Method for manufacturing underwear products, especially bras

Abstract

Method for manufacturing a brassiere, comprising the following steps: providing a first fabric layer (11) designed to realize the outer layer of an underwear article, a second fabric layer (13) designed to realize the inner layer of the underwear article, and a third material (17) made of a heat-bonding polyurethane film designed to realize a permanent joining element between the two fabric layers (11, 13) in the finished article; spraying a reactive "hot-melt" polyurethane glue capable of being reactivated only once on the first fabric layer (11) on the side thereof intended to face the second fabric layer (13); spraying a third material (17) made of a heat-bonding polyurethane film ... The heat-bonding polyurethane film (17) is applied to one side of a first fabric layer (11); two fabric layers (11, 13) are stacked, with the side of the first fabric layer covered with glue facing the second layer, and the heat-bonding polyurethane film portion (17) applied to the second fabric layer facing the first fabric layer; the two fabric layers (11, 13) are joined by hot pressing with the heat-bonding polyurethane film portion (17) inserted therebetween, the reactive polyurethane glue is activated to temporarily be in a liquid phase, and then a cross-linking process is triggered to finally solidify the glue to fix the component; and the product is thermoformed according to a desired shape.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing underwear products, in particular brassieres. Background Art

[0002] This type of article must obviously generally have good elastic properties in order to be able to guarantee a high level of comfort for the wearer, preventing discomfort or even skin irritation.

[0003] In order to obtain the desired degree of elasticity, elastic fabric strips are usually used, however, these strips usually do not ensure optimal results in terms of comfort and do not prevent the formation of marks on the skin, for example due to the pressure generated by such elastics.

[0004] Particularly in the case of brassieres formed from two superimposed fabric layers, an alternative may consist in using silicone elements that act both as elastic elements and as joining elements for the two fabric layers.

[0005] However, silicone is often frowned upon due to its health risks. Furthermore, the use of silicone elements can cause problems during the final thermoforming step of the bra, which is used to shape it into the desired final form for both aesthetics and wearability. In practice, thermoforming is typically performed at temperatures approaching 200°C, which carries the risk of melting the silicone material and damaging the product. Summary of the Invention

[0006] A general object of the present invention is to overcome the above-mentioned drawbacks by providing a method for manufacturing an undergarment article, in particular a brassiere, which does not require elastics for achieving the desired wearing properties.

[0007] Another object of the present invention is to provide a method for making a bra that does not contain silicone material.

[0008] In view of this purpose, according to the present invention, a method for manufacturing an underwear article, in particular a brassiere, is proposed, comprising the following steps:

[0009] - providing a first textile layer designed to realize the outer layer of said underwear article, cut according to a shape substantially corresponding to a planar projection of the underwear article when flattened;

[0010] - providing a second fabric layer designed to realize an inner layer of said underwear article, cut according to a shape substantially corresponding to a planar projection of the underwear article when flattened;

[0011] - providing a third film material designed to realize a permanent joining element between the first and second fabric layers in the finished undergarment article, said third film material being cut to form at least one central underbreast portion, a pair of upper portions intended to be arranged corresponding to the shoulder straps of the brassiere, and a pair of side portions intended to be arranged corresponding to the sides of the brassiere, and said third film material being a “silicone-free” heat-bonded polyurethane film;

[0012] - spraying the first textile layer, on its side intended to face the second textile layer, with a reactive "hot melt" polyurethane glue capable of being reactivated only once by heating within a reactivation period of at least 3 days from application, preferably within 5 days from application;

[0013] - coating the above-mentioned heat-bonding polyurethane film portion on a position of the second fabric layer that is intended to face the first fabric layer, and heat-sealing the portion to the second fabric layer by heat pressing;

[0014] - overlapping the first fabric layer and the second fabric layer, with the side of the first fabric layer covered by the reactive polyurethane glue facing the second fabric layer, and the heat-bonded polyurethane film portion applied to the second fabric layer facing the first fabric layer;

[0015] - during said reactivation period of the reactive "hot melt" polyurethane adhesive, the two fabric layers cut according to their respective shapes are joined by hot pressing with the aforementioned portion of the heat-bonding polyurethane film interposed between them, reactivating the reactive polyurethane adhesive so as to temporarily be in a liquid phase, suitable for penetrating the fibers of the fabrics to be joined, and then triggering a chemical cross-linking process to allow it to finally cure, in order to finally and permanently fix the parts;

[0016] - At the end of the cross-linking process of the polyurethane glue, the underwear article is thermoformed according to the desired shape;

[0017] - Applying straps, hooks, labels and other possible accessories to finalize the underwear article. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to clarify the innovative principle of the present invention and its advantages over the prior art, a possible illustrative embodiment of the invention applying such principle will be described below with the aid of the accompanying drawings.

[0019] Figure 1 Shows a plan cross-sectional view of the first forming fabric layer prior to assembly.

[0020] Figure 2 Shows a plan cross-sectional view of the second forming fabric layer prior to assembly.

[0021] Figure 3Shows a plan view of the various elements used to connect the two forming fabric layers that make up the brassiere.

[0022] Figure 4 Shown is a plan view of a second forming fabric layer having the above-described connecting elements applied thereto prior to joining it to the first forming fabric layer.

[0023] Figure 5 Shows a plan view of two forming fabric layers superimposed on each other with the interposition of the above-mentioned connecting elements, which are covered by a protective paper before the individual parts are thermally joined.

[0024] Figure 6 Shows a plan view of an undergarment article assembled with two fabric layers, prior to the operation of trimming excess edges. DETAILED DESCRIPTION

[0025] The brassiere according to the manufacturing method of the invention is of the type consisting of two superimposed fabric layers, the outer layer having a strictly aesthetic function and the inner layer adapted to ensure high comfort and wearing characteristics for the wearer.

[0026] The method for manufacturing an undergarment according to the invention first envisages providing a first fabric layer 11 designed to realize the outer layer of a brassiere, cut according to a shape 12 corresponding to the planar projection of the undergarment when flattened, but with dimensions slightly larger than the shape that the article itself must have once finished.

[0027] The term "planar projection of the flattened article" is used herein to refer to the shape of the article (or a portion thereof) when flattened on a plane. Basically, such a shape corresponds to a shape known in the art of tailoring / clothing as a "pattern", i.e., the outline according to which the fabric must be cut to make a garment.

[0028] The manufacturing method according to the invention further envisages providing a second fabric layer 13 designed to realize an inner layer of a brassiere, cut according to a shape 14 that substantially corresponds to a planar projection of the flattened undergarment article.

[0029] Therefore, the first fabric layer 11 has slightly larger dimensions relative to the second fabric layer 13 .

[0030] The first and second fabric layers 11 , 13 may be provided as continuous strips or in finished-size panels, depending on the specific organizational requirements of the production site. Figure 1 and Figure 2 Schematically shown are strips or panels 15, 16 of fabric from which the shapes 12, 14, respectively, are cut.

[0031] The type of material constituting the first fabric layer 11 will be selected substantially according to the desired aesthetic characteristics of the article. For example, such material may be selected from lace, tulle, microfiber, silk, stretch cotton, etc.

[0032] On the contrary, the type of material constituting the second fabric layer 13 will be selected substantially according to the comfort and wearability characteristics required for the article. For example, such material can be selected from microfiber, tulle, silk, stretch cotton, etc.

[0033] The manufacturing method according to the invention further envisages providing a third film material 17 designed to realize a permanent joining element between the first textile layer 11 and the second textile layer 13 in the finished underwear article.

[0034] like Figure 3 As schematically shown in FIG, the third film material 17 is cut into suitable shapes to respectively form at least one central underbust portion 18, a pair of upper portions 19, 19' intended to be arranged corresponding to the bra straps, and a pair of side portions 20, 20' intended to be arranged corresponding to the sides of the bra.

[0035] The film material 17 used to realize said permanent joining element between the first fabric layer 11 and the second fabric layer 13 is a “silicone-free” heat-bonding polyurethane film material.

[0036] Advantageously, two different weights of said thermo-bonded polyurethane films are used: a first material, so-called "heavy", for realizing the central lower chest portion 18 and the upper belt portions 19, 19', and a second material, so-called "light", for realizing the side portions 20, 20', which has a lower thickness and weight per square meter than the previous material.

[0037] More specifically, for the "heavy" heat-bonding polyurethane film, a film having a thickness of 180 μm and a weight of 210 g / m 2 For light thermal adhesive polyurethane film, a film with a thickness of 75 μm and a weight of 90 g / m 2 membrane.

[0038] For example, for both types of thermally bonded polyurethane materials, films manufactured by FaitPlast, Inc., designated "Easy-Tech 1381" and "Easy-Tech 897," respectively, have been found to be optimal for use.

[0039] Depending on the operating characteristics of the production equipment, the first and second fabric layers 11, 13 and the heat-bonded polyurethane film 17 can be supplied, prepared and cut simultaneously, or a specific sequence can be envisaged while remaining within the scope of the innovative principles of the present invention.

[0040] The manufacturing method according to the invention further comprises spraying onto the first fabric layer 11, on its inner side (i.e. the side intended to face the second fabric layer 13), a reactive "hot melt" polyurethane adhesive (PUR) which can be reactivated only once by heating within a reactivation period of at least 3 days from application, preferably within 5 days from application.

[0041] The application of the glue on the fabric is carried out by heating it at about 140° C. so that it is in a liquid state. After about 30 seconds, the glue applied on the fabric will turn into a solid state, which will remain until its subsequent reactivation.

[0042] For this purpose, it has been found to be particularly advantageous to use a reactive polyurethane glue manufactured by the company Kleiberit and known as "Kleiberit 900.7.9967".

[0043] Depending on the operating characteristics of the production plant, glue may be applied to the first fabric layer 11 before or after the fabric is cut according to the shape 12 .

[0044] The manufacturing method according to the present invention further envisages coating the central lower chest portion 18, upper shoulder strap portions 19, 19' and side portions 20, 20' made of the heat-bonded polyurethane film 17 at appropriate locations on the inner side of the second fabric layer 13 (i.e., the side intended to face the first fabric layer 11), as described above. Figure 4 As shown, the portion is heat-sealed to the fabric layer 13 using a heat press at a temperature of about 160° C. for about 15-20 seconds, preferably 16 seconds.

[0045] As is well known to those skilled in the art, once the portions 18 , 19 , 19 ′, 20 , 20 ′ have been secured to the fabric layer 13 , the protective support of the heat-bonded polyurethane film 17 is removed, leaving only the elastic portions of the polyurethane film 17 coupled to the fabric layer 13 .

[0046] After carrying out the operations described so far, but while the "hot melt" reactive polyurethane glue is still reactive, the joining of the two textile layers 11, 13 (previously cut according to the respective shapes 12, 14) can begin, with the portions 18, 19, 19', 20, 20' of the thermo-adhesive polyurethane film 17 being inserted between them, until the components are finally and permanently fixed.

[0047] In order to carry out the step of joining the two fabric layers 11, 13, it is advantageous to arrange the first fabric layer 11 (intended to realize the outer layer of the bra) on a plane turned upwards with one side covered with reactive polyurethane glue, so that the second fabric layer 13 (intended to realize the inner layer of the bra) is placed on it, with the part of the heat-adhesive polyurethane film 17 turned downwards, and taking care to adapt the shape 14 of the second fabric layer 13 to the shape 12 of the first fabric layer 11.

[0048] In this way, the portions 18 , 19 , 19 ′, 20 , 20 ′ of the thermo-adhesive polyurethane film 17 will be properly inserted between the two fabric layers 11 , 13 .

[0049] The assembly of the two fabric layers 11, 13 with the portion of the thermo-adhesive polyurethane film 17 interposed therebetween is then advantageously covered with paper 21, such as Figure 5 Its function will be described below.

[0050] At this point, hot pressing is performed on the two superposed fabric layers 11, 13. Due to the above-mentioned properties of the glue used, this operation can be performed within 5 days from the application of the glue itself.

[0051] To do this, the assembly of superposed fabric layers 11 , 13 interposed with portions of heat-adhesive polyurethane film 17 and covered with protective paper layer 21 is positioned below the plane of a heat press, heating the material to approximately 120° C. for at least 10 seconds.

[0052] This heating reactivates the "hot-melt" reactive polyurethane glue (PUR), returning it to a liquid state and thus penetrating the fibers of the fabrics to be joined. This reaction of the glue initially creates a first mechanical "grip" step and further triggers a chemical crosslinking process, leading to its final solidification, making the glue itself impossible to remove without mechanically tearing the two edges of the fabric. Complete crosslinking of the glue type used in the manufacturing method according to the invention occurs within approximately 7 days.

[0053] The paper sheet 21 has the function of preventing the “hot melt” polyurethane glue from sticking to the press plane beyond the shape 14 of the second fabric layer 13 at the edge of the first fabric layer 11 during the heating step in the press and liquefaction of the glue.

[0054] Once the hot pressing of the two superposed fabric layers 11, 13 has taken place, the paper sheet 21 is removed and the underwear article looks like Figure 61 , wherein the second fabric layer 13 partially covers the first fabric layer 11 and portions 18, 19, 19', 20, 20' of the heat-bonded polyurethane film 17 are interposed between the two fabric layers 11, 13. Since, as can be seen, the first fabric layer 11 is initially formed to a size slightly larger than the second fabric layer 13, the underwear article will now temporarily have a peripheral edge 22 that exceeds that formed by the first fabric layer 11.

[0055] Once at least 7 days have passed since the hot pressing (i.e., the time necessary to ensure that the polyurethane glue is completely cross-linked), the product is thermoformed to give the bra the desired cup shape and size. Such methods are well known to those skilled in the art and, therefore, will not be described in detail herein.

[0056] At this point, the excess edge 22 of the first fabric layer 11 is trimmed according to the contours of the finished garment (here also according to techniques and methods known to those skilled in the art).

[0057] Finally, the garment can be finished by applying adjustable straps, hooks, labels, etc., continuing with normal sewing operations.

[0058] It is now clear how the method for manufacturing an underwear article according to the invention makes it possible to obtain a garment having optimal donning characteristics, despite not using elastomer or silicone-based materials.

[0059] It is obvious that the above description of the embodiments applying the innovative principles of the present invention has been given by way of illustrative examples thereof and therefore should not be considered as limiting the scope of the patent claimed herein.

[0060] For example, in addition to the portions 18, 19, 19', 20, 20' of the polyurethane thermal adhesive film 17 designed to achieve joining of the two fabric layers 11, 13, other portions may be provided at appropriate locations, depending on specific aesthetic and / or functional properties that may sometimes be desired or necessary.

[0061] Additionally, the shape of the garment and the fabrics comprising it may likewise be selected based on specific desired properties.

Claims

1. A method for manufacturing a brassiere, comprising the steps of: - providing a first fabric layer (11) designed to realize the outer layer of said brassiere, cut according to a shape (12) corresponding to the planar projection of the brassiere when flattened; - providing a second fabric layer (13) designed to realize the inner layer of said brassiere, cut according to a shape (14) corresponding to the planar projection of the brassiere when flattened; - providing a third film material (17) designed to realize a permanent joining element between the first fabric layer (11) and the second fabric layer (13) in the finished brassiere, said third film material (17) being cut to form at least one central underbust portion (18), a pair of upper portions (19, 19') intended to be arranged corresponding to the shoulder straps of the brassiere, and a pair of side portions (20, 20') intended to be arranged corresponding to the sides of the brassiere, and said third film material (17) being a "silicone-free" heat-bonded polyurethane film; - spraying onto the first fabric layer (11), on its side intended to face the second fabric layer (13), a reactive "hot melt" polyurethane glue capable of being reactivated only once by heating within a reactivation period of at least 3 days from application; - coating portions (18, 19, 19', 20, 20') of the aforementioned "silicone-free" heat-adhesive polyurethane film on a side of the second fabric layer (13) intended to face the first fabric layer (11), and heat-sealing the portions (18, 19, 19', 20, 20') to the second fabric layer (13) by hot pressing; - superimposing the first and second fabric layers (11, 13), with the side of the first fabric layer (11) covered by the reactive "hot melt" polyurethane glue facing the second fabric layer (13), and the portions (18, 19, 19', 20, 20') of the "silicone-free" heat-adhesive polyurethane film applied to the second fabric layer (13) facing the first fabric layer (11); - joining the two fabric layers (11, 13) cut according to the respective shapes (12, 14) by means of hot pressing with the portion (18, 19, 19', 20, 20') of "silicone-free" heat-adhesive polyurethane film interposed between them during said reactivation of the reactive "hot-melt" polyurethane glue, reactivating the reactive "hot-melt" polyurethane glue so as to temporarily place it in a liquid phase suitable for penetrating the fibers of the fabrics to be joined, and then triggering a chemical cross-linking process for its final curing in order to finally and permanently fix the parts; - Thermoforming of the bra according to the desired shape at the end of the crosslinking process of the reactive "hot melt" polyurethane glue; -Apply straps, hooks, tabs to finalize the bra.

2. A method of manufacturing a brassiere according to claim 1, wherein the "silicone-free" heat-bonded polyurethane film (17) is provided in a first, heavier weight to realize the central underbust portion (18) and the upper shoulder strap portions (19, 19'), and in a second, lighter weight to realize the side portions (20, 20').

3. The method of manufacturing a brassiere according to claim 2, wherein the thickness of the "silicone-free" heat-adhesive polyurethane film according to the first heavier weight is 180 microns and the weight is 210 g / m 2 , and according to the second lighter weight "silicone-free" thermal adhesive polyurethane film having a thickness of 75 microns and a weight of 90 g / m 2 .

4. A method of manufacturing a brassiere according to claim 1, wherein the portion (18, 19, 19', 20, 20') of the "silicone-free" heat-adhesive polyurethane film is heat-sealed to the second fabric layer (13) by heat pressing at a temperature of 160°C for 15-20 seconds.

5. A method for manufacturing a brassiere according to claim 1, wherein the coating of the reactive "hot melt" polyurethane glue on the first fabric layer (11) is carried out at a temperature of 140°C.

6. Method for manufacturing a brassiere according to claim 1, wherein the joining of the two fabric layers (11, 13) with the portion (18, 19, 19', 20, 20') of "silicone-free" heat-adhesive polyurethane film interposed between them is carried out by heat pressing at a temperature of 120°C for at least 10 seconds.

7. A method of manufacturing a brassiere according to claim 1, wherein the second fabric layer (13) is cut according to a shape (14) the size of which corresponds to the shape the brassiere should have when finished, and the first fabric layer (11) is cut according to a shape (12) which is slightly larger than the shape the brassiere should have when finished.

8. A method of manufacturing a brassiere according to claim 7, wherein the superpositioning of the first and second fabric layers (11, 13) with the portion (18, 19, 19', 20, 20') of "silicone-free" heat-bonded polyurethane film interposed therebetween is performed so that the shape (14) of the second fabric layer (13) is maintained within the shape (12) of the first fabric layer (11), thereby defining a peripheral excess edge (22) of the first fabric layer (11).

9. The method of manufacturing a brassiere according to claim 8, wherein: After the bra is thermoformed to the desired shape, the aforementioned peripheral excess edge (22) is trimmed according to the contours of the finished bra.

10. The method of manufacturing a brassiere according to claim 8, wherein: Before hot pressing, the entirety of the two fabric layers (11, 13) cut according to the respective shapes (12, 14) with the portion (18, 19, 19', 20, 20') of the "silicone-free" heat-adhesive polyurethane film inserted therebetween is covered with a protective paper (21) in order to prevent the reactive "hot-melt" polyurethane glue from adhering to the press plane corresponding to the peripheral excess edge (22) of the first fabric layer (11) sprayed with glue during the press heating phase and the subsequent liquefaction of the reactive "hot-melt" polyurethane glue.

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