Method for coating surface of paper-plastic product with paint

Abstract

The invention discloses a method for coating a coating on the surface of a paper-plastic product, which comprises the following steps of: uniformly coating the coating on a coating carrier tape, and then pressing the coating carrier tape by adopting a coating and pressing concave die matched with a coating area of the paper-plastic product, and the coating carrier tape is attached to the coating area of the paper-plastic product, the paint on the coating carrier tape is transferred to the paper-plastic product under the action of pressure, and coating of the coating of the paper-plastic product is completed. In order to provide supporting force for the paper-plastic product during coating and pressing, a supporting male die used for supporting the paper-plastic product is further arranged, and the coating and pressing female die is matched with the supporting male die to complete coating and pressing. In order to ensure the adsorbability of the coating carrier tape, facilitate deformation and improve the fitting degree with the molded surface of a paper-plastic product, the coating carrier tape is a textile fabric with certain water absorption and has certain telescopic elasticity. The method can ensure that the oily paint and the water-based paint can be uniformly attached to the surface of the paper-plastic product, can adapt to a complex molded surface structure of the paper-plastic product, and can be widely applied to the field of surface coating of the paper-plastic product.

Description

Technical Field

[0001] This invention relates to the field of paper-plastic product manufacturing and processing, specifically to a method for coating the surface of paper-plastic products with a coating. Background Technology

[0002] In the production and processing of paper-plastic products such as paper-plastic cup lids and cups, depending on the usage scenario, the surface of the paper-plastic products is covered with coatings such as coloring, printing, and waterproofing / oil-proofing. Waterproofing / oil-proofing coatings are generally applied by spraying, and some flat surfaces are coated using pad printing. The disadvantages of spraying are that it atomizes the paint through a spray nozzle, evenly adhering it to the product surface. While this offers good uniformity, it also results in paint scattering and adhering everywhere, requiring operators to wear goggles, dust masks, and other personal protective equipment. Furthermore, it is wasteful and has low utilization rates. Additionally, it requires a highly sealed workshop environment, making equipment maintenance and cleaning inconvenient and potentially harmful to operator health. Pad printing, on the other hand, uses rubber or silicone tips to pick up paint from a gravure plate and transfer it to the area of ​​the product requiring coating. However, pad printing is only suitable for flat products and generally uses oil-based paints, offering good adhesion and controllable evaporation time. If water-based coatings are to be applied to the surface of paper-plastic products, the high surface tension and poor adhesion of these coatings can lead to uneven material feeding during pad printing, resulting in poor coating uniformity. Therefore, a new coating method needs to be developed that can address both the defects of spray coating and the uniformity issues associated with pad printing for water-based coatings. Summary of the Invention

[0003] The purpose of this invention is to provide a method for coating the surface of paper-plastic products. This method can solve the problem of low coating utilization in spray coating process and the problem of poor uniformity and inability to adapt to complex shapes when applying water-based coatings in pad printing process.

[0004] The technical solution adopted by the present invention to solve its technical problem is: a method for coating the surface of paper-plastic products, wherein the coating is uniformly coated on a coating carrier, and then a coating die adapted to the coating area of ​​the paper-plastic product is used to press the coating carrier, so that the coating carrier is in contact with the coating area of ​​the paper-plastic product and the coating on the coating carrier is transferred to the paper-plastic product under the action of pressure, thereby completing the coating of the paper-plastic product.

[0005] To provide support for the paper-plastic product during coating, a support punch is also provided to support the paper-plastic product. The coating die and the support punch cooperate to complete the coating process.

[0006] To ensure the absorbency and ease of deformation of the coated carrier tape, thereby improving its fit with the surface of the paper-plastic product, the coated carrier tape is a textile fabric with a certain degree of water absorption and elasticity.

[0007] To facilitate multiple uses of the coated carrier tape, the coated carrier tape is first coated in the coating unit and then enters the coating die for coating. After coating, the coated carrier tape returns to the coating unit for coating again, and this process is repeated.

[0008] Furthermore, the coating unit includes a coating box for holding the coating and a set of coating rollers that dip the coating into the coating box and attach it to the coating carrier belt.

[0009] Preferably, the coating roller assembly includes a pick-up roller located above the coating box, the lower part of which is immersed in the coating material in the coating box, and the coating carrier belt located above the pick-up roller. The pick-up roller picks up the coating material in the coating box and coats it onto the surface of the coating carrier belt.

[0010] A driven roller is also provided above the feeding roller, and the coating carrier belt passes between the feeding roller and the driven roller; the gap between the driven roller and the feeding roller is adjustable to control the amount of coating material applied to the coating carrier belt.

[0011] In another embodiment, the coating roller assembly includes a take-up roller, at least its lower part of which is immersed in the coating material in the coating box, and the coating carrier belt passes under the take-up roller and is immersed in the coating material in the coating box; the discharge end of the coating box is provided with a leveling roller assembly for controlling the amount and uniformity of coating material on the coating carrier belt, the leveling roller assembly includes a leveling upper roller and a leveling lower roller that cooperate with each other, and a gap is provided between the leveling upper roller and the leveling lower roller for the coating carrier belt to pass through.

[0012] Preferably, the coating carrier belt is a circulating carrier belt, which enters from the feed end of the coating box, exits from the discharge end, then enters from one end of the supporting punch, exits from the other end, and returns to the feed end of the coating box.

[0013] To further reduce paint waste, a coating box is provided on each side of the supporting punch, and a take-up and untake-up roller is provided at the feed end of the coating box. The coating carrier belt reciprocates between the two take-up and untake-up rollers.

[0014] The beneficial effects of this invention are as follows: This invention employs a coating die in conjunction with a coating carrier belt to apply coating material from the carrier belt onto the paper-plastic product. Because the carrier belt has a flexible structure, it can conform to the complex shape of the paper-plastic product under the action of the coating die, ensuring proper coating and effectively solving the problem of existing pad printing processes being unable to handle complex applications. Simultaneously, the coating die can be adjusted according to the area of ​​the paper-plastic product to be coated; the coating area can be continuous or discontinuous, and different coating dies can be replaced as needed, making adjustment convenient. This method minimizes paint waste, thereby reducing high production costs. The coating carrier belt can adhere not only to oil-based coatings but also to water-based coatings, ensuring smooth transfer of coating material to the paper-plastic product. The coating unit can apply coating material to the carrier belt and ensure the uniformity of the coating, thus ensuring the uniformity of the coating material on the surface of the paper-plastic product after coating.

[0015] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 .

[0017] Figure 2 This is a schematic diagram of the structure of the coating die and the paper-plastic product in the separated state in this invention.

[0018] Figure 3 This is a schematic diagram of the structure of the coating die and the paper-plastic product in this invention.

[0019] Figure 4 This is a schematic diagram of the structure in which the coating carrier and the coating unit cooperate in this invention. Figure 1 .

[0020] Figure 5 This is a schematic diagram of the structure of the intermediate coating carrier tape and coating unit in this utility model. Figure 2 .

[0021] Figure 6 This is a schematic diagram of the structure in the present invention. Figure 2 . Detailed Implementation

[0022] Examples, such as Figures 1 to 6As shown, a method for coating the surface of a paper-plastic product aims to solve the problem that existing coating methods cannot adapt to coating complex shapes. It also addresses the issues of high paint waste and inaccurate spraying in spray painting processes, and incomplete transfer and poor coating uniformity in pad printing methods for water-based coatings. The method involves uniformly coating the paint onto a coating carrier belt 3, then pressing the coating carrier belt 3 with a coating die 2 adapted to the coating area of ​​the paper-plastic product 10. This causes the coating carrier belt 3 to adhere to the coating area of ​​the paper-plastic product 10, and under pressure, the paint on the coating carrier belt 3 is transferred to the paper-plastic product 10, completing the coating process. To provide support for the paper-plastic product 10 during coating, a support punch 1 is also provided. The coating die 2 cooperates with the support punch 1 to complete the coating process.

[0023] To ensure the absorbency of the coated carrier tape 3 and facilitate deformation to improve its fit with the paper-plastic product surface, the coated carrier tape 3 is a textile fabric with a certain degree of water absorption and elasticity.

[0024] To ensure timely application of coating material to the coating carrier belt 3, a coating unit 5 is also provided. The coating unit 5 applies the coating material to the coating carrier belt 3. The coating carrier belt 3 can be in a cyclical motion, such as... Figure 1 As shown, reciprocating motion can also be used, such as... Figure 6 As shown. By using a cyclic motion, the entire coating carrier belt 3 is wetted with coating material, while by using a reciprocating motion, only a portion of the coating carrier belt 3 needs to be wetted with coating material, thus reducing coating waste.

[0025] The coating unit 5 includes a coating box 51 for holding coatings and a set of coating rollers 52 that dip coatings from the coating box 51 and attach them to the coating carrier belt 3. To control the movement of the coating carrier belt 3, a coating carrier belt traction device 4 is also provided, which conveys the coating carrier belt 3 forward at a certain tension. The traction device 4 includes at least one power roller 41, a set of support rollers 42, and tension adjusting rollers 43 disposed on the left and right sides of the coating die 2. The tension adjusting rollers 43 can adjust and move the coating carrier belt 3 as it is pressed down by the coating die 2 to maintain a certain tension. The tension adjusting rollers 43 are a common tension adjustment structure used in material conveying and are existing technology, therefore they will not be described in detail here.

[0026] The coating carrier belt 3 can operate in a cyclic motion. It enters from the feed end of the coating box 51 and exits from the discharge end, loading the coating material. Then, it enters below the coating die 2, completes the coating process, and returns to the coating box 51 for reloading. This process is repeated. Figure 1As shown. A reciprocating motion is employed. A coating box 51 is provided on each side of the supporting punch 1. The feeding end of each coating box 51 is equipped with a take-up / feed roller 6, which serves as a power roller 41. The coating carrier belt 3 reciprocates between the two take-up / feed rollers 6. Figure 6 As shown, only one section of the coating carrier 3 needs to be wetted, while the other parts of the coating carrier 3 do not need to carry the coating. Therefore, the amount of coating adsorbed by the coating carrier 3 can be minimized.

[0027] The adhesive coating roller assembly 52 has two configurations, one of which is as follows: Figure 3 As shown, the coating roller assembly 52 includes a pick-up roller 521 located above the coating box 51. The lower part of the pick-up roller 521 is immersed in the coating material in the coating box 51. The coating carrier belt 3 is located above the pick-up roller 521. The pick-up roller 521 is a power roller 41. The pick-up roller 521 rotates to pick up the coating material in the coating box 51 and coat it on the surface of the coating carrier belt 3.

[0028] To smoothly carry the coating out of the coating box 51, the pick-up roller 521 can be used in several ways. One method is to cover the surface of the pick-up roller 521 with a layer of cloth or microporous silicone 5211, which will adsorb the coating and transfer it to the surface of the coating carrier belt 3. Another method is to directly use a metal roller as the pick-up roller 521 and set grooves on the surface of the pick-up roller 521. The groove structure will carry the coating out of the coating box 51 and rotate it to the surface of the coating carrier belt 3.

[0029] To facilitate the forward movement of the coating carrier belt 3 and to control the amount and uniformity of coating on the belt, a driven roller 522 is provided above the take-up roller 521. The coating carrier belt 3 passes between the take-up roller 521 and the driven roller 522, moving forward under their influence. The amount of coating on the carrier belt 3 can be adjusted by regulating the gap between the driven roller 522 and the take-up roller 521, ensuring uniform adhesion of the coating to the carrier belt 3 under the action of the driven roller 522 and the take-up roller 521.

[0030] Another structure, such as Figure 4As shown, the coating roller assembly 52 includes a take-up roller 521, at least its lower part of which is immersed in the coating material in the coating box 51. The coating carrier belt 3 draws up coating material from below the take-up roller 521, passing over the coating material immersed in the coating box 51. To control the amount and uniformity of coating material on the coating carrier belt 3, a leveling roller assembly 53 is provided at the discharge end of the coating box 51 to control the amount and uniformity of coating material on the coating carrier belt 3. The leveling roller assembly 53 includes a leveling upper roller 531 and a leveling lower roller 532 that cooperate with each other, with a gap between the leveling upper roller 531 and the leveling lower roller 532 for the coating carrier belt 3 to pass through. The amount and uniformity of coating material on the coating carrier belt 3 are controlled by adjusting the size of the gap between the leveling upper roller 531 and the leveling lower roller 532. The leveling upper roller 531 or the leveling lower roller 532 serves as a power roller 41.

[0031] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A method for coating the surface of a paper-plastic product with a coating, characterized in that: The coating is evenly applied to the coating carrier belt. Then, a coating die adapted to the coating area of ​​the paper-plastic product is used to press down the coating carrier belt, so that the coating carrier belt is in contact with the coating area of ​​the paper-plastic product. Under the action of pressure, the coating on the coating carrier belt is transferred to the paper-plastic product, thus completing the coating of the paper-plastic product.

2. The method for coating the surface of paper-plastic products according to claim 1, characterized in that: It is also provided with a support punch for supporting paper-plastic products, and the coating die cooperates with the support punch to complete the coating process.

3. The method for coating the surface of paper-plastic products according to claim 1, characterized in that: The coated carrier belt is a textile fabric with a certain degree of water absorption and elasticity.

4. The method for coating the surface of paper-plastic products according to claim 1, characterized in that: The coating carrier belt is first coated in the coating unit and then enters the coating die for coating. After coating, the coated carrier belt returns to the coating unit for coating again, and this process is repeated.

5. The method for coating the surface of paper-plastic products according to claim 1, characterized in that: The coating unit includes a coating box for holding coatings and a set of coating rollers that dip coatings from the coating box and attach them to the coating carrier belt.

6. The method for coating the surface of paper-plastic products according to claim 5, characterized in that: The coating roller assembly includes a pick-up roller located above the coating box, the lower part of which is immersed in the coating material in the coating box, and the coating carrier belt located above the pick-up roller. The pick-up roller picks up the coating material in the coating box and coats it onto the surface of the coating carrier belt. A driven roller is also provided above the feeding roller, and the coating carrier belt passes between the feeding roller and the driven roller; the gap between the driven roller and the feeding roller is adjustable to control the amount of coating material applied to the coating carrier belt.

7. The method for coating the surface of paper-plastic products according to claim 5, characterized in that: The coating roller assembly includes a take-up roller, at least its lower part of which is immersed in the coating material in the coating box. The coating carrier belt passes under the take-up roller and is immersed in the coating material in the coating box. The discharge end of the coating box is provided with a leveling roller assembly to control the amount and uniformity of coating material on the coating carrier belt. The leveling roller assembly includes a leveling upper roller and a leveling lower roller that cooperate with each other, and a gap is provided between the leveling upper roller and the leveling lower roller to allow the coating carrier belt to pass through.

8. The method for coating the surface of paper-plastic products according to claim 5, characterized in that: The coating carrier belt is a circulating carrier belt. The coating carrier belt enters from the feed end of the coating box, exits from the discharge end, then enters from one end of the supporting punch, exits from the other end, and returns to the feed end of the coating box.

9. The method for coating the surface of paper-plastic products according to claim 5, characterized in that: A coating box is provided on each side of the supporting punch. The feeding end of the coating box is equipped with take-up and feed rollers, and the coating carrier belt reciprocates between the two take-up and feed rollers.

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