. a yarn possessing high wear resistance mechanical properties, called a "technical" yarn in the field, which is suitable for making fabrics for manufacturing work gloves and other safety garments.

[0002] The invention further relates to a yarn obtainable with such method, and a fabric or garment made from such yarn .

[0003] There are several types of technical yarns.

[0004] For example, the document EP 2679108 Al by the same applicant describes a yarn which is composed of a filament on which at least three different coverings are superposed, where making the outermost covering entails a distancing of the coils of the first covering and a reduction of the interspaces of the second covering to retain the discontinuous fibers that make up the outer covering .

[0005] Despite the yarn made according to the teaching of such document being advantageous from a plurality of viewpoints, the main disadvantage of this technical solution is the cost of manufacture which - obviously - must take into account the working time for creating the three covers and the price of raw materials.

[0006] Further examples of yarn are shown in the documents

EP1486595A1 and US4495760A.

[0007] The present invention fits into this context by proposing to provide a new type of method capable of binding the core strands or filaments in a reliable manner but with simple technical-productive operations and that are therefore of low cost.

[0008] Nevertheless, the yarn obtained with the method object of the present invention shows a high resistance to blade shear and abrasion, a considerable machinability in weaving garments and a considerable wearing comfort for the user.

[0009] In addition to this, with the same resistance to blade shear and abrasion as a fabric produced with traditional yarns, the fabric produced with the yarn of the present invention is lighter and hence makes a more comfortable article of clothing.

[0010] This object is achieved by a manufacturing method according to claim 1, according to a fabric or garment according to claim 15, and by means of a yarn according to claims 13 and 14. The claims dependent on these show preferred embodiments.

[0011] The object of the present invention will now be described in detail with the aid of the accompanying figures, provided by way of illustrative and non-limiting example, wherein:

- figure 1 shows a schematic of the production of the yarn, object of the present invention, according to one possible variant;

- figures 2a, 2b, 2c are three enlargements of the areas A, B, C indicated in figure 1 ;

- figures 3, 4 show enlarged photographs of two yarns, according to different embodiments, both with final titer Nm 18, wherein the first of these figures shows a variant in which a covering strand is wound around a core filament (variant I. discussed below), and wherein the second of these figures shows a variant in which a covering filament is wound around a core strand (variant II . ) .

[0012] The above objectives are solved by means of a method for the production of a yarn 1 comprising the steps of: i) providing at least one core strand or filament 2 ;

ii) providing at least one covering filament or strand 4 ; wherein one between the core strand 2 of the covering strand 4 has an original twisting (or initial twisting) in a first winding direction Rl;

iii) winding the covering strand 4 around the core filament 2, or winding the covering filament 4 around the core strand 2, in a second winding direction R2, opposite to the first direction Rl;

wherein step iii) comprises the sub-steps of:

a) reducing, e.g. up to substantially eliminating, the original twisting of the covering strand 4, or the original twisting of the core strand 2, in order to increase the longitudinal length thereof; and

b) inducing a forced twisting on the core filament 2, or on the covering filament 4, in the second winding direction R2 ;

iv) rotating the core filament 2, or the covering filament 4, in a direction R3 opposite to the second winding direction R2, so as to free it at least partially from the forced twisting;

wherein - in step iv) - the covering strand 4, or the core strand 2, receives an induced twisting in the opposite direction R3, which reduces the longitudinal length of the covering strand 4, or of the core strand 2, and generates an anchoring tightness on the core filament 2, or on the covering filament 4.

[0013] Therefore, during step iii) of winding, the covering strand or the core strand is made to lose its original twist, so that said strand is in an "untwisted" or "open" condition .

[0014] It should be noted that, within this description, the term "substantially eliminated" shall mean a reduction equal to or greater than about 80% of the value of the original twisting, e.g. 85-99%.

[0015] Thus, the principle underlying this invention is to wrap with each other a strand (respectively a core strand or a covering strand) and a filament (respectively a covering filament or a core filament) so as to substantially zeroing the original twisting of the strand and, in step iv) , to cause on said strand an induced twisting which - by shortening the longitudinal length of the strand - generates the anchoring tightness on the filament .

[0016] In other words, this principle can be exploited in at least two independent embodiments, namely:

I. in a first variant wherein at least one core filament 2 and at least one covering strand 4 are used; or

II. in a second variant wherein at least one core strand 2 and at least one covering filament 4 are used.

[0017] According to an embodiment, by virtue of the intimate winding between the strand and the filament, and thanks to the greater covering capability of the open- and-reclosed strand with respect to the filament, a prevalent or substantially complete covering of the filament will be obtained anyway, both whether the strand is initially in the core or is initially in covering.

[0018] In accordance with one embodiment, step iv) comprises an elastic return of the core filament 2 or of the covering filament 4.

[0019] In other words, this variant provides that the core filament 2, or the covering filament 4, is of a shape- memory type, so as to be able to resume - substantially in a spontaneous way - its own dimensional conformation previous to the forced twist.

[0020] In accordance with one embodiment, step iv) comprises a mechanically induced return from the outside, for example through a second hollow spindle 24 arranged downstream of the point of winding of the covering strand 4 (or of the core strand 2) on the core filament 2 (or on the covering filament 4) .

[0021] In accordance with one embodiment, in sub-step a) , the fibers and/or filaments 6 which make up the covering strand 4 or the core strand 2 are substantially parallel to each other.

[0022] In other words, according to this embodiment, the original twisting is substantially eliminated.

[0023] In accordance with one embodiment, in sub-step a) , the covering strand 4 of the core strand 2 has its own maximum longitudinal length and its own minimum tensile strength .

[0024] In accordance with one embodiment, sub-step a) and sub-step b) are the consequence of a winding friction between the covering strand 4 (or the core strand 2) and the core filament 2 (or the covering filament 4) .

[0025] In accordance with one embodiment, at the end of step iii), the covering strand 4, or the core strand 2, is superposed onto the core filament 2, or onto the covering filament, with closed coiling 8.

[0026] In other words, according to this variant, the strand 4 of the first covering 8 achieves a continuous layer that completely covers filament 2, because the coils of that strand 4 are axially tangential one to another, so as to leave no free spaces therebetween from which the underlying core 2 could emerge.

[0027] In accordance with one embodiment, at the end of step iii), the covering strand 4 or the core strand 2 is superposed onto the core filament 2 or covering filament 4 with an open coiling.

[0028] In accordance with one embodiment, the anchoring tightness is distributed in a helical and uniform manner along a longitudinal development direction X of the core filament 2 or of the covering filament 4.

[0029] In accordance with one embodiment, the original twisting and the induced twisting of the covering strand 4 or of the core strand 2 are performed in opposite winding directions with substantially the same number of windings per linear meter. [0030] In accordance with one embodiment, the original twisting and the induced twisting of the covering strand 4 or of the core strand 2 are performed in opposite winding directions, each with a different number of windings per linear meter with respect to the other.

[0031] In accordance with one embodiment, the numbers of windings per linear meter of the original twisting and the induced twisting may differ by a percentage greater than 5%.

[0032] In accordance with one embodiment, the core filament 2 or the covering filament 4 is continuous, or is a combination of continuous filaments and of discontinuous strands .

[0033] In accordance with various embodiments, a single filament may be used as a continuous filament, or a plurality of distinct filaments, optionally of different composition/nature as illustrated below.

[0034] In accordance with one embodiment, the core filament 2 or the covering filament 4 has a linear density in the range of 22-2200 dtex, preferably 40-1600 dtex, and even more preferably 40-680 dtex.

[0035] In accordance with one embodiment, the covering strand 4 or the core strand 2 is a discontinuous filament, or is a combination of discontinuous strands with at least one continuous filament. [0036] In accordance with one embodiment, at least one covering strand 4 or a core strand 2 has a linear density in the range of 100-900 dtex, preferably 150-850 dtex, and still more preferably 200-800 dtex, e.g. 200-300 dtex.

[0037] In accordance with one embodiment, the core filament 2 or the covering filament 4 is at least partially made of glass, steel, ceramic, polymer, ultra-high molecular weight polyethylene, aramid, or combinations thereof.

[0038] In accordance with one embodiment, one or more covering strands 4 or one or more core strands 2 are independently selected from the group consisting of polyamide, polyester, (para- ) aramide, polyethylene, ultra-high molecular weight polyethylene, natural fibers such as wool or cotton, and mixtures thereof.

[0039] For embodiments which provide for strands 2, 4 or filaments 2, 4 of a polymeric nature, such strands/ filaments may be formed from any of the materials known under the trade names of Dyneema®, Kevlar® or Technora®.

[0040] In accordance with one embodiment, the method comprises a step of: v) winding at least one external strand/ filament 10 superposed on the covering strand 4 or on the core strand 2, so as to form an outer covering 12.

[0041] In accordance with one embodiment, step v) comprises the winding of a plurality of external strands or filaments 10, such as those that have different chemical compositions and/or technical characteristics.

[0042] In accordance with one embodiment, the outer covering 12 is made with an open or closed coiling.

[0043] In accordance with one embodiment, the outer covering 12 is made with an "S" or "Z" winding.

[0044] With regard to the additional features of the external strand or filament 10, reference is made - mutatis mutandis - to the features of the covering strand 4.

[0045] In accordance with one embodiment, the outer covering 12 is in direct contact with the first covering strand 4 or with the first core strand 2.

[0046] In accordance with one embodiment, at least an intermediate layer or winding is interposed between the outer covering 12 and the first covering strand 4 (or between the outer covering and the first core strand 2) .

[0047] According to different variants also contextually implementable, at least the outer covering 12 may possess elastic properties, flame retardant properties, soft hand and/or fireproof properties.

[0048] In accordance with one embodiment, step i) comprises a step of providing a bundle of strands or a bundle of filaments, optionally parallel or optionally wrapped around the longitudinal direction of development X.

[0049] In accordance with one embodiment, step i) of providing the core strand or filament 2 comprises the sub-steps of:

c) providing a core;

d) winding around the core a first strand in a third winding direction with a first number of windings per linear meter to obtain a first covering of said core filament 2 or of said covering filament 4 ;

e) winding a second strand in a fourth winding direction, opposite to the third with a second number of windings per linear meter, so as to superpose a second covering with an open coiling on the first covering, wherein the second number of windings is less than the first number of windings;

f) creating at least one third covering on the second covering by means of winding at least one roving comprising discontinuous fibers in the same winding direction as the second strand so as to position said fibers in at least the interspaces of the open coiling; forming the third covering entailing a distancing of the coils of the first covering and a reduction of the interspaces of the open coiling to receive and retain said fibers.

[0050] The above objectives are also achieved by means of a yarn 1 made with the method according to any one of the preceding embodiments and by means of a fabric or garment produced at least partially with the yarn 1 described herein .

[0051] The above objectives are finally achieved by means of a yarn 1, which comprises:

i) at least one core strand or filament 2 ;

ii) at least one covering filament or strand 4 ;

wherein the covering strand 4 is wound around the core filament 2, or wherein the covering filament 4 is wound around the core strand 2, in a winding direction R2 ; and wherein the covering strand 4 or the core strand 2 has a twisting induced by the core filament 2 or by the covering filament 4, which reduces the longitudinal length of the strand and generates an anchoring tightness thereof on the core filament 2 or on the covering filament 4.

[0052] With regard to the preferred or additional features of such yarn, please refer to the preceding description of the method.

[0053] In accordance with one embodiment, the present yarn shows abrasion and blade shear resistance features and breathability and comfort properties that make it particularly suitable for the manufacture of protective garments or fabrics for the manufacture of such garments. [0054] In accordance with one embodiment, the aforementioned yarn has been specifically designed for the production of protective gloves.

[0055] Finally, with reference to figure 1, the manufacturing process is illustrated therein as an example .

[0056] The core strand or filament 2 is fed in a feed direction F (which develops from the top downwards), by means of a core reel 20.

[0057] During this feed, initially fed is the covering strand 4, which has its own original twisting in the winding direction Rl .

[0058] The winding of the core strand 4 around the core strand/ filament 2 is carried out by twisting in the second winding direction R2 (for example by means of a first hollow spindle 22) .

[0059] The detail A, immediately downstream of the first hollow spindle 22, shows the point of contact between the covering strand 4 and the core strand/ filament 2, wherein the strands or filaments 4 have become parallel by virtue of the second winding direction R2, which causes at least a partial loss of the original twist.

[0060] In such condition, the covering strand 4 has its own maximum length due to the loss of the initial twisting, whereas on the core strand/ filament 2 a forced twisting has been imprinted in the same winding direction R2.

[0061] After a certain interval, in correspondence with the detail B, the core strand/ filament 2 will rotate (or will be made to rotate) in the direction R3 opposite to the second winding direction R2, so as to release (or be released from), at least partially, the forced twist.

[0062] In this step, the covering strand 4 receives from the core strand/ filament 2 an induced twisting in the opposite direction R3, which reduces the longitudinal length of the covering strand 4 and generates the anchoring tightness on the core strand/ filament 2.

[0063] In an optional subsequent step, at least one external strand or filament 10 could be wrapped to superpose the covering strand 4 to form the external covering 12, by using a second hollow spindle 24.

[0064] The direction R3 of such winding is shown opposite to the second winding direction R2, but this should not be considered essential for the purposes of the present invention, as the second hollow spindle 24 could form an "S" or a "Z" winding.

[0065] Finally, after the yarn 1 has been completed in the above manner, it is wound onto a take-up reel 26, which is used as the feed in the subsequent production phase of the fabric or garment/glove.

[0066] Merely by way of non-limiting example, below are some examples of formulation of the present yarn, each with the related resistance tests.

A. Yarn with final titer Nm 16 (dtex 625)

B. Yarn with final titer Nm 18 (dtex 560)

C. Yarns with a final titer Nm 14 (dtex 714); 35 Nm

(28 0 dtex) ; 42 Nm (230 dtex)

Yarn External

Core Covering strand

no . strand continuous II III

I strand

filament strand strand stainless UHMWP PA PA PES

3

steel (100%) (100%) (100%) (100%) stainless UHMWP PA --

4 -- steel (100%) (100%) stainless UHMWP --

5 -- -- steel (100%)

[0067] Yarns have been prepared according to the previous tables, where the abbreviations correspond to PES = polyester, AR = para-aramid, PA = polyamide; UHMWP = ultra-high molecular weight polyethylene.

[0068] In reference to yarns of composition conforming to the above tables, hereinafter are shown the results of tests to which gloves made wholly from such yarns have been subjected, and their results:

Yarn Abrasion Blade shear no . resistance resistance

1 Level 4 Level 5

2 Level 5 Level 5

3 Level 5 Level 5

4 Level 5 Level 5 Level 5 Level 5

[0069] As may be seen from the preceding tests, both carried out according to UNI EN388:2004, protective garments made in accordance with the present invention are extremely high-performing from both points of view.

[0070] In fact, a level 4 in the abrasion resistance test essentially corresponds to approximately 8,000 cycles carried out without any defect in the glove.

[0071] Moreover, the level 5 in the blade shear resistance test corresponds to the maximum coefficient provided by the standard.

[0072] What the aforementioned tests are unable to demonstrate, however, is the fact that the increased robustness of the fabric and the corresponding garment go hand in hand with a substantial reduction in the weight by surface area of the fabric, and therefore the lowest titer value of the yarn.

[0073] Innovatively, the method object of the present invention has been designed to bind the reinforcement core of the yarn quickly and reliably.

[0074] In fact, the reduction in length of the covering strand or of the core strand which occurs at the winding on the core filament or on the covering filament causes an extremely firm adhesion between covering and core. [0075] Advantageously, the method object of the present invention has been designed to make a covering that encloses and completely traps the innermost filament.

[0076] Advantageously, the method object of the present invention exploits the mere friction between the strands so that they create the necessary manufacturing twisting.

[0077] Advantageously, the method object of the present invention allows obtaining a yarn with an extremely reduced hairiness.

[0078] Advantageously, the method object of the present invention allows to obtain a yarn with superficial anti- slip features.

[0079] To the embodiments of the aforementioned yarn, fabric/garment and method, a person skilled in the art, in order to meet specific needs, might introduce variants and variations or substitutions of elements with others that are functionally equivalent.

[0080] These variants are also contained within the scope of protection as defined by the following claims.

[0081] In addition, each variant described as belonging to a possible embodiment may be achieved independently of the other variants described.

Claims

1. Method of making a yarn (1) comprising the steps of: i) providing at least one core strand or filament (2) ; ii) providing at least one covering filament or strand ( 4 ) ;

wherein one between core strand (2) or covering strand (4) has an original twisting in a first winding direction ( Ri ) ;

iii) winding the covering strand (4) around the core filament (2), or winding the covering filament (4) around the core strand (2), in a second winding direction ( R₂ ) , opposite to said first direction ( Ri ) ;

wherein step iii) comprises the sub-steps of:

a) reducing, up to substantially eliminating, the original twisting of the covering strand (4), or the original twisting of the core strand (2), in order to increase the longitudinal length thereof; and

b) inducing a forced twisting on the core filament (2) , or to the covering filament (4), in the second winding direction ( R₂ ) ;

iv) rotating the core filament (2) , or the covering filament (4), in a direction (R3) opposite to the second winding direction ( R₂ ) , so as to free it at least partially from the forced twisting;

wherein - in step iv) - the covering strand (4) , or the core strand (2), receives an induced twisting in the opposite direction (R3) , which reduces the longitudinal length of the covering strand (4), or of the core strand (2), and generates an anchoring tightness thereof on the core filament (2) or on the covering filament (4) .

2. Method according to claim 1, wherein the anchoring tightness is distributed in a helical and uniform manner along a longitudinal development direction (X) of the core filament (2) or of the covering filament (4) .

3. Method according to any one of the preceding claims, wherein :

the original twisting and induced twisting of the covering strand (4), or of the core strand (2), are carried out in opposite winding directions, substantially with the same number of windings per linear meter; or

- the original twisting and the induced twisting of the covering strand (4), or of the core strand (2), are carried out in opposite winding directions, each with a different number of windings per linear meter with respect to the other, the numbers of windings per linear meter of the original twisting and the induced twisting being different by a percentage higher than 5%.

4. Method according to any one of the preceding claims, wherein, in sub-step a), fibers and/or filaments (6) that make up the covering strand (4), or that that make up the core strand (2), are substantially parallel to each other .

5. Method according to the preceding claim, wherein, in sub-step a), the covering strand (4) or the core strand (2) has its own maximum longitudinal length and its own minimum tensile strength.

6. Method according to any one of the preceding claims, wherein sub-step a) and sub-step b) are the consequence of a winding friction between the covering strand (4) and the core filament (2), or between the covering filament (4) and the core strand (2) .

7. Method according to any one of the preceding claims, wherein, at the end of step iii), the covering strand (4), or the core strand, is superposed on the core filament (2), or on the covering filament, with a closed coiling ( 8 ) .

8. Method according to any one of the preceding claims, wherein the core filament (2) or the covering filament (4) is a continuous filament, or is a combination of discontinuous filaments with at least one continuous filament .

9. Method according to any one of the preceding claims, wherein the core filament (2) or the covering filament (4) is at least partially made of glass, steel, ceramic, polymer, ultra-high molecular weight polyethylene, aramid, or combinations thereof.

10. Method according to any one of the preceding claims, wherein step i) comprises the sub-steps of:

c) providing a core;

d) winding a first strand around the core in a third winding direction with a first number of windings per linear meter to obtain a first covering of said core filament (2) or covering filament (4) ;

e) winding a second strand in a fourth winding direction, opposite to the third with a second number of windings per linear meter, so as to superpose a second covering with an open coiling on the first covering, wherein the second number of windings is smaller than the first number of windings;

f) creating at least one third covering on the second covering by winding at least one roving comprising discontinuous fibers in the same direction as the second strand winding so as to position said fibers in at least the interspaces of the open coiling;

forming the third covering entailing a distancing of the coils of the first covering and a reduction of the interspaces of the open coiling to receive and retain said fibers.

11. Method according to any one of the preceding claims, comprising a step of: v) winding at least one external strand or filament (10) superposed on the covering strand (4) or on the core strand (2), so as to make an external covering (12), with open or closed coiling, with an "S" or "Z" winding.

12. Method in accordance with any of the preceding claims, wherein one or more covering strands (4) or core strands (2) are independently selected from the group consisting of polyamide, polyester, (para- ) aramide, polyethylene, ultra-high molecular weight polyethylene, natural fibers such as wool or cotton, and blends thereof .

13. Yarn (1) produced with the method according to any one of the preceding claims.

14. Yarn (1) comprising:

i) at least one core strand or filament (2);

ii) at least one covering filament or strand (4);

wherein the covering strand (4) is wound around the core filament (2) or wherein the covering filament (4) is wound around the core strand (2) in a winding direction (R₂) ;

wherein the covering strand (4) or the core strand (2) has a twisting induced by the core filament (2) or by the covering filament (4), which reduces the longitudinal length of the strand (4; 2) and generates an anchoring tightness thereof on the core filament (2) or on the covering filament (4) .

15. Fabric or garment produced at least partially with the yarn (1) in accordance with any one of claims 13 or 14.