Patent Application
20200255989
The invention relates to a textile provided with controlled elastic characteristics. It is particularly suitable for application, in particular, in elements of underwear, of garments, such as, for example, brassiere straps, elastic waistbands of underwear or of sports shorts. Another of its fields of application is orthopedics, more particularly implementing an elastic compression action, or also the field of seats, such as in particular seat bottom pieces or seat backrests likely to be used, in particular, in passenger transport.
The term controlled elasticity means, in the sense of the invention, the ability developed by the considered textile to stretch if it is submitted to an effort, while opposing an elastic return force, such a stretching capacity being however limited.
In other words, the main object of the present invention is the concurrent search for the user's comfort and for the holding in case of an effort of higher intensity or frequency.
The very notion of an elastic fabric, and generally of an elastic textile, is currently widespread and, incidentally, widely implemented. Its main fields of application essentially comprise shoulder straps and waistbands of underwear or of sportswear, the manufacturing of orthoses (for example, the forming of bandages, knee pads, shoulder pads, abdominal belts, etc.), in addition to all the elastic compression aspects.
Conventionally, the involved textiles are generally woven or knitted items having a high elasticity in the warp direction, and having an elastic return power (high compression effect). The yarns constitutive of such fabrics developing elastic characteristics are conventionally yarns of covered type, typically formed of a core made of elastodiene or preferably of elastofibre, such as elastane, and of covering yarns made of another material.
Typically, the stretching capacity of such textile items, particularly woven, is in the range from 60 to 130% in the longitudinal direction, and when such articles develop elastic characteristics in both directions (warp direction and weft direction), the stretching capacity is typically greater than or equal to 30% in the weft direction.
Thereby, and to take into account prior art textiles, the designer has to arbitrate between the use of elastic components with a short stretching, intended to provide a strong compression and damping during significant or high-frequency efforts on the article to which they are integrated, and the use of elastic components having a long stretching, which will provide the article to which they are integrated comfort and flexibility at rest or when submitted to light efforts.
The use of short stretch elastic components however results in a prejudice to the user's comfort due to too high a compression and in a stiffness or discomfort at rest or when submitted to light efforts.
As a corollary, elastic components having a long stretching do not ensure the compression and the damping required when submitted to stronger, more intense, and/or higher-frequency efforts.
The object of the present invention precisely is to provide a textile element capable of both ensuring the comfort of the user of the underwear, of the garment, of the orthosis, or of the seat integrating the textile, and at the same time, of having elastic characteristics such that they comply with the desired elastic compression result, particularly in case of significant and/or high-frequency efforts.
For this purpose, the invention aims at a textile for the forming of elements of underwear, of garments, of orthoses, or of seat elements having a controlled elasticity, integrating, at least in the main stress direction, high stretch yarns.
According to the invention, said high stretch yarns are associated with yarns which are also extensible along a same direction, but having stretching characteristics more limited than those of the high stretch yarns, and typically close to 50% of those of the high stretch yarns, such short stretch elastic yarns typically forming an elastic stop.
Concurrently, according to the invention, the return force exerted by the yarns of limited extensibility is in the range from 25 to 50% of that exerted by the high stretch yarns. If the return force of the yarns of limited extensibility is smaller than 25% of that exerted by the high stretch yarns, the damping or compression effect desired for the considered textile, particularly when the latter is submitted to significant or high-frequency efforts (intense efforts, sports, etc.) is not ensured, thus causing the loss of the benefit desired for said textile. At the same time, in the case where said return force is greater than 50% than that exerted by the high stretch yarns, the desired effect of comfort at rest or when said textile is submitted to light efforts is absent.
In other words, such a double combination of characteristics enables to associate yarns having a differentiated extensibility and return force, and thus to provide the desired result combining both the comfort and the elastic compression. Such a combination was by no means obvious, since those skilled in the art could naturally be prone to considering the limiting factor due to the specific characteristics of the yarns of low extensibility, and be deterred from implementing them or, on the contrary, to prefer their compression efficiency while sacrificing comfort.
The notions of extensibility, of elasticity, or of stretching such as used in the context of the present invention have the meanings conventionally assigned thereto; thus, an elastic deformation, in the case in point, linear, is a reversible deformation, that is, which disappears when the efforts having caused said deformation disappear. It being a textile element having a unidirectional extension, the elasticity will result a variation of the length, whereby the notion of stretching.
As a corollary, the very notion of elasticity, such as recalled hereabove, generates that of return force, itself linked to the nature of the elastic material or to the structure thereof.
According to the invention, the yarns having an elastic characteristic integrated in the textile, be the latter of woven, knitted, or braided nature, are covered yarns, having their core advantageously made of elastane, of polyurethane, of silicone, or of elastodiene, and their covering advantageously made of polyamide, of polyester, or of other materials, and particularly of other synthetic yarns or fibers.
According to the invention, the stretching capacity of the short stretch elastic yarns is close to 50% of that of the long stretch elastic yarns, and advantageously close to the maximum stretching capacity desired for the considered textile.
According to a first application of the invention, more particularly directed towards the forming of a sportswear shoulder strap, the maximum stretching of said strap is approximately 90% with respect to its initial length, for a return force for a 30% stretching close to 400 cN/cm.
Another application of the invention concerns the forming of a shorts or underwear waistband, particularly for a use in sports, which then has a maximum stretching from approximately 120 to 150% of the initial length of the fabric forming said waistband, for a return force for a 30% stretching in the range from 220 to 300 cN/cm.
According to the invention, and to enable the textile having the yarns of differentiated elasticity integrated therein to stretch, the weave of the implemented structure has a shrinkage (the shrinkage being defined as the ratio of the length of the yarns used and the length of the fabric at rest), such a shrinkage being selected to always be greater than the stretching capacity of the elastic yarns having the largest stretching capacity.
The foregoing features and advantages of the present invention will now be discussed in the following non-limiting description of a specific embodiment, in relation with the accompanying drawings.
As already indicated, the following embodiment more specifically concerns the forming of a woven band for the manufacturing of a shoulder strap for a brassiere or a sports brassiere, that is, for the forming of an element of a portion of a garment likely to be submitted to significant mechanical efforts, in the case in point, while practicing a sport.
Such an embodiment uses a conventional loom with a reed density of 10.25 dents per cm. It uses a double weft (T), each formed of a textured polyamide yarn measuring 2/78 decitex, the take-up of the finished fabric being 110 picks per inch.
Referring to
high stretch yarns (A) of covered yarn type, with a maximum 90% stretching, linearly inserted between the face weft and the back weft to favor the elastic return, formed of a 310-decitex elastane core covered with two layers of textured polyamide yarns measuring 2/78 decitex;
high stretch yarns (A1) of covered yarn type, with a maximum 160% stretching, linearly inserted between the face weft and the back weft to favor the elastic return, formed of a 940-decitex elastane core covered with two layers of textured polyamide yarns measuring 1/78 decitex;
yarns called “core yarns” (B), each being formed of a textured polyamide yarn measuring 2/78 decitex worked in a 3/1 rep weave on the two wefts;
yarns called “shuttle threads” (C), each being formed of a textured polyamide yarn measuring 2/78 decitex worked in a 3/1 rep weave on the back weft;
yarns called “binder yarns” (D), each being formed of a textured polyamide yarn measuring 2/78 decitex worked in a taffetas weave on the two wefts.
The textile element thus formed has a maximum stretching capacity of approximately 90% with respect to the initial length, and develops a return force for a 30% stretching in the order of 400 cN/cm.
Advantageously, to obtain the desired result, that is, the comfort on the one hand, and the holding on the other hand, the respective proportion of long stretch yarns and short stretch yarns is close to 50-50; only the elastic yarns on each selvedge are formed with long stretch elastic yarns to ease the forming of the edge.
Of course, the elastic characteristics of the textile element depend on its final application.
Thus, in the context of the forming of a shorts or underwear waistband, particularly for a use in sports, a textile structure similar to that previously described, but which this time has a maximum stretching from approximately 120 to 150% with respect to the initial length, in addition to a return force for a 30% stretching typically in the range from 200 to 300 cN/cm, is formed.
To vary the elastic characteristics of the involved yarns, the size of the core of the covered yarns and the actual covering are varied. Such a control of the stretching and of the consecutively generated return force is perfectly well known and within the abilities of those skilled in the art.
The described example concerns a woven article.
The invention also applies to textile structures obtained by knitting or by braiding, the main elements of the invention being kept.
One can understand the benefits of the present invention, which enables to simply obtain, whatever the envisaged application, a textile structure simultaneously enabling to ensure the function of elastic compression which is mainly required from it, and the comfort, which is desired in case of light effort or of no effort. This is thus particularly true when practicing a sport, although it is not limited to this type of application only.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1901442 | Feb 2019 | FR | national |
