CN112172024A - Rapid in-mold simulation surface decoration process - Google Patents

Abstract

The invention belongs to the field of automobile part manufacturing processes, and particularly relates to a rapid in-mold simulation surface decoration process. The molding process of the injection molding part comprises the following steps: carrying out injection molding on a thermoplastic base material in a first mold cavity by adopting a rapid cooling and rapid heating process to form a highlight injection molding part, wherein the inner surface of the first mold cavity is preprocessed with nano or femtosecond laser textures so that the highlight injection molding part has a nano or femtosecond laser texture structure; rapidly cooling the first die cavity, opening the die, approximately rotating the rotary table for 180 degrees, and closing the second die cavity; directly coating the high-gloss injection molding part with the two-component coating in the second mold cavity, and reacting and curing the two-component coating in the second mold cavity to form a transparent coating on the surface of the high-gloss injection molding part; and cooling the second die cavity and opening the die to form the high-gloss injection molding with the nano or femtosecond laser texture structure and the scratch-resistant surface. The rapid in-mold simulation surface decoration process has obvious cost advantage, and the formed high-gloss injection molding surface coating is attractive in appearance, ideal in hardness and good in scratch resistance; in addition, the combination of the nano or femtosecond laser texture structure and the transparent coating is added, so that the highlight injection molding piece has a three-dimensional decoration effect on the whole, and the product has more advantages and competitiveness.

Description

Rapid in-mold simulation surface decoration process

Technical Field

The invention belongs to the field of automobile part manufacturing processes, and particularly relates to a rapid in-mold simulation surface decoration process.

Background

In recent years, the automobile industry has been rapidly developed, especially the yield and social preservation of cars have kept high acceleration, automobile plastics have irreplaceable effects in the aspects of beauty, safety, light weight and the like, and meanwhile, the new automobile technology is developing towards more environmental protection, safety, comfort and individuation.

At present, the automobile decoration part mostly adopts an injection molding spraying process, the whole process at least comprises an injection molding link, a spraying link and a final assembly link, and each single link comprises a plurality of specific small links. Therefore, the traditional injection molding and spraying process has complicated steps and complex whole flow, so that the process has high energy consumption and high cost of manpower and material resources, and the spraying process pollutes the environment and is not environment-friendly enough. On the other hand, the automobile decoration of above-mentioned traditional injection molding spraying technology production, the process is loaded down with trivial details, and the defective rate is higher, also exists not enoughly on the product surface quality, for example: the parts are easy to have quality defects of orange peel, sagging and the like, the surface gloss of the product is not ideal, the structure and the style of the product are single, the depth three-dimensional sense of the parts is poor, and the parts are not aesthetic and fashionable.

In view of the above disadvantages of the prior art, the present invention aims to provide a novel surface decoration process, namely a rapid in-mold simulation surface decoration process, which has the advantages of fewer steps, high yield, lower process energy consumption and cost, and smaller required equipment space, and the decoration obtained by the rapid in-mold simulation surface decoration process not only has high gloss and multi-angle stereoscopic micro texture, but also has the advantages of ideal product surface hardness, superior scratch resistance, scratch self-healing property, etc. The product surface formed by the process has effective combination of various structures, is rich in variety and is attractive and fashionable.

Disclosure of Invention

In order to achieve the above object, one of the key points of the rapid in-mold simulation surface decoration process according to the present invention is a rapid cooling and rapid heating injection molding process. This technique is a method of thermally cycling the mold surface temperature during the injection molding cycle. And (3) before injection, quickly raising the surface temperature of the mold to be higher than the glass transition temperature (Tg) of the material, performing injection molding, and quickly reducing the mold temperature to the ejection temperature after the injection molding is finished. Which is essentially a variable mold temperature forming process in the forming process. The rapid cooling and heating injection molding process adopts high mold temperature, improves the flowability of raw materials in a mold, and effectively eliminates some defects of conventional injection molding, such as weld marks, exposed glass fibers, orange peel, air lines and the like. Meanwhile, the material has high fluidity in the die cavity, so that the surface state of the die is effectively copied, and the molded decorating part has a high-gloss surface.

Another key point of the rapid in-mold simulation surface decoration process according to the present invention is the in-mold laser texture technology, i.e. nano laser texture or femtosecond laser texture is formed in the mold cavity of the rapid cooling and heating mold, so that a microscopic nano or femtosecond laser texture structure with functionality can be formed on the substrate in the injection molding process of the thermoplastic substrate. Therefore, on parts obtained by rapid cooling and rapid heating injection molding, the parts have the effect of high surface gloss, and also have a nano or femtosecond laser texture structure, and have different three-dimensional effects and/or color effects visually from different angles, so that injection molded parts are attractive and fashionable. Meanwhile, the nano or femtosecond laser texture in the die can be customized, and the product has high flexibility and can meet different customer requirements.

The other key point of the rapid in-mold simulation surface decoration process is a reaction injection molding process, namely, the traditional spraying process is integrated into the injection molding process, so that the whole part production process is completed in one step, the production efficiency is improved, and the cost is saved. Specifically, in the reaction injection molding process, a two-component coating is used to perform overflow treatment on a base material subjected to previous injection molding in a closed injection mold, and after the coating is cured for a period of time, the finished glazing part can be ejected from the mold. In the whole process, the parts are in the same die, so that the quality and the dimensional stability of the parts can be obviously improved.

According to a first aspect of the invention, a process for molding an injection molded part comprises the steps of: performing injection molding on a thermoplastic substrate in a first mold cavity by adopting a rapid cooling and rapid heating process to form a highlight injection molding part, wherein the inner surface of the first mold cavity is preprocessed with nano laser textures or femtosecond laser textures, so that the highlight injection molding part has a nano laser texture structure or a femtosecond laser texture structure; rapidly cooling the first die cavity, opening the die, approximately rotating the rotary table by 180 degrees, and closing the second die cavity; directly coating the high-gloss injection molding part with a two-component coating in the second mold cavity, wherein the two-component coating reacts and cures in the second mold cavity to form a transparent coating on the surface of the high-gloss injection molding part; and cooling and opening the second die cavity to form the high-gloss injection molding with the nano or femtosecond laser texture structure and the scratch-resistant surface.

According to the rapid in-mold simulation surface decoration process, preferably, the rapid cooling and rapid heating process comprises the following steps: before mold closing, the mold temperature of the first mold cavity is rapidly heated to be higher than the glass transition temperature of the material, and mold closing injection is carried out after the temperature reaches a first set temperature value; and after the die closing and injection are finished, the die temperature of the first die cavity is quickly reduced to the ejection temperature, and the workpiece is ejected after the temperature reaches a second set temperature value.

According to the rapid in-mold simulation surface decoration process of the invention, preferably, the mold temperature of the first mold cavity is rapidly changed by one or more of the following ways: steam-assisted variable mold temperature, water-assisted variable mold temperature, oil-assisted variable mold temperature, and electromagnetic induction variable mold temperature.

According to the rapid in-mold simulation surface decoration process, preferably, the waterway of the first mold cavity is designed to be close to the following pipeline of the mold cavity, and the diameter of the waterway, the distance between the water pipes and the surface distance from the waterway to the product are designed to make the surface temperature of the first mold cavity consistent.

According to the rapid in-mold simulation surface decoration process, preferably, the mold core of the first mold cavity is designed to be heat-insulating, so that heat loss is prevented, and heating efficiency is improved.

According to the rapid in-mold simulation surface decoration process, preferably, the first mold cavity is provided with a temperature sensor so as to realize closed-loop control of the rapid cooling and rapid heating process among the mold end, the mold temperature machine and the injection molding machine through feedback of the temperature sensor.

According to another aspect of the present invention, there is provided an injection molded part produced by a rapid in-mold simulation surface decoration process, having a layered structure, comprising: the substrate layer is prepared by adopting a rapid cooling and rapid heating process and is formed into a highlight injection molding piece with a nano laser texture structure or a femtosecond laser texture structure; the transparent coating covers on the substrate layer and is formed by reaction and curing of a two-component coating so as to improve the surface scratch resistance of the highlight injection molding, and the transparent coating further enables the highlight injection molding with a nano or femtosecond laser texture structure to have different three-dimensional effects and/or color effects through visual observation from different angles.

According to the high-gloss injection-molded part with the laser texture structure, the substrate layer with the nano or femtosecond laser texture structure and the transparent coating layer are preferably molded in one step by means of a turntable.

According to the high-gloss injection-molded part with the laser texture structure, the hardness of the transparent coating of the injection-molded part is preferably at least higher than Shore D70.

According to the high-gloss injection-molded part with the laser texture structure, the transparent coating of the injection-molded part preferably has self-healing characteristics, and the generated scratches can be gradually disappeared through treatment in a set temperature environment.

Advantageous technical effects

In summary, the rapid in-mold simulation surface decoration process of the present invention has the following technical key points, and all the key points are organically combined: firstly, a rapid cooling and rapid heating injection molding process; ② laser texture technique in mould; and thirdly, a coating process of a rapid turntable.

Based on the technical key points, compared with the prior art, the rapid in-mold simulation surface decoration process can omit a plurality of originally necessary steps, so that the whole process flow is shorter, the required space is smaller, the labor cost is lower, the energy consumption of the process is lower, the yield is high, the process is more environment-friendly, and the like.

Compared with the prior art, the injection molding product produced by the process has the following advantages:

(1) the injection molding part formed by the rapid cooling and rapid heating injection molding process has the surface highlight characteristic, and the transparent coating formed by the coating process has ideal surface hardness, so that the surface scratch resistance of the injection molding part product is improved, and the surface also has certain self-healing property for the generated micro scratches;

(2) the transparent coating is combined with the laser texture, so that the whole injection molding part has a three-dimensional depth effect, and the product is combined with functional aesthetics, so that the aesthetic texture and fashion of the product are improved; furthermore, if femtosecond laser textures are adopted, the product has more layering and better three-dimensional effect, the three-dimensional effect viewed at different angles is different, the generated color and ripple effect are also different, and dynamic and fashionable visual advantages are brought to the product;

(3) the laser texture in the mould or the specific pattern of the femtosecond laser texture and the like can be customized, so that the texture on the product is more flexibly selected, various requirements can be met, the application is wider, and the whole product has more market competitiveness.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below.

It is to be understood that the drawings in the following description are directed to only some embodiments of the invention and are not intended as a limitation on the invention.

In the drawings:

fig. 1 shows a schematic representation of the steps in a reaction injection molding process according to the present invention.

FIG. 2 shows a temperature profile of a rapid cooling and rapid heating injection molding according to the present invention.

Fig. 3 shows a schematic diagram of mold temperature control for a rapid cooling and rapid heating injection molding process according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.

Reaction injection molding process

Fig. 1 shows a schematic representation of the steps in a reaction injection molding process according to the present invention. In the reaction injection molding process, the spray process is integrated into the injection molding process. In particular, the glazed parts can be ejected from the mold after a period of time of flood curing of the thermoplastic substrate in a closed injection mold using a two-component PUR/PUA coating or coating material. Throughout the process, the parts are actually in the same mold. Thus, the reaction injection molding process according to the present invention can significantly provide high part quality and dimensional stability.

In the injection molding process according to the invention, the PUR is used in two components A & B. In the case of a product of the applicant, wherein the a component may be a polyol/polyamine compound, see in particular table 1 below; the B component can be an isocyanate compound, as listed in Table 2 below. The two-component material can also be polyurea or polyurethane material according to the product requirement.

Table 1 component A in PUR

Chemical name	CAS number	By weight%
			1, 4-butanediol	110-63-4	12.5-20
Dimethyl bis [ (neodecanoyl) oxy)]Dimethyl tin	68928-76-7	<0.5
			Phosphorous acid phenyl diisodecyl ester	25550-98-5	<0.5

Table 2 component B in PUR

Chemical name	CAS number	By weight%
			Homopolymers of 1, 6-diisocyanatohexane	28182-81-2	50-100
1, 6-hexamethylene diisocyanate	822-06-0	<0.5

The equipment set of the reaction injection molding process of the present invention, particularly the mixing head, can achieve precise coating amounts in each cycle.

Referring to fig. 1, in the reaction injection molding process according to the present invention, the following steps are mainly included:

(1) injection molding a thermoplastic substrate;

(2) maintaining the pressure, and cooling the thermoplastic plastics;

(3) opening the mold, rotating the turntable by about 180 degrees, and closing the mold;

(4) PUR/PUA injection, simultaneously with the injection of the thermoplastic substrate of the next cycle;

(5) PUA/PUR reaction, pressure maintaining and cooling of the thermoplastic;

(6) and opening the mold and demolding.

The reaction injection molding process shown in fig. 1 described above according to the present invention is effectively improved in the above-described aspects, compared to the conventional plastic spray coating process. As is known, the conventional plastic spraying process at least includes three processes, i.e., an injection molding process, a coating process, and a final assembly process, and each process at least includes several sub-steps. In contrast, the reaction injection molding process according to the present invention is less in waste, low in energy consumption, labor-saving, and an environmentally friendly process route.

According to the above reaction injection molding process of the present invention, optimized coatings with different characteristics can be obtained. In particular, the advantages are at least as follows:

100% free of any solvent;

no external release agent is required;

a high degree of scratch resistance;

freely definable surface hardness;

surfaces that can self-heal;

extremely broad color range: clear, color or metallic effects;

high UV resistance and weathering resistance;

OEM specific requirements can be achieved.

According to the rapid in-mold simulation surface decoration process, the thickness of the coating can be further defined in the reaction injection molding process, such as 0.4 mm-0.8 mm. At the same time, the above process also provides more flexibility in the design of the coating, such as a clear coating, a colored coating, or an effect color coating, etc.

In addition, the coating of the rapid in-mold simulation surface decoration process has self-healing property, namely, when fine or small scratches appear, the coating has a self-healing function under a certain set temperature environment, and the scratches can disappear gradually.

One specific example of the above reaction injection molding process is as follows:

item name: research on intelligent self-repairing technology of automobile decorative plate

Part name: drinking cup rack panel

Raw materials: PUR for covering PC/ABS surface of substrate

Product size: 109*156*16.5

PC/ABS weight: 43g

PC/ABS color: black color

PUR thickness: 0.4mm

Weight of PUR: 10 g

PUR hardness: shore D70

PUR color: piano black

The surfaces obtained were subjected to adhesion tests: class 0 according to GB/T9286-1998; and (3) carrying out scratch test: using an ERICHSEN scratch tester with a tip diameter of 0.75mm, a pressure of 20N, a surface contacted with hot air at 60 ℃ immediately disappeared scratches.

Rapid cooling and heating injection moulding

Fig. 2 shows a temperature control curve of a rapid cooling and rapid heating injection molding process according to the present invention.

The rapid cooling and rapid heating injection molding process according to the present invention is a method of thermally cycling the surface temperature of a mold during an injection molding cycle. Before injection, the mold surface temperature is rapidly raised to above the glass transition temperature (Tg) of the material, and injection molding is performed. And after the injection molding is finished, quickly reducing the mold temperature to the ejection temperature. In the forming process, a variable mold temperature forming process is adopted. According to the process disclosed by the invention, the high mold temperature is adopted, the flowability of the raw material in the mold is improved, the surface state of the mold can be effectively copied, and meanwhile, some defects of the surface of a conventional injection molding product, such as weld marks, exposed glass fibers, orange peel, air lines and the like, are eliminated. Therefore, the surface gloss of the molded product is good, so the method is also called a high-gloss injection molding process.

Referring to fig. 2, a process route of the rapid cooling and rapid heating injection molding according to the present invention is exemplified as follows:

opening the die and heating;

secondly, after the first preset temperature is reached, die assembly and injection molding are carried out;

cooling;

and fourthly, demolding and taking the workpiece after the second preset temperature is reached.

Compared with the traditional injection molding process, the rapid cooling and heating process has the advantages of at least the following performance:

solving the problem of fiber floating on the surface of the traditional injection molding product;

eliminating the defects of welding marks, stress marks and the like on the surface of a product in the traditional process;

high mold temperature, improved material flowability, effective replication of mold surface morphology;

enhance the surface gloss of the product;

the product can realize effective combination of highlight injection molding and mold laser texture;

the product can realize effective combination of high light and low light;

for high-brightness black products, injection molding is completed in one step, and a subsequent paint spraying process can be eliminated.

The quenching and rapid heating process according to the invention adopts the following variable mold temperature medium.

(1) Steam-assisted mold temperature changing technology

The quenching and quick heating process can adopt a steam heating mode. The heating conductivity of the steam is higher, and the temperature rising speed is faster than that of hot water.

(2) Water-assisted temperature changing technology

The quenching and quick heating process can adopt a water-assisted temperature changing technology. Compared with steam type and electromagnetic induction heating type, the device has the advantages of low equipment investment cost, high temperature control precision, combination with a standard mold temperature controller and high equipment universality.

(3) Oil-assisted temperature changing technology

The quenching and quick heating process can adopt an oil-assisted temperature changing technology. The control system is the same as the water-assisted variable mold temperature, and the equipment investment cost is lower. The cooling adopts water medium, and because the heating medium is different from the cooling medium, the die is provided with two sets of circulating paths for heating and cooling circulation.

(4) Electromagnetic induction strain mold temperature auxiliary forming

The rapid cooling and heating process can adopt an electromagnetic induction variable mold temperature auxiliary forming technology. The surface of the die is heated by high-frequency induction, the heating power is high, the temperature is quickly raised, and the surface temperature of the die can be raised to more than 200 ℃ in a short time.

In the aspect of the equipment involved in the rapid cooling and rapid heating process according to the invention, the equipment can comprise a rapid cooling and rapid heating mould, a rapid cooling and rapid heating highlight traceless machine, an injection molding machine, a soft water system, a cooling water tower, an air compressor unit and the like. Among them, for example, a highlight non-marking machine device for a decorative strip includes an ESR control valve (having two small water tanks inside to control the inlet and outlet of water), a mixing bed, a constant delivery pump, and the like.

As an exemplary embodiment, the highlight traceless machine apparatus for the trim strip has the following operating characteristics:

(1) the fully closed system adopts an electric heating mode and liquid water as a working medium. Heating water to working temperature, pumping the water to the mold end by a water pump, and continuously controlling the water temperature by a temperature sensor.

(2) The medium design avoids the consumption of high energy source for converting the phase state of water into steam, and also avoids the extra time of drying the steam by using compressed air in the steam-cold water type variable-mould-temperature process.

(3) The high temperature causes the water quality change, the conductivity rises, the incrustation scale and the scale easily appear, the equipment contains a set of water treatment equipment (mixing bed, constant delivery pump), carries out water quality treatment before the system mends water.

In the aspect of manufacturing the rapid cooling and heating die, the invention has the following characteristics.

(1) Selection of steel

According to the rapid cooling and rapid heating injection molding process (RHCM), the die is required to be continuously in a cold and hot cycle, stress fatigue is easily generated, and therefore the requirements on high temperature resistance and hardness are considered for selecting die steel. Meanwhile, high-gloss products require high-quality steel with good polishing property, high purity, high mirror surface and the like on the surface of the die.

(2) Waterway design

The rapid cooling and heating process needs rapid temperature rise and temperature reduction processes of the mold, the consistency of the surface temperature of the mold cavity directly affects the product quality, and if the water channel design is unreasonable, the defects of product deformation, color difference, local scorching and the like are often caused. Therefore, the mold waterway according to the present invention needs to be designed in consideration of the following factors:

A) designing a conformal pipeline close to the cavity;

B) diameter of the waterway;

C) the distance between the water pipes;

D) distance from the waterway to the surface of the product;

E) special sealing washer and water route connect.

(3) Mold insulation design

The RHCM process has higher mold temperature, and needs to make heat insulation design on the mold core part to prevent heat loss and improve heating efficiency.

(4) Mold gate design

The design of the mold gate needs to consider reducing the welding line as much as possible, reducing the shearing generated during the injection molding of the material, and reducing the generation of orientation and flow marks on the surface of the material.

(5) Mold surface temperature detection

The mold temperature control of the rapid cooling and rapid heating injection molding process according to the present invention is shown in fig. 3.

The rapid cooling and rapid heating process adopts a cold and hot water circulation mode to carry out variable mold temperature control on the surface temperature of the mold. The mold end is provided with a temperature sensor, so that closed-loop control among the mold end, the highlight traceless machine and the injection molding machine can be realized. This control reduces human intervention and setup. The whole rapid cooling and heating process can be effectively controlled by the real-time temperature in the die derived by the temperature sensor, and the smooth realization of production is effectively ensured.

Aspects of raw materials

Through the research of the inventor, in order to realize the spraying-free high-gloss injection molding, a high-gloss plastic material is selected firstly.

Requirements for such materials include:

(1) the material has good fluidity so as to better reproduce the surface of the mold;

(2) the material has scratch resistance and good hardness;

(3) the material has good thermal stability and is not easy to generate volatile matters. The heat resistance is improved, the volatilization of volatile matters is reduced, and the corrosion of a mold is prevented;

(4) the glossiness of the material is good;

the existing highlight spraying-free materials are mainly as follows: high light grade ABS, high light grade PA, PC, PMMA, PC/ABS, PMMA/ABS, etc. For nylon materials, the material is crystalline and has moisture absorption property, so that the product is easy to deform after molding, and only small-size parts can be produced.

Comparing the rapid cooling and heating with the traditional spraying process

The quenching and flash heating process according to the present invention is in all respects more detailed than conventional plastic spraying, as listed in table 3 below.

TABLE 3 comparison of conventional Process with Rapid Cooling and heating Process

Laser texturing process

According to the invention, the in-mold laser texture technology, namely the nano laser texture or the femtosecond laser texture is formed in the mold cavity of the rapid cooling and rapid heating mold, so that a microscopic nano or femtosecond laser texture structure can be formed on the base material in the injection molding process of the thermoplastic base material. Therefore, on parts obtained by rapid cooling and rapid heating injection molding, the parts have the effect of high surface gloss, and also have a nano or femtosecond laser texture structure, and have different three-dimensional effects and/or color effects visually from different angles, so that injection molded parts are attractive and fashionable. Meanwhile, the nano or femtosecond laser texture in the die can be customized, and the product has high flexibility and can meet different customer requirements.

According to the invention, the processing mode of the laser 3D texture in the mould mainly comprises the following processes:

(1) and providing a universal 3D drawing file of the die, which completely conforms to the size of the workpiece.

(2) And designing the required texture.

(3) And rendering the texture to the surface to be processed through software processing.

(4) The laser processing program is generated by software calculation.

(5) And (4) importing the processing program into a machine, adjusting and setting various parameters, and then directly performing laser burning.

(6) After laser processing is finished, the die can be directly produced.

According to the invention, in the principle of laser 3D texture processing, processing is carried out in a layered mode, and the depth and the layer number form texture precision. The more levels at the same depth, the higher the machining precision.

Besides the nano laser texture introduced above, the laser texture in the mold of the invention can also be processed by femtosecond laser technology, and the formed femtosecond laser texture has more layering and better three-dimensional effect. Specifically, the femtosecond laser textures have different visual stereoscopic effects at different angles, and the color and ripple effects generated by the principles of light diffraction and the like are different, so that dynamic and fashionable visual advantages are brought to products.

Specifically, the femtosecond laser texture in the mold can be processed by combining an ultrashort pulse femtosecond laser source and an ytterbium-doped fiber laser, so that ideal processing quality can be obtained. The configuration has almost no heat affected zone, no fine cracks, no re-melting layer, no burr, and no subsequent processing steps to obtain clean, clear, high-sharpness and high-stereoscopic texture effect.

In summary, the rapid in-mold simulation surface decoration process of the present invention has the following technical key points, and all the key points are organically combined: firstly, a rapid cooling and rapid heating injection molding process; ② laser texture technique in mould; and thirdly, a coating process of a rapid turntable.

Based on the technical key points, compared with the prior art, the rapid in-mold simulation surface decoration process can omit a plurality of originally necessary steps, so that the whole process flow is shorter, the required space is smaller, the labor cost is lower, the process energy consumption is lower, the process is more environment-friendly, and the like.

Compared with the prior art, the injection molding product produced by the process has the following advantages:

(1) the injection molding part formed by the rapid cooling and rapid heating injection molding process has the surface highlight characteristic, and the transparent coating formed by the coating process has ideal surface hardness, so that the surface scratch resistance of the injection molding part product is improved, and the surface also has certain self-healing property for the generated micro scratches;

(2) the transparent coating is combined with the laser texture, so that the whole injection molding part has a three-dimensional depth effect, and the product is combined with functional aesthetics, so that the aesthetic texture and fashion of the product are improved; furthermore, if femtosecond laser textures are adopted, the product has more layering and better three-dimensional effect, the three-dimensional effect viewed at different angles is different, the generated color and ripple effect are also different, and dynamic and fashionable visual advantages are brought to the product;

(3) the laser texture in the mould or the specific pattern of the femtosecond laser texture and the like can be customized, so that the texture on the product is more flexibly selected, various requirements can be met, the application is wider, and the whole product has more market competitiveness.

Finally, it should be noted that, when describing the positions of the components and the matching relationship therebetween, the present invention is usually illustrated by one/a pair of components, however, it should be understood by those skilled in the art that such positions, matching relationship, etc. are also applicable to other/other pairs of components.

The above description is intended to be illustrative of the present invention and not to limit the scope of the invention, which is defined by the claims appended hereto.

Claims (10)

1. A molding process of an injection molded part, comprising the following steps:

performing injection molding on a thermoplastic substrate in a first mold cavity by adopting a rapid cooling and rapid heating process to form a highlight injection molding part, wherein the inner surface of the first mold cavity is preprocessed with nano laser textures or femtosecond laser textures, so that the highlight injection molding part has a nano laser texture structure or a femtosecond laser texture structure;

rapidly cooling the first die cavity, opening the die, approximately rotating the rotary table by 180 degrees, and closing the second die cavity;

directly coating the high-gloss injection molding part with a two-component coating in the second mold cavity, wherein the two-component coating reacts and cures in the second mold cavity to form a transparent coating on the surface of the high-gloss injection molding part;

and cooling and opening the second die cavity to form the high-gloss injection molding with the nano or femtosecond laser texture structure and the scratch-resistant surface.

2. The molding process of the injection molded part according to claim 1, wherein the rapid cooling and heating process comprises:

before mold closing, the mold temperature of the first mold cavity is rapidly heated to be higher than the glass transition temperature of the material, and mold closing injection is carried out after the temperature reaches a first set temperature value;

and after the die closing and injection are finished, the die temperature of the first die cavity is quickly reduced to the ejection temperature, and the workpiece is ejected after the temperature reaches a second set temperature value.

3. The process of molding an injection molded part according to claim 1 or 2, wherein the rapid change in mold temperature of the first mold cavity is performed by one or more of the following: steam-assisted variable mold temperature, water-assisted variable mold temperature, oil-assisted variable mold temperature, and electromagnetic induction variable mold temperature.

4. The molding process of the injection molded part according to claim 1 or 2, wherein the waterway of the first mold cavity is designed to be close to the following pipe of the mold cavity, and the waterway diameter, the water pipe interval and the waterway-to-product surface distance are designed to make the surface temperature of the first mold cavity consistent.

5. The process for molding an injection molded part according to claim 1 or 2, wherein the core of the first cavity is designed to be thermally insulated to prevent heat loss and improve heating efficiency.

6. The molding process of the injection molded part according to claim 1 or 2, wherein the first mold cavity is provided with a temperature sensor to enable closed-loop control of the rapid cooling and rapid heating process between the mold end, the mold temperature machine and the injection molding machine through feedback of the temperature sensor.

7. An injection molded part having a layered structure comprising:

the substrate layer is prepared by adopting a rapid cooling and rapid heating process and is formed into a highlight injection molding piece with a nano laser texture structure or a femtosecond laser texture structure;

the transparent coating covers on the substrate layer and is formed by reaction and curing of a two-component coating so as to improve the surface scratch resistance of the highlight injection molding, and the transparent coating further enables the highlight injection molding with a nano or femtosecond laser texture structure to have different three-dimensional effects and/or color effects through visual observation from different angles.

8. The injection molded part according to claim 7, wherein the substrate layer and the transparent coating layer having the nano or femtosecond laser texture structure are molded at one time by means of a turntable.

9. The injection molded part of claim 7 or 8, wherein the clear coat layer of the injection molded part has a hardness of at least above Shore D70.

10. The injection molded part according to claim 7 or 8, wherein the transparent coating of the injection molded part has self-healing properties, and the scratches generated are gradually eliminated by treatment in a set temperature environment.

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