Coating process for water transfer printing of aluminum alloy wheel

Abstract

The invention belongs to the technical field of coating, and relates to an aluminum alloy wheel water transfer printing coating process which comprises the following steps: firstly, placing a pretreated wheel at the bottom of a container filled with water, and controlling the water level to submerge the wheel by a certain height; after the release layer is stripped off, the base film of the hydrophobic water transfer printing film is stripped off, the hydrophobic water transfer printing film is horizontally placed on the water surface, the hydrophobic water transfer printing film at least comprises a water-soluble coating, a hydrophobic image-text layer, the release layer and the base film in sequence, the surface of the water-soluble coating is placed in water, after the water-soluble coating is dissolved, the wheel is slowly lifted, and then the water-soluble coating is removed; the hydrophobic image-text layer is transferred to the surface of the wheel through water pressure, and the condition is kept for 5-20 min so that the transfer film can be stably adsorbed to the surface of the wheel; taking out the transferred wheel, cleaning the residual film and the floating layer, and drying; and spraying transparent paint, drying and curing, and discharging the finished product. An organic activating agent is not used for activating the image-text layer any more, and environmental pollution is reduced. Individualized, multi-color and complex patterns can be coated on the surface of the wheel, and the scratch resistance of the wheel can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coating, relates to wheel coating, and in particular to a water transfer coating process for aluminum alloy wheels. Background Art

[0002] In the aluminum alloy wheel manufacturing industry, the appearance of the wheel is limited by the structure and production process of the product itself, and there are still two shortcomings: 1. Consumers can only choose from existing simple patterns and colors, and the pattern colors cannot be too complicated; 2. For the personalized patterns provided by consumers themselves, it is often impossible to reflect them in the wheel paint and meet the needs of consumers.

[0003] Water transfer technology is a process technology that uses water pressure and interfacial adhesion to cover images and texts on the surface of an object and perform transfer printing. According to the specific characteristics of the technology that can be achieved, it can be divided into watermark transfer and water drape transfer. Watermark transfer is a technology that completely transfers images and texts on watermark transfer paper to the surface of the substrate. Watermark transfer paper is a transfer image and text produced by screen printing or offset printing on a substrate, and is suitable for the transfer of flat images and texts. Water drape transfer refers to a technology that uses a water-soluble flexible film to attach to the surface of an object and transfer the pattern on the film to the surface of the object. Among them, the water drape transfer film is a film with a color pattern printed on the surface of a water-soluble plastic film using gravure printing or inkjet printing and special inks. It is mainly used for overall transfer on the surface of an object, but the carrier will be stretched and deformed during the transfer process. The traditional water drape transfer process first prepares a polyvinyl alcohol (PVA) water-soluble film, then prints the pattern on the PVA film by gravure printing or inkjet printing, and then performs water transfer. Water transfer printing technology is widely used for printing on non-planar objects, such as car steering wheels, welcome pedals, car interiors, baby carriages, toys and craft decorations.

[0004] Traditional paint coating of wheels cannot meet the personalized appearance display, but water transfer printing can solve this problem. Consumers can not only paint their favorite pictures and texts on the wheels, but also meet the needs of personalized complex patterns. CN106423804 discloses a color matching process for aluminum alloy wheels, which applies water transfer printing technology to color matching on the wheel surface to achieve mass production of color matching wheels, but does not optimize the water transfer printing technology, and the quality of the water transfer printing process cannot be guaranteed. Summary of the invention

[0005] In order to overcome the defects of the prior art, the present invention discloses a water transfer painting process for aluminum alloy wheels.

[0006] Technical Solution

[0007] A water transfer coating process for aluminum alloy wheels comprises the following steps:

[0008] A. Place the pre-treated wheel at the bottom of a container filled with water, and control the water level to submerge the wheel to a certain height;

[0009] B. After peeling off the release layer, peel off the base film of the hydrophobic water transfer film and place it horizontally on the water surface. The hydrophobic water transfer film includes at least a water-soluble coating, a hydrophobic image layer, a release layer and a base film in sequence. Place the surface of the water-soluble coating in water. After the water-soluble coating is dissolved, slowly raise the wheel and use water pressure to transfer the hydrophobic image layer to the wheel surface. Keep it for 5 to 20 minutes so that the transfer film is stably adsorbed on the wheel surface;

[0010] C. Take out the wheel after transfer, clean the residual film and floating layer, and dry it;

[0011] D. Spray transparent paint, dry and solidify before the finished product comes off the line.

[0012] In a preferred embodiment of the present invention, the pretreatment in step A includes pre-cleaning, pre-degreasing, degreasing, washing, pickling, washing, passivation, washing, primer sealing, and drying of the bare wheel, so that a passivation film is formed on the wheel surface. The surface energy of the passivation film is reduced, which can increase the adhesion between the hydrophobic transfer film and the wheel, making the wheel surface smoother and easier to transfer the hydrophobic image layer.

[0013] Furthermore, the color of the primer is consistent with the color tone of the image to be transferred, and the thickness is 10 to 25 μm.

[0014] In a preferred disclosed embodiment of the present invention, the water temperature in step A is 20-30° C., and the height is 5-20 cm.

[0015] In a preferred embodiment of the present invention, in step B, the hydrophobic water transfer film is peeled off the base film and then placed horizontally on the water surface for 10 to 20 minutes, preferably 15 minutes, so that the water-soluble coating is completely dissolved in the water.

[0016] In a preferred embodiment of the present invention, the hydrophobic water transfer film in step B, the water-soluble coating is formed by coating with a water-soluble polymer solution such as polyacrylamide, polyacrylic acid, polyvinyl pyrrolidone, polyvinyl alcohol, polymaleic anhydride, polyethylene glycol, etc., preferably a polyvinyl alcohol or polyethylene glycol coating.

[0017] In a preferred embodiment of the present invention, the hydrophobic water transfer film in step B, the main components of the hydrophobic graphic layer include but are not limited to polyolefins, polycarbonates, polyamides, polyacrylonitrile, polyesters, siloxanes and polymers thereof, epoxy resin E51, organic-inorganic hybrid materials, etc., preferably siloxanes and polymers thereof.

[0018] In a preferred embodiment of the present invention, the hydrophobic water transfer film in step B and the pattern and text of the hydrophobic pattern and text layer are optional.

[0019] In a preferred embodiment of the present invention, the hydrophobic water transfer film, the release layer and the base film in step B are conventionally selected in the art.

[0020] In a preferred embodiment of the present invention, the drying temperature in step C is lower than the melting point of the film.

[0021] In a preferred disclosed embodiment of the present invention, in step D, the drying temperature is 110-130° C., and the drying time is 5-15 min.

[0022] Beneficial Effects

[0023] Compared with the existing water transfer film, the aluminum alloy wheel water transfer coating process disclosed by the present invention no longer uses an organic activator to activate the image layer, thereby reducing environmental pollution. A lifting device is provided at the bottom of the additional transfer water tank so that the wheel can be lifted and lowered in the tank. The wheel surface can be painted with personalized, multi-color, and complex patterns, and the anti-scratch performance of the wheel can also be improved. The water transfer film can make the wheel surface present multi-color and complex patterns, which has great advantages in meeting customers' demand for personalization and seizing the market. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with the embodiments so that those skilled in the art can better understand the present invention, but the present invention is not limited to the following embodiments.

[0025] Example 1

[0026] A water transfer coating process for aluminum alloy wheels comprises the following steps:

[0027] A. Pre-cleaning, pre-degreasing, degreasing, washing, pickling, washing, passivation, washing, primer sealing, and drying of the bare wheel to form a passivation film on the wheel surface. Then place the pre-treated wheel at the bottom of a container filled with water, control the water level so that it submerges the wheel by 5 cm, and the water temperature is 30°C;

[0028] B. After peeling off the release layer, peel off the base film of the hydrophobic water transfer film and place it horizontally on the water surface for 10 to 20 minutes. The hydrophobic water transfer film includes at least a water-soluble coating, a hydrophobic image layer, a release layer and a base film in sequence. After peeling off the release layer, place the surface of the water-soluble coating in water. After the water-soluble coating is dissolved, slowly raise the wheel and use water pressure to transfer the hydrophobic image layer to the wheel surface. Keep it for 5 to 20 minutes.

[0029] 20 minutes to allow the transfer film to be stably adsorbed on the wheel surface; the water-soluble coating is formed by coating with a polyvinyl alcohol water-soluble polymer solution; the main components of the hydrophobic graphic layer are siloxane and its polymer;

[0030] C. Take out the wheel after transfer, clean the residual film and floating layer, and dry it;

[0031] D. Spray transparent paint, dry and cure at 110℃ for 15 minutes, and then the finished product will be off the line.

[0032] Example 2

[0033] A water transfer coating process for aluminum alloy wheels comprises the following steps:

[0034] A. Pre-cleaning, pre-degreasing, degreasing, washing, pickling, washing, passivation, washing, primer sealing, and drying of the bare wheel to form a passivation film on the wheel surface. Then place the pre-treated wheel at the bottom of a container filled with water, control the water level so that it submerges the wheel by 20 cm, and the water temperature is 20°C;

[0035] B. After peeling off the release layer, peel off the base film of the hydrophobic water transfer film, and place it horizontally on the water surface for 20 minutes. The hydrophobic water transfer film includes at least a water-soluble coating, a hydrophobic image layer, a release layer and a base film in sequence. After peeling off the release layer, place the surface of the water-soluble coating in water. After the water-soluble coating is dissolved, slowly raise the wheel, use water pressure to transfer the hydrophobic image layer to the wheel surface, and keep it for 20 minutes so that the transfer film is stably adsorbed on the wheel surface; the water-soluble coating is formed by coating a water-soluble polymer solution of polyvinyl pyrrolidone, and the main component of the hydrophobic image layer includes polyolefin;

[0036] C. Take out the wheel after transfer, clean the residual film and floating layer, and dry it;

[0037] D. Spray transparent paint, dry and cure at 130℃ for 15 minutes, and then the finished product will be off the line.

[0038] Example 3

[0039] A water transfer coating process for aluminum alloy wheels comprises the following steps:

[0040] A. Pre-cleaning, pre-degreasing, degreasing, washing, pickling, washing, passivation, washing, primer sealing, and drying of the bare wheel to form a passivation film on the wheel surface. Then place the pre-treated wheel at the bottom of a container filled with water, control the water level to submerge the wheel 100cm, and the water temperature is 25℃;

[0041] B. After peeling off the release layer, peel off the base film of the hydrophobic water transfer film, and place it horizontally on the water surface for 5 minutes. The hydrophobic water transfer film includes at least a water-soluble coating, a hydrophobic image layer, a release layer and a base film in sequence. After peeling off the release layer, place the surface of the water-soluble coating in water. After the water-soluble coating is dissolved, slowly raise the wheel, use water pressure to transfer the hydrophobic image layer to the wheel surface, and keep it for 10 minutes so that the transfer film is stably adsorbed on the wheel surface; the water-soluble coating is formed by coating a polyethylene glycol water-soluble polymer solution, and the main component of the hydrophobic image layer is polyester;

[0042] C. Take out the wheel after transfer, clean the residual film and floating layer, and dry it;

[0043] D. Spray transparent paint, dry and cure at 120℃ for 10 minutes, and then the finished product will be off the line.

[0044] Example 4

[0045] A water transfer coating process for aluminum alloy wheels comprises the following steps:

[0046] A. Pre-cleaning, pre-degreasing, degreasing, washing, pickling, washing, passivation, washing, primer sealing, and drying of the bare wheel to form a passivation film on the wheel surface. Then place the pre-treated wheel at the bottom of a container filled with water, control the water level so that it submerges the wheel by 18 cm, and the water temperature is 25°C;

[0047] B. After peeling off the release layer, peel off the base film of the hydrophobic water transfer film and place it horizontally on the water surface for 10 to 20 minutes. The hydrophobic water transfer film includes at least a water-soluble coating, a hydrophobic image layer, a release layer and a base film in sequence. After peeling off the release layer, place the surface of the water-soluble coating in water. After the water-soluble coating is dissolved, slowly raise the wheel and use water pressure to transfer the hydrophobic image layer to the wheel surface. Keep it for 5 to 20 minutes.

[0048] 20 minutes to allow the transfer film to be stably adsorbed on the wheel surface; the water-soluble coating is formed by coating a polymaleic anhydride water-soluble polymer solution, and the main component of the hydrophobic graphic layer includes an organic-inorganic hybrid material;

[0049] C. Take out the wheel after transfer, clean the residual film and floating layer, and dry it;

[0050] D. Spray transparent paint, dry and cure at 118℃ for 18 minutes, and then the finished product will be off the line.

[0051] Example 5

[0052] A water transfer coating process for aluminum alloy wheels comprises the following steps:

[0053] A. Pre-cleaning, pre-degreasing, degreasing, washing, pickling, washing, passivation, washing, primer sealing, and drying of the bare wheel to form a passivation film on the wheel surface. Then place the pre-treated wheel at the bottom of a container filled with water, control the water level so that it submerges the wheel by 12 cm, and the water temperature is 22°C;

[0054] B. After peeling off the release layer, peel off the base film of the hydrophobic water transfer film, and place it horizontally on the water surface for 12 minutes. The hydrophobic water transfer film includes at least a water-soluble coating, a hydrophobic image layer, a release layer and a base film in sequence. After peeling off the release layer, place the surface of the water-soluble coating in water. After the water-soluble coating is dissolved, slowly raise the wheel, use water pressure to transfer the hydrophobic image layer to the wheel surface, and keep it for 10 minutes so that the transfer film is stably adsorbed on the wheel surface; the water-soluble coating is formed by coating a polyethylene glycol water-soluble polymer solution, and the main components of the hydrophobic image layer include siloxane and its polymer;

[0055] C. Take out the wheel after transfer, clean the residual film and floating layer, and dry it;

[0056] D. Spray transparent paint, dry and cure at 125℃ for 13 minutes, and then the finished product will be off the line.

[0057] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the specification of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A water transfer coating process for aluminum alloy wheels, characterized in that: The steps include: A. Place the pre-treated wheels at the bottom of a container filled with water and control the water level to submerge the wheels to a certain height; B. After peeling off the release layer, peel off the base film of the hydrophobic water transfer film and place it horizontally on the water surface. The hydrophobic water transfer film includes at least a water-soluble coating, a hydrophobic image layer, a release layer and a base film in sequence. Place the surface with the water-soluble coating in the water. After the water-soluble coating is dissolved, slowly raise the wheel and use water pressure to transfer the hydrophobic image layer to the wheel surface. Keep it for 5 to 20 minutes so that the transfer film is stably adsorbed on the wheel surface; C. Take out the wheel after transfer, clean the residual film and floating layer, and dry it; D. Spray transparent paint, dry and solidify before the finished product comes off the production line.

2. The aluminum alloy wheel water transfer coating process according to claim 1 is characterized in that: The pretreatment in step A includes the steps of pre-cleaning, pre-degreasing, degreasing, washing, pickling, washing, passivation, washing, primer sealing, and drying of the bare wheel, so that a passivation film is formed on the wheel surface.

3. The water transfer coating process for aluminum alloy wheels according to claim 2 is characterized in that: The color of the primer is consistent with the color tone of the image to be transferred, and the thickness is 10 to 25 μm.

4. The aluminum alloy wheel water transfer coating process according to claim 1 is characterized in that: In step B, the hydrophobic water transfer film is peeled off the base film and then placed horizontally on the water surface for 10 to 20 minutes, preferably until the water-soluble coating is completely dissolved in the water.

5. The aluminum alloy wheel water transfer coating process according to claim 4 is characterized in that: The placement time is 15 minutes.

6. The aluminum alloy wheel water transfer coating process according to claim 1, characterized in that: The hydrophobic water transfer film in step B, the water-soluble coating is formed by coating with a water-soluble polymer solution of polyacrylamide, polyacrylic acid, polyvinyl pyrrolidone, polyvinyl alcohol, polymaleic anhydride, or polyethylene glycol.

7. The aluminum alloy wheel water transfer coating process according to claim 1 is characterized by: The water-soluble coating in step B is a polyvinyl alcohol or polyethylene glycol coating.

8. The aluminum alloy wheel water transfer coating process according to claim 1 is characterized in that: The main components of the hydrophobic graphic layer in step B include polyolefin, polycarbonate, polyamide, polyacrylonitrile, polyester, siloxane and polymers thereof, epoxy resin E51 or organic-inorganic hybrid materials.

9. The aluminum alloy wheel water transfer coating process according to claim 1, characterized in that: The main components of the hydrophobic graphic layer in step B include siloxane and its polymer.

10. The aluminum alloy wheel water transfer coating process according to claim 1, characterized in that: In step D, the drying temperature is 110-130° C. and the drying time is 5-15 min.