CN111295232A

CN111295232A - Bottom board of table tennis racket

Info

Publication number: CN111295232A
Application number: CN201880070744.7A
Authority: CN
Inventors: 丹羽明彦; 大川淳也
Original assignee: Tamasu Co ltd; Daio Paper Corp
Current assignee: Tamasu Co ltd; Daio Paper Corp
Priority date: 2017-11-07
Filing date: 2018-10-30
Publication date: 2020-06-16
Anticipated expiration: 2038-10-30
Also published as: DE112018005309B4; KR20200083436A; DE112018005309T5; JP2019084073A; KR102623642B1; WO2019093191A1; JP6535065B2; CN111295232B

Abstract

To provide a novel feature which can improve the power of playing a ball. [ solution ] A base plate for a pool racket, and a pool racket provided with the base plate, the base plate being provided with a plate-like body configured to contain cellulose nanofibers.

Description

Bottom board of table tennis racket

Technical Field

The invention relates to a bottom plate of a table tennis racket.

Background

The table tennis racket has: a sole plate (a billiard racket body); a gripping member secured to the base plate and constituting a handle to be gripped by a user during use; and a billiard rubber adhered to the sole plate to form a playing surface (for example, patent document 1).

The bottom plate has a flat plate shape and is constituted by a single plate-like body or a laminated body having a plurality of plate-like bodies bonded to each other.

Generally, as can be seen from the current regulations (wood content: 85% or more), the bottom plate of a pool racket is mainly constructed by using wood, but on the other hand, a bottom plate made of a non-wood material is also suggested.

For example, there is known a floor panel having a laminated structure including a plurality of plate-like bodies, and in the laminated structure, a fiber reinforced resin plate formed of an ULC (Uniaxial Light Carbon) formed by aligning Carbon fibers in one direction and curing the fibers with a resin is used as one or more plate-like bodies in order to further improve the impact resistance of the floor panel.

Further, there is known a soleplate in which carbon fibers having a higher elastic modulus are used, or in which a fiber-reinforced resin plate formed of ZLF or SP-ZLC formed by vertically or horizontally weaving different kinds of fibers and curing the fibers with a resin is used.

Further, patent document 2 proposes that the bottom plate has a laminated structure including a plurality of plate-like bodies, and plastic or metal is used as the plate-like body. Further, in the floor panel described in patent document 2, an invention is made with an intention of improving the reaction force of the floor panel.

Reference list

Patent document

Patent document 1: japanese patent laid-open publication No. 2010-227371

Patent document 2: japanese patent laid-open No. 2000-342733

Disclosure of Invention

Technical problem

It is an object of the present invention to provide a novel technique which improves the power of a ball strike.

Solution to the problem

In terms of flexibility in product design, it is preferable that the bottom plate of the pool racket can be improved by various methods, and thus it is desirable to propose an additional novel configuration.

The present inventors have not only paid attention to improving the speed of a ball hit by simply increasing the reaction force of the sole plate, but also paid attention to improving the power of the ball hit, and therefore have conceived an idea of further increasing the energy efficiency of the sole plate.

The energy efficiency is a value representing the power of hitting a ball, and a higher value means a lower energy loss of the ball before and after hitting.

When the energy loss is low, the velocity energy and the spin energy of the ball before striking can be efficiently transmitted, thereby making the velocity of the ball striking higher. As a result, for example, faster ball draws and knocks can be easily provided.

Further, when the energy loss is low, the velocity energy and the rotational energy of the ball before striking can be efficiently transmitted, thereby improving the turning performance. As a result, for example, the spin imparted to the ball can be easily provided for the drawing, chipping, and launching.

As a result of intensive studies, the present inventors found that when a base plate of a pool racket is constructed using Cellulose Nanofibers (CNF), energy efficiency of the base plate can be improved, and thus completed the present invention. Herein, the Cellulose Nanofibers (CNF) refer to fine cellulose fibers, generally cellulose fibers including cellulose fine fibers having a fiber width of a nanometer size of 1nm or more and 1000n or less, which are obtained by defibering pulp (pulp fibers) as a plant raw material.

The subject of the invention is as follows.

[1] A bottom plate of a table tennis racket comprises a plate-shaped body containing cellulose nanofibers.

[2] The racket case according to [1], wherein the racket case has a laminate structure including one or more plate-shaped bodies containing cellulose nanofibers.

[3] The base plate for a pool racket according to [1] or [2], wherein the cellulose nanofibers are contained in the plate-like body containing the cellulose nanofibers in an amount of at least 40 mass% per plate-like body.

[4] A billiard racket having the billiard racket base plate according to any one of [1] to [3 ].

The invention has the advantages of

According to the present invention, a novel technique capable of improving the power of a ball striking can be provided.

Drawings

Fig. 1 shows a perspective view of a billiard racket according to the present embodiment.

Fig. 2 shows a cross-sectional view along line XX' in fig. 1.

Fig. 3 is a view showing a relationship between each soleplate and energy efficiency in an example.

Detailed Description

Hereinafter, one embodiment of the present invention will be described in detail.

The present embodiment relates to a bottom plate of a table tennis racket, which includes a plate-shaped body containing Cellulose Nanofibers (CNF).

Hereinafter, as a table tennis racket including the bottom plate according to the present embodiment, a cross-grip type table tennis racket (hereinafter, also simply referred to as a table tennis racket) for playing a ball at both faces will be described as an example. However, the base plate of the present invention is not limited to the base plate applied to the racket of the bar grip type, and may be, for example, a racket type base plate.

Fig. 1 shows a perspective view of a billiard racket 100 according to the present embodiment. Fig. 2 shows a cross-sectional view along line XX' in fig. 1.

The billiard racket 100 of the present embodiment includes: a flat-plate-shaped base plate (racket body) 10, on both sides of which billiard rubber 20 is bonded; and

grip members

31 and 33 fixed to the base plate 10 and constituting handles to be gripped by a user during use of the racket.

The holding member is constituted by two members fixed to sandwich the base plate 10, the holding member 31 is disposed on the front side and the holding member 33 is disposed on the rear side. The shape and thickness of these gripping

members

31 and 33 may also be appropriately changed, and are not particularly limited.

As described above, in the present embodiment, the rubber 20 is adhered to the surface (front side and rear side) of the chassis base by using an adhesive or the like. In the present embodiment, the shape, constitution, and the like of the rubber 20 are not particularly limited, and a rubber selected according to the preference of the user or the like can be suitably used.

In the present embodiment, the billiard racket having the upright-type handle is illustrated as a cross-grip-type billiard racket, but is not limited thereto, and may be a waisted type, a gourd type, a cone type, or the like.

Next, the bottom plate 10 of the present embodiment will be described.

The bottom plate 10 of the present embodiment is composed by using a CNF-containing plate-like body, and specifically, has a laminated structure composed of a plurality of plate-like bodies including a CNF-containing plate-like body.

As shown in fig. 2, in the present embodiment, the bottom plate 10 is composed by stacking seven plate-shaped bodies.

More specifically, two plate-like bodies 15 are arranged so as to sandwich the plate-like body 11, and further, two plate-like bodies 17 are arranged so as to sandwich a laminated body constituted by the plate-

like bodies

11 and 15. Further, the two plate-like bodies 20 are arranged so as to sandwich the stacked body composed of the plate-

like bodies

11, 15, and 17. The plate-like bodies are bonded to each other by, for example, an adhesive. Further, the rubber 20 is adhered to the surface of the plate-like body 20 opposite to the plate-like body 17, for example, by using an adhesive.

In the present embodiment, the plate-like body 17 is composed of CNF, and the other plate-like bodies are composed of wood.

The thickness and the like of each plate-like body are not particularly limited and may be appropriately set by those skilled in the art.

The method for producing the CNF-containing plate-like body is not particularly limited, but can be suitably produced by the following method.

In one example of a manufacturing method of a CNF compact, first, CNF is dispersed in a dispersion medium such as water to form a slurry. In addition to the CNF obtained by treating pulp or the like by a known method, a commercially available CNF may be used, but the CNF is not particularly limited.

Next, the obtained slurry is subjected to a pressing process to form a plate-like body. Specifically, CNF including a dispersion medium was subjected to the following process to form a plate-like body: the pressing is performed in the thickness direction during the heating. Further, a pre-dehydration process is preferably included before the pressurization process. As the preliminary dehydration process, the following process may be employed: the CNF-containing slurry is dewatered by a mesh member. Specifically, it is preferable to subject the CNF slurry to a pre-dehydration process to form a plate shape and then to a pressurization process, thereby providing the CNF-containing plate-shaped body according to the present embodiment. The manufacturing method may include processes other than these processes.

To the extent that the object of the present invention can be achieved, other materials may be added in addition to the CNF in order to manufacture the CNF-containing plate-like body according to the present embodiment. Specifically, pulp may be exemplified. In this context, pulp refers to an aggregate of cellulose fibers extracted by mechanical or chemical treatment of plants such as wood.

In the plate-like body containing CNF according to the present embodiment, CNF is preferably 40 to 100 mass%, more preferably 60 to 95 mass%, even more preferably 70 to 90 mass%, based on the entire plate-like body. When the content of CNF is 40 mass% (the above lower limit value) or more, the number of points of hydrogen bonds per unit area can be increased and the strength or the like can be improved as compared with the case outside the above range, so that the energy efficiency per unit density can be improved.

In the present embodiment, the weight of the soleplate 10 is not particularly limited and can be appropriately set by those skilled in the art.

On the other hand, when the soleplate 10 of the present embodiment is used, energy efficiency can be improved while suppressing weight increase.

It is also important for a table tennis racket to be able to swing the racket completely, and therefore the above-described improvement in the power of hitting a ball is preferably achieved by a method that does not cause an increase in weight.

In this respect, it is first considered that, in order to improve energy efficiency by the related art, a laminated body composed of a plurality of plate-shaped bodies is used as a base plate and a fiber reinforced resin plate is used as one or a plurality of plate-shaped bodies, and further, the density of the fiber reinforced resin plate is increased. However, in such a case where an attempt is made to increase the density of the fiber reinforced resin sheet, an increase in weight cannot be avoided while maintaining the thickness or the like.

On the other hand, as in the case of the bottom plate 10 of the present embodiment, when the plate-like body is composed using the CNFs, the improvement of the energy efficiency per unit density is more, and therefore the energy efficiency can be improved while suppressing the weight increase.

Therefore, according to the present embodiment, when the backplane is composed using the CNF, a billiard racket backplane having higher energy efficiency can be obtained. As a result, it is possible to provide a table tennis racket having improved power for hitting a ball, although the level of improvement varies depending on the individual technique, the characteristics of the laminated rubber, and the like.

The invention is not limited to the embodiments described herein, and other aspects are, of course, possible. For example, when the bottom plate has a laminated structure, the number and configuration of plate-like bodies composed using CNFs may be different from those illustrated in fig. 2. For example, the number of plate-like bodies constituting the laminated body may be changed, and in addition, a plate-like body in which the CNF composition is adjacent to the rubber may be used. Further, the chassis itself is not limited to those having a laminated structure, and for example, the chassis may be composed of one plate-like body, and the plate-like body may be composed using CNF.

On the other hand, the base plate is preferably constituted such that the base plate has a laminated structure including a CNF-containing plate-like body (specifically, the laminated structure includes a CNF-containing plate-like body and a CNF-free plate-like body) in terms of thickness and weight of the base plate.

Further, in terms of further improving the energy efficiency per unit density, as described above, when the floor is composed such that the floor has a laminated structure including the CNF-containing plate-like body and the CNF-free plate-like body, the proportion of the CNF-containing plate-like body occupied with respect to the length of the entire laminated structure in the thickness direction (lamination direction) is more preferably 40% or less. Even more preferably, the CNF-containing plate-like body is not in contact with the billiard rubber, and the thickness of the CNF-containing plate-like body is even more preferably 0.25mm or more and 0.40mm or less (even more preferably 0.30mm or more and 0.37mm or less).

Examples of the invention

The present invention will be described more specifically by using the following examples, but the present invention is not limited to these examples.

[ production of the base plate of example ]

CNF and hardwood bleached kraft pulp manufactured by treating hardwood bleached kraft pulp were mixed in water so that the weight ratio of solids was 8: 2. the obtained mixture was used as a raw material, and water contained in the mixture was extruded by applying a preload in the thickness direction using a metal die. Then, the mixture was pressurized in the thickness direction while being heated, and dried, to obtain a plate-like body having a thickness of 0.32mm and containing CNF.

A plate-like body having a thickness of 0.35mm and containing CNF was obtained in a similar manner.

The CNF-containing plate-like body thus obtained and a laminated wood material (density of 0.35 to 0.54 g/cm) were laminated by using a urethane resin³And a density of 0.30 to 0.35g/cm³Asian wood) to obtain a bottom plate of a pool racket according to an example. Specifically, as shown in table 1, plate-shaped bodies called a support core 1 and a support core 2 or surface plates were laminated in order in the thickness direction to a plate-shaped body called an intermediate plate to form a seven-layer laminated body having the intermediate plate in the middle. The plate-like bodies containing CNF were used for the surface plate, the support core 1 and the support core 2, which proved to have a strong influence on the energy efficiency.

As a comparative example, the above ULC (manufactured by aligning carbon fibers (manufacturer: toray industries, Inc.), product name: Toray (TORAYCA)) in one direction and curing the fibers with epoxy resin), ZLF (manufactured by weaving PBO fibers (manufacturer: toyobo co., LTD.), product name: Zylon) vertically and horizontally and curing the fibers with epoxy resin) or SP-ZLC (manufactured by weaving the above PBO fibers as warp and weaving the above carbon fibers as weft vertically and horizontally and curing the fibers with epoxy resin) was used as a plate body to constitute a billiard board of the comparative example.

[ Table 1]

Specific materials used are CNF, SP-ZLC, ZLF or ULC.

[ measurement of energy efficiency ]

8cm by 8cm square rubber having a thickness of 3.88mm was laminated to both sides of the bottom plate of the example or comparative example using an adhesive (manufacturer: Butterfly, product name: Free Chack II) to form a pool racket.

The racket is inclined so that the playing surface has an inclination angle of 45 degrees, and a handle portion of the racket is fixed using a fixing tool.

Then, a billiard ball (manufacturer: Butterfly (Butterfly), product name: Three-Star (Three-Star) ball G40+) was shot on the rubber using a billiard shooter. In this case, the ball speed was set to 7.5m/s, and the number of revolutions was set to 61 rps. Moving images of the ball were collected from the moment before the ball hit the rubber to the moment after the ball hit the rubber (specifically, 10ms before and after the hit) using a camera (manufacturer: nac image technology corporation, product name: MEMRECAM fx K4).

The collected images were analyzed using analysis software (manufacturer: nac graphic arts corporation, software: LAA measurement) to calculate the number of revolutions and speed of the ball before and after the ball hit in rubber. Further, the energy efficiency per unit density of each example and comparative example was calculated from the obtained number of revolutions and speed of the ball before and after striking.

The energy efficiency is calculated based on the following formula.

m: ball mass (kg)

v₁: speed of ball before impact (m/s)

v₂: speed of ball after hit (m/s)

I: moment of inertia (kg. m) of ball²)

ω₁: rotation of ball before striking (radian)

ω₂: rotation of ball after beating (radian)

The results are shown in FIG. 3. In fig. 3, an average value of energy efficiency per unit density is calculated from the results of 3 image acquisitions performed for each example and comparative example, and a difference with respect to comparative example 3 is shown.

As can be seen from fig. 3, it can be understood that the energy efficiency per unit density is significantly improved in the table tennis racket using the sole plate of the example.

List of reference numerals

10 base plate

11. 15 and 17 plate-like body

20 rubber

31 and 33 gripping members

100 billiard racket.

Claims

1. A bottom plate of a table tennis racket comprises a plate-shaped body containing cellulose nanofibers.

2. A racket mat as claimed in claim 1, wherein the racket mat has a laminated structure comprising one or more plates containing cellulose nanofibers.

3. A racket mat for a billiards racket as claimed in claim 1 or 2, wherein, in the plate-shaped body containing cellulose nanofibers, the cellulose nanofibers are contained in an amount of at least 40 mass% per plate-shaped body.

4. A billiard racket comprising a billiard racket chassis according to any one of claims 1 to 3.