1. Working principle of Open Type Rotary Screen Printer

Screen printing is to transfer the pattern LOGO trademark to the product through the stamping method through the silk printing steel plate and the silk printing rubber head. Using the principle of imaging, the pattern to be printed is etched on the steel plate, and then on an open rotary screen printing machine. Use soft rubber pad (silicone rubber head to transfer ink from the steel plate to the object to be printed. Screen printing can be suitable for printing of various workpieces, shapes, positions and high-speed printing, and the effect of the decorative pattern is better than screen printing. The methods of oil injection, ironing, and stickers are more detailed and beautiful.

2. Problems and solutions in the printing process of the open rotary screen printing machine

1 The ink squeegee applies the ink to the etched recesses, and then the blade scrapes the ink on the steel plate back into the ink container on the return stroke. The etched ink left after evaporation can increase its surface viscosity.

2 The print head moves down to contact with the etching of printing.

3 When the print head rises, the ink in the etching will be sucked on the glue head.

4 During the process of moving to the printing part on the steel plate at the printing head, the attached ink solvent gradually volatilizes, so that the viscosity of the ink increases again, and the printing head will stay in the horizontal position above the printed matter.

5 The print head presses down on the printed part to transfer the attached ink to the surface of the printed matter.

6 The printing head rises again to return to the original position of the printing board.

3. Scope of application

Suitable for daily necessities, electrical products, optical products, plastics, toys, electronics, glass and metal industries.

4. Hot Air Stenter

The open rotary screen printing machine is the core of screen printing production. It uses compressed air as the original power, and uses electrical signals to control the movement of the plastic head and the screen printing action (such as the number of prints) to print single-color or overprint two-color to multi-color patterns. Perform 1-3 times flow printing, 1-2 color turntable printing and 2-6 color push disk printing. (Note: The large pattern area of ​​silk screen printing needs to be printed in sections, but it is necessary to pay attention to the problem of misalignment of printing.) Choose an open rotary screen printing machine according to the area and volume of the printed object, and choose monochrome, two-color or rolling printing according to needs And other functions, according to the operation manual of the k machine, select the dial and keys, determine the corresponding functions and set the process parameters.

5. Selection of steel plate, screen printing glue head and ink

(1) The choice of etching steel plate

1 The printed board includes steel plate, nylon board and quick printing board. Steel printing plates are the most durable and can be used almost indefinitely for a long time. The service life of nylon plates and rapid printing plates can only be printed from 5,000 to 10,000 times. The cost of steel plates is much higher than nylon plates and rapid printing plates.

2 The etching depth of the printed board is 0.015MM-0.035MM, the thickness of the screen printing ink film is 0.004-0.008MM, depending on the etching depth of the printed board type and the hardness and shape of the print head, other such as temperature, humidity, and environment may also be Make the ink film thickness vary.

3 The size of the printed board is measured by the area of ​​the printed pattern, usually the area of ​​the printed board does not need to be too large, otherwise it is difficult to fix the steel plate on the oil pan. Therefore, steel plates of different sizes need to be matched with equivalent oil pans, blades and oil scrapers.

(2) The choice of screen printing glue

1 Hardness

General screen printing glue can be divided into three kinds of hardness: soft S (30°A), medium M (35°A), and hard H (40°A). For finer printing patterns, harder screen printing glue can be used. The printed parts are uneven, it is better to use softer screen printing glue to reduce the loss. If the ink and thinner water have an erosive effect on the screen printing glue head, you should choose an alternative ink or change the composition of the screen printing glue.

2 Volume

Compared with the pattern of the volume and size of the screen printing glue, it is best to be just enough. The volume of the glue head is too wasteful. Different types of printed parts need to use different types of screen printing glue.

3 Shape

The shape of the silk-screen printing head needs to be adjusted according to the unevenness of the silk-screen printing piece. If the surface of the printed piece is not flat, it is the key to choose the shape of the silk-screen printing piece. The screen printing glue should bring the ink on the flat steel plate to the uneven printed object, then the end of the screen printing glue must be very elastic, and the shape of the screen printing glue must be suitable for the width of the printed object, and the pressure on the end of the screen printing glue It can spread evenly so as to avoid the oblique printing of the screen printing glue on the plane of the printed object.

4 The glue head is made of three raw materials: rubber paste, silicone oil and drier.



(3) Selection of ink

1 Printed parts of different materials should use different series of inks.

2 Understand the gloss, hiding power and setting speed characteristics of ink.

3 Understand that ink and thinning water will not erode the screen printing head.

4 The speed of ink solidification should not be too fast, otherwise it is easy to air dry in the oil pan, at this time it can be diluted with thinner water. If you want to speed up the air drying speed, you can use quick drying agent or hair dryer to assist,

5 The ink should be adjusted to an appropriate viscosity. If the ink is too sticky, the lack of activity leads to difficulty in printing (easy to fluff); if the ink is too thin, the color of the printed pattern is not clear enough or the lines are not good; therefore, the blending of the ink is A major job. Pay attention to the viscosity of the ink on the steel plate. There are many types of inks, and it is necessary to use inks that match the characteristics to get the best results.

(4) Screen printing bottom mold

Do a good job of fixing the position on the worktable of the printed item. It must be positioned accurately during printing and cannot be moved, and it can be easily taken in and out of the printed item. Therefore, there must be a set of suitable fixtures for the printed item. Determine manufacturing.

The bottom mold can be made of bakelite, bakelite, metal materials, plastic, gypsum, epoxy mud and other materials. The form is eclectic based on the principle of practicality.

(5) The biggest threat to working in screen printing is dust. Therefore, dust prevention is also an extremely important task. Don't take it lightly.