Printing process for improving adhesive force of ink on surface of metal material

Abstract

The invention discloses a printing process for improving the adhesive force of ink on the surface of a metal material, which comprises the following steps: treating a metal aluminum sheet to obtain a smooth surface; the total thickness of the ink protection layer needing to be printed is divided into n layers, and n is larger than or equal to 3; first-time ink spraying printing is carried out, first-time pre-curing treatment is carried out, and a first ink protection layer is formed; carrying out second ink spraying printing, carrying out second pre-curing treatment to form a second ink protection layer,..., carrying out nth ink spraying printing, carrying out nth pre-curing treatment to form an nth ink protection layer; and after the nth ink spraying printing and the pre-curing treatment are completed, final curing is performed, and a total ink protection layer is formed. According to the technology, the adhesive force of the ink on the metal surface is improved by spraying and printing for multiple times and controlling the thickness of a single-time spraying film and the curing energy of the single-time spraying film in order to solve the problem that the adhesive force of the UV ink is greatly influenced by high curing speed and large curing shrinkage stress of the UV ink.

Description

Technical Field

[0001] The invention relates to a printing process of ink on the surface of a metal material, and in particular to a printing process for improving the adhesion of ink on the surface of a metal material. Background Art

[0002] During the production of power battery shells, a layer of insulating protective ink needs to be sprayed on the surface. The insulating protective ink layer is generally formed by a spraying process, but the current spraying is a one-time spraying process. Due to the fast curing speed of UV ink and the large curing shrinkage stress, it has a great impact on adhesion, and the performance and quality cannot be guaranteed. Summary of the invention

[0003] In view of the above-mentioned deficiencies, the purpose of the present invention is to provide a printing process for improving the adhesion of ink on the surface of metal materials, by performing multiple spray printings and controlling the thickness of a single spray film and its curing energy, thereby improving the adhesion of ink on the metal surface.

[0004] The technical solution adopted by the present invention is: a printing process for improving the adhesion of ink on the surface of metal materials, comprising the following steps:

[0005] Treat the aluminum sheet to obtain a smooth surface;

[0006] Divide the total thickness of the ink protection layer to be printed into n layers, where n≥3;

[0007] Perform the first ink spray printing and perform the first pre-curing treatment to form a first ink protective layer; perform the second ink spray printing and perform the second pre-curing treatment to form a second ink protective layer... Perform the nth ink spray printing and perform the nth pre-curing treatment to form an nth ink protective layer;

[0008] After the nth ink spray printing and pre-curing process is completed, final curing is performed to form a total ink protection layer.

[0009] Preferably, the first, second, ... nth ink spray printing has a single printing thickness of 18.1-18.5 um.

[0010] Preferably, the pre-curing light intensity and pre-curing energy of the first, second, ... nth pre-curing treatments conform to the variable rules of increasing, decreasing, and normal distribution curves; wherein the maximum value of the pre-curing light intensity is 2200mw / cm2, the minimum value is 220mw / cm2, the maximum value of the pre-curing energy is 390mj, and the minimum value is 40mj.

[0011] Preferably, the final curing has a final curing light intensity of 21300-21400 mw / cm2 and a final curing energy of 31100-31300 mj.

[0012] As a more preferred solution, n is equal to 6, and a total of 6 ink jet printing and pre-curing processes are performed; and, in the first, second, ... nth pre-curing processes, the pre-curing light intensity and pre-curing energy conform to a decreasing variable law; specifically as follows:

[0013] The first ink spray printing is performed, with a single printing thickness of 18.1-18.5um, and the first pre-curing treatment is performed, with a pre-curing light intensity of 2100-2200mw / cm2 and a pre-curing energy of 370-390mj;

[0014] Perform the second ink spray printing, with a single printing thickness of 18.1-18.5um, and perform the second pre-curing treatment, with a pre-curing light intensity of 1900-2000mw / cm2 and a pre-curing energy of 340-350mj;

[0015] The third ink spray printing is performed, the single printing thickness is 18.1-18.5um, and the third pre-curing treatment is performed, the pre-curing light intensity is 1600-1700mw / cm2, and the pre-curing energy is 280-290mj;

[0016] The fourth ink spray printing is performed, the single printing thickness is 18.1-18.5um, and the fourth pre-curing treatment is performed, the pre-curing light intensity is 1300-1400mw / cm2, and the pre-curing energy is 240-250mj;

[0017] The fifth ink spray printing is performed, the single printing thickness is 18.1-18.5um, and the fifth pre-curing treatment is performed, the pre-curing light intensity is 600-650mw / cm2, and the pre-curing energy is 110-120mj;

[0018] Perform the sixth ink spray printing, with a single printing thickness of 18.1-18.5um, and perform the sixth pre-curing treatment, with a pre-curing light intensity of 220-270mw / cm2 and a pre-curing energy of 40-50mj;

[0019] Carry out final curing, the final curing light intensity is 21300~21400mw / cm2, and the final curing energy is 31100~31300mj.

[0020] More preferably, in step 2), the thickness of the first ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 2198mw / cm2, and the pre-curing energy is 380mj;

[0021] In step 3), the thickness of the second ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 1972mw / cm2, and the pre-curing energy is 346mj;

[0022] In step 4), the thickness of the third ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 1608mw / cm2, and the pre-curing energy is 284mj;

[0023] In step 5), the thickness of the fourth ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 1377mw / cm2, and the pre-curing energy is 242mj;

[0024] In step 6), the thickness of the fifth ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 625mw / cm2, and the pre-curing energy is 112mj;

[0025] In step 7), the thickness of the sixth ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 246mw / cm2, and the pre-curing energy is 42mj;

[0026] In step 8), the final curing light intensity is specifically 21356 mw / cm2, and the final curing energy is specifically 31209 mj.

[0027] The present invention has the following advantages:

[0028] Through multiple spray printing, and controlling the single spray film thickness and curing energy, the adhesion of ink on the metal surface is improved. Among them, the control of pre-curing light conforms to variable rules such as increasing, decreasing, and normal distribution curves.

[0029] It is more preferred to divide the ink printing into six or more times (i.e. at least six times), preset the thickness of each printing to be controlled at about 18um, and control the pre-curing light intensity and pre-curing energy of a single inkjet so that the pre-curing light intensity and pre-curing energy of each inkjet are gradually reduced from about 2200mw / cm2 and about 380mj to about 250mw / cm2 and about 40mj, respectively; in this way, the adhesion of the ink on the surface of the metal material can be significantly improved.

[0030] This printing process for improving the adhesion of ink on the surface of metal materials can be scientifically and rationally combined with automated ink jet printing and curing equipment to improve product quality through multiple spray printing and curing.

[0031] The present invention will be further described below in conjunction with specific implementation modes. DETAILED DESCRIPTION

[0032] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described below in conjunction with embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0033] The first set of embodiments

[0034] A single-mode laser was used to process 100*25*1.6mm aluminum sheets for spraying. Five aluminum sheet samples were selected, and each sample was subjected to the following printing process to improve the adhesion of ink on the metal material surface, and its shear strength was tested respectively.

[0035] The printing process for improving the adhesion of ink on the surface of metal materials includes the following steps:

[0036] 1) Laser treatment of aluminum sheet to obtain a smooth surface;

[0037] 2) Perform the first ink spray printing, with a single printing thickness of 18.3um, and perform the first pre-curing treatment, with a pre-curing light intensity of 2198mw / cm2 and a pre-curing energy of 380mj;

[0038] 3) Perform a second ink spray printing, with a single printing thickness of 18.3um, and perform a second pre-curing treatment, with a pre-curing light intensity of 1972mw / cm2 and a pre-curing energy of 346mj;

[0039] 4) Perform the third ink spray printing, the single printing thickness is 18.3um, and perform the third pre-curing treatment, the pre-curing light intensity is 1608mw / cm2, and the pre-curing energy is 284mj;

[0040] 5) Perform the fourth ink spray printing, the single printing thickness is 18.3um, and perform the fourth pre-curing treatment, the pre-curing light intensity is 1377mw / cm2, and the pre-curing energy is 242mj;

[0041] 6) Perform the fifth ink spray printing, the single printing thickness is 18.3um, and perform the fifth pre-curing treatment, the pre-curing light intensity is 625mw / cm2, and the pre-curing energy is 112mj;

[0042] 7) Perform the sixth ink spray printing, the single printing thickness is 18.3um, and perform the sixth pre-curing treatment, the pre-curing light intensity is 246mw / cm2, and the pre-curing energy is 42mj;

[0043] 8) Carry out final curing, the final curing light intensity is 21356mw / cm2, and the final curing energy is 31209mj.

[0044] Three other groups of embodiments (Group 2, Group 3, Group 4)

[0045] The pre-curing light intensity and pre-curing energy of each inkjet in the three groups of embodiments are not gradually reduced, but adopt variable rules such as increasing and normal distribution curves. They also use single-mode laser to process 100*25*1.6mm aluminum sheets for spraying, and each group has five aluminum sheet samples, each sample is sprayed six times, and the spraying thickness is also controlled at about 18.3um.

[0046]

[0047] The first group of examples (5 samples) and the last three groups of examples (5 samples each, a total of 15 samples) were sprayed with different treatment methods, aged for 12 hours, and then tested for their shear strength. The specific test values ​​are as follows (after being tabulated):

[0048]

[0049]

[0050] First, the first, second, third and fourth groups of embodiments are compared with the traditional process. Among them, the shear strength of the above four groups of embodiments is greater than 10Mpa, and the highest exceeds 20Mpa, which is significantly better than the traditional one-time spraying and curing process, because the shear strength of the traditional one-time spraying and curing process is generally below 10Mpa.

[0051] It can be seen that by spraying and printing multiple times and controlling the single spray film thickness and its curing energy, the adhesion of the ink on the metal surface can be significantly improved.

[0052] In addition, in comparison between the four groups of embodiments, the shear strength of the first group of embodiments is greater than 19 MPa, and the shear strength of the second, third and fourth groups of embodiments is less than 16 MPa.

[0053] It can be seen that the ink printing is divided into more than six times, and the preset thickness of each printing is controlled at about 18um. By controlling the pre-curing light intensity and pre-curing energy of a single inkjet, the pre-curing light intensity and pre-curing energy of each inkjet are gradually reduced from about 2200mw / cm2 and about 380mj to about 250mw / cm2 and about 40mj respectively; in this way, the adhesion of the ink on the surface of the metal material can be further significantly improved.

[0054] The present invention is not limited to the above-mentioned embodiments. Other printing processes for improving the adhesion of ink on the surface of metal materials obtained by adopting the same or similar technical features as the above-mentioned embodiments of the present invention are within the protection scope of the present invention.

Claims

1. A printing process for improving the adhesion of ink on the surface of a metal material, characterized in that: The steps include: Treat the aluminum sheet to obtain a smooth surface; Divide the total thickness of the ink protection layer to be printed into n layers, where n≥3; Perform the first ink spray printing and perform the first pre-curing treatment to form a first ink protective layer; perform the second ink spray printing and perform the second pre-curing treatment to form a second ink protective layer... Perform the nth ink spray printing and perform the nth pre-curing treatment to form an nth ink protective layer; After the nth ink spray printing and pre-curing treatment is completed, final curing is performed to form a total ink protection layer.

2. The printing process for improving the adhesion of ink on the surface of metal materials according to claim 1, characterized in that: The first, second, ... nth ink spray printing has a single printing thickness of 18.1 to 18.5 um.

3. The printing process for improving the adhesion of ink on the surface of metal materials according to claim 1, characterized in that: The first, second ... nth pre-curing treatments, the pre-curing light intensity and pre-curing energy conform to the variable rules of increasing, decreasing and normal distribution curves; wherein, the maximum value of the pre-curing light intensity is 2200mw / cm2, the minimum value is 220mw / cm2, the maximum value of the pre-curing energy is 390mj, and the minimum value is 40mj.

4. The printing process for improving the adhesion of ink on the surface of metal materials according to claim 1, characterized in that: The final curing has a final curing light intensity of 21300-21400 mw / cm2 and a final curing energy of 31100-31300 mj.

5. The printing process for improving the adhesion of ink on the surface of metal materials according to claim 1, characterized in that: n is equal to 6, and a total of 6 ink spray printing and pre-curing processes are performed; and, in the first, second, ... nth pre-curing processes, the pre-curing light intensity and pre-curing energy conform to a variable law of decreasing; specifically as follows: The first ink spray printing is performed, with a single printing thickness of 18.1-18.5um, and the first pre-curing treatment is performed, with a pre-curing light intensity of 2100-2200mw / cm2 and a pre-curing energy of 370-390mj; Perform the second ink spray printing, with a single printing thickness of 18.1-18.5um, and perform the second pre-curing treatment, with a pre-curing light intensity of 1900-2000mw / cm2 and a pre-curing energy of 340-350mj; The third ink spray printing is performed, the single printing thickness is 18.1-18.5um, and the third pre-curing treatment is performed, the pre-curing light intensity is 1600-1700mw / cm2, and the pre-curing energy is 280-290mj; The fourth ink spray printing is performed, the single printing thickness is 18.1-18.5um, and the fourth pre-curing treatment is performed, the pre-curing light intensity is 1300-1400mw / cm2, and the pre-curing energy is 240-250mj; The fifth ink spray printing is performed, the single printing thickness is 18.1-18.5um, and the fifth pre-curing treatment is performed, the pre-curing light intensity is 600-650mw / cm2, and the pre-curing energy is 110-120mj; Perform the sixth ink spray printing, with a single printing thickness of 18.1-18.5um, and perform the sixth pre-curing treatment, with a pre-curing light intensity of 220-270mw / cm2 and a pre-curing energy of 40-50mj; Carry out final curing, the final curing light intensity is 21300~21400mw / cm2, and the final curing energy is 31100~31300mj.

6. The printing process for improving the adhesion of ink on the surface of metal materials according to claim 5, characterized in that: In step 2), the thickness of the first ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 2198mw / cm2, and the pre-curing energy is 380mj; In step 3), the thickness of the second ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 1972mw / cm2, and the pre-curing energy is 346mj; In step 4), the thickness of the third ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 1608mw / cm2, and the pre-curing energy is 284mj; In step 5), the thickness of the fourth ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 1377mw / cm2, and the pre-curing energy is 242mj; In step 6), the thickness of the fifth ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 625mw / cm2, and the pre-curing energy is 112mj; In step 7), the thickness of the sixth ink spray printing is specifically 18.3um, the pre-curing light intensity is specifically 246mw / cm2, and the pre-curing energy is 42mj; In step 8), the final curing light intensity is specifically 21356 mw / cm2, and the final curing energy is specifically 31209 mj.

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