Screen Printing Corrosion Placard Printing Formula and Printing Process (I)

Corrosion signs produced by screen printing are traditional signage, such as sandblasted oxide-filled paint signage of instrumentation, instrument panel, vehicle-vessel license plate, equipment numberplate, and corrosion and drying paint signs of nameplates of various machine tools, and are also used to compare the industrial environment. Bad copper and chrome plated signs for electromechanical products, porcelain oxide overlay paint signs for instrument and instrument surfaces, and high-cursive cards.

In the old-fashioned way, the graphic on the label was obtained by photochemical imaging using liquid photosensitive adhesive (protein gel, bone glue, gelatin, polyvinyl alcohol glue, etc.) and then etched. Although this method has the advantage of having a small picture and text distortion, it also has many manufacturing processes, low production efficiency, labor intensity and high energy consumption. The use of screen printing methods to produce graphic signs can increase production efficiency and save a lot of auxiliary materials and energy. The process of screen printing corrosion signs is roughly:

Printing material preparation and prepress surface treatment → Preparation of printing materials → Production of screen printing plates → Printing → Inspection and finishing → Corrosion → Cleaning and drying → Finished products.

1. Surface treatment of substrates

If a copper-based or iron-based substrate is used to make the sign, the surface oxide layer needs to be removed in dilute sulfuric acid, washed with running water, and dried to print. Aluminum-based materials generally need to remove oil stains in a heated sodium carbonate solution. After cleaning and drying, they can be screen printed on the Internet. Oil removal can use organic solvents such as gasoline, banana water, trichloroethylene, cyclohexanone, etc., detergent, detergent, special diluents, etc. can also be used. If the metal surface has serious pits, scratches, oxidation spots, etc., it can be treated by mechanical polishing or rubbing and brushing, and then degreasing.

2. Printing materials

There are many varieties of screen printing materials used in screen printing, but the printing materials used to etch screen printing are generally only resist printing materials. Anti-corrosion printing materials should have good film-forming properties, easy drying, good network resistance, corrosion resistance, and easy removal. Commonly used anti-corrosion printing materials are as follows:

1) thick lacquer printing material. Thick lacquer printing is a traditional printing material. Thick paint is generally selected from dry thick paint, adding a certain amount of phenolic varnish, alkyd varnish, asphalt acid paint and other preparation, commonly used formulas are:

Formula A:

Special grade thick white paint 50% alkyd varnish 50% gasoline Formula B:

Special grade thick zinc white paint 79% alkyd varnish 16% asphalt acid paint 5% white dry oil micro formula C:

Thick black paint 80% Alkyd varnish 15% 120# Gasoline 5%
Preparation method: mix according to the ratio, fully stir or roll, and then use about 200 mesh / inch screen filter.

Rejection of printing materials: Copper and iron-based labels can be used to remove the film from the alkali solution; aluminum-based labels are removed using organic solvents (such as banana water, xylene, etc.).

(to be continued)