阅读说明：本技术 一种高亮手机后盖图案的丝网印刷工艺 (Screen printing process for pattern of rear cover of highlight mobile phone ) 是由 吴建晓 于 2020-12-14 设计创作，主要内容包括：本发明公开了一种高亮手机后盖图案的丝网印刷工艺,其包括如下步骤：提供第一丝网模版,将高亮膜层材料印刷手机后盖上；预烘以赶走高亮膜层材料内的溶剂,并使高亮膜层材料部分硬化；提供第二丝网模版,将图案印料印刷至部分硬化后的高亮膜层材料上；图案烘烤以赶走图案印料内的溶剂,并使图案印料部分硬化；曝光以使高亮膜层材料部分感光聚合；显影以将未经过感光聚合的高亮膜层材料利用化学反应得以去除；后固化烘烤以使高亮膜层材料彻底硬化。本发明大幅缩短高亮膜层印刷到丝印图案的时间,避免了曝光、显影、后固化烘烤三个工序对油墨表面的污染,减少由于时效和污染导致的图案与高亮膜层之间结合力不良而导致的脱落现象。(The invention discloses a screen printing process of a pattern of a rear cover of a highlight mobile phone, which comprises the following steps: providing a first silk screen stencil, and printing a high-brightness film layer material on the back cover of the mobile phone; pre-baking to drive off the solvent in the high-brightness film material and partially hardening the high-brightness film material; providing a second silk screen stencil, and printing the pattern printing material on the partially hardened highlight film layer material; baking the pattern to drive off the solvent in the pattern printing material and partially hardening the pattern printing material; exposing to make the highlight film material partially polymerized; developing to remove the material of the high brightness film layer which is not subjected to the photosensitive polymerization by using a chemical reaction; and post-curing and baking to completely harden the high-brightness film layer material. The invention greatly shortens the time from printing the highlight film layer to the silk-screen pattern, avoids the pollution of the three procedures of exposure, development and post-curing baking on the surface of the printing ink, and reduces the falling phenomenon caused by poor binding force between the pattern and the highlight film layer due to aging and pollution.)

1. A screen printing process of a pattern of a rear cover of a highlight mobile phone is characterized by comprising the following steps:

s1), providing a first silk screen stencil, enabling a highlight film layer material to penetrate through the first silk screen stencil, and printing the highlight film layer on the first silk screen stencil to the rear cover of the printing mobile phone to realize highlight film layer printing;

s2) pre-baking to drive off the solvent in the high-brightness film material and partially harden the high-brightness film material;

s3) providing a second silk screen stencil, enabling pattern printing materials to penetrate through the second silk screen stencil, and printing patterns on the second silk screen stencil onto the partially hardened high-brightness film layer material to realize silk screen printing patterns;

s4) pattern baking to drive off the solvent in the pattern print and partially harden the pattern print;

s5) exposing to make the highlight film material partially photosensitive polymerization;

s6) developing to remove the highlight film material which is not photopolymerized by chemical reaction;

s7) post-cure baking to completely harden the highlight film layer material.

2. The screen printing process of the high-brightness mobile phone rear cover pattern as claimed in claim 1, characterized in that: the material of the high-brightness film layer is liquid photosensitive ink.

3. The screen printing process of the high-brightness mobile phone rear cover pattern as claimed in claim 2, characterized in that: ultraviolet curing ink is added into the liquid photosensitive ink.

4. The screen printing process of the high-brightness mobile phone rear cover pattern as claimed in claim 1, characterized in that: the first silk screen stencil and the second silk screen stencil are obtained by coating photosensitive glue on silk screens, drying, covering a photographic bottom plate, and exposing and developing.

5. The screen printing process of the high-brightness mobile phone rear cover pattern as claimed in claim 1, characterized in that: the screen printing process further comprises a pretreatment step of removing impurities on the surface of the rear cover of the printing mobile phone and increasing the board surface roughness of the rear cover of the printing mobile phone before the high-brightness film layer is printed.

6. The screen printing process of the pattern of the back cover of the high-brightness mobile phone according to any one of claims 1 to 5, characterized in that: the pre-drying step is to bake the mixture in a hot air circulation oven at the temperature of 70-80 ℃ for 30-40 min.

7. The screen printing process of the pattern of the back cover of the high-brightness mobile phone according to any one of claims 1 to 5, characterized in that: the pattern baking step is baking in a hot air circulation oven at a temperature of 150 ℃ for 30 min.

8. The screen printing process of the pattern of the back cover of the high-brightness mobile phone according to any one of claims 1 to 5, characterized in that: and in the step S5), the exposure step is to expose the substrate in an exposure machine at 5-7 KW power and light energy within the range of 300-500 mJ/cm < 2 >, and the temperature in the exposure machine is 19-23 ℃.

9. The screen printing process of the pattern of the back cover of the high-brightness mobile phone according to any one of claims 1 to 5, characterized in that: and in the step S6), developing by using a Na 2CO 3 solution with the concentration of 1%, a spray pressure of 0.2-0.3 MP/cm < 2 >, a temperature of 28-32 ℃, a time of 60-80S and a development point of 50-60% in a developing machine.

10. The screen printing process of the pattern of the back cover of the high-brightness mobile phone according to any one of claims 1 to 5, characterized in that: and the post-curing baking step is baking for 40-60 min in a hot air circulating oven at the temperature of 150 ℃.

Technical Field

The invention relates to the technical field of mobile phone rear covers, in particular to a silk-screen printing process of a pattern of a high-brightness mobile phone rear cover.

Background

Screen printing belongs to stencil printing and is known as four major printing methods along with lithographic, embossing and gravure printing. Stencil printing includes yu writing, stencil printing, spray printing, screen printing, and the like. The principle of stencil printing is: when printing, the printing plate (paper film plate or other plate base is provided with holes capable of passing through ink) transfers the ink to the printing stock (paper, ceramic, etc.) through the holes of the hole plate by certain pressure to form images or characters. Repurposing printing is the simplest stencil printing. In stencil printing, screen printing is the most widely used. The silk screen printing is that silk fabric, synthetic fiber fabric or metal screen is stretched on a screen frame, and a screen printing plate is manufactured by adopting a manual paint film engraving or photochemical plate making method. The modern screen printing technology is to use photosensitive material to make screen printing plate by means of photoengraving (the meshes of the image-text part on the screen printing plate are through holes, but the meshes of the non-image-text part are blocked). When printing, the ink is transferred to the printing stock through the meshes of the image-text part by the extrusion of the scraper, and the image-text same as the original is formed.

In the pattern production of the back cover of the modern mobile phone, the pattern also adopts the screen printing technology. In the process of manufacturing the pattern of the rear cover of the mobile phone, a highlight film layer is often required to be formed on the rear cover of the mobile phone to ensure the highlight effect of the rear cover of the mobile phone, and then the pattern is printed on the highlight film layer to show the brand, promote manufacturers, beautify products and the like. And printing the pattern after forming the high bright film layer, two problems can occur: 1) the surface of the printing ink is easily polluted when the high-brightness film layer is formed, and the aging is longer; 2) the problem that the pattern is easy to fall off due to poor bonding force between the pattern and the highlight film layer after the pattern is printed is easily caused.

Disclosure of Invention

The invention provides a screen printing process of a pattern of a rear cover of a highlight mobile phone, aiming at the defects of the prior art.

The technical scheme adopted by the invention for realizing the purpose is as follows:

a screen printing process of a pattern of a rear cover of a highlight mobile phone comprises the following steps:

s1), providing a first silk screen stencil, enabling a highlight film layer material to penetrate through the first silk screen stencil, and printing the highlight film layer on the first silk screen stencil to the rear cover of the printing mobile phone to realize highlight film layer printing;

s2) pre-baking to drive off the solvent in the high-brightness film material and partially harden the high-brightness film material;

s3) providing a second silk screen stencil, enabling pattern printing materials to penetrate through the second silk screen stencil, and printing patterns on the second silk screen stencil onto the partially hardened high-brightness film layer material to realize silk screen printing patterns;

s4) pattern baking to drive off the solvent in the pattern print and partially harden the pattern print;

s5) exposing to make the highlight film material partially photosensitive polymerization;

s6) developing to remove the highlight film material which is not photopolymerized by chemical reaction;

s7) post-cure baking to completely harden the highlight film layer material.

In a further improvement, the material of the high-brightness film layer is liquid photosensitive ink.

In a further improvement, ultraviolet curing ink is added into the liquid photosensitive ink.

The first and second screen stencils are obtained by coating photosensitive glue on the screen, drying, covering with photographic plate, exposing and developing.

The screen printing process further comprises a pretreatment step of removing impurities on the surface of the rear cover of the printing mobile phone and increasing the board surface roughness of the rear cover of the printing mobile phone before the printing of the highlight film layer.

The further improvement is that the pre-baking step is baking for 30-40 min in a hot air circulation oven at the temperature of 70-80 ℃.

Further improved, the step of baking the pattern is baking for 30min in a hot air circulation oven at a temperature of 150 ℃.

The further improvement is that in the step S5), the exposure step is carried out in an exposure machine with 5-7 KW power and light energy within the range of 300-500 mJ/cm 2, and the temperature in the exposure machine is 19-23 ℃.

In the step S6), the developing step is to develop in a developing machine by using 1% Na 2CO 3 solution, 0.2-0.3 MP/cm 2 spray pressure, 28-32 ℃ temperature, 60-80S time and 50-60% of developing point.

The further improvement is that the post-curing baking step is baking in a hot air circulating oven at the temperature of 150 ℃ for 40-60 min.

The invention has the beneficial effects that: the silk-screen printing process of the invention advances the silk-screen pattern to be carried out before the exposure of the highlight film layer, thereby greatly shortening the time between the printing of the highlight film layer and the silk-screen pattern, avoiding the pollution of the exposure, the development and the post-curing baking to the surface of the printing ink, reducing the falling phenomenon caused by poor binding force between the pattern and the highlight film layer due to aging and pollution, leading the highlight effect of the mobile phone rear cover to be better, ensuring the display effect of the pattern, and playing a good role in showing brands, publicizing manufacturers, beautifying products and the like.

The invention is further described with reference to the following detailed description and accompanying drawings.

Drawings

Fig. 1 is a schematic flow chart illustrating a step of a screen printing process of a rear cover pattern of a high-brightness mobile phone according to the embodiment.

Detailed Description

The following description is only a preferred embodiment of the present invention, and does not limit the scope of the present invention.

In an embodiment, referring to fig. 1, a screen printing process for a pattern of a back cover of a high-brightness mobile phone includes the following steps:

s1), providing a first silk screen stencil, enabling a highlight film layer material to penetrate through the first silk screen stencil, and printing the highlight film layer on the first silk screen stencil to the rear cover of the printing mobile phone to realize highlight film layer printing;

s2) pre-baking to drive off the solvent in the high-brightness film material and partially harden the high-brightness film material;

s3) providing a second silk screen stencil, enabling pattern printing materials to penetrate through the second silk screen stencil, and printing patterns on the second silk screen stencil onto the partially hardened high-brightness film layer material to realize silk screen printing patterns;

s4) pattern baking to drive off the solvent in the pattern print and partially harden the pattern print;

s5) exposing to make the highlight film material partially photosensitive polymerization;

s6) developing to remove the highlight film material which is not photopolymerized by chemical reaction;

s7) post-cure baking to completely harden the highlight film layer material.

The material of the high-brightness film layer is liquid photosensitive ink.

Ultraviolet curing ink is added into the liquid photosensitive ink.

The first silk screen stencil and the second silk screen stencil are obtained by coating photosensitive glue on silk screens, drying, covering a photographic bottom plate, and exposing and developing.

The screen printing process further comprises a pretreatment step of removing impurities on the surface of the rear cover of the printing mobile phone and increasing the board surface roughness of the rear cover of the printing mobile phone before the high-brightness film layer is printed.

The pre-drying step is to bake the mixture in a hot air circulation oven at the temperature of 70-80 ℃ for 30-40 min.

The pattern baking step is baking in a hot air circulation oven at a temperature of 150 ℃ for 30 min.

And in the step S5), the exposure step is to expose the substrate in an exposure machine at 5-7 KW power and light energy within the range of 300-500 mJ/cm < 2 >, and the temperature in the exposure machine is 19-23 ℃.

And in the step S6), developing by using a Na 2CO 3 solution with the concentration of 1%, a spray pressure of 0.2-0.3 MP/cm < 2 >, a temperature of 28-32 ℃, a time of 60-80S and a development point of 50-60% in a developing machine.

And the post-curing baking step is baking for 40-60 min in a hot air circulating oven at the temperature of 150 ℃.

The silk-screen printing process of the invention advances the silk-screen pattern to be carried out before the exposure of the highlight film layer, thereby greatly shortening the time between the printing of the highlight film layer and the silk-screen pattern, avoiding the pollution of the exposure, the development and the post-curing baking to the surface of the printing ink, reducing the falling phenomenon caused by poor binding force between the pattern and the highlight film layer due to aging and pollution, leading the highlight effect of the mobile phone rear cover to be better, ensuring the display effect of the pattern, and playing a good role in showing brands, publicizing manufacturers, beautifying products and the like.

The present invention is not limited to the above embodiments, and other screen printing processes for highlighting mobile phone rear cover patterns, which are obtained by using the same or similar structures, devices, processes or methods as those of the above embodiments of the present invention, are within the scope of the present invention.