​Several important factors that need to be controlled in the process of automatic pad printing

During the printing process of the automatic pad printer, the depth of the steel plate, the size, shape, and hardness of the rubber head, the characteristics of the ink, the volatilization speed, and the surface characteristics of the substrate (material, smooth or rough surface, arc size of the printed pattern, etc., work Environmental control (such as temperature, color, humidity, dustproof, etc.). The changes in the above-mentioned related parameters must be handled and adjusted to achieve a perfect and successful printing effect.

1) Whether the depth of the steel plate is appropriate

1. Measured with a depth gauge, the depth of the conventional pad printing plate is about 2.4 microns. Such as small text, the line is 2 microns

2. The actual depth depends on the requirements of the pattern and ink layer. If the same kind of graphics, if the surface of the substrate is smooth or rough, the required depth of the steel plate will have a printing effect.

For example: if there is oil return, the picture and text are blurred, the greater the possibility is that the steel plate is too deep.

If bubbles (trachoma) appear, they may be too shallow.

If the ink on the pad is already dry when the pad is not printed on the object, the steel plate is too light.

If the ink on the rubber head is uneven (orange skin texture), the steel plate is too deep.

Since the glue head can only pick up the ink in a small part of the pattern area of the steel plate, too much etching depth will not have any benefit. When the etching depth is 2.5 microns, the glue head can only pick up the 1.2-micron ink film, and the rest is left on the steel plate. Since the ink film contains at least 40% of the diluent, this part of the diluent is completely evaporated during the ink transfer and drying, so the final ink layer on the printed matter is about 7 microns.

2) The characteristics of the ink: the automatic pad printing machine requires fast drying with oil and water to avoid that the plastic head can not achieve ink transfer well, and the silk screen requires slow drying, which avoids the screen blocking the network. This is also the difference between silk screen and pad printing thinner. But under certain conditions (such as dry and high temperature) silk-screen printing oil and water can be used for pad printing.

Single-component ink, the rubber head has better durability. However, two-component inks are usually more corrosive and easy to foam, which will cause the silicone oil of the rubber head to be consumed faster, and the service life of the rubber head will be shortened. When the plastic head is not printed on the object to be printed, and the ink on the plastic head dries, the thinner dries too quickly. When the printing is finished, the pictures and texts on the printed matter will appear fluffing, wire drawing, and dry too quickly. If the oil return is blurred, it will dry too slowly, and if it has broken into pieces, it will have no adhesion. If it is too fast to dry and cannot print, it will dry too quickly.

3). Working environment of pad printer: room temperature (best 18-20°C). The humidity is (best 60%-070%). dust-proof. Light white walls and so on.