Surface printing related issues

Curved silk screen printing refers to the screen printing on the surface of the round surgical shape, such as bottles, medicine bottles, wine bottles, etc. Most of them are cylindrical or almost cylindrical surfaces, (the curved surface of the flat bottle is cylindrical Shaped surface), rarely also conical, spherical. Regardless of the kind of curved surface, the principle of printing is only one, that is, the silk screen surface should be purely rolled with the screen. In the scroll, the curved surface and the screen are tangent to the deposition point of the squeegee. The extension line always points to the center of the circle.

The design of the curved screen printing machine is also based on this principle, and it is generally based on the rack-and-pinion transmission of the rack and pinion. In the telecontrol, the screen version is equivalent to a rack. The surface is equivalent to a gear. The radius of the surface is the same as the radius of the common circle of the gear. When printing, the center of the curved surface is coaxially aligned with the center of the gear. The screen printing is carried out into the rack and the screen to make the horizontal linear motion gear and the printing hand rotate under the concentric circle of the curved surface under the pulling of the rack. Under normal circumstances, the bottle is positioned with the bottle positioned low and then the bottle is tightly closed. For a round bottle, there is a distance between the bottle center and the center of the circle. There are two ways to print the circle: the first is a fixed center, the squeegee does not move, the bottle rotates around the center of the circle, and the screen moves horizontally. It is generally used for automatic machines. As shown in the following figure: At present, the widely used curved screen printing machine is based on semi-automatic machines, because this type of machine is more suitable for some small and medium enterprises, manufacturers of small batch orders, the type of replacement is quick, easy to operate, the cost of purchase Relative to the phase automatic screen printer is low. However, if you want to equip a surface processor and a curing machine, you have to use more workers to operate it. The automatic screen printing machine, automatic feeding, flame surface treatment, screen printing, curing as a high efficiency, less labor, is more suitable for larger quantities of manufacturers. Automatic machines are divided into monochrome automata and multicolor automata. Multi-color automatons are generally more suitable for long-term and large-scale orders. It can print two colors to five colors on one machine, and the fastest production efficiency is 5000P/H.

Due to the high selling price of fully automatic screen printing machines, the models must be selected at the time of purchase. The functions of the fully automatic machines produced at each factory are basically the same, but the design of the structure is very different. A high-efficiency, high-speed operation of a fully-automated machine, smooth transfer of bottles, and accurate color printing are the key to mechanical design. The traditional screen printing machine has many defects in the mechanical design. In the following, we use the monochrome automatic machine (collectively referred to as 101) to divide the board.

1. When the bottle moves from one worker to another, the starting angle is small. When the bottle is moved, it easily hits the edge of the groove and generates an eccentric position. Then, when it moves to the next slot, it shifts and falls. The transfer will not be smooth.

2. The transmission mechanism also has a degree of iron close to the dead point. The impact is large and the mechanism is fragile and cannot be operated at high speed.

3, silk screen swing, but also affect the love of the male set.

4. The adjustment mechanism is cumbersome, and the adjustment personnel do not know its principle. It takes a lot of effort to find the right position and requires a fairly skilled tuning personnel to adjust it well. This gives many manufacturers no trouble in recruiting industry personnel, sometimes. Manufacturers bought the machine but could not find the staff to adjust the machine.

In response to this problem, the company produced the smoothest and fastest machinery. All adjustments are made before the factory leaves the factory. The advantages are:

1. The bottle iron is 180 degrees, and the bottle will be in a vertical direction at the moment of landing. It will not hit the slot.

2. Large transmission angle, away from dead point, high speed and low speed.

3, silk screen institutions to strengthen the treatment, will not produce left and right swing, so that overprint accuracy.

4. When replacing varieties and tooling, there are few advantages, such as mobilization, drawings, etc.;

In recent years, due to the progress and development of other packaging and printing processes, the surface screen printing industry has been hit hard, (Taiwan labeling, sleeve labeling). Therefore, some people think that curved screen printing is outdated, and some manufacturers have thus loved certain influences, but we believe that the potential of curved screen printing has not yet been fully excavated, but people in the industry continue to work hard and have a long way to go.

Source: Greater China Graphic Arts