With the rapid rise of printing industry, people’s requirements on printing products will become increasingly stringent.Accurate to flower, color, etc., printed patterns with high fineness, multi-color patterns to meet the market demand will become the inevitable trend of the development of the industry.One of the most important devices is the positioning device between the bedplate and the printing screen frame, which directly determines the texture quality of the fabric.

There are many ways to locate the platen and the screen frame, among which the more common ones are the backer method, the double groove positioning method, the groove roller method and so on.

(1) Backer method

The backer method is that the printing screen frame is fixed, and the platform slowly leans under the screen frame.In net box installed on a fixed two vertical positioning pin, in the counter also install two lateral positioning pin, pin on the net box and the pin on the counter belong to a cross section, network frame and the bedplate nicely, mutual screens, using the positioning pin can make the network frame and the bedplate every time accurate positioning, the current orientation of this kind of technology is suitable for the manual printing, need workers hands carry net frame a station location mobile positioning printing, only small printing workshop and this way of positioning, the way time-consuming, low efficiency, and high failure rate, as factory labor costs more and more high,This way of positioning will gradually be eliminated completely.

(2) Double card slot positioning method

Clamping groove positioning is a positioning method suitable for automatic equipment. Two boss are fixed on both sides of the platform. The concave table corresponds to the boss one to one to form a pair of clamping groove.Using the cylinder to drive the concave table, positioning the table plate.

This positioning method is simple, inexpensive and widely used. However, it also has some disadvantages:

(1) In the running process of the platform, it is easy to generate offset, concave platform in the process of positioning, or will be stuck in the platform, the impact of the platform transmission mechanism.

The platform is prone to deformation.In the positioning process, the cylinder is used to drive the depression stuck to the boss, and the positioning, the depression in the process of progress, the impact force is greater, the speed of the depression will increase, easy to make the table transverse deformation, damage the table, affect the cutting sheet printing accuracy.

(3) The clearance of the positioning system will increase, in the long-term operation of wear and tear, the concave and lug will produce a certain friction loss, damage the platform, so that the positioning accuracy decreased.

(3) Clamping groove roller method

Compared with the positioning method of double clamping groove with rollers, the positioning method of clamping groove with rollers is slightly more convenient. By using the positioning between single boss and concave tables, the double rollers on the left side of the platform can make the platform move slightly at the moment of positioning and reduce wear.

The positioning method also has some errors, mainly including:

(1) mechanical wear brought by the positioning is not accurate, because the platform is running on the roller, the roller working time is longer, so that the gap between the roller and the bearing is more and more large, so that the positioning accuracy of the platform is reduced.

(2) concave table in the positioning, will give the impact of the platform in one direction, the left side of the platform every time the roller will be impacted by the concave table, so that the roller has a certain deformation, will also reduce the positioning accuracy.

(3) In the positioning process, the friction loss between the positioning system will also reduce the positioning accuracy.In screen printing equipment, the precision of positioning device directly determines the fine level of a device.Most of these devices adopt chain drive, which has low transmission accuracy and serious wear and tear. There are some shortcomings, which make the printing quality of cutting pieces cannot be guaranteed for a long time. After analysis, there are mainly the following deficiencies:

(1) Low precision of printing platen transmission mode.In most screen printing equipment, the transmission of the platen is chain transmission, chain transmission accuracy is low, and the large inertia of many platen, unreasonable friction is a lot.

(2) more tandem table action, as long as there is a problem, will lead to the entire equipment to stop working, resulting in high equipment failure rate.

(3) the parallelism of guide easy to produce errors, so that the platform in the longitudinal offset, so that the platform positioning is not accurate.All the above factors may lead to inaccurate positioning during the operation of the equipment, so it is necessary to avoid these situations as much as possible, such as adopting other transmission modes instead of chain transmission, and adopting fine-tuning mechanism for the screen frame, etc.

In order to realize the accurate positioning between the screen frame and the platen, we designed a new positioning device between the screen frame and the platen.In the equipment, a new positioning method is used to locate the platen and the screen frame.