CN115464900A

CN115464900A - Carbon fiber composite material shell, preparation method thereof and electronic equipment

Info

Publication number: CN115464900A
Application number: CN202211167990.9A
Authority: CN
Inventors: 金毅
Original assignee: Goertek Techology Co Ltd
Current assignee: Goertek Techology Co Ltd
Priority date: 2022-09-23
Filing date: 2022-09-23
Publication date: 2022-12-13

Abstract

The invention discloses a carbon fiber composite material shell, a preparation method thereof and electronic equipment. The preparation method of the carbon fiber composite material shell comprises the following steps: preforming a carbon fiber composite material on the thermoplastic core mold to obtain a preformed piece; the glass transition temperature of the thermoplastic core mold is higher than the gel point temperature of the carbon fiber composite material, and the surface structure of the outer surface of the thermoplastic core mold is covered by the carbon fiber composite material; putting the preformed piece into a mould, and carrying out hot-press molding treatment to solidify the carbon fiber composite material; and (3) demolding the preformed piece subjected to the hot-press molding treatment to remove the thermoplastic core mold in the preformed piece so as to obtain the carbon fiber composite material shell. The technical scheme of the invention can solve the problems of the existing blow molding process of the hollow integrated carbon fiber composite shell.

Description

Carbon fiber composite material shell, preparation method thereof and electronic equipment

Technical Field

The invention relates to the technical field of composite materials, in particular to a carbon fiber composite material shell, a preparation method thereof and electronic equipment.

Background

Electronic equipment, especially wearing equipment all has higher requirement to weight, intensity and outward appearance, selects carbon-fibre composite material light in weight, high strength and high outward appearance feel to be a selection that has the comparison advantage. At present, a hollow integrated carbon fiber composite shell is usually manufactured by adopting a blow molding process. In the process, the carbon fiber prepreg coated on the outer surface of the nylon air bag is inflated and pressed on the inner wall of a die cavity by inflating and expanding the shaped nylon air bag in the die, so that shaping is completed. The nylon air bag relies on manual bundling force, so that the problem of unstable air pressure in the forming process is easily caused, and the problems of poor wall thickness consistency, unstable appearance size and the like of a finished product are caused; moreover, once the carbon fiber prepreg is improperly laid, the resin cannot flow to a uniform wall thickness by pressurization, and therefore, high dimensional accuracy is not achieved; moreover, after the nylon air bag is shaped, the foaming material for assisting the nylon air bag in shaping is generally removed in a mode of dissolving the nylon air bag by using a liquid medicine, so that the foaming material cannot be reused, and resource waste is caused. Namely, the existing blowing forming process is complex and tedious in process, low in efficiency, high in labor concentration degree and large in human resource investment; and the obtained finished product has poor consistency and does not have high dimensional precision.

Disclosure of Invention

The main object of the present invention is to solve at least one of the above technical problems. Therefore, the carbon fiber composite material shell, the preparation method thereof and the electronic equipment are provided, and the purpose is to solve the related problems of the existing blow molding process adopted by the hollow integrated carbon fiber composite material shell.

In order to achieve the purpose, the preparation method of the carbon fiber composite material shell provided by the invention comprises the following steps:

preforming a carbon fiber composite material on the thermoplastic core mold to obtain a preformed piece; the glass transition temperature of the thermoplastic core mold is higher than the gel point temperature of the carbon fiber composite material, and the surface structure of the outer surface of the thermoplastic core mold is covered by the carbon fiber composite material;

putting the preformed piece into a mould, and carrying out hot-press molding treatment to solidify the carbon fiber composite material;

and (3) demolding the preformed piece subjected to the hot-press molding treatment to remove the thermoplastic core mold in the preformed piece so as to obtain the carbon fiber composite material shell.

In an embodiment of the present invention, the step of preforming the carbon fiber composite material on the thermoplastic core mold to obtain the preform further includes:

the thermoplastic mandrel is dipped in a release agent.

In an embodiment of the present invention, in the step of immersing the thermoplastic core mold in the release agent, an immersion time of the thermoplastic core mold is 10min to 20min.

In an embodiment of the present invention, in the step of immersing the thermoplastic core mold in the release agent, the release agent is a solvent-based release agent.

In one embodiment of the present invention, the outer surface of the thermoplastic core die is inserted into an insert, and the portion of the insert exposed at the outer surface of the thermoplastic core die forms the surface structure.

In an embodiment of the present invention, before the step of preforming the carbon fiber composite material on the thermoplastic core mold to obtain the preform, the method further includes:

preparing a thermoplastic core mold through an injection molding process, and forming an insertion position on the outer surface of the thermoplastic core mold;

soaking a thermoplastic core mold in a release agent;

and inserting the insert into the insertion position of the thermoplastic core mold soaked with the release agent.

In one embodiment of the invention, the thermoplastic core mold is a hollow structure.

In an embodiment of the invention, the resin in the carbon fiber composite material is epoxy resin, and the thermoplastic core mold is made of one of polyvinyl chloride, modified polypropylene, modified polyethylene and modified polyethylene terephthalate.

In order to achieve the above purpose, the carbon fiber composite shell provided by the invention is prepared by a preparation method of the carbon fiber composite shell, and the preparation method of the carbon fiber composite shell comprises the following steps:

and (3) performing demoulding treatment on the preformed piece subjected to the hot-press forming treatment to remove the thermoplastic core mould in the preformed piece so as to obtain the carbon fiber composite material shell.

In order to achieve the above object, the electronic device provided by the present invention includes a carbon fiber composite shell, wherein the carbon fiber composite shell is prepared by a carbon fiber composite shell preparation method, and the carbon fiber composite shell preparation method includes the following steps:

The preparation method of the carbon fiber composite shell is a forming process of a hollow integrated carbon fiber composite shell, and compared with the existing blowing forming process, the process does not need complicated shaping, dissolving, blowing and other procedures, and has the advantages of high efficiency, low labor intensity, low human resource investment and the like. Wherein, utilize the glass transition temperature of thermoplasticity mandrel and the temperature difference of the gel point of carbon fiber composite, alright realize better carbon fiber composite plastic effect promptly:

before the mold is gradually heated until the temperature reaches the gel point temperature of the carbon fiber composite material, the thermosetting resin in the carbon fiber composite material has low viscosity and good fluidity, and the temperature does not reach the glass transition temperature of the thermoplastic core mold, so that the thermoplastic core mold always has high rigidity and compressive strength, the mold closing pressure can be transmitted to the inside of the carbon fiber composite material, the resin in a thicker area flows to a thinner area, the effect of adjusting the thickness to be uniform is achieved, and the disadvantages of poor consistency and no high size precision of a finished product are improved.

And then, when the temperature of the mold is continuously raised until the gel point temperature of the carbon fiber composite material is reached, the viscosity of the thermosetting resin in the carbon fiber composite material is increased suddenly, the thermosetting resin in the carbon fiber composite material is not deformed any more, and the molding process is finished.

Then, when the temperature of the mould is continuously raised until the curing temperature of the carbon fiber composite material is reached, the thermosetting resin in the carbon fiber composite material starts to be cured, and the curing is completed at the temperature; and the solidified carbon fiber composite material is demoulded from the thermoplastic core mould to obtain the carbon fiber composite material shell.

In the process, the thermoplastic core mold has higher hardness before reaching the glass transition temperature, so that the inner surface of the carbon fiber composite material is smooth and has no folds, and the thermoplastic core mold is convenient to be subsequently removed; meanwhile, after the thermoplastic core mold is separated, the thermoplastic core mold can be repeatedly used due to the self thermoplasticity, and the resource waste is avoided.

In addition, according to the preparation method of the carbon fiber composite material shell, the surface structure (such as the concave, the convex, the groove, the convex rib, the texture and the like) is designed on the outer surface of the thermoplastic core mold, when the thermosetting resin of the carbon fiber composite material reaches the gel point temperature and the thermoplastic core mold does not reach the glass transition temperature, the surface structure of the outer surface of the thermoplastic core mold is repeatedly engraved on the inner surface of the carbon fiber composite material, so that the required structure (such as the convex, the concave, the convex rib, the groove, the texture and the like) is formed on the inner surface of the carbon fiber composite material, and the carbon fiber composite material shell can be conveniently assembled with other structures or devices during subsequent application of a finished product, so that more abundant functions are realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic flow chart of a first embodiment of a method for manufacturing a carbon fiber composite shell according to the present invention;

FIG. 2 is a schematic flow chart of a second embodiment of a method for manufacturing a carbon fiber composite shell according to the present invention;

FIG. 3 is a schematic flow chart of a third embodiment of a method for manufacturing a carbon fiber composite shell according to the present invention;

FIG. 4 is a schematic flow chart of a fourth embodiment of a method for manufacturing a carbon fiber composite shell according to the present invention;

FIG. 5 is a schematic flow chart of a fifth embodiment of a method for manufacturing a carbon fiber composite shell according to the present invention;

FIG. 6 is a schematic flow chart of a sixth embodiment of a method for manufacturing a carbon fiber composite shell according to the present invention;

FIG. 7 is a schematic flow chart of a seventh embodiment of a method for manufacturing a carbon fiber composite shell according to the present invention;

FIG. 8 is a schematic structural view of an embodiment of a thermoplastic core mold in the method for manufacturing a carbon fiber composite shell according to the present invention; wherein the surface structure of the outer surface of the thermoplastic core mold is texture;

FIG. 9 is a schematic structural view of another embodiment of a thermoplastic core mold in the method for producing a carbon fiber composite shell according to the present invention; wherein, the surface structure of the outer surface of the thermoplastic core mold is an insert mounting position;

FIG. 10 is a schematic structural diagram of a carbon fiber composite shell prepared by the method for preparing a carbon fiber composite shell according to the present invention; wherein, the chamber wall of the inner chamber of carbon-fibre composite shell inlays and is equipped with the inserts.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.

In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The invention provides a preparation method of a carbon fiber composite shell, aiming at solving the related problems of the existing blow molding process of a hollow integrated carbon fiber composite shell.

The following will explain the preparation method of the carbon fiber composite shell proposed by the present invention in specific examples:

fig. 1 shows a first embodiment of the method for producing a carbon fiber composite shell according to the present invention. In this embodiment, the preparation method of the carbon fiber composite shell includes the following steps:

step S100, preforming a carbon fiber composite material on a thermoplastic core mold to obtain a preformed piece; the glass transition temperature of the thermoplastic core mold is higher than the gel point temperature of the carbon fiber composite material, and the surface structure of the outer surface of the thermoplastic core mold is covered by the carbon fiber composite material;

specifically, the step of preforming the carbon fiber composite material on the thermoplastic core mold to obtain the preform is performed in a clean space at a temperature of 20 to 26 ℃ and a relative humidity of 60 to 80 percent. The shape of the carbon fiber composite material can be obtained by blanking according to design requirements and a two-dimensional drawing after the outer surface of a product is unfolded, so that a required three-dimensional shell prototype can be obtained after the prototype is preformed on a thermoplastic core mold. The acquisition mode of the two-dimensional drawing after the outer surface of the product is unfolded can be various, for example:

scanning the outer surface profile of a product, obtaining a 2D layering spreading diagram with an approximate area through 3D layering spreading software, and obtaining a layering knife model drawing for blanking after processing; or, the outer surface of the product is stroked and spread by using masking tape, and the product is scanned and processed by software to obtain a layering knife model drawing for blanking.

Step S200, putting the preformed piece into a mould, and carrying out hot-press molding treatment to solidify the carbon fiber composite material;

specifically, after the preformed piece is placed into a lower die of a die, the lower die of the die is combined, the die is placed into a high-tonnage hot press, and hot press forming treatment is carried out after setting according to forming parameters.

And step S300, demolding the preformed piece subjected to the hot press molding treatment to remove the thermoplastic core mold in the preformed piece, so as to obtain the carbon fiber composite material shell.

The preparation method of the carbon fiber composite shell provided by the embodiment is a molding process of the hollow integrated carbon fiber composite shell, and compared with the existing blowing molding process, the process does not need complicated and tedious procedures of shaping, dissolving, blowing and the like, and has the advantages of high efficiency, low labor intensity, low human resource investment and the like. Wherein, utilize the glass transition temperature of thermoplasticity mandrel and the temperature difference of the gel point of carbon fiber composite, alright realize better carbon fiber composite plastic effect promptly:

Then, when the temperature of the mould is continuously raised until the curing temperature of the carbon fiber composite material is reached, the thermosetting resin in the carbon fiber composite material starts to be cured, and the curing is finished at the temperature; and the carbon fiber composite material after solidification is demoulded from the thermoplastic core mould, and the carbon fiber composite material shell can be obtained.

In the process, the thermoplastic core mold has higher hardness before reaching the glass transition temperature, so that the inner surface of the carbon fiber composite material is smooth and has no folds, and the thermoplastic core mold is convenient to be subsequently removed; meanwhile, after the thermoplastic core mold is separated, the thermoplastic core mold can be repeatedly used due to the self thermoplasticity, so that the resource waste is avoided.

In addition, according to the preparation method of the carbon fiber composite shell provided by the embodiment, since the surface structure (such as the recess, the protrusion, the groove, the convex rib, the texture and the like) is designed on the outer surface of the thermoplastic core mold, when the thermosetting resin of the carbon fiber composite material reaches the gel point temperature and the thermoplastic core mold does not reach the glass transition temperature, the surface structure of the outer surface of the thermoplastic core mold is repeatedly engraved on the inner surface of the carbon fiber composite material, so that a required structure (such as the protrusion, the recess, the convex rib, the groove, the texture and the like) is formed on the inner surface of the carbon fiber composite material, and the carbon fiber composite shell can be conveniently assembled with other structures or devices during subsequent application of a finished product, so that more abundant functions are realized.

It is understood that the gel point temperature of the carbon fiber composite material refers to the gel point temperature of the thermosetting resin in the carbon fiber composite material.

Fig. 2 shows a second embodiment of the method for manufacturing a carbon fiber composite material outer shell according to the present invention. This embodiment is different from the first embodiment in that the step S300 of the first embodiment, namely, the step of "performing a demolding process on the preform subjected to the hot press molding process to demold the thermoplastic core mold in the preform to obtain the carbon fiber composite material outer shell", includes:

step S310, cooling the preformed piece subjected to the hot-press forming treatment, and releasing the preformed piece from the mold to obtain a semi-finished product;

step S320, heating the thermoplastic core mold in the semi-finished product to the glass transition temperature thereof, and extracting the softened thermoplastic core mold to obtain the carbon fiber composite shell.

It should be noted that, when the curing temperature of the carbon fiber composite material is higher than the glass transition temperature of the carbon fiber composite material, the "rigidity" of the carbon fiber composite material just after the curing is finished disappears after a short time, and the "high elastic state" property appears. At this time, although the thermoplastic core mold is softened and can be removed, the removal process inevitably applies force to the carbon fiber composite material, which is very likely to cause irreversible damage to the internal structure of the carbon fiber composite material, thereby affecting the performance of the finally obtained carbon fiber composite material shell.

In order to avoid the above problems, in the present embodiment, a manner of cooling (so that the carbon fiber composite material becomes "rigid" when coming below the glass transition temperature) and then heating the thermoplastic core mold to the glass transition temperature (so that the thermoplastic core mold is softened) is adopted, and since the carbon fiber composite material which is solidified at the glass transition temperature of the thermoplastic core mold still has high "rigidity", even though the releasing process inevitably applies force to the carbon fiber composite material, the internal structure of the carbon fiber composite material is not affected, thereby ensuring that the performance of the finally obtained carbon fiber composite material shell is not affected.

Of course, except for the above-mentioned "cooling before heating" releasing manner, when the curing temperature of the carbon fiber composite material is lower than the glass transition temperature of the carbon fiber composite material, the carbon fiber composite material which has been cured is kept in a "glass state" and has higher "rigidity"; at this time, the mold can be opened directly at the curing temperature, the carbon fiber composite material can be demolded from the thermoplastic core mold by drawing out the softened thermoplastic core mold, and then the carbon fiber composite material shell can be obtained by cooling.

It is understood that the curing temperature of the carbon fiber composite material refers to the curing temperature of the thermosetting resin in the carbon fiber composite material. The glass transition temperature of the carbon fiber composite material is the glass transition temperature of the thermosetting resin in the carbon fiber composite material.

Fig. 3 shows a third embodiment of the method for producing a carbon fiber composite shell according to the present invention. The present embodiment is different from the second embodiment in that the step S310 of the second embodiment, namely, the step of "cooling the preform subjected to the hot press molding process and releasing the preform from the mold to obtain a semi-finished product" includes:

and step S310', cooling the preformed piece subjected to the hot-press forming treatment to be below 80 ℃ at room temperature, and opening the mold to obtain a semi-finished product.

In the embodiment, the temperature boundary of 80 ℃ is set, so that the sufficient curing molding of the carbon fiber composite material can be ensured, and the performance of the obtained carbon fiber composite material shell can be ensured; and the temperature is still maintained at a higher temperature, so that the semi-finished product can be heated more quickly, on one hand, the removal efficiency of the thermoplastic core mold can be improved, the manufacturing process of the whole carbon fiber composite shell is accelerated, on the other hand, the data consumed by heating can be saved, and the purpose of reducing resource consumption is achieved.

In an embodiment of the invention, the glass transition temperature of the thermoplastic core mold is 10-30 ℃ higher than the gel point temperature of the carbon fiber composite material.

It will be appreciated that the glass transition temperature of the thermoplastic core is preferably not too low above the gel point temperature of the carbon fiber composite, nor too high above the gel point temperature of the carbon fiber composite, because:

if the glass transition temperature of the thermoplastic core mold is too low, the glass transition temperature of the thermoplastic core mold is too close to the gel point temperature of the carbon fiber composite material; as such, when the temperature of the preform reaches the gel point temperature of the carbon fiber composite, the temperature of the preform will also approach the glass transition temperature of the thermoplastic core, which will cause some "softening" of the thermoplastic core; at this moment, the higher rigidity and the compressive strength of the thermoplastic core mold can be reduced to a certain degree, so that the molding effect of the carbon fiber composite material is greatly influenced, and the final finished product is deformed and is poor.

Too much means that the glass transition temperature of the thermoplastic core mold is too far away from the gel point temperature of the carbon fiber composite material and too close to the curing temperature of the carbon fiber composite material; at this time, the glass transition temperature of the thermoplastic core mold may be close to the glass transition temperature of the carbon fiber composite material; in this case, when the thermoplastic core mold is reheated after cooling to be separated from the carbon fiber composite material, or the thermoplastic core mold is directly removed at a high temperature, the carbon fiber composite material is likely to be in a state close to a high elastic state, which makes it difficult to remove the thermoplastic core mold, and the carbon fiber composite material may be deformed or even broken.

Therefore, in this embodiment, the glass transition temperature of the thermoplastic core mold is set to be higher than the gel point temperature of the carbon fiber composite material by a value in the range of 10 to 30 ℃. Specifically, the glass transition temperature of the thermoplastic core mold higher than the gel point temperature of the carbon fiber composite material may be a value of: 11 ℃, 12 ℃, 13 ℃, 14 ℃, 15 ℃, 16 ℃, 17 ℃, 18 ℃, 19 ℃, 20 ℃, 21 ℃, 22 ℃, 23 ℃, 24 ℃, 25 ℃, 26 ℃, 27 ℃, 28 ℃, 29 ℃ and 30 ℃.

In the embodiment, the epoxy resin-based carbon fiber composite material is a commonly-used carbon fiber composite material, has excellent and stable performance, is used for preparing a carbon fiber composite material shell, and can endow a finished product with excellent mechanical properties. Moreover, the gel point temperature and the curing temperature of the epoxy resin-based carbon fiber composite material are both proper, which are not too high, so that the epoxy resin-based carbon fiber composite material is easy to achieve, the problems of difficult heating, overlong heating time and the like are avoided, and the resources can be saved to a certain extent; the temperature difference between the two is proper, the thermoplastic core mold can be matched with the thermoplastic core mold, the material variety is more, the thermoplastic core mold is easy to obtain, and the difficulty in preparation can not be brought; these all provide greater feasibility for the method of making the carbon fiber composite shell.

In order to match the epoxy resin-based carbon fiber composite material, the material of the thermoplastic core mold can be one of polyvinyl chloride, modified polypropylene, modified polyethylene and modified polyethylene terephthalate, and the materials can meet the condition that the glass transition temperature of the thermoplastic core mold is 10-30 ℃ higher than the gel point temperature of the carbon fiber composite material, and can be directly used for molding the thermoplastic core mold, so that the method is simple and convenient.

It should be noted that, since polypropylene, polyethylene, and polyethylene terephthalate cannot directly satisfy the condition setting that "the glass transition temperature of the thermoplastic core mold is 10 to 30 ℃ higher than the gel point temperature of the carbon fiber composite material", they can be used to form the thermoplastic core mold after being modified; wherein, the glass transition temperature of the polypropylene and the polyethylene is too low, and the polypropylene and the polyethylene can be selected to be blended with thermoplastic resin with higher glass transition temperature to realize modification; if the glass transition temperature of the polyethylene terephthalate is too high, the polyethylene terephthalate can be selected to be blended with a thermoplastic resin with a lower glass transition temperature or a plasticizer can be added to realize modification.

Fig. 4 shows a fourth example of the method for producing a carbon fiber composite shell according to the present invention. This embodiment is different from the first embodiment in that step S100 in the first embodiment, i.e., "preforming a carbon fiber composite on a thermoplastic core mold to obtain a preform; wherein the glass transition temperature of the thermoplastic core mold is higher than the gel point temperature of the carbon fiber composite material, and the surface structure of the outer surface of the thermoplastic core mold is covered by the carbon fiber composite material, the steps of:

step S110, sequentially preforming a plurality of carbon fiber prepregs arranged in a stacked mode on a thermoplastic core mould to obtain a carbon fiber composite material; the glass transition temperature of the thermoplastic core mold is higher than the gel point temperature of the carbon fiber composite material, and the surface structure of the outer surface of the thermoplastic core mold is covered by the carbon fiber composite material.

In this embodiment, the carbon fiber composite material comprises a plurality of carbon fiber prepreg that range upon range of setting, and a plurality of carbon fiber prepreg that range upon range of setting can solidification shaping through once hot pressing, obtains final required carbon fiber composite shell, and the technological process is simple, swift, high-efficient, and inner structure comprises a plurality of carbon fibers that range upon range of setting in advance, and mechanical properties is more excellent.

For example, a plurality of carbon fiber unidirectional prepregs are sequentially stacked in an alternating manner of 0 ° and 90 °; or a plurality of carbon fiber unidirectional prepregs are sequentially stacked according to a 0-degree and 90-degree alternating mode, and two sides of the carbon fiber unidirectional prepregs are respectively covered by two carbon fiber woven prepregs. Of course, according to the requirements of the actual application scenario, those skilled in the art may also perform other stack designs, which are not described herein again.

Fig. 5 shows a fifth embodiment of the method for manufacturing a carbon fiber composite material outer shell according to the present invention. This embodiment differs from the third embodiment in that after step S110 in the fourth embodiment, a plurality of carbon fiber prepregs arranged in layers are "sequentially premolded on a thermoplastic core mold to obtain a carbon fiber composite material; wherein, the step of the thermoplastic core mold having a glass transition temperature higher than the gel point temperature of the carbon fiber composite material and the surface structure of the outer surface of the thermoplastic core mold being covered with the carbon fiber composite material further comprises:

in step S120, vacuum is applied to exhaust interlayer air.

In this embodiment, after a plurality of carbon fiber prepregs are laminated, the interlayer air can be discharged to a great extent through vacuum treatment. Therefore, the interlayer bonding force is favorably enhanced, and the carbon fiber composite material with better integrity is formed, so that the performance of the final finished product is guaranteed; but also can reduce the defect problem caused by bubbles and further optimize the performance of the finished product.

Fig. 6 shows a sixth embodiment of the method for producing a carbon fiber composite shell according to the present invention. This embodiment differs from the first embodiment in that the outer surface of the thermoplastic core mold has a surface structure constituted by the thermoplastic core mold itself (i.e., the outer surface of the thermoplastic core mold is not all flat surfaces, and there may be convex portions or concave portions to constitute surface structures such as recesses, projections, grooves, ribs, etc.), and that before step S100 in the first embodiment, a preform is obtained by "preforming a carbon fiber composite on the thermoplastic core mold; wherein, before the steps that the glass transition temperature of the thermoplastic core mold is higher than the gel point temperature of the carbon fiber composite material, and the surface structure of the outer surface of the thermoplastic core mold is covered by the carbon fiber composite material, the method further comprises the following steps:

in step S400, the thermoplastic core mold is immersed in a mold release agent.

It should be noted that, because the outer surface of the thermoplastic core mold is designed with a surface structure, the contact area between the thermoplastic core mold and the carbon fiber composite material will be increased, and the difficulty in releasing the thermoplastic core mold will also be increased. At this time, the thermoplastic core mold is soaked in the release agent, so that the surface of the thermoplastic core mold is covered with a layer of the release agent, which can help the thermoplastic core mold to be better removed, thereby avoiding the damage of the structure transferred to the inner surface of the carbon fiber composite material.

Wherein the soaking time of the thermoplastic core mold is 10-20 min.

It should be noted that the soaking time of the thermoplastic core mold in the mold release agent is not too long nor too short: if the length is too short, the release agent is not completely infiltrated into the thermoplastic core mold, and the release agent cannot be well adhered to the surface of the thermoplastic core mold, which easily causes the problem that the release is difficult in the later-stage partial region, thereby increasing the risk of structural damage. And if the length is too long, the time cost is too high, and the production efficiency is low.

Therefore, the soaking time of the thermoplastic core mold in the mold release agent is preferably set within a range of 10min to 20min. Specifically, the soaking time of the thermoplastic core mold in the release agent may be 10min, 11min, 12min, 13min, 14min, 15min, 16min, 17min, 18min, 19min, 20min.

Wherein the release agent is a solvent release agent.

The aqueous release agent has a poor release effect, and thus the structure transferred to the inner surface of the carbon fiber composite material is easily damaged or the release is difficult. The residual rate of the oily release agent is high, the oily release agent is difficult to clean due to the fact that the release is carried out from the inner surface of the carbon fiber composite material, and the high residual rate can easily cause difficulty in assembling other structures or devices in the finished product. Therefore, the solvent release agent is selected, so that the release effect can meet the requirement, and the residual rate is low.

Based on the first embodiment of the present invention, another embodiment of the present invention may also be proposed, that is: the outer surface of the thermoplastic core mold is inserted into the insert, and the part of the insert exposed out of the outer surface of the thermoplastic core mold forms the surface structure.

That is, unlike the above-described embodiment in which the surface structure of the outer surface of the thermoplastic core mold is constituted by the thermoplastic core mold itself, the surface structure of the outer surface of the thermoplastic core mold of the present embodiment is constituted by the insert inserted on the outer surface thereof. Because the insert is inserted on the outer surface of the thermoplastic chip, when the insert is used for the pre-molded carbon fiber composite material along with the thermoplastic chip and is sent into a die along with the carbon fiber composite material for hot press molding, the resin on the inner side of the insert is coated and adhered to the insert along with the solidification of the carbon fiber composite material; later, when deviating from the internal surface of the compound material of carbon fiber who has accomplished the solidification with the thermoplastic mandrel that softens, the mode of pegging graft no longer can fix the inserts, and the inserts just can remain at the internal surface of the compound material of carbon fiber, has realized the equipment of inserts and going on in step of the compound material solidification of carbon fiber, and is not only simple, convenient, has promoted production efficiency, and inserts post assembling stability is stronger moreover for the function of realization will also be more reliable.

Fig. 7 shows a seventh embodiment of the method for manufacturing a carbon fiber composite material outer shell according to the present invention. In this embodiment, on the basis of the embodiment that "the outer surface of the thermoplastic core mold is inserted into the insert, and the portion of the insert exposed on the outer surface of the thermoplastic core mold forms the surface structure", a pretreatment scheme of the thermoplastic core mold is proposed, that is, the pretreatment scheme is as follows: before step S100 in the first embodiment, "a carbon fiber composite material is premolded on a thermoplastic core mold to obtain a preform; wherein, before the steps that the glass transition temperature of the thermoplastic core mold is higher than the gel point temperature of the carbon fiber composite material, and the surface structure of the outer surface of the thermoplastic core mold is covered by the carbon fiber composite material, the method further comprises the following steps:

step S500, preparing a thermoplastic core mold through an injection molding process, and forming an insertion position on the outer surface of the thermoplastic core mold;

step S600, soaking a thermoplastic core mold in a release agent;

and S700, inserting the insert into the insertion position of the thermoplastic core mold soaked with the release agent.

It should be noted that the thermoplastic core mold is prepared by an injection molding process, so that the shape and the size of the thermoplastic core mold are more accurate, and the carbon fiber composite shell with more accurate shape and size can be prepared and obtained by using the thermoplastic core mold for molding the carbon fiber composite material. And the thermoplastic core mold is prepared by an injection molding process, and has the advantages of simple process, high efficiency and the like.

In addition, before the insert is installed, the thermoplastic core mold is soaked in the release agent, so that the release agent is prevented from being carried on the surface of the insert, which is in contact with the carbon fiber composite material, and the bonding strength of the insert and the carbon fiber composite material is guaranteed; at the same time, it can help the thermoplastic core mold to be better ejected.

Wherein the soaking time of the thermoplastic core mold is 10-20 min.

It should be noted that the soaking time of the thermoplastic core mold in the mold release agent is not too long nor too short: if the length is too short, the release agent does not completely infiltrate the thermoplastic core mold, and the release agent does not adhere well to the surface of the thermoplastic core mold, which easily causes the problem that the release is difficult in the later-stage partial region, thereby increasing the risk of structural damage. And if the length is too long, the time cost is too high, and the production efficiency is low.

Therefore, the soaking time of the thermoplastic core mold in the mold release agent is preferably set within a range of 10min to 20min. Specifically, the soaking time of the thermoplastic core mold in the mold release agent may be 10min, 11min, 12min, 13min, 14min, 15min, 16min, 17min, 18min, 19min, 20min.

Wherein the release agent is a solvent release agent.

The insert can be a metal piece or a plastic piece. When the insert is a plastic part, the plastic can be made of a material with a glass transition temperature higher than the curing temperature of the carbon fiber composite material, such as Polycarbonate (PC), polyethyleneimine (PEI) and the like.

It is to be understood that the embodiments of "the surface structure of the outer surface of the thermoplastic core mold is formed by the thermoplastic core mold itself" and "the surface structure is formed by the portion of the outer surface of the thermoplastic core mold that is inserted into the insert and exposed to the outer surface of the thermoplastic core mold" can be performed simultaneously or alternatively.

Based on the first embodiment of the present invention, another embodiment of the present invention may also be proposed, that is: the thermoplastic core mold is of a hollow structure.

It can be understood that, because the outer surface of the thermoplastic core mold is also designed with a surface structure, the contact area between the thermoplastic core mold and the carbon fiber composite material is increased, and the disengagement difficulty of the thermoplastic core mold is also increased. At this time, the thermoplastic core mold is designed to be a hollow structure, so that the thermoplastic core mold can be inwards collapsed after the thermoplastic core mold reaches the glass transition temperature, and is more conveniently separated, thereby avoiding damaging the structure transferred to the inner surface of the carbon fiber composite material.

In view of the technical problems mentioned in the background, the present invention also provides a carbon fiber composite shell, which is prepared by the method for preparing a carbon fiber composite shell as described above, and the specific implementation of the method for preparing a carbon fiber composite shell refers to the foregoing examples. Since the carbon fiber composite material shell adopts all the technical solutions of all the embodiments, at least all the beneficial effects brought by all the technical solutions of all the embodiments are achieved, and no further description is given here.

In view of the technical problems mentioned in the background, the present invention also provides an electronic device including the carbon fiber composite housing as described above, and the specific structure of the carbon fiber composite housing refers to the foregoing embodiments. Since the electronic device adopts all the technical solutions of all the embodiments, at least all the beneficial effects brought by all the technical solutions of all the embodiments are achieved, and no further description is given here.

Specifically, the electronic device may be AR glasses, the housing of which includes a lens frame and temples; that is, it is possible to have the lens frame including the carbon fiber composite housing as described above; the temple may also include a carbon fiber composite shell as previously described; it is also possible that both comprise a carbon fibre composite shell as described before.

The method for producing the carbon fiber composite material outer shell of the present invention will be described below by way of specific examples:

example 1:

the carbon fiber composite material shell is prepared by the following steps:

the first step is as follows: and (4) blanking according to design requirements and a product development drawing to obtain the carbon fiber prepreg with the shape meeting the design requirements.

The second step: according to the core mold 3D model, namely according to the inner cavity size design of the target carbon fiber composite material shell, the thermoplastic core mold 1 with the textures 11 is injected (as shown in figure 8); the thermoplastic core mold 1 is made of modified PVC materials, the glass transition temperature of the thermoplastic core mold is 90 ℃, and the texture 11 is a long groove type texture, so that the assembly and the guiding of accessories are facilitated. After that, the thermoplastic core mold 1 is soaked in a solvent-based mold release agent for 10 minutes, taken out, and dried for use.

The third step: preforming the carbon fiber prepreg obtained in the first step; in the selected carbon fiber prepreg, the gel point temperature of resin is 75 ℃, the glass transition temperature of the resin is 100 ℃, the forming temperature is 135 ℃, and the selected fiber is 3K plain woven cloth; specifically, performing preforming in a clean room with the temperature of 2323 ℃ and the relative humidity of 60-80%, preforming the carbon fiber prepreg obtained in the first step on a thermoplastic core mold 1, enabling the fiber direction to be along the length direction of a product, namely the fiber angle to be 0 DEG or 90 DEG, paving the carbon fiber prepreg layer by layer in a rolling mode, putting the carbon fiber prepreg into a vacuum bag, vacuumizing until the vacuum degree reaches below-0.095 MPa, and exhausting interlayer air to obtain a preformed piece;

the fourth step: closing the mold; wherein, the material of the die is P20 steel; the method comprises the following steps of putting a preformed piece into a lower die of a die, combining an upper die of the die, putting the preformed piece and the die on a workbench of a high-tonnage hot press, setting the heating temperature to be 135 ℃, the die assembly pressure to be 2MPa, and the heat preservation and pressure maintaining time to be 10 minutes, and preparing a product rough blank according to molding parameters.

The fifth step: and (3) cooling, demolding, standing, cooling to below 80 ℃ at room temperature, and opening the mold to obtain a semi-finished product of the carbon fiber composite material containing the PVC inner core.

And a sixth step: heating to remove the PVC inner core and obtain the carbon fiber composite material shell.

Example 2:

the carbon fiber composite material shell is prepared according to the following steps:

The second step: according to the core mold 3D model, namely according to the inner cavity size design of the target carbon fiber composite material shell, the thermoplastic core mold 1 with the insert mounting position 13 is injected (as shown in figure 9); wherein, the material of the thermoplastic core mould 1 is a modified PVC material, the glass transition temperature of the thermoplastic core mould is 90 ℃, the insert mounting position 13 is in a groove form, the insert is convenient to fix, the material of the used insert is a PEI material, and the glass transition temperature of the insert is 215 ℃. After that, the thermoplastic core mold 1 is soaked with a solvent-based release agent for 10 minutes, taken out, dried, and the insert is inserted into the insert mounting position 13 for use.

The third step: preforming the carbon fiber prepreg obtained in the first step; in the selected carbon fiber prepreg, the gel point temperature of resin is 75 ℃, the glass transition temperature of the resin is 100 ℃, the forming temperature is 135 ℃, and the selected fiber is 3K plain woven cloth; specifically, performing preforming in a clean room with the temperature of 2323 ℃ and the relative humidity of 60-80%, preforming the carbon fiber prepreg obtained in the first step on the thermoplastic core mold 1, enabling the fiber direction to be along the length direction of a product, namely enabling the fiber angle to be 0 degree or 90 degrees, paving the carbon fiber prepreg layer by layer in a rolling mode, putting the carbon fiber prepreg into a vacuum bag, vacuumizing until the vacuum degree reaches below-0.095 MPa, and exhausting interlayer air to obtain a preformed piece;

the fourth step: closing the mold; wherein, the material of the die is P20 steel; the method comprises the following steps of putting a preformed piece into a lower die of a die, combining an upper die of the die, putting the preformed piece and the die on a workbench of a high-tonnage hot press, setting the heating temperature to be 140 ℃, the die assembly pressure to be 3MPa, and the heat preservation and pressure maintaining time to be 15 minutes, and preparing a product rough blank according to molding parameters.

The fifth step: and (3) cooling and demolding, standing and cooling to the temperature below 80 ℃ at room temperature after solidification, and opening the mold to obtain the semi-finished product of the carbon fiber composite material containing the PVC inner core.

And a sixth step: heating to remove the PVC inner core and obtain the carbon fiber composite material shell; wherein, the cavity wall of the inner cavity of the carbon fiber composite material shell is embedded with an insert 10, which is transferred by the insert embedded in the insert mounting position 13 (as shown in fig. 10).

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent structural changes made by using the content of the present specification or other related technical fields within the spirit of the present invention are included in the scope of the present invention.

Claims

1. The preparation method of the carbon fiber composite material shell is characterized by comprising the following steps of:

2. The method of manufacturing according to claim 1, wherein the surface structure of the outer surface of the thermoplastic core mold is formed by the thermoplastic core mold itself, and the step of preforming the carbon fiber composite material on the thermoplastic core mold to obtain the preform further comprises:

the thermoplastic mandrel is dipped in a release agent.

3. The method according to claim 2, wherein in the step of immersing the thermoplastic core mold in the release agent, the immersion time of the thermoplastic core mold is 10 to 20min.

4. The method of manufacturing according to claim 2, wherein the step of immersing the thermoplastic core mold in a release agent is a solvent-based release agent.

5. The method of making of claim 1, wherein an outer surface of the thermoplastic core is inserted into an insert, and wherein a portion of the insert exposed at the outer surface of the thermoplastic core forms the surface features.

6. The method of claim 5, wherein the step of preforming the carbon fiber composite over the thermoplastic core to form the preform further comprises, prior to the step of preforming the carbon fiber composite over the thermoplastic core:

soaking the thermoplastic core mold in a release agent;

7. The method of making of claim 1, wherein the thermoplastic mandrel is a hollow structure.

8. The method according to any one of claims 1 to 6, wherein the resin in the carbon fiber composite material is epoxy resin, and the thermoplastic core mold is made of one of polyvinyl chloride, modified polypropylene, modified polyethylene and modified polyethylene terephthalate.

9. A carbon fiber composite material outer shell produced by the production method for a carbon fiber composite material outer shell according to any one of claims 1 to 8.

10. An electronic device comprising the carbon fiber composite housing of claim 9.