AUXETIC SEAMLESS KNITTED FABRIC AND GARMENTS MADE FROM THE FABRIC

Abstract

 The present invention relates to an auxetic seamless knitted fabric and garments made from the fabric. The auxetic fabric of the present invention comprising at least one of the following structures: a first structure (2) having a first pattern such that the first pattern comprises parallel columns of fibers with a gap between each two adjacent columns; and a second structure (3) having a second pattern such that the second pattern comprises identical parallel columns of fibers with a gap between each two adjacent columns, wherein the fibers of the fabric are made of a mixture of polyamide, elastane, and cationic polyester. The fabric of the present invention has the auxetic properties thanks to the combination of the patterns of the structures that forms the fabric and the type of fibers, without losing any of the characteristics associated with garments and products produced with the seamless technology.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to an auxetic seamless knitted fabric. The present invention also relates to the garments made from the auxetic fabric.

BACKGROUND ART

[0002] Auxetic materials are different from most conventional materials in that they exhibit a negative Poisson's ratio (NPR). They expand laterally when stretched and contract laterally when compressed. This counterintuitive behaviour gives auxetic materials various beneficial effects, such as enhanced shear stiffness, increased plane strain fracture toughness, increased indentation resistance, and improved energy absorption properties [1,2].

[0003] At present, auxetic materials can be produced in different materials including polymers, metals, ceramics, and composites [3]. For example, auxetic materials are used in composite materials to promote fiber reinforcement in textiles for crash helmets and sports clothing, as sponges, as ropes, in filtration and as shock absorbing materials [4]. They have a lot of potential applications, from biomedical to automotive and defence industries. Also, these materials could potentially be used for completely new structures with special functions [5].

[0004] Auxetic materials stand out for their unique characteristics that allow their use in numerous applications. The main inherent characteristic of these materials is the stretching behaviour of the cross-section when there is tension in the longitudinal section. This particularity endows the material with unique characteristics, both from a functional and visual point of view.

[0005] Compared to common materials, due to this behaviour and intrinsic characteristics, auxetic materials also stand out for their high resistance to fracture and shear. If the material presents a crack, in the expansion process the crack tends to be closed due to transversal elongation. Furthermore, the fact that this type of materials assumes a synclastic curve when submitted to an out-of-plane stress allows the material not to be forced to assume an unstable conformation, thus decreasing the probability of fracture [6].

[0006] The properties of auxetic materials give them unique characteristics in behaviour and response to impacts, as well as energy absorption and physical change in response to external forces [6].

[0007] At an aesthetic-functional level, when auxetic material are subjected to tensile forces, has associated changes in its geometric/spatial conformation. Therefore, the structures of the auxetic material can be incorporated into products that are not only functional, but also have an attractive design.

[0008] In this respect, many seamless knitted garments have appeared on the market in which these auxetic materials could be used.

[0009] The main problem to be solved in the seamless knitted garments is transparency. The problem is that the garments, specifically leggings, currently available on the market have transparency in certain voluminous parts, such as the buttocks, and when stretching movements are made, this transparency compromises the intimacy and well-being of the user.

[0010] At present, there is no known garment produced with seamless technology that avoids transparency.

[0011] Therefore, there is a need to provide a garment composed of a fabric that is comfortable, that allows for proper breathability, moisture management, that is able to adjust to the different body shapes and sizes of the user, and that is attractive, cheap and easy to manufacture. With the adaptability to different body sizes and shapes, transparency of garments could be avoided, as mentioned above.

SUMMARY OF INVENTION

[0012] In view of the problems of the prior art, the main object of the present invention is to provide an auxetic seamless knitted fabric and garments made from the auxetic fabric. The fabric of the present invention has the auxetic properties thanks to the combination of the patterns of the structures that forms the fabric and the type of fibers, without losing any of the characteristics associated with garments and products produced with the seamless technology.

[0013] Therefore, thanks to this auxetic properties, the auxetic fabric presents improved properties that allow its application in different garments, such as leggings or T-shirts, offering a range of products to the user with the following advantages: no transparency since is able to adjust to the different body shapes and sizes of the user, comfort, ergonomics and attractive design.

[0014] In a first aspect, the present invention refers to an auxetic seamless knitted fabric comprising at least one of the following structures:

• a first structure having a first pattern such that the first pattern comprises parallel columns of fibers with a gap between each two adjacent columns; and
• a second structure having a second pattern such that the second pattern comprises identical parallel columns of fibers with a gap between each two adjacent columns, wherein the fibers of the fabric are made of a mixture of polyamide, elastane, and cationic polyester.

[0015] Preferably, the fibers of the fabric have between 70-80% of polyamide, between 15-25% of cationic polyester and a 5% of elastane.

[0016] In a second aspect, the present invention refers to a garment that comprises the auxetic fabric of the present invention.

[0017] The term "garment", as used herein, refers to any article or garment configured to be worn on a human. Examples of garments thus include shirts, pants, tights, leggings, shorts, and sleeves, as well as numerous other products configured to be worn on a person.

BRIEF DESCRIPTION OF DRAWINGS

[0018] The following figures are described below. These illustrate the exemplary embodiments and are not limiting their scope.

Figure 1 shows a first structure of the fabric.

Figure 2 shows a second structure of the fabric.

Figure 3 shows the frontal view of a tights made entirely with the second structure (3).

Figure 4 shows the back view of a tights made entirely with the second structure (3).

Figure 5 shows the frontal view of a tights made entirely with the first structure (2).

Figure 6 shows the back view of a tights made entirely with the first structure (2).

Figure 7 shows the frontal view of a tights which comprises the first structure (2) located in pelvic zone and upper legs of the user.

Figure 8 shows the back view of a tights which comprises the first structure (2) located in pelvic zone and upper legs of the user.

Figure 9 shows the frontal view of a tights which comprises the second structure (3) located in pelvic zone and upper legs of the user.

Figure 10 shows the back view of a tights which comprises the second structure (3) located in the buttocks zone of the user.

DESCRIPTION OF EMBODIMENTS

[0019] The auxetic seamless knitted fabric of the present invention comprises different structures.

[0020] Figure 1 shows the pattern of the first structure (2). This first structure has a first pattern such that the first pattern comprises parallel columns of fibers with a gap between each two adjacent columns.

[0021] Figure 2 shows the pattern of the second structure (3). This second structure (3) has a second pattern such that the second pattern comprises identical parallel columns of fibers with a gap between each two adjacent columns.

[0022] Figures 3-10 illustrates several garments (1) that can be constructed from the auxetic seamless knitted fabric of the present invention. Specifically, tights for sport activities.

[0023] In a first embodiment (figures 3 and 4), the garment is a sport garment, specifically tights for sport activities. The garment of this embodiment is made entirely with the second structure (3).

[0024] In a second embodiment (figures 5 and 6), the garment is a sport garment, specifically tights for sport activities. The garment of this embodiment is made entirely with the first structure (2).

[0025] In a third embodiment (figures 7 and 8), the garment is a sport garment, specifically tights for sport activities. The garment of this embodiment comprises the first structure (2) located in pelvic zone and upper legs of the user.

[0026] In a fourth embodiment (figures 9 and 10), the garment is a sport garment, specifically tights for sport activities. The garment of this embodiment comprises the second structure (3) located in pelvic zone and upper legs of the user.

[0027] The garments comprising the auxetic fabric show improvements over those on the market in two categories: structural and functional. In the structural area, improvements have been obtained in their mechanical or physical properties. On the other hand, they respond specifically to a given stimulus.

[0028] In a perspective of transparency mitigation of the garment, the two structures presented are the ones with the best negative poison coefficients, evidencing their auxecticity and, therefore, the ideal combination of structural and functional properties to solve the problems of the state of the art.

REFERENCES

[0029] 

[1] Evans K. E. and A. Alderson, Auxetic Materials : Functional Materials and Structures from lateral thinking , Advance Materials, 2000, 12, 617-628.

[2] Yang, W., Z. M. Li, W.Shi, B. H. Xie and M. B. Yang, The Use of Auxetic Materials in Smart Structures , Journal Material Science, 2004, 39, 3269-3279.

[3] Darja, R., Tatjana, R., & Alenka, P. C. Auxetic textiles. Acta Chimica Slovenica, 2014, 60(4), 715-723.

[4] Kocer, C., D. R. McKenzie, and M. M. Bilek. "Elastic properties of a material composed of alternating layers of negative and positive Poisson's ratio." Materials Science and Engineering: A 505.1-2, 2009, 111-115.

>Se Prawoto, Y. "Seeing auxetic materials from the mechanics point of view: a structural review on the negative Poisson's ratio." Computational Materials Science 58, 2012, 140-153.

[6] Liu, Y. and Hu, H. "A review on auxetic structures and polymeric materials" Sci. Res. Essays, vol. 5, no. 10, 2010, pp. 1052-1063.

Claims

1. An auxetic seamless knitted fabric comprising at least one of the following structures:

- a first structure (2) having a first pattern such that the first pattern comprises parallel columns of fibers with a gap between each two adjacent columns; and

- a second structure (3) having a second pattern such that the second pattern comprises identical parallel columns of fibers with a gap between each two adjacent columns,

wherein the fibers of the fabric are made of a mixture of polyamide, elastane, and cationic polyester.

2. The auxetic fabric according to claim 1, wherein the fibers of the fabric have between 70-80% of polyamide, between 15-25% of cationic polyester and a 5% of elastane.

3. A garment (1) comprising the auxetic fabric according to any one of claims 1 to 2.

4. The garment (1) according to claim 4, wherein the garment is made entirely with the first structure (2) of the auxetic fabric.

5. The garment (1) according to claim 4, wherein the garment is made entirely with the second structure (3) of the auxetic fabric.

6. The garment (1) according to claim 4, wherein the garment comprises the first structure (2) of the auxetic fabric located in pelvic zone and upper legs of the user.

7. The garment (1) according to claim 4, wherein the garment comprises the second structure (3) of the auxetic fabric located in pelvic zone and upper legs of the user.

Drawing