Vacuum coating process for plastic product

Abstract

The invention discloses a vacuum coating process for a plastic product. The vacuum coating process comprises the following steps: S1, material preparation: determining a to-be-processed plastic part, a coating material and a PVD vacuum coating machine; s2, pretreatment: (1) cleaning the plastic product, and removing oil stains and impurities on the surface; (2) the surface of the plastic product is polished and subjected to sand blasting; s3, checking: debugging the equipment, ensuring normal operation of the equipment, adjusting parameters of the coating machine, and meanwhile, carrying out pre-coating test on the PVD vacuum coating machine by utilizing the test workpiece; and S4, coating preparation: (1) putting a coating material into a PVD (Physical Vapor Deposition) vacuum coating machine. According to the vacuum coating process of the plastic product, the microporous screen plate assembly capable of moving in a reciprocating manner is arranged in the coating chamber in the PVD vacuum coating machine, so that a coating material can be accurately and uniformly attached to the surface of the plastic part to be coated according to mesh distribution of the microporous screen plate to form a compact coating layer, and the coating effect of the plastic product is controllable; and the laminating effect of the plastic product is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of powder spraying technology, and in particular relates to a vacuum coating process for plastic products. Background Art

[0002] Plastic products are a general term for daily and industrial products made from plastic as the main raw material. They include products made from injection molding, vacuum forming and other processes using plastic as the raw material. Plastic is a type of synthetic polymer material with plasticity. Together with synthetic rubber and synthetic fiber, it forms the three major synthetic materials that are indispensable in daily life.

[0003] During the production and processing of plastic products, coating is required. Vacuum coating machine mainly refers to a type of coating that needs to be performed under a higher vacuum degree. There are many types, including vacuum resistance heating evaporation, electron gun heating evaporation, magnetron sputtering, MBE molecular beam epitaxy, PLD laser sputtering deposition, ion beam sputtering and many other types.

[0004] At present, some plastic product sheets are coated with PVD vacuum coating machines. During the coating process, after the coating material evaporates, it diffuses irregularly to the surface of the plastic parts, making the coating uniform on the surface of the plastic products generally uneven and prone to burrs, which brings inconvenience to the subsequent curing and post-coating processing. Summary of the invention

[0005] The object of the present invention is to provide a vacuum coating process for plastic products to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A vacuum coating process for plastic products comprises the following steps:

[0008] S1. Material preparation: determine the plastic parts to be processed, coating materials and PVD vacuum coating machine;

[0009] S2. Preprocessing:

[0010] (1) Clean plastic products and remove surface oil and impurities;

[0011] (2) Grinding and sandblasting the surface of plastic products;

[0012] S3, Inspection: Debug the equipment to ensure normal operation of the equipment, adjust the coating machine parameters, and use the test workpiece to perform pre-coating test on the PVD vacuum coating machine;

[0013] S4. Coating preparation:

[0014] (1) placing the coating material into a PVD vacuum coating machine, placing the plastic part on a coating rack, placing the coating rack into a coating chamber, and evacuating the coating chamber to place the plastic part in a vacuum environment;

[0015] (2) An air supply pump is installed outside the PVD vacuum coating machine;

[0016] (3) A slide rail is installed on the wall of the coating chamber, a linear motor is provided in the slide rail, and a microporous mesh plate is fixedly connected to the driving end of the linear motor;

[0017] S5, start coating:

[0018] (1) Start the linear motor to drive the microporous screen to move horizontally;

[0019] (2) The coating material is heated by a PVD vacuum coating machine, so that the coating material evaporates, passes through the mesh holes in the microporous mesh plate, and is evenly deposited on the surface of the plastic part;

[0020] S6, coating is completed: after coating is completed, the protective gas is delivered to the coating chamber through the gas supply pump, and the coated plastic product is left to stand, and the plastic part is taken out after the film layer is stably attached;

[0021] S7, post-processing:

[0022] (2) The vacuum-coated plastic parts are sent to a drying room for heating through a conveyor chain, and the film layer of the plastic parts is UV-cured;

[0023] (2) Polish the plastic parts and spray protective paint after polishing;

[0024] S8, cleaning: after the plastic parts are solidified, the burrs are smoothed;

[0025] S9. Inspection: Mainly inspect the appearance of plastic parts and coating thickness, and repair plastic workpieces that are found to have defects such as pinholes, bruises, bubbles, etc.

[0026] In a further embodiment, in S2, the plastic product is cleaned, including wiping the oily part on the surface of the plastic product with a soft cloth, rubbing the residual offset print and stubborn stains with a rubber block, cleaning with water containing a dilute acid solution, and then drying with a fan to ensure that the surface is dry and free of impurities, so as to ensure that the plastic parts can be coated in the best condition.

[0027] In a further embodiment, in S2, the grinding method is to manually use sandpaper or an electric grinding wheel to remove burrs and other protrusions, and the grinding thickness loss does not exceed two millimeters to prevent excessive loss of the plastic parts, thereby protecting the structural strength of the plastic parts themselves, and then sandblasting the surface of the plastic parts to be coated to increase the coating adhesion on the surface of the plastic parts.

[0028] In a further embodiment, in S3, the parameter adjustment of the coating machine includes coating time, temperature and vacuum degree, wherein the temperature range during coating is controlled between 40°C and 80°C, and other parameters are determined accordingly according to the size and thickness of the plastic part.

[0029] In a further embodiment, in S4, the exhaust end of the air supply pump passes through the coating chamber and is connected to the interior thereof, a solenoid valve is provided at the exhaust port, and the suction end of the air supply pump is correspondingly connected to an external nitrogen bottle. When the coating is completed, protective gas is introduced into the coating chamber, and the plastic parts are left to stand, so as to facilitate the stabilization of the film layer on the surface of the plastic parts.

[0030] In a further embodiment, in S4, the microporous mesh plate is located between the coating material and the plastic part, the mesh holes in the microporous mesh plate are distributed in a rectangular array, and the number of micropores in the microporous mesh plate can completely cover the surface of the plastic part.

[0031] In a further embodiment, in S7, the baking temperature of the plastic part is 50-60°C, the UV energy is 800-1200mJ / cm2, and the UV curing time is 5-15min.

[0032] In a further embodiment, in S9, the inspection method is manual sampling inspection to determine that the thickness of the film layer is between 55 and 90 μm. During the inspection, the film layer is subjected to an adhesion test by means of a tape. A 3MScotch tape with a length of 15-20 cm and a width of 0.5-1 inch is adhered to the aluminum layer of the aluminum-coated film, which is flattened and peeled off at a uniform speed. The area of ​​the peeled film layer is observed and estimated, so as to facilitate quality inspection of the adhesion degree of the film layer on the surface of the plastic part and ensure the coating effect.

[0033] Technical effects and advantages of the present invention:

[0034] The vacuum coating process of plastic products is achieved by providing a reciprocating microporous screen assembly in the coating chamber of the PVD vacuum coating machine, so that the coating material can be accurately and evenly attached to the surface of the plastic part to be coated according to the mesh distribution of the microporous screen, forming a dense coating layer, making the coating effect of the plastic product controllable, and greatly improving the coating effect of the plastic product.

[0035] The vacuum coating process of plastic products is achieved by adding an air supply pump in the coating chamber of the PVD vacuum coating machine. After the coating is completed, the protective gas can be quickly filled into the coating chamber to ensure the stability of the coating layer of the plastic product and reduce oxidation. After the coating layer is stable, it can be taken out for subsequent curing operations. DETAILED DESCRIPTION

[0036] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0037] The present invention provides a vacuum coating process for plastic products, and the automatic powder spraying process for metal parts will be introduced in detail below.

[0038] A vacuum coating process for plastic products comprises the following steps:

[0039] S1. Material preparation: determine the plastic parts to be processed, coating materials and PVD vacuum coating machine;

[0040] S2. Preprocessing:

[0041] (1) Clean plastic products and remove surface oil and impurities;

[0042] (2) Grinding and sandblasting the surface of plastic products.

[0043] Among them, the cleaning of plastic products includes wiping the oily parts on the surface of plastic products with a soft cloth, rubbing the residual offset prints and stubborn stains with a rubber block, cleaning them with water containing dilute acid, and then using a fan to dry them to ensure that the surface is dry and free of impurities, so as to ensure that the plastic parts can be coated in the best condition.

[0044] The grinding method is to manually use sandpaper or electric grinding wheel to remove burrs and other protrusions. The grinding thickness loss does not exceed two millimeters to prevent excessive loss of the plastic parts, thereby protecting the structural strength of the plastic parts themselves. The surface of the plastic parts to be coated is then sandblasted to increase the coating adhesion on the surface of the plastic parts.

[0045] S3. Inspection: Debug the equipment to ensure normal operation of the equipment, adjust the coating machine parameters, and use the test workpiece to perform pre-coating test on the PVD vacuum coating machine.

[0046] Among them, the parameter adjustment of the coating machine includes coating time, temperature and vacuum degree. The temperature range during coating is controlled between 40°C and 80°C. Other parameters are determined accordingly according to the size and thickness of the plastic parts.

[0047] S4. Coating preparation:

[0048] (1) placing the coating material into a PVD vacuum coating machine, placing the plastic part on a coating rack, placing the coating rack into a coating chamber, and evacuating the coating chamber to place the plastic part in a vacuum environment;

[0049] (2) An air supply pump is installed outside the PVD vacuum coating machine;

[0050] (3) A slide rail is installed on the inner wall of the coating chamber, a linear motor is arranged in the slide rail, and a microporous mesh plate is fixedly connected to the driving end of the linear motor.

[0051] The exhaust end of the air supply pump runs through the coating chamber and is connected to its interior. A solenoid valve is provided at the exhaust port. The air suction end of the air supply pump is connected to an external nitrogen bottle. When the coating is completed, protective gas is introduced into the coating chamber and the plastic parts are left to stand to facilitate the stabilization of the film layer on the surface of the plastic parts.

[0052] Among them, the microporous mesh plate is located between the coating material and the plastic part. The mesh holes in the microporous mesh plate are distributed in a rectangular array, and the number of micropores in the microporous mesh plate can completely cover the surface of the plastic part.

[0053] S5, start coating:

[0054] (1) Start the linear motor to drive the microporous screen to move horizontally;

[0055] (2) The coating material is heated by a PVD vacuum coating machine, so that the coating material evaporates, passes through the mesh holes in the microporous mesh plate, and is evenly deposited on the surface of the plastic part;

[0056] S6, coating is completed: after coating is completed, the protective gas is delivered to the coating chamber through the gas supply pump, and the coated plastic product is left to stand, and the plastic part is taken out after the film layer is stably attached;

[0057] S7, post-processing:

[0058] (3) The vacuum-coated plastic parts are sent to a drying room for heating through a conveyor chain, and the film layer of the plastic parts is UV-cured;

[0059] (2) Polish the plastic parts and spray protective paint after polishing.

[0060] The baking temperature of plastic parts is 50-60℃, the UV energy is 800-1200mJ / cm2, and the UV curing time is 5-15min.

[0061] S8, cleaning: after the plastic parts are solidified, the burrs are smoothed;

[0062] S9. Inspection: Mainly inspect the appearance of plastic parts and coating thickness, and repair plastic workpieces that are found to have defects such as pinholes, bruises, bubbles, etc.

[0063] The inspection method is manual sampling inspection to determine that the thickness of the film layer is between 55 and 90μm. During the inspection, the film layer is tested for adhesion by using tape. A 3M Scotch tape with a length of 15-20cm and a width of 0.5-1inch is attached to the aluminum layer of the aluminum-plated film. After it is flattened, it is peeled off at a uniform speed. The peeled area of ​​the coating layer is observed and estimated, which is convenient for quality inspection of the adhesion of the film layer on the surface of the plastic part to ensure the coating effect.

[0064] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A vacuum coating process for plastic products, characterized in that: The steps include: S1. Material preparation: determine the plastic parts to be processed, coating materials and PVD vacuum coating machine; S2. Preprocessing: (1) Clean plastic products and remove surface oil and impurities; (2) Grinding and sandblasting the surface of plastic products; S3, Inspection: Debug the equipment to ensure normal operation of the equipment, adjust the coating machine parameters, and use the test workpiece to perform pre-coating test on the PVD vacuum coating machine; S4. Coating preparation: (1) placing the coating material into a PVD vacuum coating machine, placing the plastic part on a coating rack, placing the coating rack into a coating chamber, and evacuating the coating chamber to place the plastic part in a vacuum environment; (2) An air supply pump is installed outside the PVD vacuum coating machine; (3) A slide rail is installed on the wall of the coating chamber, a linear motor is provided in the slide rail, and a microporous mesh plate is fixedly connected to the driving end of the linear motor; S5, start coating: (1) Start the linear motor to drive the microporous screen to move horizontally; (2) The coating material is heated by a PVD vacuum coating machine, so that the coating material evaporates, passes through the mesh holes in the microporous mesh plate, and is evenly deposited on the surface of the plastic part; S6, coating completed: After coating is completed, the protective gas is delivered to the coating chamber through the gas supply pump, and the coated plastic product is left to stand, and the plastic part is taken out after the film layer is stably attached; S7, post-processing: (1) The vacuum-coated plastic parts are sent to a drying room for heating through a conveyor chain, and the film layer of the plastic parts is UV-cured; (2) Polish the plastic parts and spray protective paint after polishing; S8, cleaning: after the plastic parts are solidified, the burrs are smoothed; S9. Inspection: Mainly inspect the appearance of plastic parts and coating thickness, and repair plastic workpieces that are found to have defects such as pinholes, bruises, bubbles, etc.

2. The vacuum coating process for plastic products according to claim 1, characterized in that: In S2, the plastic product is cleaned, including wiping the oily part on the surface of the plastic product with a soft cloth, rubbing the residual offset print and stubborn stains with a rubber block, cleaning with water containing dilute acid, and then drying with a fan to ensure that the surface is dry and free of impurities.

3. The vacuum coating process for plastic products according to claim 1, characterized in that: In S2, the grinding method is to manually use sandpaper or an electric grinding wheel to remove burrs and other protrusions, and the grinding thickness loss does not exceed two millimeters, and then the surface of the plastic part to be coated is sandblasted.

4. The vacuum coating process for plastic products according to claim 1, characterized in that: In S3, the parameters of the coating machine are adjusted, including coating time, temperature and vacuum degree.

5. The vacuum coating process for plastic products according to claim 1, characterized in that: In S4, the exhaust end of the air supply pump passes through the coating chamber and is connected to the interior thereof, a solenoid valve is provided at the exhaust end, and the air suction end of the air supply pump is correspondingly connected to an external nitrogen bottle.

6. The vacuum coating process for plastic products according to claim 1, characterized in that: In S4, the microporous mesh plate is located between the coating material and the plastic part, the mesh holes in the microporous mesh plate are distributed in a rectangular array, and the number of micropores in the microporous mesh plate can completely cover the surface of the plastic part.

7. The vacuum coating process for plastic products according to claim 1, characterized in that: In S7, the baking temperature of the plastic part is 50-60°C, the UV energy is 800-1200mJ / cm2, and the UV curing time is 5-15min.

8. The vacuum coating process for plastic products according to claim 1, characterized in that: In S9, the inspection method is manual sampling inspection to determine that the thickness of the film layer is between 55 and 90 μm. During the inspection, the film layer is subjected to an adhesion test by means of a tape. A 3M Scotch tape with a length of 15-20 cm and a width of 0.5-1 inch is adhered to the aluminum layer of the aluminum-coated film, which is flattened and then peeled off at a uniform speed to observe and estimate the area of ​​the peeled coating layer.