IT202000018310A1 - SPORTS EQUIPMENT - Google Patents

Description

Sports equipment

DESCRIPTION

Scope of the invention

The invention relates to sports equipment, such as for example a racket, comprising at least one layer of composite material. In particular, the equipment of the present invention can find application in activity? sports such as tennis, padel, paddle, squash, badminton, pickleball, beach tennis, fronton, and touchtennis.

The sports equipment of the present invention can otherwise? also be intended for use in other sports, such as cycling, golf, snowboarding, skiing, footwear and so on? away, in which can? the sporting equipment of the present invention in frame or component form may be employed.

Scenario of the invention

The main objectives that are traditionally sought in the construction of sports equipment consist in the possibility? to give the user a competitive advantage by improving equipment performance, increasing the life of the equipment, improving user comfort, or protecting the user from injury.

Therefore, to make sports equipment, there is a tendency to select materials that are resistant to wear and are suitable for absorbing impacts, damping vibrations or performing other advantageous functions, without however increasing the size and weight of the sports equipment. Often, in fact, in many areas an increase in size and weight can create discomfort for the user, hindering movement or performance.

Various attempts have been made to solve the problem of making sports equipment from strong and light materials.

An attempt to find the right balance between lightness and strength? offered by the composite materials reinforced with fibers immersed in a resin matrix.

This type of materials? been adopted for example in rackets for the practice of tennis, in which? provided a frame comprising at least one layer of composite material of the ?pre-impregnated? type? (also indicated with the term ?pre-preg?) including reinforcing fibers and a filler, of various kinds, immersed in a resin matrix.

Choosing a suitable filler is critical in determining material characteristics. In fact, the filler present in the material, if selected in the appropriate manner, can? help to significantly improve the properties? of the composite material.

Although several attempts have been made in the search for the filler pi? suitable, known solutions have drawbacks.

In fact, if some solutions allow for significant improvements in the properties? mechanical, their use often has a significant impact on production costs. In other cases, however, the fillers require complex and difficult to control production processes, with potential quality problems. Moreover, some fillers have characteristics that are potentially harmful to health and require rather complex disposal once the useful life of the equipment is over.

On the contrary, it would be desirable to make available solutions capable of overcoming the aforementioned disadvantages.

The technical problem at the basis of the present invention ? that of supplying sports equipment that is structurally and functionally designed to remedy at least in part one or more? of the drawbacks complained of with reference to the cited prior art.

Within the scope of this problem, an object of the present invention is is to provide sports equipment that has high properties? mechanical without the use of materials that significantly affect the construction costs.

Additional purpose? that of providing sports equipment in which there is no greater use of non-recyclable materials, or in any case not easily disposed of, with respect to known solutions.

? It is also an object of the present invention to provide a sports equipment which uses a composite material in which there is a filler of natural origin which, therefore, has a modest impact from an environmental point of view.

Yet another purpose ? that of providing sports equipment in which materials potentially dangerous to health are not used.

This problem ? solved and these aims are achieved by the invention by means of a sports equipment made in accordance with one or more? of the joint claims.

Sar? It is appreciated that the sports equipment of the present invention comprises at least one layer of a composite material including a matrix and reinforcing fibers surrounded at least partially by the matrix, wherein the composite material further includes a cellulosic material dispersed in the matrix.

It should be noted that, in this context, for ?cellulosic material? means a material extracted from cellulose.

Advantageously, the cellulose material has a filler function. In one aspect, the cellulosic material acts as a reinforcing filler which improves the properties of the cellulosic material. mechanical properties of the layer of composite material or, possibly, of the different layers of composite material if the equipment is formed by overlapping different pre-preg layers.

Preferably, the cellulosic material has a micrometric or nanometric size.

In some embodiments, the cellulosic material is in the form of nanocrystals.

It should be noted that, in this context, for ?cellulose nanocrystals? (in short, CNC) means cellulose crystals preferably having a substantially cylindrical shape (preferably a form of ?nanorod?) with a length of less than 500 nm (preferably a length of less than 100 nm) and a diameter of a few units? of nm (preferably a diameter between 3 and 5 nm). Advantageously, the cellulose crystals are obtained by eliminating the amorphous part of the cellulose. It should be noted that sometimes the term ?nanocrystalline cellulose? (in short, NCC) pu? be used in place of the term ?cellulose nanocrystals?, with a similar meaning.

Sar? appreciated that, advantageously, within the at least one layer of the composite material, the cellulose nanocrystals can fill any empty spaces left by the matrix, thus improving the properties mechanics of the material itself.

In fact, it must be noted that cellulose nanocrystals combine high stiffness axial, high Young's modulus, high tensile strength, low coefficient of thermal expansion, high stability thermal, and low density?.

According to a further advantageous aspect, cellulose in particular improves the properties mechanics of the composite material matrix. Therefore, cellulose nanocrystals improve the properties of anisotropic properties of the composite material.

Preferably, the matrix comprises a resin, such as for example an epoxy resin.

In some preferred embodiments, the at least one layer of composite material is a layer of pre-preg type.

It should be noted that, in this context, for ?pre-preg? means a fiber-reinforced composite material "pre-impregnated" with a matrix material (for example, epoxy resin).

In one aspect, cellulose, preferably in the form of nanocrystals, is uniformly dispersed in the matrix. According to a further advantageous aspect, the cellulose nanocrystals are dispersed in the matrix in a uniform manner but with a random orientation. In this way, advantageously, the cellulose nanocrystals create a lattice which increases the elastic modulus and the mechanical resistance of the matrix in all directions.

Sar? appreciated that cellulose nanocrystals improve the properties? mechanical properties of the matrix to an extent that depends on the formulation of the composite material.

In preferred embodiments, ? expected a plurality? of layers of the composite material. Preferably, the layers are at least partially overlapped with each other. In this case, it must be noted that the presence of cellulose nanocrystals improves not only the properties mechanical properties of each single layer but also improves the adhesion between adjacent overlapping layers of composite material, considerably increasing the shear strength and therefore also the fatigue resistance and the elastic modulus of the product including the plurality of? of layers of the composite material.

In some embodiments, the sports equipment comprises a racket. Preferably, the racket ? of the type suitable for at least one specialty? your choice of tennis, padel, paddle, squash, badminton, pickleball, beach tennis, fronton, and touchtennis. It is understood that the racket can? be replaced by other examples of sports equipment such as a golf club, a snowboard, skis, footwear and so on? Street.

Sar? appreciated that, advantageously, the? at least one layer of the composite material ? used in the manufacture of a sports equipment frame or a sports equipment component that has a structural function. Therefore, the present invention can also find application in the construction of equipment intended for other activities? sports, such as cycling, golf, etc.

In one aspect, sports equipment can include one or more components of a bicycle such as the frame, the fork, the handlebar, and so on? Street. It should be noted that, in some embodiments, the bicycle can be a pedal assisted bicycle.

According to a further advantageous aspect, sports equipment can include archery equipment, and preferably can? include an archery bow or component of a bow.

The characteristics and advantages of the invention will become clearer from the detailed description that follows of a preferred but not exclusive embodiment thereof illustrated, by way of example and not in limitation, with reference to the attached drawings in which:

- fig. 1 shows a layer of a composite material of a sports equipment according to the invention;

- fig. 2 represents two layers of fig. 1 superimposed seen in section and enlarged in detail;

- fig. 3 ? a perspective view of a racket in accordance with an embodiment of the invention;

- fig. 4 ? a side view of a bicycle in accordance with an embodiment of the invention;

- fig. 5 ? a front view of a golf club in accordance with an embodiment of the invention;

- fig. 6 ? a perspective view of a snowboard in accordance with an embodiment of the invention;

- fig. 7 ? a perspective view of a pair of skis in accordance with one embodiment of the invention;

- fig. 8 ? a perspective view of a bow for archery in accordance with an embodiment of the invention;

- fig. 9 ? a perspective view of a shoe according to an embodiment of the invention.

In the figures ? generally indicated by 1 a layer of a composite material for a sports equipment 100.

The sports equipment 100 comprises at least one layer 1 of composite material including a matrix 2 and reinforcing fibers 3 surrounded at least partially by the matrix 2.

In one aspect, the sports equipment 100 comprises a frame 10 including the at least one layer 1 of the composite material.

By way of indicative and non-limiting example, the sports equipment 100 can? include one or more choice of equipment from a racket 101, a bicycle 102, a golf club 103, a snowboard 104, a pair of skis 105, an archery bow 106, a shoe 107, or a component of any of the sports equipment just mentioned. In preferred embodiments, the sports equipment 100 comprises a plurality of of layers 1, 1? of the composite material. In this case, it will be appreciated that layers 1, 1? they can be laminated together.

L?at least one layer 1 pu? be of the pre-preg type comprising the matrix 2 reinforced with fibers 3 at least partially surrounded by the matrix 2.

The reinforcing fibers 3 can be at least partially woven or at least partially non-woven, arranged in a single direction or in several directions. directions, and may include short fibers and/or long fibers.

The reinforcing fibers 3 can comprise a selection of one or more? of the following fibers: carbon fibers, boron fibers, glass fibers, silicon carbide fibers, ceramic fibers and/or aramid fibers of the type available under the trade name KEVLAR.

The reinforcing fibers 3 can be arranged in a single layer and/or in a plurality? of layers that can be laminated together.

Matrix 2 preferably includes a resin, hardened through a ?cure? (in English ?curing?) or otherwise solidified. The matrix 2 can? advantageously include a thermosetting resin or a thermoplastic resin. According to a further advantageous aspect, the thermosetting resin can be selected from one of the following resins: an epoxy resin, a polyester resin, or a vinylester resin.

As highlighted in fig. 2, ? cellulose 4 is provided, preferably in the form of nanocrystals, to reinforce the composite material comprising the matrix 2 and the fibers 3.

Sar? appreciated that although this disclosure will? to follow reference to cellulose nanocrystals, the present invention also includes the use of cellulose in another form, provided that? nanometric or micrometric in size, as in the case of nanocellulose and cellulose nanofibrils.

Advantageously, the cellulose 4 nanocrystals can be extracted from agricultural, forestry (lignocellulosic biomass) and/or bacterial sources, in a sustainable way and without impacting the environment. Furthermore, these sources represent derivatives or waste from other productions (both industrial and food), to the advantage of sustainability? and circularity.

In one aspect, the cellulose nanocrystals 4 have an elongated shape and can be assimilated to nanofibres, i.e. fibers having structural dimensions on the nanometric scale. Preferably, the cellulose nanocrystals have a length of up to 500 nm and a thickness of between 3 and 5 nm.

Preferably, the cellulose nanocrystals 4 are mixed with and/or used as a filler and/or as an additive in the matrix 2. The mixing can? take place in the matrix resin 2 in liquid form, before the cellulose nanocrystal enriched resin 4 is used to make the pre-preg layers. Advantageously, after mixing, the cellulose nanocrystals 4 are dispersed in the matrix 2. Sar? appreciated that, when the matrix 2 is cured, the strength and elastic modulus of the matrix 2 are enhanced by the cellulose nanocrystals 4. Furthermore, the matrix 2 and the reinforcing fibers 3 can firmly join with the cellulose nanocrystals 4. Therefore, the intralaminar strength and compressive strength of layer 1 are significantly higher than those of a conventional pre-preg layer.

In one aspect, the cellulose nanocrystals 4 constitute substantially 5% or less of the 5% of a mixture that the cellulose nanocrystals 4 form with the matrix 2. Preferably, the cellulose nanocrystals 4 constitute substantially 5% or less of the 5 % by weight and/or by volume of the mixture that the cellulose nanocrystals 4 form with the matrix 2. In one aspect, the cellulose nanocrystals 4 constitute substantially 3% or less than the 3% of a mixture that the cellulose nanocrystals 4 form with the matrix 2. Preferably, the cellulose nanocrystals 4 constitute substantially 3% or less of the 3% by weight and/or by volume of the mixture which the cellulose nanocrystals 4 form with the matrix 2. preferably, the cellulose nanocrystals 4 substantially constitute between 0.005% and 2% of the mixture which the cellulose nanocrystals 4 form with the matrix 2. Advantageously, the cellulose nanocrystals 4 substantially constitute between 0.005% and 2% by weight and/or by volume of the mixture that the cellulose nanocrystals 4 form with the matrix 2.

In one aspect, the cellulose nanocrystals 4 substantially constitute between 0.005% and 1.5% of the mixture which the cellulose nanocrystals 4 form with the matrix 2. Advantageously, the cellulose nanocrystals 4 substantially constitute between 0.005% and 1.5%. 1.5% by weight and/or by volume of the mixture that the cellulose nanocrystals 4 form with the matrix 2.

According to a further advantageous aspect, the cellulose nanocrystals 4 constitute substantially between 0.5% and 1.5% of the mixture which the cellulose nanocrystals 4 form with the matrix 2. Advantageously, the cellulose nanocrystals 4 substantially constitute 0.5% and 1.5% by weight and/or by volume of the mixture that the cellulose nanocrystals 4 form with the matrix 2.

In some preferred embodiments, the cellulose nanocrystals 4 constitute substantially 1% of the mixture that the cellulose nanocrystals 4 form with the matrix 2. Preferably, the cellulose nanocrystals 4 constitute substantially 1% by weight and/or by volume of the mixture that the cellulose nanocrystals 4 form with the matrix 2.

By setting the composition of the mixture in one or more? of these intervals, you can? guarantee an optimal distribution and/or dispersion of the cellulose nanocrystals 4 in the matrix 2 and it is possible to avoid a deterioration of the properties? properties of the mixture due to uneven distribution and/or dispersion.

The volumetric content of the reinforcing fibers 3 in layer 1 can? substantially be between 10% and 85%. By setting the volumetric content of the reinforcing fibers 3 in this range, ? is it possible to obtain a balance between the resistance on the plane of the layer 1 that can? be based mainly on the resistance imparted by the reinforcing fibers 3, and other types of resistance such as for example the compressive strength of the layer 1 which can? rely mainly on the resistance imparted by the matrix 2.

According to a further advantageous aspect, the cellulose 4 nanocrystals improve the properties mechanical properties of the composite material between two layers 1, 1? adjacent overlapping, as shown in Fig. 2. In fact, it must be observed that the cellulose nanocrystals 4 arranged in correspondence with the interlaminar region 5 considerably increase the shear strength between layers 1, 1? adjacent and reduce delamination phenomena.

Sar? appreciated that the enrichment of the resin of the matrix 2 with the nanocrystals of cellulose 4 offers properties? superior mechanics such as to allow the following options:

- maximization of the performance to parity? of the quantity? of resin and the quantity? of reinforcing fibers,

- reduction of the quantity? of resin and the quantity? of reinforcing fibers equal? of performances,

- a combination of the two previous options.

The invention solves so? the proposed problem achieving numerous advantages including:

- limited weight and size,

- best properties of the composite material,

- better intralaminar and interlaminar strength,

- use of an ecological material derived from cellulose.

Claims (15)

1. Sports equipment (100) comprising at least one layer (1) of a composite material including a resin matrix (2), and reinforcing fibers (3) surrounded at least partially by said matrix (2), characterized in that said material the composite also includes a cellulosic material (4) in micrometric and/or nanometric size dispersed in said matrix (2). 2. Sports equipment (100) according to claim 1, wherein said cellulosic material (4) in micrometric and/or nanometric dimension constitutes a reinforcing filler in said composite material. The sports equipment (100) according to claim 1 or 2, wherein said cellulosic material (4) is in the form of cellulose nanocrystals and/or cellulose nanofibrils and/or nanocellulose. 4. Sports equipment (100) according to any one of the preceding claims, comprising a frame (10) including the at least one layer (1) of said composite material. 5. Sports equipment (100) according to any one of the preceding claims, comprising a plurality of of layers (1, 1?) of said composite material. 6. Sports equipment (100) according to any one of the preceding claims, wherein said cellulosic material (4) is uniformly dispersed with random orientation in said matrix (2). 7. Sports equipment (100) according to any one of the preceding claims, wherein said matrix (2) comprises a resin, preferably said matrix (2) comprising an epoxy resin, even more preferably the at least one layer (1) of said composite material being a layer of the pre-preg type. 8. Sports equipment (100) according to any one of the preceding claims, wherein said cellulosic material (4) is dispersed in said matrix (2) in a quantity? between 0 and 5% by weight of said matrix (2). The sports equipment (100) according to any one of claims 1 to 7, wherein said cellulosic material (4) is dispersed in said matrix (2) in a quantity? between 0 and 3% by weight of said matrix (2). The sports equipment (100) according to any one of claims 1 to 7, wherein said cellulosic material (4) is dispersed in said matrix (2) in a quantity? between 0.005% and 2% by weight of said matrix (2) The sports equipment (100) according to any one of claims 1 to 7, wherein said cellulosic material (4) is dispersed in said matrix (2) in a quantity? between 0.5% and 1.5% by weight of said matrix (2). Sports equipment (100) according to any one of the preceding claims, wherein said sports equipment (100) comprises a racket (101). The sports equipment (100) according to claim 12, wherein said racket (101) is of the type suitable for at least one specialty? your choice of tennis, padel, paddle, squash, badminton, pickleball, beach tennis, fronton, and touchtennis. Sports equipment (100) according to any one of claims 1 to 11, wherein said sports equipment (100) comprises a component of a bicycle (102). 15. Sports equipment (100) according to any one of claims 1 to 11, wherein said sports equipment (100) comprises equipment chosen from among a golf club (103), a snowboard (104), skis (105 ), a bow (106) for archery, a component of a bow (106) for archery, and footwear (107).