CN1079919A

CN1079919A - Games racket frame

Info

Publication number: CN1079919A
Application number: CN93101731A
Authority: CN
Inventors: G·格林宁; P·萨盖; R·罗斯; P·伊特曼
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1992-01-29
Filing date: 1993-01-29
Publication date: 1993-12-29
Also published as: ATE153247T1; JPH05253322A; DE59306477D1; ES2102535T3; DE4202335A1; EP0555666A1; EP0763372A3; EP0763372A2; EP0555666B1

Abstract

The invention discloses a kind of games racket frame, this framework by a kind of be that the tubular fiber composite of base is made with thermoplastic fiber/carbon fibre blend, bridge between handle two arms is equally also made by the tubular fiber composite, but is filled with the thermoplastic of foaming in this tubular fiber.

Description

Games racket frame

The present invention relates to a kind of games racket frame, this framework by a kind of be that the tubular fiber composite of base constitutes with thermoplastic fibre/carbon fibre blend.This blend that is evenly mixed by thermoplastic fibre and reinforcing fibre is applied to make high performance composite in recent years more and more.It is very pliable and tough that blend reaches the braid of the flat member of producing thus, thereby can make the very little goods of radius of curvature.When thermoplastic had been higher than under the softening point temperature cure under pressure, the material fusing also constituted matrix, and reinforcing fibre then aligns by required mode and is embedded in wherein.

This blend braid is used to make the framework of tennis racket equally.At first adopt a kind of tubing that is inserted with inflatable air bag, it is bent to the shape of tennis racket, put into metal pattern, inflation then, heating mould makes fabric be solidified into the fiber reinforced pipe.The problem that exists in this processing technology is that " bridge " that be used for the reinforcing network racket that link handle two arms is shaped.

The air bag that is used for the tennis racket housing be placed bridge equally, be impossible so that bridge can directly be connected and be consolidated with frame with the tubing that constitutes housing.So people once attempted the blend braid is wrapped on the thermosetting polyurethane foam of making bridge shape, and put between two arms of frame and make it to be solidified togather with frame.Yet, do being not enough in bridge, produce sufficiently high internal pressure like this, cause the blend braid to solidify at this place fully, the porous zone can appear in the result, therefore, when part on the bridge of tennis racket is subjected to big torsion and pulling force, will cause the bridge fracture.

Task of the present invention is to seek the more good method that addresses the above problem.

According to the present invention, the scheme that addresses this problem is a kind of graininess of filling or a block expandable thermoplastic material in the blend braid that constitutes bridge.When to mold heated, foamed plastic expands, and according to what of blowing agent, produces enough internal pressures in bridge.

In view of the above, the invention provides a kind of framework of tennis racket, this framework is made of the hollow tubular product of embowment, the two ends of pipe also form handle together, thermoplastic fibre/carbon fibre the blend of pipe wall material for solidifying, wherein the bridge between handle two arms is that a kind of fixed thermoplastic fibre/carbon fibre mixes thread pipe, is filled with the thermoplastic foam that density is the 20-400 grams per liter in the pipe.

Fig. 1 shows the sketch of games racket frame finished product, and wherein (1) is handle, and (2) are two arms of handle, and (3) are bridge.

Fig. 2 shows the sketch of bridge attaching on games racket frame two arms.

A kind of production has been described by carbon fibre and thermoplastic fibre blend of forming and the method for producing this line and producing composite with this line among the EP-B-156599.Wherein also mentioned being made into the braid that can be processed into composite product, as be used to make the braid of games racket frame with this blend.

The plastics of recommending that are used for thermoplastic fibre for example have: polypropylene, PET, polybutylene terephthalate, polyphenylene sulfide, polysulfones, polyether sulfone and polyether-ketone (polyether ketones).Particularly suitable be polyamide, as nylon 6, nylon 66.

The thermoplastic that is used to foam substantially can be identical with the thermoplastic that is used for fiber, and their softening point temperature numerically should have identical magnitude or the former is lower than the latter slightly.The solidification temperature of selecting foamed plastic to make its softening temperature be lower than blend slightly is an important condition.The plastics of recommending to use have: polyamide, polyester and PEI (polyetger imides), perhaps polysulfones and polyether sulfone.

As described in DE-A-3925740, foamed plastic granular or monoblock can be obtained by the expanded beads extruding.Blowing agent is preferably selected low boiling for use, can not dissolve the liquid that plastics but can expanding plastics, and consumption is preferably 1%～20% by weight, and 2%～10% is better.Suitable blowing agent has halogenated hydrocarbons (as carrene, chlorobenzene), ketone (as acetone, methyl ethyl ketone), ethers, alcohols, water and composition thereof.Also can use CBA such as azo-compound, carbonate in principle.

The manufacture craft of games racket frame of the present invention is as follows: at first make tubular braid with blend, the diameter of tubular braid decides according to the wall thickness of any point on the tennis racket frame, and in general handle place tube wall should be thicker than elliptical ring place tube wall.The thickness of braid is the order of magnitude of 1-2 millimeter.Then a softness of preferably being made by rubber or high-melting plastics film, thin-walled (0.05～2 millimeter), inflatable air bag are inserted in the tubular braid, then tubular braid is curved the shape of games racket frame.

The manufacture craft of bridge is as follows: reprocess a tubulose blend braid, the length of its length and required bridge is close, and every end of bridge has two ligule ledges.Fill out the foamed plastic with graininess or monoblock in the braid, that foamed plastic can be packed into easily is a flat sennit, soft, in the capsule of thin-walled, and this capsule is preferably made by the plastics identical with thermoplastic fibres or more dystectic thermoplastic.The quantity of foamed plastic particle and the amount of contained blowing agent thereof will determine the size of the internal pressure that produces in the size of density of the foam through adding thermosetting and the foam expansion process.The density of foam should be preferably in 50～200 grams per liter scopes in the scope of 20～400 grams per liters; Internal pressure is the order of magnitude of 5-10 crust.Then as shown in Figure 2, by means of the ligule ledge at braid two ends two arms are surrounded and with the bridge of this tubulose mixed weaving spare as framework two arms.

Then this member is put into a metal die that separates, the shape of the finished product of the shape of mould inner surface and required games racket frame matches.Closed die and inflation, making its internal pressure is the 5-10 crust, thereby the blend braid is pressed on the mould inner wall.Again mold heated also is incubated about 5-30 minute to the temperature that is higher than the thermoplastic fibre fusing point.Can in heating mould or after mould heats up, give airbag aeration.For Fypro, mold temperature should be about 300 ℃.Fiber fusing and fixed formation are embedded with the matrix of the carbon fibre of the state of aligning.The two ends of tubing bond together the handle part that constitutes games racket frame, and the tongue-shaped member of bridge is bonded on two arms, and bridge is attached firmly on the framework.The same fusion of sufficiently high mold temperature the thermoplastic granulates in the bridge, the blowing agent of gaseous state is expanded, and the braid wall that will constitute bridge is pressed on the die wall, make this part blend braid obtain curing equally.Mold cools down is got off, the framework demoulding that molding is good.If desired, also can polish framework.Soft air bag can be extracted out or stay in the framework.

Claims

1, a kind of games racket frame, it comprises the hollow tubular product of the handle that an embowment, two ends also form together, thermoplastic fibre/carbon fibre the blend of its pipe wall material for solidifying, wherein being positioned at bridge (3) between handle (1) two arm (2) and being a kind of is that the thermoplastic fibre/carbon fibre of curing of the thermoplastic foam of 20-400 grams per liter mixes thread pipe by being filled with density.

2, games racket frame as claimed in claim 1, wherein above-mentioned thermoplastic fiber materials is a polyamide.

3, games racket frame as claimed in claim 1, wherein above-mentioned thermoplastic foam is polyamide, polysulfones or polyether sulfone.

4, a kind of technology of making games racket frame as claimed in claim 1 may further comprise the steps:

Make tubular braid with thermoplastic fibre/carbon fibre blend;

In tubular braid, insert softness, thin-walled, inflatable air bag;

Tubular braid is bent to the shape of games racket frame;

A tubulose blend braided part is placed between framework two arms as bridge (3), by means of two ligules that form bridge two arms is closed up mutually by this way;

This member is put into metal die separately, and closed die:

The inflation air bag clings to braid on the die wall so that produce pressure on the blend braid;

To the temperature that is higher than thermoplastic fibers melt point, make the blend braid be solidified into the fiber reinforced pipe mold heated;

Cold is the mould and the demoulding;

Wherein, be filled with graininess or the foamable thermoplastic of monoblock in the blend braid that constitutes bridge (3), when heating mould, foamed plastic expands and produce pressure on the blend braid, and braid is close on the mold wall.

5, processing technology as claimed in claim 4, wherein expanded beads is contained in softness, thin-walled, the inflatable capsule, and this capsule inserts in the bridge (3) that is made by the blend braid.