EP2220951B1 - Elastic knitwear lingerie item with added glued edge - Google Patents

Description

The present invention relates to a thin elastic knitted lingerie article, and in particular an article of footwear.

The invention more particularly relates to a tights obtained by knitting. It is known, for example by the documents GB 1,427,777 and EP 0 034 981 manufacturing pantyhose by knitting two tubes on a circular loom, opening the top of each tube along a substantially vertical cut and assembling the two tubes at the edges of said cutouts so as to form the panty portion of tights. The waistband portion of the pantyhose is formed by sewing an attached belt band or more traditionally by a double knit thickness obtained during the knitting itself and whose dimensions and texture vary depending on the construction characteristics and thickness of the the lower part at the waist. In the case of classic tights, this texture is particularly thin and elastic.

This type of belt construction, if it provides the maintenance function satisfactorily, however provides discomfort due to a large force (which compresses the belly, marks the skin, ...) and has an unsightly appearance linked to the excessively large allowance inherent in these known constructions (with a disadvantage regretted by the users which is to let see the belt of the tights under clothing and / or roll).

We know from the document EP 2,002,740 a lingerie article, such as a stocking, in which is fixed a cylindrical sleeve such as a lace garter at the top and bottom of the bottom, by fusing it with a tape of adhesive not wide deposited peripherally. The exact constitution of the upper part of the bottom is not described. The decorative part which is thus glued is not a highly elastic part and is glued so as to be relatively free from the bottom, outside the narrow band (1 cm) of adhesive by which it is glued to the bottom .

It is also known from the document US 2008/0282451 pants whose leg or waist openings are provided with an elastic band presenting in the form of a flattened tube which one comes to heat-bonding one of the faces on the knit. This results in the openings thus reinforced at least three layers of knitting that may be uncomfortable to wear.

The object of the invention is to provide a new type of belt, or more generally a holding edge, for a thin elastic knitted article, particularly a tights, which does not have these disadvantages, and is instead very comfortable to wear.

The invention achieves its goal through a fine elastic knitted lingerie article, having a knitted body in a fine knit and ending on the side of an opening by an elastic holding edge comprising a knit edge portion in the continuity of the knit end of the body and a strip of heat-bonded elastic material on said knitted edge portion, characterized in that said knitted edge portion is constituted by a single thickness of fine knit fabric whose surface weight is greater than that of the knitted body and greater than or equal to at 150 g / m ² and has an elongation at 15 Newton equal to or greater than 150%, and in that the band of elastic material is itself an elastic knit with a surface weight of between 180 and 210 g / m ² which has an elongation at 15 Newtons of the band greater than 130% and is heat-sealed to said single thickness of fine elastic knit over substantially its entire height.

The invention also relates to a method of manufacturing a thin elastic knitted lingerie article having a knit body in a fine knit and terminating at an opening side by an elastic holding edge comprising a knit edge portion in the continuity of the thin knit of the body and a strip of heat-bonded elastic material on said knitted edge portion, characterized in that a single thickness of fine knit fabric is used for the knitted edge portion, the surface weight of which is greater than that of the knitted body and greater than or equal to 150 g / m ² and has an elongation at 15 Newton equal to or greater than 150%, and in that for the strip of elastic material is itself an elastic knit with a weight per unit area of between 180 at 210 g / m ² which has an elongation at 15 Newtons of the band greater than 130% and in that said elastic material band is heat-treated to said thickness of tric ot elastic end on substantially its entire height.

According to an important aspect of the process of the invention, an adhesive in the form of a film of synthetic material associated with the strip, with a thickness of less than 100 μm, is associated with the band of elastic material at a temperature of association. corresponding to or slightly greater than the softening point of the adhesive, and then the complex thus obtained is thermocouple at a heat-sealing temperature which may be higher than the association temperature but which remains below the melting temperature of the adhesive film.

Thanks to the lightness and elasticity of the knitted materials used for the invention, and the fact that there are only two layers of thin knit at the level of the edge (that of the actual edge and that of the elastic band). ), it is both comfortable to wear while ensuring very good maintenance function on the body.

Advantageously, the band of elastic material is a fine elastic knit based on polyamide and elastane. It is preferably a charmeuse (soft and dense to wear) incorporating polyamide, preferably about 20% elastane. The elongation at 15 Newtons (according to BS 4952) of the elastic band is greater than 130% and for example between 130% and 160%. The strength of the strip at 80% elongation in the length direction is advantageously 220 to 430 cN. The weight of the knit of the strip is advantageously of the order of 180 to 210 g / m ² (ISO 3801 standard). The base knit of the article has, at the level of the edge, advantageously an elongation at 15 Newtons equal to or greater than 150%.

Advantageously, the strip of elastic material is heat-bonded by means of a very thin film associated with the strip, that is to say whose thickness before gluing is advantageously less than 100 μm, and preferably less than or equal to 50 μm. .mu.m. The film is advantageously a continuous film of synthetic material, in particular thermofusible. Preferably, it is a polyurethane film. As already mentioned, the association of the film with the strip is controlled so as to be sufficient to allow the handling of the strip / film complex, but is light enough not to block the elasticity of the knit or that of the polyurethane film itself. even. As such, the use of the charmeuse, with very dense surface and almost frozen, is particularly advantageous in that it offers less blocking lock to the adhesive film.

For example, in the case of a polyurethane film, the combination is made at a temperature corresponding to the softening point of the polyurethane (typically about 94 ° C) or slightly higher at this point, which allows the polyurethane to impregnate weakly the adjacent knitting fibers and achieve the requested association.

The elongation of the complex thus obtained at 15 N is advantageously at least 120%, and preferably of the order of 120% to 150%.

The subsequent heat-bonding of the complex to the base knit is at a temperature which can be and is advantageously greater than the association temperature of the complex, but which remains in any case lower than the melting point of the film (for example about 190 ° C. C for a polyurethane film) so as not to degrade the elasticity of the film.

In practice, for the production of a tack, the complex (the strip and its associated film) is arranged on the edge of a knitted tube in single thickness and open, in the stretched state; the complex is applied using a press adapted to thermocollate, thanks to the conditions of heat and pressure, the band at the edge of the tube through the film. Once fixed, the heat-sealed strip and the underlying knit are cut, for example by ultrasound and according to a straight edge, curved or in waves providing a more feminine aesthetic side, so that, after cutting, the heat-sealed strip and the edge of the knitted tights thicker than the body of the tights are arranged on each other exactly, over their entire height of a few centimeters (for example 3 centimeters) which gives the appearance of a unitary border.

Two tubes thus treated are assembled according to the traditional technique to form a tights.

Preferably, the strip is bonded to the inner side of the edge, to maintain a uniform appearance on the outside. This band thus bonded gives a more dressed and less low-end, especially on a type of "sticky".

In a very advantageous embodiment of the invention, the article to which it applies is a knitted tights having an overall weight per unit area of less than 100 g / m ² with the exception of the holding edge whose weight per unit area by knitting a value substantially equal to or greater than 150 g / m ² . This higher knit density at the edge is important not only for the strength and elongation characteristics, but also so that the adhesive of the complex does not penetrate this knit thickness and is not visible.

Tests were conducted to compare strength / aspect ratio by size on a pantyhose A manufactured with a conventional double-thickness belt 30 mm in height, and a pantyhose B manufactured with a single-thickness belt on which was laminated a strip of 30 mm high charmeuse polyamide / elasthane marketed by LIEBAERT under the reference CN 1985 using a polyurethane film of 50 microns. The results are as follows: Strength (g) Lengthening (cm) A size 1-2 250-670 58-75 A size 3-4 250-570 60-77 B size 1-2 220-310 55-65 B size 3-4 220-310 57-65

In a particular comparative example between a type A adhesive and a type B adhesive, it was found that the force / elongation diagram was substantially straight in both cases but shifted in the ordinate: for the belt of the invention, elongations of about 59.7 cm to 64.4 cm correspond to forces of about 230 to 300 grams, while the same elongations correspond to forces of about 510 to 580 grams for a belt of the prior art.

These results show that the belts according to the invention exert less stress on the user, and are therefore comfortable to wear.

The process of the invention is particularly interesting as has been said for fine knits, that is to say of a weight generally between 100 g / m ² and 250 g / m ² , and preferably between 150 g / m ² and 200 g / m ² . Their thickness at the bonding zone is of the order of 0.60 mm and, with the glued strip, of the order of 1.20 mm.

According to an advantageous characteristic of the invention, it can be applied to an article of footwear such as a tights whose surface weight is generally less than 100 g / m ² , or even 80 g / m ² in the legs, but whose weight per unit area at the belt where is applied the heat-bonded film is increased relative to the weight of the surrounding region, to be preferably close to 150 g / m ² or greater than this value. This increase is advantageously obtained during knitting by adding larger threads (with the use of microfibers to give the swelling and the attachment) and / or by using tighter meshes than on the surrounding part of the body of the article. .

Naturally, although a preferred application relates to pantyhose belts, the same principle can be applied for the production of an elastic edge for holding other lingerie articles, such as stockings, knee-highs, socks, breeches, etc. .

It is also possible to use in combination with the complex of the invention a silicone coating on the holding edge.

Claims (9)

1. A thin elastic knitted underwear item, having a knitted body in a thin knitted part and ending on an opening side by a holding elastic edge comprising a knitted edge part extending from the body thin knitted part and a strip of elastic matter heat sealed on said knitted edge part, characterized in that said knitted edge part consists in a single layer of thin knitted part whose specific weight is higher than that of the knitted body and equal to, or higher than, 150 g/m2 and presents a lengthening under 15 Newton equal to, or higher than, 150%, and in that the strip of elastic matter is itself an elastic knitted part having a specific weight ranging from 180 to 210 g/m2 which presents a strip lengthening under 15 Newton higher than 130% and is heat sealed on said single layer of thin elastic knitted part substantially on all its height.
2. The item according to claim 1, characterized in that the strip of elastic matter is a knitted part containing polyamide and elastane.
3. The item according to any of claims 1 or 2, characterized in that the strip of elastic matter is heat sealed by means of a film from a heat set adhesive synthetic matter associated to the strip, and having a thickness lower than 100 µm.
4. The item according to claim 3, characterized in that the film is a polyurethane film.
5. The item according to any of claims 1 to 4, characterized in that the strip is pasted on the edge internal side.
6. The item according to any of claims 1 to 5, characterized in that it is a knitted stocking of an overall specific weight lower than 100 g/m2 excepted for the holding edge whose the specific weight reaches, by knitting, a value substantially equal to, or higher than, 150 g/m2.
7. A method for manufacturing a thin elastic knitted underwear item, having a knitted body in a thin knitted part and ending on an opening side by a holding elastic edge comprising a knitted edge part extending from the body thin knitted part and a strip of elastic matter heat sealed on said knitted edge part, characterized in that it is used for the knitted edge part a single layer of thin knitted part whose specific weight is higher than that of the knitted body and equal to, or higher than, 150 g/m2 and presents a lengthening under 15 Newton equal to, or higher than, 150%, and in that it is used for the strip of elastic matter (is itself) an elastic knitted part having a specific weight ranging from 180 to 210 g/m2 which presents a strip lengthening under 15 Newton higher than 130% and in that said strip of elastic matter is heat sealed on said single layer of thin elastic knitted part substantially on all its height.
8. The manufacturing method according to claim 7, characterized in that an adhesive as a synthetic matter film associated to the strip, of a thickness lower than 100 µm, is associated to the elastic matter strip at a bonding temperature corresponding to, or slightly higher than, the softening point of the adhesive, and then the thus obtained complex is heat sealed at a heat sealing temperature which can be higher than the bonding temperature but which remains lower than the melting temperature of the adhesive film.
9. The method according to claim 8, characterized in that two tubes on which an elastic strip is heat sealed are manufactured, and in that the thus produced two tubes are assembled to form a stocking.