CN115972487A - In-mold curved surface transfer printing method based on thermosetting bearing and photo-curing release - Google Patents

Abstract

The invention provides an in-mold curved surface transfer printing method based on thermosetting bearing and photo-curing release, which comprises the following steps: preparing a modified film roll; unreeling the modified film roll, then placing the modified film roll into a vacuum curved surface hot-pressing mold, heating and softening the modified film roll so as to extend the modified film to form a curved surface decorative film; the plastic melt is bonded with the plastic bonding film of the curved surface decorative membrane to form a decorative surface plastic structural part precursor; carrying out primary photocuring operation on the facing plastic structural part precursor so as to realize primary photocuring crosslinking operation on the bearing release type hardening mask; the reverse rubbing three-dimensional pattern group of the bearing release hardening facial mask is exposed, and then secondary photocuring operation is carried out, so that secondary photocuring crosslinking operation of the bearing release hardening facial mask is realized, and a finished product of the veneer plastic structural component is obtained.

Description

In-mold curved surface transfer printing method based on thermosetting bearing and photo-curing release

Technical Field

The invention relates to the technical field of surface curved surface transfer printing of plastic parts, in particular to an in-mold curved surface transfer printing method based on thermosetting bearing and photo-curing release.

Background

At present, the traditional appearance surface treatment industry of plastic structural parts (mobile phones, automotive interiors and household appliances) is mainly realized by three mainstream schemes of spraying, PVD and printing, but the traditional appearance surface treatment industry has the problems of large VOC (volatile organic compound) emission, large organic pollutant emission and unfriendliness to the environment.

Taking a printing and spraying process as an example, a curved surface modification structure on the surface of a mobile phone back shell plastic part is manufactured, firstly, a curved surface bearing main body of the curved surface modification structure is preformed through injection molding, then a functional layer is formed through multiple times of glue brushing (realized through printing or spraying), and the glue brushing needs to be cured once for shaping each time, so that the next smooth proceeding of the glue brushing process is ensured, the curved surface bearing main body attached with the curved surface modification structure needs to be subjected to frame waste material routing operation and polishing operation through a CNC (computer numerical control) processing procedure, and finally a curved surface modification structure is formed, finally, a plastic material is injected through an in-film injection molding mode to form a mobile phone back shell plastic part and a curved surface modification structure into a whole, so that a mobile phone back shell plastic part finished product is obtained, but the problem of coating embrittlement can be caused by multiple times of glue brushing curing operation, so that the problem of local cracking and abrasion easily occur in the injection molding operation and the CNC operation of the curved surface modification structure, and the whole part is scrapped. Secondly, the curved surface modification structure manufactured by the traditional repeated glue brushing process has the problems of single surface treatment, poor three-dimensional function effect, poor function expression abundance and the like.

In order to solve the above problems, a novel curved surface decoration structure manufacturing process-in-mold vacuum curved surface transfer molding process (IMD, also called in-mold decoration technology, coating-free technology, etc.) appears on the market, and the basic principle is as follows: the printed Film is made into a circulating roller coiled belt, is arranged in an injection molding machine and an injection mold, and is produced by full-automatic movable circulating belt movement mode like a Label stuck on the front mold surface; this is known as IMD (transfer moulding in a mould). The other is produced by printing a Film, forming the Film by a Forming machine, shearing the Film and then placing the Film into an injection mould. Namely the so-called IML (in-mold injection). This Film can be generally divided into three layers: the base material (generally PET), the INK layer (INK) and the gluing material (mostly a special adhesive). After the injection molding is finished, the Film and the plastic are tightly combined and fused into a whole through the action of the adhesive, and the PET with the front surface coated with the wear-resistant protective Film has the functions of wear resistance and scratch resistance at the outermost layer, so that the surface hardness can reach 3H, and the Film can be brighter. The injection molding materials are mostly PC, PMMA, PBT and the like.

For example, chinese patent 201310018766.8-a far infrared heating in-mold transfer injection molding method discloses: (1) Opening the die of the injection molding machine, and conveying the membrane to a designated position between the male die and the female die by the membrane conveying machine; (2) The manipulator drives the far infrared heating plate to move to a specified heating position right in front of the membrane, and the membrane is heated and softened; (3) The diaphragm is tightly pressed on the female die by the pressing template, a closed space is formed by the diaphragm and a cavity of the female die, and then the diaphragm is absorbed on the surface of the cavity of the female die by vacuumizing; meanwhile, the mechanical hand drives the sucker to move to a specified position right in front of the molded plastic part, and the molded part is adsorbed, taken away and returned to a standby position; (4) And closing the mold, performing injection molding, maintaining the pressure, cooling and entering the next transfer molding cycle.

Although the technical scheme disclosed by the patent can solve the cracking problem of the curved surface modification structure through softening and injection bonding so as to improve the good products, the problem of function richness of the curved surface modification structure is not solved, and particularly the problem of realizing the visual and tactile three-dimensional functions of the modified surface is not solved.

Such as Chinese invention patent application 201910448818.2-a plastic piece in-mold insert spraying process, discloses: a, step a: printing a predetermined texture pattern on the PET release film on a printer; step b: installing the printed PET release film on a heat transfer printing thermoprinting machine, carrying out heat transfer printing on an ABS base film with the thickness of 0.4mm, so that the texture pattern is transferred onto the ABS base film, and tearing off the PET release film; step c: forming the ABS base film into the surface shape of a plastic part to be printed by a hot plastic suction process, and punching and cutting off the residual edge to obtain an ABS membrane; step d: placing the ABS membrane in an injection mold, injecting raw materials, forming a plastic piece with a texture pattern and taking out the plastic piece; step e: and spraying wear-resistant varnish on the plastic part with the texture pattern, and drying.

Although the technical solution disclosed in the above patent can also solve the problem of cracking of the curved surface decoration structure to improve the quality of the product, the problem of functional abundance of the curved surface decoration structure is still not solved, especially the problem of realizing three-dimensional functions of visual and tactile sense of the decoration surface is not solved.

In addition, the patent application 201910448818.2, a spraying process for an in-mold insert of a plastic part, also has the problems that after the pattern layer is thermally cured, the degree of crosslinking of the pattern layer is high, so that the brittleness of the polymer pattern layer is also high, if the pattern layer and the release layer still have certain peeling viscosity, the integrity of the polymer pattern layer can be affected based on the peeling viscosity when the release layer is peeled off, and the problem that the local part of the polymer pattern layer is torn or scratched can occur.

Similarly, the photo-curing transfer pattern layer has the same problems, such as the Chinese patent 201480080939.1-photo-curing coating composition, coating film forming method and water pressure.

The prior patent documents also include:

CN100424144C，2008.10.08；

CN100424144C，2008.10.08；

CN102649895A,2012.08.29 and the like.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the in-mold curved surface transfer printing method based on thermosetting bearing and photo-curing release, which has higher structural function richness, higher three-dimensional function and capability of reducing the problems of peeling, tearing and tearing marks.

The purpose of the invention is realized by the following technical scheme:

an in-mold curved surface transfer printing method based on thermosetting bearing and photo-curing release comprises the following steps:

preparing a support base film, and coating a release base film on the support base film; the release base film is made of polyetherimide;

coating a bearing release hardening surface film on the release base film, wherein the bearing release hardening surface film also forms a back rubbing three-dimensional pattern group in the pattern three-dimensional groove group; the material of the bearing release hardening mask is photo-thermal dual-curing acrylic resin;

coating N layers of functional films on the bearing release hardening facial mask, wherein N is more than or equal to 1;

coating a plastic adhesive connecting film on the N layers of functional films to obtain a decorative film, and rolling to obtain a decorative film roll;

the decoration film roll is placed in a vacuum curved surface hot pressing die after being unreeled, the decoration film is heated and softened, and then the concave die of the vacuum curved surface hot pressing die is vacuumized to enable the curved surface of the decoration film to be attached to the inner wall of the cavity of the concave die, so that the decoration film is extended to form a curved surface decoration film;

controlling a male die of the vacuum curved surface hot pressing film to move towards the female die, injecting plastic melt liquid into a glue filling gap between the female die and the male die through a glue injection channel of the male die, bonding the plastic melt liquid and the plastic bonding film of the curved surface decorative membrane together, and tearing off the supporting base film to form a decorative surface plastic structural part precursor;

carrying out primary photocuring operation on the facing plastic structural part precursor so as to realize primary photocuring crosslinking operation on the bearing release hardening mask;

and tearing off the release base film from the bearing release type hardening facial mask so as to expose the reverse rubbing three-dimensional pattern group of the bearing release type hardening facial mask, and then carrying out secondary photocuring operation so as to realize secondary photocuring crosslinking operation on the bearing release type hardening facial mask, thereby obtaining a finished product of the veneer plastic structural part.

In one embodiment, the material of the supporting base film is PET.

In one embodiment, the parameters of the primary photocuring operation are: UV irradiation energy is 800-1200mj/cm, line passing linear speed is 6-8m/min, and UV irradiation time is 2-5S;

the parameters of the secondary photocuring operation are as follows: UV irradiation energy is 1000-1800mj/cm, the linear speed of the threading is 2-5m/min, and the UV irradiation time is 3-10S.

In one embodiment, the pattern solid groove group comprises a circular groove, a polygonal groove, a square groove and/or a special-shaped groove;

the anti-rubbing stereo pattern group comprises a plurality of stereo pattern bulges, and the thicknesses of the stereo pattern bulges are consistent or different.

In one embodiment, the heating and softening operation is specifically:

and heating the decorative film to 120-150 ℃ by adopting a constant-temperature water vapor heating process, and continuously heating for 5-20S to soften the decorative film, so that the decorative film has the function of stretching.

In one embodiment, the decorative film has an aspect ratio of at least 20-30% at 120-150 ℃.

In one embodiment, the female die is provided with a heating device, and a vacuum valve and a pressure release valve which are respectively communicated with the cavity, and the vacuum valve is used for being communicated with an external air compressor.

In one embodiment, the vacuum curved surface hot pressing mold further comprises a pressing and fixing plate, and the pressing and fixing plate is used for pressing and fixing the decorative film before the vacuum pumping operation is performed on the concave mold of the vacuum curved surface hot pressing mold.

In one embodiment, the pressing fixing plate is provided with a position avoiding channel for the male die to pass through.

In one embodiment, the vacuum pumping operation of the female die of the vacuum curved hot pressing film is specifically to form 0.1-1Mpa in 5-10S.

Compared with the prior art, the invention has at least the following advantages:

1. according to the invention, the photo-thermal dual-curing acrylic resin material can be filled in the pattern three-dimensional groove group by utilizing fluidity through forming the pattern three-dimensional groove group on the release base film and coating the bearing release hardening facial mask, so that the bearing release hardening facial mask can form the back-rubbing three-dimensional pattern group in the pattern three-dimensional groove group, and thus, after the bearing release hardening facial mask is cured, the effects of modifying surface vision and three-dimensional tactile functions can be realized through the back-rubbing three-dimensional pattern group. Further, bear and to peel off type sclerosis facial mask owing to adopt the photo-thermal dual cure acrylic resin material, work as bear and carry out vacuum heating curved surface when extending tensile from type sclerosis facial mask, can possess better toughness and certain mechanical strength based on the nature of thermosetting, it is right N layer functional film plays good support and bears the function, when carrying out UV photocuring back end operation again, can make bear and further strengthen from the crosslinking degree of type sclerosis facial mask, can greatly reduce bear and peel off viscidity from between the type basement membrane bear and tear off on the type sclerosis facial mask during from the type basement membrane, can greatly alleviate and peel off tear mark problem.

2. According to the invention, the N layers of functional films are coated on the bearing release type hardening facial mask, so that the effect of higher structural function richness can be realized through the N layers of functional films.

3. According to the invention, the veneer plastic structural member precursor is subjected to double photocuring operations, and a stripping operation is inserted between the two photocuring operations, so that a better stripping and releasing effect can be obtained on the premise that the anti-rubbing three-dimensional pattern group is improved, the structural function richness is higher, and the three-dimensional function is higher.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a flowchart illustrating steps of an in-mold curved surface transfer method based on thermosetting loading and photo-curing release according to an embodiment of the present invention;

FIG. 2 is a flow chart of a process for manufacturing a decorative film according to an embodiment of the present invention;

fig. 3a to 3g are process flow charts of an embodiment of an in-mold curved surface transfer method based on thermosetting loading and photo-curing release.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a single embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The application provides an in-mold curved surface transfer printing method based on thermosetting bearing and photo-curing release, which comprises the following steps: preparing a supporting base film, and coating a release base film on the supporting base film; the release base film is made of polyetherimide; coating a bearing release hardening surface film on the release base film, wherein the bearing release hardening surface film also forms a back rubbing three-dimensional pattern group in the pattern three-dimensional groove group; the material of the bearing release hardening mask is photo-thermal dual-curing acrylic resin; coating N layers of functional films on the bearing release hardening facial mask, wherein N is more than or equal to 1; coating a plastic adhesive connecting film on the N layers of functional films to obtain a decorative film, and rolling to obtain a decorative film roll; after the decoration film roll is unreeled, placing the decoration film roll into a vacuum curved surface hot pressing mold, heating and softening the decoration film, and then enabling the curved surface of the decoration film to be attached to the inner wall of the cavity of the female mold through the vacuumizing operation of the female mold of the vacuum curved surface hot pressing mold so as to enable the decoration film to form a curved surface decoration film after being extended; controlling a male die of the vacuum curved surface hot pressing film to move towards the female die, injecting plastic melt liquid into a glue filling gap between the female die and the male die through a glue injection channel of the male die, bonding the plastic melt liquid and the plastic bonding film of the curved surface decorative membrane together, and tearing off the supporting base film to form a decorative surface plastic structural part precursor; carrying out primary photocuring operation on the facing plastic structural part precursor so as to realize primary photocuring crosslinking operation on the bearing release type hardening mask; and tearing the release base film from the bearing release type hardening facial mask so as to expose the reverse rubbing three-dimensional pattern group of the bearing release type hardening facial mask, and then carrying out secondary photocuring operation so as to realize secondary photocuring crosslinking operation on the bearing release type hardening facial mask to obtain a finished veneer plastic structural part.

In order to better understand the in-mold curved surface transfer method based on thermosetting carrier and photo-curing release of the present application, the in-mold curved surface transfer method based on thermosetting carrier and photo-curing release of the present application is further explained as follows:

referring to fig. 1, an embodiment of an in-mold curved surface transfer method based on thermosetting loading and photo-curing release includes the following steps:

step S110: preparing a support base film 100a and coating a release base film 200a on the support base film 100 a; wherein the release film is made of Polyetherimide (PEI for short).

Referring to fig. 2, in order to better realize the continuous non-intermittent process of the subsequent curved surface transfer process, the supporting base film 100a has a linear long belt-shaped sheet structure, and can be wound to form a film roll based on flexibility. In one embodiment, the supporting base film is made of Polyethylene terephthalate (PET or PEIT).

It should be noted that the PEI film material and the PET film material are purchased from PEI films and PET films sold by guangdong new material science and technology limited, and through practical production verification, the PEI films and PET films have good peeling performance in the subsequent transfer peeling process, of course, the support base film is not limited to PET, the release base film is not limited to PEI, and as long as the PEI films have good peeling performance in the subsequent transfer peeling process, those skilled in the art can select other film materials produced by other manufacturers according to practical requirements.

Step S120: forming a pattern three-dimensional groove group on the release base film 200a, coating a bearing release hardening facial mask 300a on the release base film 200a, and forming a reverse rubbing three-dimensional pattern group in the pattern three-dimensional groove group by the bearing release hardening facial mask; the material of the bearing release hardening mask is photo-thermal dual-curing acrylic resin.

Referring to fig. 2, by forming a pattern three-dimensional groove set on the release base film 200a and coating a release-bearing hardening mask 300a, the photo-thermal curable acrylic resin material is filled in the pattern three-dimensional groove set by using fluidity, so that the release-bearing hardening mask can form an inverse three-dimensional pattern set in the pattern three-dimensional groove set, and thus, after the release-bearing hardening mask is cured, the effect of modifying the surface vision and the three-dimensional tactile function can be realized by the inverse three-dimensional pattern set. Further, bear and leave type sclerosis facial mask because adopt the photo-thermal dual cure acrylic resin material, work as bear and carry out vacuum heating curved surface extension when tensile from type sclerosis facial mask, can possess better toughness and certain mechanical strength based on thermosetting nature, it is right N layer function membrane 400a plays good support and bears the function, when carrying out UV photocuring back end operation again, can make bear the cross-linking degree of bearing from type sclerosis facial mask and further strengthened, can greatly reduce bear from type sclerosis facial mask with peel off the viscidity between the type basement membrane, follow tear down on bearing from type sclerosis facial mask during from the type basement membrane, can greatly alleviate and peel off tear and tear the trace problem.

In one embodiment, the pattern solid groove group comprises a circular groove, a polygonal groove, a square groove and/or a profiled groove; the anti-rubbing stereo pattern group comprises a plurality of stereo pattern bulges, and the thicknesses of the stereo pattern bulges are consistent or different; of course, the person skilled in the art can also prepare the corresponding three-dimensional pattern according to actual requirements.

It should be noted that the photo-thermal dual-curing acrylic resin is purchased from huiyang sheng chemical coatings limited, huizhou city, and certainly, a person skilled in the art can select other manufacturers to produce the photo-thermal dual-curing acrylic resin according to actual requirements.

Step S130: and coating N layers of functional films 400a on the bearing release hardening facial mask 300a, wherein N is more than or equal to 1.

Referring to fig. 2, by coating N layers of functional films 400a on the release hardening mask 300a, the N layers of functional films 400a can achieve a higher structure function abundance effect. In one embodiment, the functional film is a layer, and the functional film is obtained by coating a mixed solution of pigment particle powder and resin on the load-bearing release hardening mask 300 a. Of course, the number of layers of the functional film and the corresponding material can be flexibly selected and realized by those skilled in the art according to actual requirements.

Step S140: and coating a plastic adhesive film 500a on the N layers of functional films 400a to obtain a decorative film, and rolling to obtain a decorative film roll.

Referring to fig. 2, the plastic adhesive film 500a is coated on the N-layer functional film 400a, so that the plastic adhesive film 500a can better protect the N-layer functional film, and simultaneously, the plastic adhesive film 500a can better react with the plastic melt to crosslink, thereby enhancing the adhesive force between the two films.

It can be understood that, for the precursors of the facing plastic structural members, each precursor of the facing plastic structural member exists independently, that is, each precursor of the facing plastic structural member needs to perform the in-mold curved surface transfer printing process independently, but in order to ensure that the whole in-mold curved surface transfer printing method based on thermosetting bearing and photo-curing release can realize continuity in an intermittent manner (only transfer printing + injection molding is intermittent), but for a plurality of precursors of the facing plastic structural members, the supporting base film needs to be continuous, so as to ensure that the feeding can be operated in a continuous manner.

In order to ensure that the in-mold curved surface transfer method can realize intermittent continuous construction operation, and further realize higher structure function abundance and higher three-dimensional function effect, and also ensure that the supporting base film is not affected by the inner layer structure when being torn off, in one embodiment, in the steps S110 to S140, the supporting base film 100a is a linear continuous film strip structure, a plurality of independent transfer sheets are formed on the supporting base film 100a, the transfer sheets include a releasing base film sub-sheet, a bearing releasing hardening film sub-sheet, an N-layer functional film sub-sheet and a plastic adhesive film sub-sheet which are sequentially stacked on the supporting base film 100a, a gap exists between each of the transfer sheets, and no peeling adhesion or tearing adhesion exists between each of the transfer sheets, from type basement membrane 200a includes a plurality of discontinuities from type basement membrane sub-piece, bear and include a plurality of discontinuities from type sclerosis facial mask 300a bear and to bear from type sclerosis facial mask sub-piece, N layer functional film 400a includes a plurality of discontinuities N layer functional film sub-piece, plastic bonding film 500a includes a plurality of discontinuities the plastic bonding sub-piece, so, because every there is the clearance between the transfer printing piece, but all independently bond in supporting on the basement membrane 100a, enough ensuring under the prerequisite that intermittent type continuity construction operation can be realized to the interior curved surface rendition method, can also realize the higher and three-dimensional higher effect of function of a structural function richness, and can also ensure when supporting the basement membrane from the type is torn, can not exert an influence to the inner layer structure.

Further, in step S110-S140, the release base film, the carrier release hardening facial mask, the N-layer functional film and the plastic adhesive film are coated by one layer in a continuous coating process, after the decorative film is obtained, a vertical glue scraping operation is performed to scrape a plurality of air glue partition gaps on the decorative film in sequence, the air glue partition gaps can enable the two sides of the support base film 100a in the air glue gap area to be exposed, so as to obtain a plurality of transfer sheets, each transfer sheet is separated by the air glue partition gaps, and thus, the whole glue coating process can be greatly simplified. Furthermore, the width of the air gel partition gap is 5cm-15cm, and of course, the width of the air gel partition gap can be flexibly selected by a person skilled in the art according to actual requirements.

Steps S150-S180 are explained in detail below, with reference to FIGS. 3 a-3 g to aid understanding of the description.

Step S150: and putting the decoloured film roll into a vacuum curved surface hot-pressing die after unreeling, heating and softening the decoloured film, and then enabling the curved surface of the decoloured film to be attached to the inner wall of a cavity of the female die through vacuumizing operation of the female die of the vacuum curved surface hot-pressing die so as to enable the decoloured film to form a curved surface decoloured film sheet after extending.

Through heating and softening add decorative film (transfer sheet), can improve decorative film's extensibility ability and tensile properties, recycle vacuum curve hot pressing membrane's die passes through the evacuation operation, makes form the negative pressure in the die cavity of die, based on the produced suction of negative pressure, can make and be softened add decorative film (transfer sheet) closely attached on the die cavity inner wall of die, so that form the curved surface after decorative film extends and add decorative film, so, can accomplish the curved surface adds the moulding plastic effect of curved surface of decorative film.

In one embodiment, the heating and softening operation is specifically: heating the decorative film to 120-150 ℃ by adopting a constant-temperature water vapor heating process, and continuously heating for 5-20 seconds to soften the decorative film, so that the decorative film has the function of extension and stretching; further, the decorative film at 120-150 ℃ has at least 20-30% of aspect ratio.

In one embodiment, the female die is provided with a heating device, and a vacuum valve and a pressure release valve which are respectively communicated with the cavity, wherein the vacuum valve is used for being communicated with an external air compressor; further, the vacuum curved surface hot pressing mold further comprises a pressing and fixing plate, and the pressing and fixing plate is used for pressing and fixing the decorative film before the vacuum pumping operation is carried out on the female die of the vacuum curved surface hot pressing mold; furthermore, a position avoiding channel for the male die to pass through is formed in the pressing and holding fixing plate; further, the vacuum pumping operation of the female die of the vacuum curved surface hot pressing film is specifically to form 0.1-1Mpa in 5-10S.

Step S160: and controlling the male die of the vacuum curved surface hot pressing film to move towards the female die, injecting plastic melt liquid into a glue filling gap between the female die and the male die through a glue injection channel of the male die, bonding the plastic bonding film of the curved surface decorating film together, and tearing the supporting base film to form a decorative surface plastic structural part precursor.

When the curved surface adds the moulding plastic of curved surface of completion back of decorating the diaphragm, control vacuum curved surface hot pressing membrane's terrace die to the die direction motion forms the die with the filler clearance of terrace die, the shape in this filler clearance is the same unanimous with the structure of the plastic structure spare that the place formed of moulding plastics, and when passing through the gluey passageway of penetrating of terrace die to the die with when the filler clearance of terrace die jets into the plastic melt, the plastic melt can fill up this filler clearance, and then the plastic structure shaping of messenger, simultaneously, the plastic melt with the curved surface adds the decorating diaphragm the plastic bonding membrane carries out cross-linking reaction or takes place intermolecular force to make the plastic structure spare pass through the plastic bonding membrane with the curved surface adds the decorating diaphragm and bonds together completely, will support the base film and follow it keeps away from the die bed membrane when tearing off the side of the three-dimensional ditch groove of pattern group, can obtain the plastic facing precursor structure spare.

Step S170: and carrying out primary photocuring operation on the facing plastic structural member precursor so as to realize primary photocuring crosslinking operation on the bearing release type hardening mask.

It should be particularly noted that, in order to enable the anti-rubbing three-dimensional pattern group on the carrier cured surface film 300a to be directly exposed in the air (when a finished product of a facing plastic structural member is assembled with other components, a formed terminal product can be finally in direct contact with a user's hand or other parts), that is, the anti-rubbing three-dimensional pattern group on the carrier cured surface film 300a can be directly sensed and contacted, the carrier cured surface film 200a must be torn off from the carrier cured surface film, since the carrier cured surface film is made of a photo-thermal dual-cured acrylic resin material and the material of the carrier cured surface film is Polyetherimide (PEI for short), the two materials are different, a cross-linking reaction does not occur at a contact interface, but an intermolecular acting force exists, when the carrier cured surface film is still in the vacuum curved surface hot-press mold, the carrier cured surface film is heated and completes a thermosetting operation, that a preliminary thermal fixing operation is completed, but the cross-linking degree of each monomer reaction in the carrier cured surface film is low, the carrier cured mechanically cured surface, and the cured surface is still torn off, and the carrier cured surface film is damaged by the carrier cured mechanically, and the carrier cured surface film is still damaged by the carrier cured by the anti-rubbing three-dimensional pattern group, or the carrier cured surface film is damaged by the carrier cured surface.

Through will veneer plastic structure precursor can improve through the photocuring operation for the first time bear and tear from type sclerosis facial mask solidification intensity, rethread step S180 follow bear and tear from type sclerosis facial mask when leaving the type basement membrane, then can be better realize the reverse expansion space pattern group improves structural function richness higher, and under the higher prerequisite of three-dimensional function, can also gain better peeling off from the type effect.

Step S180: and tearing off the release base membrane from the bearing release type hardening facial mask so as to expose the reverse rubbing three-dimensional pattern group of the bearing release type hardening facial mask, and then carrying out secondary photocuring operation so as to realize secondary photocuring crosslinking operation on the bearing release type hardening facial mask, thereby obtaining a finished product of the decorative surface plastic structural member.

In addition, since the first photo-curing operation cannot completely fix the load-bearing release hardening surface film of the decorative plastic structural member precursor, a final hardening and molding process is required after the release base film is peeled off.

Certainly, if once only photocuring technology then comes to follow tear off from bearing from type sclerosis facial mask the type basement membrane also can cause the quality hidden danger, it is well known, work as bear after the thermosetting + the full solidification of photocuring is accomplished to type sclerosis facial mask, bear the type sclerosis facial mask and also can produce the higher problem of fragility in step when improving the hardness, also can accompany the product problem of becoming brittle when the final hardness of cross-linking degree product promptly, if follow at this moment tear off from bearing from type sclerosis facial mask the type basement membrane, each three-dimensional pattern arch in the anti-open three-dimensional pattern group also can lead to easily bear on the type sclerosis facial mask anti-open three-dimensional pattern group appear partially tear easily or tear off or damaged or cause peel off viscidity such as tear mark in addition bear the higher quality problem that causes of type sclerosis facial mask fragility. Synchronously, the secondary photocuring operation after the release operation has a certain self-healing effect for micro tearing traces due to deep crosslinking reaction.

Therefore, the problems can be better avoided by performing the double photocuring and adjusting the first photocuring degree to be weaker than the second photocuring degree, and performing the release operation between the two processes.

In one embodiment, the parameters of the primary photocuring operation are: UV irradiation energy is 800-1200mj/cm, line passing linear speed is 6-8m/min, and UV irradiation time is 2-5S; the parameters of the secondary photocuring operation are as follows: the UV irradiation energy is 1000-1800mj/cm, the linear speed of the passing line is 2-5m/min, and the UV irradiation time is 3-10S, so that the intensity of the double light curing operation can be better adjusted, and the method is used for better adapting to the stripping and releasing operation.

In one embodiment, the support base film has a thickness of 70 to 100 micrometers (μm); the thickness of the release base film is 120-450 microns; the thickness of the bearing release hardening mask is 10-50 microns, and the thickness of the pattern three-dimensional groove group is 5-20 microns; the thickness of the N-layer functional film is 30-50 microns; the thickness of the plastic adhesive film is 10-15 microns.

In order to further alleviate the tear problem, improve surface compensation self-healing performance in step S180, carry out before the secondary photocuring operation, still to naked bear and leave type hardening facial mask the anti-extension solid pattern group surface spraying compensation restoration layer, compensation restoration layer with bear and leave type hardening facial mask' S the material the same, the thickness that compensates the restoration layer is 0.5 mu m-1 mu m, so, can further alleviate the tear problem, improve surface compensation self-healing performance.

It should be noted that: bear and play from type sclerosis facial mask be used for right the reverse expansion three-dimensional pattern group and N layer functional film plays the bearing function, bear and still be used for playing with play from type basement membrane plays from type peeling effect, bear and still play the sclerosis effect from type sclerosis facial mask.

Compared with the prior art, the invention has at least the following advantages:

1. according to the invention, the photo-thermal dual-curing acrylic resin material can be filled in the pattern three-dimensional groove group by utilizing fluidity through forming the pattern three-dimensional groove group on the release base film and coating the bearing release hardening mask, so that the bearing release hardening mask can form the back-rubbing three-dimensional pattern group in the pattern three-dimensional groove group, and thus, after the bearing release hardening mask is cured, the effects of modifying surface vision and three-dimensional tactile sense functions can be realized through the back-rubbing three-dimensional pattern group. Further, bear and leave type sclerosis facial mask because adopt the optothermal dual cure acrylic resin material, work as bear and carry out vacuum heating curved surface extension when tensile from type sclerosis facial mask, can possess better toughness and certain mechanical strength based on thermosetting nature, it is right N layer function membrane plays good support bearing function, when carrying out UV photocuring back end operation again, can make bear the cross-linking degree of bearing from type sclerosis facial mask and further strengthened, can greatly reduce bear and leave type sclerosis facial mask with peel off the viscidity between the type basement membrane, work as follows tear down on bearing from type sclerosis facial mask during the type basement membrane, can greatly alleviate and peel off tear mark problem.

2. According to the invention, the N layers of functional films are coated on the bearing release type hardening facial mask, so that the effect of higher structural function richness can be realized through the N layers of functional films.

3. According to the invention, the veneer plastic structural member precursor is subjected to double photocuring operations, and a stripping operation is inserted between the two photocuring operations, so that a better stripping and releasing effect can be obtained on the premise that the anti-rubbing three-dimensional pattern group is improved, the structural function richness is higher, and the three-dimensional function is higher.

The following examples are given by way of illustration, but it is to be understood that the following examples are not intended to be exhaustive of all possible and that the materials used in the following examples are commercially available without specific recitation.

Example 1

1. Purchasing PEI membrane materials and PET membrane materials sold by Guangdong Dongli New Material science and technology Co., ltd; the photo-thermal dual-curing acrylic resin (pre-heating and curing to form a film after being coated on a PET film) sold by Huiyang Sanchen chemical coating company Limited in Heizhou city is purchased, wherein the film material can be uniformly stretched (the difference of the aspect ratio and the tensile ratio is about 20-30%) to form a thin film material (10-500 mu m in thickness) under high temperature resistance (120-250 ℃).

2. The coating resin with double curing conditions (thermal curing and light curing conditions) is prepared by firstly maintaining the toughness and the application property of the coating of the related material under the thermal curing conditions in the process, and then performing secondary light curing (namely final curing) after all the processes are finished to finish the performance of the coating.

3. The heating system finishes heating and softening in the range of 5-20S on the supporting diaphragm and the coating on the diaphragm to present extensibility, meanwhile, one side of the mould is sealed (the single side of the diaphragm and the mould cavity) and air is pumped in 5-10S to form a vacuum negative pressure value of 0.1-1Mpa, the material is made to have extensibility through the last temperature softening, and the film and the process layer on the bearing are uniformly attached to the surface of the mould cavity along with the shape by utilizing pressure difference.

4. The mold system has the functions of injection compression molding, a vacuumizing pressure storage system, a single-side cavity closing system, a rapid circulating heating system and a PLC program control system, and comprehensively completes sequential actions and time nodes.

The whole process is as follows:

the manufactured appearance process release film is placed into one side of a mold cavity by a mechanical arm to be fixed, mold starting mold closing force is performed on one side of the placed film to press the film and the single-side cavity, a sealed cavity is formed, a sensor is triggered to perform delayed vacuumizing preparation, the delay process is a heating process (120-150 ℃), constant-temperature water vapor is used for heating, delay is performed for 5-20S, the film and a process layer on the film are softened in a preset softening point, the characteristic of a uniformly extending material is formed, vacuumizing is started according to sequence and time nodes under the control of a PLC node, and the planar film is adsorbed on one side of the cavity; then the injection molding machine starts the whole process of injection compression molding, the product is taken out, the bottom film is peeled off, the process layer is transferred to the injection molding product, and the whole product is subjected to secondary (primary release and secondary full curing) UV irradiation (800-1800mj, 3-10 s).

The case of the 3D curved surface appearance process integrated molding of the back cover of the mobile phone, the drawing of the notebook a shell (housing), and the integrated molding of the woven texture, and the integration of the pattern and the IME process of the outer surface of the automotive interior trim part has been successfully carried out by using the method for transferring the curved surface in the mold based on the thermosetting bearing and the photo-curing release of the embodiment 1.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. An in-mold curved surface transfer printing method based on thermosetting bearing and photo-curing release is characterized by comprising the following steps:

preparing a support base film, and coating a release base film on the support base film; the release base film is made of polyetherimide;

coating a bearing release hardening surface film on the release base film, wherein the bearing release hardening surface film also forms a back rubbing three-dimensional pattern group in the pattern three-dimensional groove group; the material of the bearing release hardening mask is photo-thermal dual-curing acrylic resin;

coating N layers of functional films on the bearing release type hardening facial mask, wherein N is more than or equal to 1;

coating a plastic adhesive connecting film on the N layers of functional films to obtain a decorative film, and rolling to obtain a decorative film roll;

the decoration film roll is placed in a vacuum curved surface hot pressing die after being unreeled, the decoration film is heated and softened, and then the concave die of the vacuum curved surface hot pressing die is vacuumized to enable the curved surface of the decoration film to be attached to the inner wall of the cavity of the concave die, so that the decoration film is extended to form a curved surface decoration film;

controlling a male die of the vacuum curved surface hot pressing film to move towards the female die, injecting plastic melt liquid into a glue filling gap between the female die and the male die through a glue injection channel of the male die, bonding the plastic melt liquid and the plastic bonding film of the curved surface decorative membrane together, and tearing off the supporting base film to form a decorative surface plastic structural part precursor;

carrying out primary photocuring operation on the facing plastic structural part precursor so as to realize primary photocuring crosslinking operation on the bearing release type hardening mask;

and tearing off the release base membrane from the bearing release type hardening facial mask so as to expose the reverse rubbing three-dimensional pattern group of the bearing release type hardening facial mask, and then carrying out secondary photocuring operation so as to realize secondary photocuring crosslinking operation on the bearing release type hardening facial mask, thereby obtaining a finished product of the decorative surface plastic structural member.

2. The method for transferring the curved surface in the mold based on thermosetting carrier and photocurable release as claimed in claim 1, wherein the supporting base film is made of PET.

3. The method for transferring a curved surface in a mold based on thermosetting carrier and photocurable release according to claim 1,

the parameters of the primary photocuring operation are as follows: UV irradiation energy is 800-1200mj/cm, line passing linear speed is 6-8m/min, and UV irradiation time is 2-5S;

the parameters of the secondary photocuring operation are as follows: UV irradiation energy is 1000-1800mj/cm, the linear speed of the threading is 2-5m/min, and the UV irradiation time is 3-10S.

4. The thermosetting carrying and photocurable releasing based in-mold curved surface transfer printing method as recited in claim 1, wherein the pattern three-dimensional groove set includes circular grooves, polygonal grooves, square grooves and/or shaped grooves;

the anti-rubbing stereo pattern group comprises a plurality of stereo pattern bulges, and the thicknesses of the stereo pattern bulges are consistent or different.

5. The method for transferring the curved surface in the mold based on thermosetting carrier and photocurable release as claimed in claim 1, wherein the heating and softening operation is specifically as follows:

and heating the decorative film to 120-150 ℃ by adopting a constant-temperature water vapor heating process, and continuously heating for 5-20S to soften the decorative film, so that the decorative film has the function of stretching.

6. The thermosetting carrying and photocurable releasing based in-mold curved surface transfer method as recited in claim 5, wherein said decorative film has an aspect ratio of at least 20-30% at 120-150 ℃.

7. The method for transferring the curved surface in the mold based on thermosetting bearing and photo-curing release as claimed in claim 1, wherein the female mold is provided with a heating device, and a vacuum valve and a pressure release valve respectively communicated with the cavity, and the vacuum valve is used for being communicated with an external air compressor.

8. The method for in-mold curved surface transfer printing based on thermosetting carrier and photocurable release as claimed in claim 1, wherein the vacuum curved surface hot press mold further comprises a pressing and fixing plate for pressing and fixing the decorative film before the vacuum pumping operation is performed on the female mold of the vacuum curved surface hot press mold.

9. The method for transferring the curved surface in the mold based on thermosetting bearing and photo-curing release as claimed in claim 8, wherein the pressing and fixing plate is provided with a channel for the male mold to pass through.

10. The method for transferring a curved surface in a mold based on thermosetting carrier and photocurable release as claimed in claim 1, wherein the vacuum pumping operation of the female mold of the vacuum curved surface hot pressing mold is specifically performed to form 0.1-1Mpa in 5-10S.

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