The main process of screen printing electroplate plaques

The plaque is also a product produced by many signage factories. The plaque is mainly made of metal materials and requires generous, obvious and decorative materials. In traditional metal plaques, the brass bottom, corrosion word, and black lacquer plaque are the most common. With the constant change of people's aesthetic point of view, there are new requirements for the quality of plaques. As the sign industry introduced screen printing technology, it also provided technical means for the sign industry to develop new products. The use of screen printing method to produce new electroplating plaques is the result of the combination of sign plating and screen printing. The basic method is to use screen printing on copper plates to make negative pictures and pictures, cover the non-graphical parts with ink layers, expose the bare copper surface of the graphic part, carry out electroplating, and then plastically shape and protect the processing.

1. Process flow

The process involves electroplating, screen printing, copper plate processing and painting and metal processing. There are many processes, and the process flow is as follows:

Copper blanking → prepress processing → reexamination inspection → silk screen printing → screen printing → drying → pretreatment → electroplating nickel layer → cleaning → electroplating chromium layer → cleaning and drying → removal of printing material → plastic welding frame → Spray cover paint → check factory

2. The main process specification

1) Screen Printing

Use nylon mesh or polyester mesh above 150 mesh/inch. When direct photoengraving is used, it is preferable to coat the diazo photosensitive resin more often so that a thick protective ink film can be obtained during printing.

2) printing

The copying light source is a 1000W metal halide xenon lamp with a lamp distance of 45mm and the exposure time is about 5 minutes. The printing material is a plating resist ink.

3) Pre-plating treatment

Plating pretreatment solution formulation and process conditions are as follows:

H2SO4 160ml/L H2O2 140ml/L CH3CH2OH 120ml/L CH3COOH 30ml/L
Temperature Room Temperature 0.5 to 1 Minute Weak Corrosion Activation Solution H2SO4 10% Solution

4) Bright nickel plating

The electroplating nickel formulation and process conditions are as follows:

NiSO4 350g/L NaCl 20g/L H3BO3 40g/L Saccharin 0.8-1.0g/L BE Additive 0.6ml/L Copper Dodecylsulfate 0.05～0.1g/L pH 4 Temperature 50～55°C Current Density 3～5A /dm2 Agitation cathode movement time 30-40 minutes 5) Chrome plating

Plating solution formulation and process conditions are as follows:

CrO3 300g/L H2SO4 2.7 to 30g/L Cr 2 to 5g/L Current density 25A/dm2 Temperature 50 to 55°C Time 2 minutes

6) Plastic welding frame

Welding frame can be folded up and down, left and right welding plug; also can be folded around, up and down welding plug; or four folding edge, four welding plug.

7) spray cover light protection paint

Since the plaque is all-metal and has no ink and ink graphic, a variety of transparent paints can be sprayed as required. However, good transparency, lightfastness, and a strong lacquer layer are preferred.

Author: Zheng Dehai Source: printing technology