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(11) | EP 2 042 047 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Method for production of a composite material |
| (57) A method for creating a selectively reinforced composite material (15, 25), comprising
the steps of: a) providing a first portion (11, 21) of a first flexible material;
b) positioning on said first portion (11, 21) a plurality of reinforcement members
(12, 22) according to a preset pattern, each of said reinforcement members (12, 22)
having a preferential direction of development; and c) fixing said reinforcement members
(12, 22) to said first portion (11, 21).
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[0001] The present invention refers to a method for creating a flexible composite material, in particular for obtaining a material that be selectively reinforced in some portions thereof and therefore exhibit strength and elasticity differentiated according to the tensile direction. Said flexible material may, e.g., be leather, fabric or the like.
[0002] Garments worn on in sports (in particular, motor biking) practice, are contrived and designed to offer a high level of protection to the user, who must be safeguarded against the consequences of a possible accident. Therefore, such garments must withstand the very high stresses that may be produced in case of fall; in particular, they should withstand tensile stress and abrasion to avoid tearing of the garment itself, and therefore loss of its protective function.
[0003] Analysis of fall dynamics and user interaction allows to single out the garment regions that are most subjected to stress, and moreover which are the preferential stress directions. The known art envisages making said regions stronger, by applying thereat leather or fabric reinforcements having greater strength than the remainder of the garment, thereby creating a "patchwork-like" garment.
[0004] A first drawback of the known art lies in that said reinforcements are usually applied by means of seaming; this entails both a greater machining complexity and a local weakening of the strength of the material, owing to the presence of the seam holes, as well as the chance that rain may leak into the garment, through the same seam holes.
[0005] Moreover, the known art does not allow for an effective region-wise calibration and differentiation of garment properties, as this would be feasible only through the applying of a vast number of said reinforcements, in addition having differentiated shapes, in order to specifically take into account the behaviour required from the garment depending on stresses directions and extent; such a solution in accordance with the known art is not easily feasible, due to evident practical and economic reasons.
[0006] Lastly, such applied reinforcements can prove less than comfortable to the user, as they increase the thickness and the overall rigidity of the garment, thereby restricting the freedom of movement of the same user.
[0007] Moreover, it should not be neglected that, in general, user's comfort and garment performances can be increased by making some garment parts more elastic or more rigid than other ones, in particular along preferential directions, so as to assist correct postures and promote certain movements. This can also result in a lesser physical tiring of the user, as part of the postural function usually performed by the muscle apparatus is instead performed by the garment.
[0008] However, to date the foregoing is hardly implementable through the teachings of the known art, save by using a plurality of different materials and fabrics joined thereamong according to needs. Moreover, consider that usually the materials used exhibit isotropic behaviour, therefore not being susceptible to a calibration of the garment behaviour that may be differentiated along different directions.
[0009] Hence, the present invention stems from the technical problem of providing a method for production of a flexible composite material having features of strength and elasticity that be differentiated and calibrated depending on needs, obviating to the drawbacks mentioned above with reference to the known art.
[0010] This is attained by providing a method for creating a selectively reinforced composite material that, as defined in the independent claim 1, comprises the steps of: a) providing a first portion of a first flexible material; b) positioning on said first portion a plurality of reinforcement members according to a preset pattern, each of said reinforcement members having a preferential direction of development; c) fixing said reinforcement members to said first portion.
[0011] Secondary features of the present invention are defined in the corresponding dependent claims thereof.
[0012] The present invention provides several relevant advantages. The main advantage lies in that the method of the invention allows to obtain a flexible composite material whose strength and elasticity may be engineered according to the needs of the garment for which it is intended.
[0013] Another advantage lies in obtaining a material in which said properties can be differentiated and calibrated according to the tensile direction.
[0014] Yet another advantage lies in obtaining a composite material allowing to greatly simplify the production of an end garment, in particular by reducing the number of components required and the number of seams, and also simplifying the modcs for producing it.
[0015] Further advantages, features and the operation modes of the present invention will be made evident from the following detailed description of some embodiments thereof, given by way of example and not for limitative purposes. Reference will be made to the figures of the annexed drawings, wherein:
- Figure 1 is a plan view of a portion of composite material obtained through the method according to the present invention;
- Figure 2A is a first perspective view related to the steps of the method for creating the portion of material of Figure 1;
- Figure 2B is a second perspective view related to the steps of the method for creating the portion of material of Figure 1;
- Figure 3 is a sectional view of the portion of material of Figure 2B;
- Figure 4 is a perspective view related to the steps of a second embodiment of the method according to the present invention;
- Figure 5 is a perspective view of a portion of composite material obtained through the method of Figure 4; and
- Figure 5A is a sectional view of the portion of material of Figure 5.
[0016] The method of the present invention is described hereinafter with reference to preferred embodiments thereof, in which it is used for creating a portion of an item of clothing, in particular for sports use.
[0017] Referring to Figures 2A and 2B, a first flexible material is provided, which may be a natural-fibre or a synthetic-fibre fabric, or a spunbonded or an elasticated fabric, or leather or the like. Of course, the selection of said first flexible material depends on the needs of the subsequent use thereof in creating a garment for sports use.
[0018] In particular, it is provided a first portion 11 of said first flexible material, which will be selectively reinforced according to the modes set forth below.
[0019] In fact, on said first portion 11 a plurality of reinforcement members 12 is positioned, each of which has a preferential direction of development.
[0020] Said reinforcement members 12 are fixed to said first portion 11 of material, e.g. by means of adhesive tape 13 applied to each of said members 12; said adhesive tape 13, of course having a width greater than that of the members 12 to be fixed, allows to fix the reinforcement members 12 substantially along their entire length. The fixing of the members 12 can be carried out also by means of glue, of an adhesive film allowing to concurrently fasten plural members 12, or by means of other fixing systems, such as by seaming or heat sealing.
[0021] Thanks to said fixing, the stress forces applied to a composite material 15 thus obtained are transmitted to the reinforcement members 12, which provide strength and elasticity differentiated along the directions of the stresses themselves. In fact, the reinforcement members 12 are positioned and fixed on said first portion 11 according to a preset pattern, which is specifically studied on the basis of the features required from the portion of composite material 15.
[0022] In particular, said reinforcement members 12 are substantially thread-shaped and, in the specific instance shown in Figures 1 to 3, arranged so as to form an orthogonal lattice. The method for production of the invention may provide a step of fixing a pre-positioned reinforcing member 12 prior to proceeding to the positioning and fixing of a next member 12, or it may provide the positioning of a plurality of members 12 and the entailed concomitant fixing thereof.
[0023] Moreover, the method of the present invention can comprise a preliminary step during which said reinforcement members 12 are joined thereamong prior to the positioning on said first portion 11; thus, a support is created, comprised of reinforcement members 12, which is positioned as a whole on the portion 11 and fixed thereat, with a saving of machining times and costs.
[0024] The reinforcement members 12 are made, e.g., of Carbon fibre, Kevlar®, other fibre materials, polyurethane material, plastics material or elastomer material; evidently, it is also possible that a part of said reinforcement members 12 be made of one of the above-indicated materials, whereas another part is made of another one of said materials.
[0025] However, said reinforcement members 12 typically have a tensile modulus of elasticity that is greater than the tensile modulus of elasticity of said first portion 11 of said first material, i.e., forces by surface units being equal, they exhibit a lesser relative strain.
[0026] Hence, the described method allows to transform a portion of isotropic material 11 into a portion of selectively reinforced composite material 15, whose strength and elasticity arc engineered according to technical application needs, said properties being differentiated and calibrated along different directions thanks to the arrangement of the reinforcement members 12 and the use of a plurality of materials for the same members.
[0027] For instance, in the case of portion 15 of Figure 1, a tensile stress applied along a direction of development C-C of the reinforcement members 12 produces a strain of the portion 15 itself that is much smaller with respect to the strain produced by an equal tensile stress applied along a diagonal direction D-D.
[0028] Of course, lattices and patterns more complex than (or anyhow different from) the orthogonal one of Figure 1 may be created, so as to obtain an effective calibration and engineering of the properties of the composite material 15. Said reinforcement members 12 may, e.g., be arranged parallel to each other along preset directions, even having curvilinear patterns.
[0029] Moreover, note that said first portion 11 depicted in the figures is substantially plane; however, the method of the present invention is likewise applicable also to portions of flexible material having a curved shape, such as a portion intended to be placed at a shoulder or an elbow.
[0031] On a first portion 21 of a first flexible material a plurality of reinforcement members 22 are positioned, which are fixed by applying a second portion 26 of a second flexible material, so that said reinforcement members 22 remain enclosed between said first portion 21 and said second portion 26.
[0032] As it is shown in Figure 4, said second portion 26 may be fixed to the first portion 21 by means of glue 27 distributed on the first portion 21 itself, followed by an optional step of gluing with a press 29, which may utilize also a hot press. As a result, said first and second portion 21 and 26 adhere therebetween substantially along the entire surface, thereby implementing also the fixing of the reinforcement members 22.
[0033] In fact, note that the reinforcement members 22 might not be directly glued to the first and/or second portion 21 and 26, but they remain however appropriately fixed, by being enclosed between the mentioned material portions 21 and 26 glued therebetween as described above.
[0034] Anyhow, the described method yields a composite material 25 like that shown in Figures 5 and 5A.
[0035] Like the first flexible material, also said second flexible material may, needwise, be a natural-fibre or a synthetic-fibre fabric, or a spunbonded, or an elasticated fabric, or leather or the like. Said first and second portions 21 and 26 may be both substantially plane, or may have curved shapes, depending on what is required from their subsequent use.
[0036] Moreover, it is possible to create a support 28 comprised of reinforcement members 22, which support 28 is created prior to the positioning on said first portion 21. This can allow for a greater simplicity of production with respect to the sequential positioning of one reinforcement member 22 after another and is particularly advantageous in case the preset pattern reproduced by the support 28 be a complex pattern, like that shown in Figure 4.
[0037] E.g., said reinforcement members 22 are of polyurethane material and said support 28 is created by moulding, or it is created from a polyurethane sheet by means of a punch cutter adopting a suitable template.
[0038] From the description of the method subject-matter of the present invention it is evident how it allows to create portions of flexible and selectively reinforced composite material, which may be usefully comprised in a garment, in particular for sports use. In fact, the strength and elasticity of said portions of material may be calibrated in connection to the different parts of the garment in which they will be inserted, with a general improvement both of the mechanical features (among which tensile strength and abrasion strength) and of the performances of the garment, as well of the user's comfort.
1. A method for creating a selectively reinforced composite material (15, 25), characterised in that it comprises the steps of:
(a) providing a first portion of a first flexible material (11, 21);
(b)positioning on said first portion (11, 21) a plurality of reinforcement members (12, 22) according to a preset pattern, each of said reinforcement members (12, 22) having a preferential direction of development; and
(c) fixing said reinforcement members (12, 22) to said first portion (11, 21).
2. The method according to the preceding claim, further comprising the step of applying
a second portion (26) of a second flexible material on said first portion (11, 21),
so that said reinforcement members (12, 22) remain enclosed between said first portion
(11, 21) and said second portion (26).
3. The method according to claim 1 or 2, wherein said fixing of said reinforcement members
(12, 22) is carried out by means of adhesive tape (13).
4. The method according to claim 1 or 2, wherein said fixing of said reinforcement members
(12, 22) is carried out by means of glue.
5. The method according to claim 1 or 2, wherein said fixing of said reinforcement members
(12, 22) is carried out by means of seaming.
6. The method according to any one of the preceding claims, wherein said first portion
(11, 21) and/or said second portion (26) are substantially plane.
7. The method according to any one of the preceding claims, further comprising the step
of creating a support (28) comprised of reinforcement members (12, 22) prior to said
step of positioning on said first portion (11, 21).
8. The method according to the preceding claim, wherein said support (28) is created
by moulding.
9. The method according to claim 7, wherein said support (28) is created by means of
a punch cutter.
10. A portion of composite material (15, 25) created according to the method of any one
of the preceding claims.
11. The portion of composite material (15, 25) according to the preceding claim, wherein
said first or second material is leather or the like.
12. The portion of composite material (15, 25) according to claim 10 or 11, wherein said
first or second material is a fabric.
13. The portion of composite material (15, 25) according to any one of the claims 10 to
12, wherein said reinforcement members (12, 22) are substantially thread-shaped.
14. The portion of composite material (15, 25) according to any one of the claims 10 to
13, wherein said reinforcement members have a tensile modulus of elasticity that is
greater than the tensile modulus of elasticity of said first portion of said first
material.
15. The portion of composite material (15, 25) according to any one of the claims 10 to
14, wherein at least a part of said reinforcement members (12, 22) is of Carbon fibre.
16. The portion of composite material (15, 25) according to any one of the claims 10 to
15, wherein at least a part of said reinforcement members (12, 22) is of Kevlar®.
17. The portion of composite material (15, 25) according to any one of the claims 10 to
16, wherein at least a part of said reinforcement members (12, 22) is of polyurethane
material.
18. A garment comprising at least one portion of composite material (15, 25) according
to any one of the claims 10 to 17.