CN110205042B

CN110205042B - Production process of mobile phone explosion-proof membrane

Info

Publication number: CN110205042B
Application number: CN201910531105.2A
Authority: CN
Inventors: 侯宇飞; 黄海霞; 刘泽林; 项婷; 李欣鹏
Original assignee: Hunan Institute of Technology
Current assignee: Hunan Institute of Technology
Priority date: 2019-06-19
Filing date: 2019-06-19
Publication date: 2021-02-23
Anticipated expiration: 2039-06-19
Also published as: CN110205042A

Abstract

A production process of an explosion-proof membrane of a mobile phone relates to the technical field of 3C product accessories, and comprises the following steps: attaching: the method comprises the following steps that a transparent film is attached to the lower surface of a glass cover plate through transparent optical pressure-sensitive adhesive to obtain an assembly, after the assembly is attached, the outer edge of the film is away from the inner edge of an arc-shaped part of the glass cover plate by a certain distance, so that a recess is formed between the outer edge of the film and the inner edge of the arc-shaped part of the glass cover plate, and the periphery of the film is lapped on a black ink layer printed on the; injecting foaming glue: injecting foaming glue into the recess of the component; foaming in a mold: placing the component with the cavity injected with the foaming glue into a foaming mould, and foaming the foaming glue in the mould to finally form a foaming buffer pad in the cavity; demolding and post-treatment: the component which is foamed is taken out of the foaming mold, then the anti-oil coating is sprayed on the upper surface of the glass cover plate, and the AB glue is coated on the lower surfaces of the rubber sheet and the foaming buffer pad.

Description

Production process of mobile phone explosion-proof membrane

Technical Field

The invention relates to the technical field of 3C product accessories, in particular to a production process of an explosion-proof membrane of a mobile phone.

Background

The early outer screen rupture membrane is mostly made of PET or PC films, and the plastic material has poor wear resistance (even if the surface is hardened, the wear resistance is still not ideal), so that scratches are easily generated and are basically eliminated. The toughened glass has relatively better scratch resistance and wear resistance, and the explosion-proof membrane manufactured by the toughened glass becomes the mainstream process direction in the market at present.

The production process of the toughened glass explosion-proof membrane is mainly divided into three stages in the development process. The first stage is with the glass substrate of pure plane directly with it cut into required size of a dimension, then CNC sets up tin bore and sensor hole, send into the tempering furnace again in the intensive processing can, the rupture membrane that this technology was produced is a monoblock plane glass, because the outer screen of current smart mobile phone mostly adopts 2.5D's cambered surface glass (at glass's periphery radius angle promptly), the arc fillet position that outer screen can't be covered to pure plane rupture membrane (rupture membrane can not the full coverage touch-control screen promptly), influence whole visual effect behind the pad pasting, fallen for low-grade product (selling price about 10 yuan/piece). The second stage is that the arc-shaped part (namely the 2.5D arc-shaped full-glass explosion-proof membrane in the industry) for adhering the round corners around the mobile phone touch screen is processed on the cut plane glass through hot bending at the periphery of the plane glass, and the explosion-proof membrane produced by the process has the following defects in actual use: 1. because the arc-shaped round angle at the periphery of the smart phone is only used for ensuring the holding comfort, a manufacturer allows a factory to have larger manufacturing errors, so that the arc-shaped round angles of the mobile phones of the same model sold on the market are not all consistent, the mobile phones can be completely attached by touching the same explosion-proof film sticker, and the mobile phones attached to the same model cannot be completely attached. 2. In the same mobile phone, the fillets on the four sides of the outer screen are not completely the same, and it is also a common situation that the arc fillet of one side cannot be completely attached. 3. The manufacturing error of the explosion-proof membrane (such as the manufacturing error of glass during hot bending and the change of the curvature of the arc part caused in the tempering process in the furnace) is superposed with the manufacturing error of the mobile phone outer screen, and further the joint degree of the explosion-proof membrane at the arc corner part is poor. Because the explosion-proof membrane is made of all-glass materials and cannot be well attached to the arc-shaped round corner part, the arc-shaped part is easy to be crushed due to pressure or impact in the daily use process, and the price is not cheap (generally 30-40 yuan/piece), so that the explosion-proof membrane occupies a lower market share at present. In the third stage (i.e., the current stage), an explosion-proof membrane (e.g., a soft-edge explosion-proof membrane) adopting a splicing process is developed, the middle plane part of the explosion-proof membrane adopts toughened glass, the peripheral arc-shaped part (generally called as an "arc-shaped frame" in the industry) adopts plastic materials (e.g., PC, PET, etc.), and the toughened glass and the plastic frame are spliced to form the explosion-proof membrane. Compared with an all-glass explosion-proof film, the arc-shaped frame can be better attached to a touch screen, the situation that the arc-shaped part is cracked due to pressure or impact is avoided, the arc-shaped frame becomes a mainstream product in the market (the selling price is more than 30-100 yuan), but due to the fact that the abrasion resistance of the plastic is poor, after the arc-shaped frame is used for a period of time, obvious scratches can be formed on the arc-shaped frame. Due to the adoption of the splicing structure, manufacturing tolerance exists in the production process, obvious wiring is formed at the connected position easily in the splicing and assembling process of the plastic arc-shaped frame and the glass sheet (the wiring is generally white and is the contour line around the glass, and if the obvious white line appears, the wiring is regarded as a defective product), the reject ratio of the product is higher, in addition, the plastic and the glass have different rates of expansion with heat and contraction with cold and are influenced by temperature difference change, even if the product leaving the factory has no obvious wiring, after the user uses the plastic and the glass for a period of time, the macroscopic white wiring is likely to appear at the spliced position of the plastic and the glass gradually. Most of high-grade explosion-proof membranes (selling price is more than 70 yuan/piece) for smart phones sold in the market at present adopt a splicing structure. In order to solve the problems that the plastic frame is not wear-resistant and the white line is spliced, some explosion-proof film manufacturers add short glass fibers into plastic to improve the dimensional stability and the wear resistance of the frame, improve the splicing structure into a lapping structure (the cross section structure of the explosion-proof film of the lapping structure is shown in figure 1), reserve a step position on the side edge of a black arc-shaped frame A, then lap-joint a glass sheet B below the step position (namely, a part of the arc-shaped frame is lapped on the upper surface of the glass sheet), and when the glass sheet B is seen from top to bottom, the contour line of the glass sheet B is covered by the black arc-shaped frame A, so that the white splicing line is completely avoided, but other problems are brought, firstly, the cost is obviously increased (the explosion-proof selling price of the lapping structure basically reaches more than 90 yuan/piece), secondly, because the arc-shaped frame A is higher than the glass sheet B, dust is easily accumulated at the lap joint and is inconvenient to clean. Finally, most of the explosion-proof membranes adopting toughened glass are coated with a layer of AB glue on the binding surface, one surface of the AB glue, which is attached to the toughened glass, is OCA optical glue, one surface of the AB glue, which is attached to the touch screen, is silica gel, adsorption and attachment are realized through Van der Waals force between the surface of the silica gel and the smooth glass of the touch screen, in order to improve the self-adsorption property of the explosion-proof membrane during attachment, the silica gel binding surface of some explosion-proof membranes is subjected to electrostatic treatment, but because the AB glue is extremely thin and the back bottom of the AB glue is glass (the AB glue is attached to the glass sheet of the explosion-proof membrane), the improvement of the self-adsorption property is not obvious when the AB glue is subjected to electrostatic treatment (the adsorption is still needed.

Disclosure of Invention

The invention aims to provide a production process for producing an explosion-proof membrane of a mobile phone, which has high fitting degree and is an all-glass contact surface (the 'all-glass contact surface' means that the contact surface with a hand is made of an all-glass material in daily use), and the production process has the advantage of high yield.

In order to achieve the purpose, the invention adopts the following technical scheme: a production process of an explosion-proof membrane of a mobile phone comprises the following steps:

attaching: adhering a transparent film to the lower surface of the glass cover plate through a transparent optical pressure-sensitive adhesive to obtain an assembly; an arc-shaped part is formed on the periphery of the glass cover plate in a hot bending mode, the radian of the arc-shaped part is larger than that of the periphery of the corresponding mobile phone touch screen, a black ink layer covering the arc-shaped part is printed on the periphery of the lower surface of the glass cover plate, after the assembly is attached, the outer edge of the film is away from the inner edge of the arc-shaped part of the glass cover plate by a certain distance, so that a recess is formed between the outer edge of the film and the inner edge of the arc-shaped part of the glass cover plate, and the periphery;

injecting foaming glue: injecting foaming glue into the recess of the component, wherein the foaming completion time of the injected foaming glue is 5-60 min, and the plastic deformation amount which can be generated under the condition that the pressure of 15-20N/square centimeter continuously acts for 3-5 s after the foaming of the foaming glue is completed is 30-40%;

foaming in a mold: placing an assembly in which foaming glue is injected into a recess in a foaming mould, wherein the part of the foaming mould, which is contacted with the assembly, is made of rubber or silica gel, after the assembly is placed in the foaming mould, closing an upper mould and a lower mould of the foaming mould to enable the foaming glue to be foamed in the mould, and finally forming a foaming cushion pad in the recess, wherein the outer edge of the foaming cushion pad is slightly lower than the inner edge of the arc-shaped part or is flush with the inner edge of the arc-shaped part, and the inner edge of the foaming cushion pad is slightly lower than the outer edge of the rubber sheet or is flush with;

demolding and post-treatment: and taking out the component which is foamed to form the foaming cushion pad from the foaming mold, spraying an anti-oil coating on the upper surface of the glass cover plate, and coating AB glue on the lower surfaces of the rubber sheet and the foaming cushion pad to obtain the mobile phone explosion-proof membrane.

Further, the method further comprises the following steps before the bonding step:

cutting a glass cover plate and a rubber sheet: cutting the transparent glass substrate into a required shape and size by using a cutting machine to obtain a glass cover plate blank; punching the PC substrate or the PET substrate into a required shape and size by using a punching die office to obtain a film;

and (3) silk-screen printing: a circle of black ink layer 1c is printed on the periphery of the lower surface of the glass cover plate blank in a silk-screen mode, and the area, where the black ink is not printed, in the glass cover plate blank is used as a window area for observing the display content of a screen;

hot bending: and hot-bending the periphery of the glass cover plate blank by using a hot-bending die to process an arc-shaped part to obtain the glass cover plate, wherein the radian of the arc-shaped part is larger than the radian of the periphery of the corresponding mobile phone touch screen, and the area surrounded in the middle by the arc-shaped part is a plane part.

Furthermore, the method also comprises the following steps between the hot bending and the attaching process:

edge sweeping: polishing the edge of the glass cover plate to form a round angle so as to prevent sharp edges from cutting hands;

tempering treatment: the glass cover plate is put into a tempering furnace for strong treatment, and the surface hardness of the glass cover plate is up to over 9H after the glass cover plate is strengthened.

Preferably, the method further comprises the following steps between the silk-screen printing process and the hot bending process:

CNC finishing impression: and engraving a receiver hole site and/or a sensor hole site of a corresponding machine type on the glass cover plate blank by adopting a numerical control machine.

And the length and width dimensions of the window area and the plane part are respectively controlled in the silk-screen printing and hot bending processes, so that the length and width dimensions of the window area are smaller than those of the plane part.

Preferably, the post-processing procedure further comprises the step of performing electrostatic treatment on the surface, attached to the touch screen of the mobile phone, of the mobile phone explosion-proof film after coating the AB glue so as to improve the self-adsorption capacity of the explosion-proof film.

In the attaching process, the thicknesses of the film and the glass cover plate which are attached to each other are 0.05-0.1 mm and 0.15-0.2 mm respectively, and the thickness of the optical pressure-sensitive adhesive used for attaching the film and the glass cover plate together is 0.05-0.08 mm.

Wherein, in the post-treatment process, the thickness of the AB glue coated on the lower surfaces of the film and the foaming cushion pad is 0.03-0.05 mm.

Furthermore, the post-treatment process also comprises the step of attaching a release film on the lower surface of the coated AB glue.

The mobile phone explosion-proof membrane produced by the process adopts a process of compounding glass and a film instead of splicing, the upper layer of the explosion-proof membrane produced by the process is of a smooth full-glass structure, the wear-resistant and scratch-resistant performance of the explosion-proof membrane can be ensured, the problem that an arc-shaped plastic frame on the spliced explosion-proof membrane is not wear-resistant is solved, and the problem that dust is accumulated at a lap joint and is inconvenient to clean is also solved. In the production process of the explosion-proof mold provided by the invention, after the film is attached to the lower surface of the glass cover plate, a recess is formed between the outer edge of the film and the inner edge of the glass cover plate, foaming glue is injected into the recess, and then a foaming buffer cushion can be formed at the recess part through foaming in the mold, so that the arc part of the glass cover plate can be supported and buffered when the arc part of the glass cover plate is impacted by the outside, and because the foaming material which can generate the plastic deformation of 30-40% under the condition that the pressure of 15-20N/square centimeter continuously acts for 3-5 s is adopted, the foaming buffer cushion can generate the plastic deformation through being extruded by the arc fillet of the outer screen by pressing the glass cover plate when the explosion-proof film is attached to the outer screen, so as to 'impact' the outer screen and the manufacturing error of the glass cover plate, and therefore, the complete attachment of the explosion-proof film. It is worth mentioning in addition that, laminating the film in the glass apron below can improve the explosion-proof effect of glass apron plane portion through the film of laminating except that forming the cave between its and glass apron arc portion, in addition, this film still is used as the back of the body of AB glue, compares in the glass back of the body, and the film back of the body can show improvement electrostatic treatment effect for the self-absorption effect of rupture membrane is better. It should be noted that, although the splicing lines of the film and the foaming cushion pad also exist in the explosion-proof film produced by the above process, the splicing lines of the film and the foaming cushion pad are controlled below the black ink layer in the production process, and after the explosion-proof film is attached to the outer screen of an electronic product (such as a smart phone), the splicing lines are completely covered by the black ink layer, so that the problem that the splicing lines are exposed on the front surface in the existing splicing process is thoroughly solved, and the reject ratio in the production process is greatly reduced.

Drawings

FIG. 1 is a schematic cross-sectional structure diagram of an explosion-proof membrane produced by a conventional splicing process;

FIG. 2 is a schematic cross-sectional structure view of an explosion-proof membrane of a touch screen prepared by the production process of the invention;

FIG. 3 is a schematic cross-sectional structural view of a glass cover plate blank obtained by cutting;

FIG. 4 is a schematic cross-sectional view of the glass cover plate blank shown in FIG. 3 after a black ink layer is silk-screened;

FIG. 5 is a schematic cross-sectional view of the glass cover plate blank with the black ink layer silk-screened shown in FIG. 4 after being subjected to hot bending;

FIG. 6 is a schematic cross-sectional structure view of the glass cover plate after the edge sweeping process is completed;

FIG. 7 is a schematic cross-sectional structure of a cut film;

FIG. 8 is a schematic cross-sectional view of the resulting assembly after the bonding process;

FIG. 9 is a schematic view of the cavity of the assembly of FIG. 8 filled with a foam;

FIG. 10 is a schematic view showing the structure of a foaming mold used in an in-mold foaming process after the upper and lower molds are closed;

FIG. 11 is a schematic view of the assembly of FIG. 9 formed into a foamed cushion by in-mold foaming;

FIG. 12 is a schematic view of a foam cushion formed by in-mold foaming;

FIG. 13 is a schematic front view of a glass cover plate blank obtained by cutting;

fig. 14 is a schematic front view of the glass cover plate blank shown in fig. 13 after a black ink layer is silk-screened, wherein a dotted line is an inner contour line of the black ink layer;

FIG. 15 is a schematic front view of the glass cover blank of FIG. 14 after hot bending;

FIG. 16 is a schematic front view of a cut film;

FIG. 17 is a schematic front view of a device obtained in the bonding step;

FIG. 18 is an enlarged view of a portion I of FIG. 2;

FIG. 19 is a partial enlarged view of portion I of FIG. 4;

FIG. 20 is an enlarged view of a portion of the portion I in FIG. 6;

FIG. 21 is a partial enlarged view of portion I of FIG. 9;

in the figure:

1-glass cover plate 2-film 3-recess

4-foaming buffer pad 1 a-plane part 1 b-arc part

1 c-Black ink layer 1a 1-Window area A-arc frame

Assembly of B glass sheet C glass cover plate blank D

E, foaming glue F and a foaming mold.

Detailed Description

In order to facilitate understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.

Further, in the present invention, unless otherwise expressly specified or limited, the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, are not to be construed as limiting the present invention.

The production process flow from the initial basic raw materials (the glass substrate and the plastic substrate) to the final finished product of the mobile phone explosion-proof membrane comprises the following steps (taking the intelligent mobile phone outer screen explosion-proof membrane with the total thickness of 0.35 mm-0.4 mm as an example):

firstly, cutting a glass cover plate and a film:

1.1 cutting the glass substrate with the thickness of 0.15 mm-0.2 mm into required shape and size by using a cutting machine to obtain a glass cover plate blank C, wherein the cross section structure and the front structure of the glass cover plate blank C are respectively shown in fig. 3 and fig. 13.

1.2A PC substrate having a thickness of 0.05mm to 0.1 mm is punched out into a desired shape and size by a punching die (for example, an etching knife die) to obtain a prepreg 2 shown in FIG. 16, and the cross-sectional structure of the prepreg 2 is shown in FIG. 7.

Secondly, silk-screen printing: a circle of black ink layer 1C is silk-screened on the periphery of the lower surface of the glass cover plate blank C, and the cross section structure and the front structure of the glass cover plate blank C silk-screened with the black ink layer 1C are respectively shown in fig. 4, 14 and 19. The area of the glass cover blank C not screen-printed with black ink serves as the window area 1a 1.

Thirdly, CNC engraving: and engraving a headphone hole site and a sensor hole site of a corresponding machine type on the glass cover plate blank C by using a numerical control machine (for some machine types without headphones, the step can be omitted), wherein the hole opening effect is shown in figure 14.

Fourthly, hot bending: an arc-shaped part 1b is hot-bent around the glass cover plate blank C by using a hot-bending die (the hot-bending die is not shown in the drawing), the cross-sectional structure and the frontal structure of the glass cover plate 1 obtained after hot-bending are respectively shown in fig. 5 and 15, and the middle of the glass cover plate 1 is a plane part 1 a. Preferably, the length and width dimensions of the planar portion 1a are equal to those of the film 2. Also, the length and width dimensions of the planar portion 1a are preferably larger than those of the window area 1a 1.

Fifthly, edge sweeping: the edge of the glass cover plate 1 is ground to form a round angle to prevent sharp edge cutting, and the cross-sectional structure of the glass cover plate 1 after edge sweeping is shown in fig. 6 and 20.

Sixthly, tempering treatment: the glass cover plate 1 is placed into a toughening furnace to be physically strengthened for 4-4.5 hours at the temperature of 500-550 ℃, and the surface hardness after strengthening reaches over 9H.

Seventhly, laminating: the film 2 is attached to the lower surface of the glass cover plate 1 by an optical pressure sensitive adhesive (such as acrylic adhesive, etc.) with a thickness of 0.05mm to 0.08 mm, it is noted that in order to prevent the solvent in the pressure sensitive adhesive from corroding the film, it is preferable to use a 100% solid content pressure sensitive adhesive, and a module D is obtained, and the cross-sectional structure of the module D is shown in fig. 8. It should be noted that, when the film 2 is attached, the outer edge of the film 2 should be away from the inner edge of the arc-shaped portion of the glass cover plate 1 by a certain distance, so as to form a cavity 3 between the two for injecting the foaming adhesive E at a later stage, and in addition, when the film 2 is attached to the glass cover plate 1, it should be ensured that the peripheral edge of the film 2 overlaps the black ink layer 1c, so that the outer contour of the film 2 is not seen from the front surface of the glass cover plate 1 (i.e. the peripheral line of the film 2 cannot be seen).

Eighthly, injecting foaming glue: the effect of injecting the foaming adhesive E into the recess 3 of the component D by the vacuum dispenser is shown in fig. 9 and 21, and it should be emphasized that the foaming adhesive with a slow foaming speed (for example, the foaming adhesive with a foaming completion time of 10-20 min) should be selected so as to allow enough time for the transfer operation between the current process and the next process (in-mold foaming). In addition, unlike the high resilience performance of the foam rubber pursued in other applications, the foam rubber E should satisfy the condition of plastic deformation after being pressed, preferably 30-40% of plastic deformation under the condition that the pressure of 15-20 n/cm is continuously acted for 3-5 s (the thickness of the foam becomes 60-70% after the pressure applied in the thickness direction of the foam is removed when the deformation amount is 30-40%), for example, PU or PP foam rubber can be selected, and the resilience of the foam product can be reduced by controlling the type and content of the foaming agent, so as to meet the index requirement.

Ninthly, foaming in a mould: the component D with the cavity 3 filled with the foaming adhesive E is placed in a foaming mold F, the part of the foaming mold F contacting with the component is made of rubber or silica gel, the structure of the foaming mold F after mold closing is shown in fig. 10, and is shown in fig. 11, after the component D is placed in the foaming mold F, foaming is completed in the mold, and after foaming is completed, as shown in fig. 12, the shape of the finally formed foaming cushion pad 4 is matched with the shape of the foaming mold F.

Tenthly, demolding and post-treating: taking the explosion-proof membrane out of the foaming mold, spraying an anti-oil coating on the upper surface of the glass cover plate, coating a layer of AB glue (the AB glue and the optical pressure-sensitive adhesive are not shown in the attached drawing) with the thickness of 0.05mm on the lower surfaces of the film and the foaming cushion pad, and carrying out electrostatic treatment on the surface, attached to the touch screen of the mobile phone, of the explosion-proof membrane of the mobile phone according to needs so as to improve the self-adsorption capacity of the explosion-proof membrane. In the case of coating AB glue, a release film can be attached below the AB glue for transportation protection.

The semi-finished parts produced in the steps one to six can also be purchased from the market, and for enterprises which directly purchase the semi-finished parts to process the mobile phone rupture membrane, the steps one to six can be omitted, and the operation is directly started from the step seven.

Fig. 2 and 18 show the structure of the mobile phone explosion-proof membrane prepared by the above process, as shown in the figure, the touch panel explosion-proof membrane comprises a transparent glass cover plate 1 and a film 2, the glass cover plate 1 comprises a plane part 1a located in the middle area thereof, an arc part 1b formed by glass heat bending is arranged around the plane part 1a, a black ink layer 1c covering the arc part 1b is printed on the periphery of the lower surface of the glass cover plate 1, the area of the glass cover plate 1, on which the black ink layer 1c is not printed, is a window area 1a1 for viewing the display content of the screen, the film 2 is attached to the lower surface of the glass cover plate 1, the periphery thereof is lapped on the black ink layer 1c, the outer edge of the film 2 is at a distance from the inner edge of the arc part 1b, thereby forming a recess 3 between the two, a foaming buffer 4 capable of plastic deformation is filled in the recess 3 after being pressed, the outer edge of the foaming buffer 4 is slightly lower, the inner edge of the foam cushion pad 4 is slightly lower than or flush with the outer edge of the film 2.

The production method of the mobile phone explosion-proof membrane adopts the process of compounding glass and a film instead of splicing, the upper layer of the explosion-proof membrane produced by adopting the process is of a smooth full-glass structure, the wear-resisting and scratch-resisting performance of the explosion-proof membrane can be ensured, the problem that the plastic arc-shaped frame A of the spliced explosion-proof membrane is not wear-resisting can be avoided, and the problem that dust is accumulated at the lap joint part and is inconvenient to clean can be avoided. In the production process of the explosion-proof mold, after the film 2 is attached to the lower surface of the glass cover plate 1, a cavity 3 is formed between the outer edge of the film 2 and the inner edge of the arc-shaped part 1b of the glass cover plate 1, foaming glue is injected into the cavity 3, and then the foaming cushion pad 4 can be formed at the position of the cavity 3 through in-mold foaming, the foaming cushion pad 4 can provide support for the arc-shaped part 1b of the glass cover plate 1 and provide cushion when the arc-shaped part is impacted by the outside, because the foaming glue E with the plastic deformation amount of 30-40% can be generated under the condition that the pressure of 15-20N/square centimeter continuously acts for 3-5 s, the manufacturing error of the outer screen and the glass cover plate 1 can be 'counterpunched' through pressing the glass cover plate 1 to enable the foaming cushion pad 4 to be extruded by the arc-shaped fillet of the outer screen of the mobile phone to generate plastic deformation when the explosion, thereby realizing the complete joint of the explosion-proof membrane and the outer screen. It is worth mentioning in addition that, the film 2 attached to the lower part of the glass cover plate 1 can also improve the explosion-proof effect of the plane part 1a of the glass cover plate 1 except for forming the recess 3 together with the arc part 1b of the glass cover plate 1, and after the film 2 is coated with the AB glue, the film 2 is used as the back bottom of the AB glue, compared with the glass back bottom, the film can obviously improve the electrostatic treatment effect, so that the self-adsorption effect of the explosion-proof film is better. It should be noted that, although there are splicing lines of the film 2 and the foaming cushion pad 4 in the mobile phone explosion-proof film prepared by the above production process, the splicing lines are located below the black ink layer 1c, and after the explosion-proof film is attached to the external screen of the smart phone, the splicing lines are completely covered by the black ink layer 1c, so that the problem that the splicing lines are exposed on the front surface in the existing splicing process is thoroughly solved, and the reject ratio in the production process is greatly reduced.

Some of the drawings and descriptions of the present invention have been simplified to facilitate the understanding of the improvements over the prior art by those skilled in the art, and some other elements have been omitted from this document for the sake of clarity, and it should be appreciated by those skilled in the art that such omitted elements may also constitute the subject matter of the present invention.

Claims

1. The production process of the mobile phone explosion-proof membrane is characterized by comprising the following steps:

foaming in a mold: placing the component with the cavity injected with the foaming glue into a foaming mould, wherein the part of the foaming mould, which is contacted with the component, is made of rubber or silica gel, after the component is placed in the foaming mould, closing an upper mould and a lower mould of the foaming mould to enable the foaming glue to complete foaming in the mould, and finally forming a foaming cushion pad in the cavity, wherein the outer edge of the foaming cushion pad is slightly lower than the inner edge of the arc-shaped part or is flush with the inner edge of the arc-shaped part, and the inner edge of the foaming cushion pad is slightly lower than the outer edge of the rubber sheet or is flush with the outer edge of;

2. The process for producing an explosion-proof membrane for mobile phones according to claim 1, wherein the process further comprises, before the attaching step:

cutting a glass cover plate and a rubber sheet: cutting the transparent glass substrate into a required shape and size by using a cutting machine to obtain a glass cover plate blank; punching the PC substrate or the PET substrate into a required shape and size by using a punching die to obtain a film;

3. The process for producing the explosion-proof membrane of the mobile phone according to claim 2, further comprising the following steps between the hot bending and attaching steps:

4. The process for producing an explosion-proof membrane for mobile phones according to claim 2, further comprising the following steps between the silk-screen process and the hot bending process:

5. The production process of the explosion-proof membrane for the mobile phone according to claim 2, which is characterized in that: and respectively controlling the length and width dimensions of the window area and the plane part in the silk-screen and hot bending processes, so that the length and width dimensions of the window area are smaller than those of the plane part.

6. The production process of the mobile phone explosion-proof membrane according to any one of claims 1 to 5, characterized in that: the post-processing procedure also comprises the step of carrying out electrostatic treatment on the surface, attached to the touch screen of the mobile phone, of the mobile phone explosion-proof film after coating the AB glue so as to improve the self-adsorption capacity of the explosion-proof film.

7. The production process of the mobile phone explosion-proof membrane according to any one of claims 1 to 5, characterized in that: in the attaching process, the thicknesses of the film and the glass cover plate which are attached to each other are 0.05 mm-0.1 mm and 0.15 mm-0.2 mm respectively, and the thickness of the optical pressure-sensitive adhesive used for attaching the film and the glass cover plate together is 0.05 mm-0.08 mm.

8. The production process of the mobile phone explosion-proof membrane according to claim 7, characterized in that: in the post-treatment process, the thickness of the AB glue coated on the lower surfaces of the rubber sheet and the foaming cushion pad is 0.03-0.05 mm.

9. The production process of the mobile phone explosion-proof membrane according to any one of claims 1 to 5, characterized in that: the post-treatment process also comprises the step of sticking a release film on the lower surface of the coated AB glue.