Aluminium is widely used, excellent workability and light weight, inexpensive, sign panel manufacturing material of choice. After-treatment of the underlying decorative signs panel, increasing variety, can meet different customer and manufacturer:; demand.
We should give priority to the selection dial and decorative aluminum and aluminum alloy plate, or industrial aluminum and special aluminum. Preferred brands are: L1, L2,13,14, L5, L6, L5-1, LT66.
Bump color aluminum plate
(1) Features
Features punch signs are painted in recess, its good abrasion resistance, but also has three-dimensional effect, used machinery aluminum licensing and corporate business tablets. Traditional production method is to use artificial corrosion recesses described paint (paint with needles or injection), and then use the manual trimming, remove residual paint edge. This method is not only time-consuming, inefficient and requires the operator to have great skill, but also a system of signs often unclear edge layout word, writing deformation, the quality is very unstable. Thus, production is limited to small quantities and less chromatic number, less demanding quality, design is very simple signs.
Principle (2) screen printing electrophoresis production of aluminum plate punch
This new technology is the use of screen printing method to print colored text pattern on the surface of anodized aluminum plate, a non-conductive oxide layer and then form a colored sealing. Then use the screen printing method on the oxide layer printed material printed corrosion protection, the protection of local character pattern, the oxide layer is removed by chemical unprotected part etching method to expose the aluminum to form a conductive layer of aluminum, made out of a both the conductive layer of aluminum, another convexo-concave non-conductive plugging aluminum oxide layer. This electrophoretic coating aluminum plate and then, under the action of the electric force, electrophoretic coating negatively charged colloidal particles adsorbed by the conductive aluminum layer deposited on the surface of the recess, to achieve the purpose of partial coating. With this new technology, we can create a text pattern edge clear, colorful and beautiful multi-colored punch aluminum plate.
The process is as follows:
Aluminum pretreatment - Doo anodizing -, network color printing printed material - Bucket sealing - · Screen Printing printed materials corrosion - localized corrosion -, electrophoretic coating - · Drying - shaped bucket
(3) Process description
① pre-treatment of the aluminum plate. Polishing, drawing, and other pre-treatment process according to the design requirements.
② anodized. By electrochemical anodic oxidation process. Establish strong adsorption microporous aluminum oxide film surface.
③ network color printing printed material. Screen printing method using a water-soluble pigment printed on the anode surface oxide layer, a water-soluble pigment is modulated by the i70% to 80% of gum sticky material and 20% to 30% of a dye and a small amount of additives such as a combination. Water-soluble glue sticky material l better, no chemical reaction with the dye, and over the net with the appropriate viscosity and good passing ability staining, dryness | susceptible to water wash and so on. Generally use carboxymethyl cellulose, sodium alginate, etc. dubbed the glue-like sticky paste. Dye may be selected according to the requirements and use acid dyes, direct dyes and light fastness good, bright color reactive dyes for outdoor use;! Decorative signs can also be used Et sun fastness inorganic dye. After the completion of the screen printing toner dryness, washed with water floating surface material.
When monochromatic coloring, can flood staining, dyeing method and the traditional method of coloring the same. When the card; text pattern requires surface is aluminum silver color, this procedure can be omitted.
④ sealing. Sealing the reaction is microporous oxide layer having a dye adsorbed with water to produce hydrated alumina, oxide layer body {increase in the area, the closed pore surface, forming a non-conductive film layer (room temperature resistivity of 109fl / em2 ). There are plugged} role: to prevent re-adsorption film contamination caused; increase the firmness of coloring; improve surface abrasion resistance and weatherability; and so on. }: Sealing Method: Usually treated with steam 29.4-58.8kPa (3 ~ 6kgf / cm2) pressure of 15 ~ 20min, can also be processed in an aqueous solution of 15 ~ 20min nickel acetate heated to 90 ~ 95 ℃, the drill acetate .
⑤ Screen Printing printed materials corrosion. With screen printing method requires projection in the text portion of the surface of the printed pattern layer corrosion protection {ink layer, the protective coloring sealing oxide layer. Due to the application of modern advanced printing plate technology, we have been able to protect the character pattern; printing very fine appearance to the extent, or even add web has made halftone image and pattern.
Printing method is basically the same with the usual printing ink used to select only alkali resistance good ink, ink is best to use the board with a clear distinction of color, in order to observe the operation. Generally by oxidation conjunctiva-type, low-temperature drying type, light-curable metal screen printing inks, offset printing ink resin can also be added to a small amount of dry oil paint and preparation.
⑥ localized corrosion. Alkaline etching solution, the etched portion is protected by a screen printing ink were not protected by the oxide layer, after etching the aluminum layer is bared.
Corrosion is generally about 10% sodium hydroxide solution, the etching time according to the text pattern case may be, to ensure that the lines, complete network, both to no over-etching phenomenon, and should completely etched away the oxide layer. Corrosion is completed, use concentrated nitric acid aqueous ink Ex protection, protective oxide layer is exposed.
Through the above processing, the system will not corrode the surface of a convex shape and the oxide layer having a non-conductive, and the oxide layer etched away in a concave shape having a conductive aluminum layer composed of aluminum.
⑦ electrodeposition coating. The above-mentioned aluminum plate having conductive and non-conductive surface into a water-soluble coating solution was subjected to electrophoresis. In the above-described aluminum plate as an anode, a cathode iron. Under the action of the electric force, the paint is hydrolyzed into negatively charged ions (ion resin R · COO) to the anode mobility, is adsorbed on the conductive aluminum layer, and discharge and loss of charge deposited in the concave aluminum transfer layer surface; and a non-conductive oxide layer such reaction does not occur, it can not adsorb colloidal particles, so as to achieve partial coating.