Prefabricating process of UV coating for woodware

Abstract

The invention belongs to the technical field of wood product surface coating processing, and particularly relates to a UV coating prefabricating process for woodware, which comprises the following steps: prefabricating a UV coating on a PET film, pre-coating the surface of the PET film with the UV coating according to the required coating thickness in a yellow light environment, drying, attaching a release film to one side, back to the PET film, of the UV coating, and rolling, and after rolling, coating with light-proof aluminum foil and curing to obtain a prefabricated film of the UV coating, and after the release film is torn off, adhering the prefabricated film to the surface of the woodware to form the surface coating of the woodware. The problems that during traditional UV coating spraying construction, coating thickness control is not accurate, on-site construction equipment is complicated in type, input cost is high, energy consumption is high and the like are solved, and under the condition that the coating quality is guaranteed, the machining cost is reduced, and the use threshold of the UV coating is lowered.

Description

Technical Field

[0001] The invention belongs to the technical field of surface coating processing of wooden products, and in particular relates to a UV coating prefabrication process for wooden products. Background Art

[0002] UV coatings refer to coatings that are cured by UV radiation. They have a solid content of 100% and do not contain volatile components. They can be applied in thin layers and are widely used on glass, plastic, wood, aluminum and other substrates. They have the advantages of fast curing speed, high gloss, wear resistance and chemical resistance. With the vigorous development of the wood products industry, UV coatings for wood have become the largest coating product in the field of light curing.

[0003] Compared with traditional wood coatings, the surface paint film of wood products sprayed with UV coatings has excellent properties such as high gloss, high brightness, high hardness, high wear resistance, fullness and beauty, and high temperature resistance. However, UV coatings for wood also have some inherent disadvantages. The product cost itself is relatively high. When spraying UV coatings on the surface of wood, special UV spray curing equipment is also required, and the equipment investment cost is relatively high. In addition, the UV coating cures too fast, which affects the leveling of the coating during the spraying process, which may lead to poor uniformity of the thick film of the wood surface coating and poor adhesion between the coating and the substrate or the coating. These have limited the large-scale promotion and use of UV coatings in wood. Summary of the invention

[0004] The present invention provides a UV coating prefabrication process for wood products, so as to solve the technical problems in the prior art that the cost of processing UV coating on the surface of wood products by spraying is high, and the UV coating cures quickly, which easily leads to poor quality of UV coating on the surface of wood products.

[0005] In order to solve the above problems, the UV coating prefabrication process for wood products provided by the present invention adopts the following technical solutions: A UV coating prefabrication process for wood products comprises the following steps: prefabricate a UV coating on a PET film, pre-coat the UV coating on the surface of the PET film in a yellow light environment according to a required coating thickness, adhere a release film to the side of the UV coating facing away from the PET film after drying, and then roll it up; after rolling up, wrap it with an opaque aluminum foil and ripen it; after ripening, obtain a prefabricated film of the UV coating; and after tearing off the release film, the prefabricated film is used to be adhered to the surface of the wood product to form a surface coating of the wood product.

[0006] Preferably, the thickness of the PET film is any one of 38um, 50um, and 100um.

[0007] Preferably, the thickness of the UV coating is any one of 15um, 20um, and 25um.

[0008] Preferably, the thickness of the release film is any one of 25um, 36um, and 50um.

[0009] Preferably, the release force specification of the release film is any one of 5g / mm, 10g / mm, and 15g / mm.

[0010] Furthermore, a scraper coater is used to apply the UV coating on the PTE film through an online coating process. The scraper coater includes a drying chamber, a UV coating liquid tank, a coating roller and a scraper roller. The PET film is subjected to corona treatment before coating; the coating roller is rotatably assembled in the UV coating liquid tank, the coating roller is at least partially immersed in the UV coating liquid contained in the UV coating liquid tank so that the UV coating attached thereto can be evenly coated on the surface of the PET film when the coating roller rotates, and the scraper roller is used to scrape off excess UV coating on the surface of the PET film; the PET film passing through the scraper roller enters the drying chamber for drying, and after drying, it is laminated with the release film and rolled up.

[0011] Preferably, a scraper roller is arranged above the UV coating liquid tank to scrape excess UV coating on the surface of the PET film into the UV coating liquid tank for reuse.

[0012] Preferably, the baking temperature in the drying chamber ranges from 100° C. to 120° C., and the linear speed of the coating roller ranges from 20 m / min to 25 m / min.

[0013] Preferably, the aging temperature ranges from 50°C to 55°C, and the aging time is 3 to 5 days.

[0014] Preferably, the PET film and the release film are both PET release films.

[0015] The beneficial effects of the UV coating prefabrication process for woodware of the present invention are: The present invention adopts online coating process, and UV coating is prefabricated on PET film in advance, and can be cut into suitable size as needed when using, and release film is torn off for laminating construction, without on-site glue preparation and spraying construction, which greatly shortens the construction period, simplifies the construction steps, and can be used immediately after pasting, significantly reducing the construction difficulty. In addition, by adopting online coating process, the coating thickness can be controlled more accurately, which is beneficial to cost accounting, and indirectly reduces the coating coating cost. In addition, the one-time laminating molding process avoids the problems such as poor coating leveling, uneven coating thickness, poor adhesion of coating and substrate brought when coating is sprayed, and the laminating process reduces the use of on-site spraying equipment, and the construction cost is lower. Furthermore, the woodware after laminating only needs to be placed in a general ultraviolet light or outdoor direct sunlight environment, reducing the use of special ultraviolet light curing equipment, so that the construction cost is further reduced, and the reduction in cost greatly reduces the use threshold of UV coating, so that UV coating is expected to be widely promoted and applied in woodware. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 This is a flow chart of the UV coating prefabrication process for woodware of the present invention; Figure 2 It is a schematic diagram of the prefabrication process of UV coating for woodware of the present invention; Figure 3 A schematic diagram of coating using a blade coater; Figure 4 It is a schematic diagram of a prefabricated film obtained by the UV coating prefabrication process for woodware of the present invention.

[0017] Description of reference numerals: 1. PET film; 2. Release film; 3. UV pre-coating; 4. PET film unwinding roller; 5. Release film unwinding roller; 6. Pressing roller; 7. Conveying roller; 9. Drying chamber; 10. Winding roller; 11. Coating roller; 12. Scraper roller; 13. UV coating liquid tank; 14. UV coating liquid; 15. Support roller. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0019] The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0020] Specific embodiments of the UV coating prefabrication process for woodware provided by the present invention: The principle of the UV coating prefabrication process for woodware provided by the present invention is as follows: Figure 1 As shown, a UV coating is prefabricated on a PET film, and the UV coating is pre-coated on the surface of the PET film in a yellow light environment according to a required coating thickness. After drying, the UV coating is adhered to a release film on the side facing away from the PET film and then rolled up. After rolling up, it is wrapped with an opaque aluminum foil and aged. After aging, a prefabricated film of the UV coating is obtained. After the release film is torn off, the prefabricated film is used to be adhered to the surface of the wood to form a surface coating of the wood.

[0021] Among them, under the yellow light environment, operators can more easily see the edges and thickness changes of the UV coating, because the yellow light can reduce glare and reflection, improve the contrast between the UV coating and the PET film, and due to better visual recognition, the thickness of the UV coating can be more accurately controlled during the coating process.

[0022] Drying after coating the UV coating on the surface of the PET film can make the solvent in the UV coating evaporate quickly, promote the pre-curing of the UV coating, and enable the UV coating to cure in a short time to form a protective film with a certain hardness and glossiness, preliminarily stabilize the structure of the UV coating, and prevent the UV coating from sagging, deformation and other problems during subsequent processing or use, providing a stable foundation for subsequent aging treatment.

[0023] After being coated with opaque aluminum foil, dust, dirt and other particles can be effectively prevented from adhering to the surface of the UV coating, which is conducive to keeping the UV coating clean. In addition, if the UV coating is exposed to ultraviolet light or outdoor sunlight before it is fully cured, it may cure prematurely, affecting the final performance and curing effect of the UV coating. Opaque aluminum foil can effectively block ultraviolet light and outdoor sunlight, protecting the UV coating from accidental exposure during storage and transportation.

[0024] The aging process is to allow the molecular chains inside the preliminarily cured UV coating to continue the cross-linking reaction under certain temperature and humidity conditions. Through aging, the network structure of the UV coating is more perfect and the bonding force between molecules is stronger, which significantly improves the various properties of the UV coating, such as hardness, wear resistance, chemical resistance, adhesion, etc., so that the UV coating can better adapt to different use environments and requirements and extend the service life of the coating.

[0025] In addition, aging can also eliminate internal stress. During the drying process, the rapid curing of the UV coating may produce certain internal stress. If these internal stresses are not eliminated in time, they may cause the coating to crack, peel off and other problems during use. During the aging process, the further movement and cross-linking of the coating molecular chains can effectively release the internal stress and improve the stability and reliability of the UV coating.

[0026] The schematic diagram of the specific UV coating prefabrication process for wood products is as follows: Figure 2As shown, a PET film 1 is placed on a PET film unwinding roller 4, and the PET film 1 is transported to a UV coating liquid tank 13 containing a UV coating liquid 14 by a conveying roller 7. The UV coating liquid 14 is coated on the surface of the PET film 1 by a coating roller 11 rotatingly installed in the UV coating liquid tank 13. The PET film 1 passes through the gap between the supporting roller 15 and the coating roller 14 to complete the coating, and then is input into a drying chamber 9 by the conveying roller 7 for drying. After drying, a release film 2 is placed on the release film unwinding roller 5, and the release film 2 and the PET film 1 with UV coating are put into between two pressing rollers 6 and bonded together. At this time, the release film 2 and the PET film 1 with UV coating are respectively located on both sides of the UV coating, and finally are wound up by a winding roller 10. After winding up, it is coated with stainless steel aluminum foil and cured. After curing, a prefabricated film of UV coating can be obtained. The structure of the prefabricated film is shown as follows Figure 4 As shown, it includes a PET film 1, a UV pre-coating layer 3 and a release film 2.

[0027] In actual processing, Figure 2 The process is achieved by using a blade coater, such as Figure 2 and Figure 3 As shown, the blade coater includes a drying chamber 9, a UV coating liquid tank 13, a support roller 15, a coating roller 11 and a blade roller 12, and the UV coating is applied to the PET film 1 through an online coating process. Figure 1 As shown, the PET film 1 is subjected to corona treatment before coating to treat the surface of the PET film 1. The coating roller 11 is rotatably mounted in the UV coating liquid tank 13, and the coating roller 11 is partially immersed in the UV coating liquid 14 contained in the UV coating liquid tank 13. The corona-treated PTE film 1 passes through the gap between the supporting roller 15 and the coating roller 11. The coating roller 11 rotates and evenly coats the UV coating liquid 14 attached thereto on the surface of the PET film 1. The scraper roller 12 is arranged above the UV coating liquid tank 13 to scrape off the excess UV coating liquid 14 on the surface of the PET film 1. The excess UV coating liquid 14 is scraped off and reused in the UV coating liquid tank 13. The PET film 1 that has passed through the scraper roller 12 enters the drying chamber 9 for drying, and after drying, it is rolled up in conjunction with the release film 2, and after rolling up, it is wrapped with stainless steel aluminum foil and aged.

[0028] When actually selecting materials, the thickness specification of the PET film 1 is any one of 38um, 50um, and 100um.

[0029] The thickness specification of UV coating is any one of 15um, 20um and 25um.

[0030] The thickness specification of the release film 2 is any one of 25um, 36um, and 50um, and the release force specification of the release film 2 is any one of 5g / mm, 10g / mm, and 15g / mm.

[0031] The baking temperature in the drying chamber 9 is in the range of 100° C. to 120° C., and the linear speed of the coating roller 11 is in the range of 20 m / min to 25 m / min.

[0032] The aging temperature ranges from 50°C to 55°C, and the aging time is 3 to 5 days.

[0033] It should be noted that although the above provides the optional thickness of the PET film 1, the thickness of the UV coating, the thickness of the release film 2, the release force specification of the release film 2, the baking temperature range of the drying chamber 9, the linear speed range of the coating roller 11, the aging temperature range and the aging time range; however, in the actual processing process, one of the specific PET film thickness, UV coating thickness, release film thickness, release force specification of the release film, baking temperature of the drying chamber, linear speed of the coating roller, aging temperature and aging time should be selected according to specific needs.

[0034] Of course, the coating is not limited to the blade coater used in this embodiment, and a roller coater, slit coater, or other coater that can implement the coating process may also be used.

[0035] In addition, the PET film 1 and the release film 2 located on both sides of the UV pre-coating layer 3 can also be made of the same material when actually selected.

[0036] The present invention prefabricates the UV coating on the PET film by adopting an online coating process, and can be cut into a suitable size as needed when used, and the release film can be torn off to carry out lamination construction on the surface of the woodware, without the need for on-site glue preparation and spraying construction, which greatly shortens the construction period, simplifies the construction steps, and can be used immediately after pasting, significantly reducing the construction difficulty. When adopting the online coating process, the coating thickness can be more accurately controlled, which is beneficial to cost accounting while indirectly reducing the coating coating cost. In addition, the one-time lamination molding process avoids the problems of poor coating leveling, uneven coating thickness, poor adhesion between the coating and the substrate brought about by the coating spraying, and the lamination process reduces the use of on-site spraying equipment, and the construction cost is lower. At the same time, the woodware after lamination only needs to be placed in a general ultraviolet light or outdoor direct sunlight environment, reducing the use of special ultraviolet light curing equipment, so that the construction cost is further reduced, and the reduction in cost greatly reduces the use threshold of the UV coating, so that the UV coating is expected to be widely promoted and applied in woodware.

[0037] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. UV coating prefabrication process for wood, characterized in that: The UV coating is prefabricated on the PET film, and the UV coating is pre-coated on the surface of the PET film in a yellow light environment according to the required coating thickness. After drying, the UV coating is adhered to the release film on the side facing away from the PET film and then rolled up. After rolling up, it is coated with an opaque aluminum foil and aged. After aging, a prefabricated film of the UV coating is obtained. After the release film is torn off, the prefabricated film is used to be adhered to the surface of the wooden article to form the surface coating of the wooden article.

2. The UV coating prefabrication process for woodware according to claim 1, characterized in that: The thickness of the PET film is any one of 38um, 50um and 100um.

3. The UV coating prefabrication process for woodware according to claim 1, characterized in that: The thickness of the UV coating is any one of 15um, 20um, and 25um.

4. The UV coating prefabrication process for woodware according to claim 1, characterized in that: The thickness of the release film is any one of 25um, 36um, and 50um.

5. The UV coating prefabrication process for woodware according to claim 4, characterized in that: The release force specification of the release film is any one of 5g / mm, 10g / mm, and 15g / mm.

6. The UV coating prefabrication process for woodware according to any one of claims 1 to 5, characterized in that: The UV coating is applied to the PTE film by an online coating process using a blade coater, which includes a drying chamber, a UV coating liquid tank, a coating roller and a blade roller. The PET film is subjected to corona treatment before coating. The coating roller is rotatably mounted in the UV coating liquid tank, and at least a part of the coating roller is immersed in the UV coating liquid contained in the UV coating liquid tank so that the UV coating attached thereto can be evenly coated on the surface of the PET film when the coating roller rotates. The scraper roller is used to scrape off excess UV coating on the surface of the PET film; the PET film passing through the scraper roller enters the drying chamber for drying, and after drying, is laminated with the release film and rolled up.

7. The UV coating prefabrication process for woodware according to claim 6, characterized in that: The scraper roller is arranged above the UV coating liquid tank to scrape the excess UV coating on the surface of the PET film into the UV coating liquid tank for reuse.

8. The UV coating prefabrication process for woodware according to claim 6, characterized in that: The baking temperature in the drying chamber ranges from 100° C. to 120° C., and the linear speed of the coating roller ranges from 20 m / min to 25 m / min.

9. The UV coating prefabrication process for woodware according to any one of claims 1 to 5, characterized in that: The aging temperature ranges from 50°C to 55°C, and the aging time is 3 to 5 days.

10. The UV coating prefabrication process for woodware according to any one of claims 1 to 5, characterized in that: The PET film and the release film are both PET release films.

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