Screen Frame Parts
The function of the screen frame part is mainly to complete screen printing. The wire mesh frame components include a wire mesh frame structure, a scraper frame structure, a scraper frame lifting structure and a horizontal support structure.
(1) Wire mesh frame structure: mainly used to install and fix wire mesh.
(2) Scraper frame structure: a scraper and an ink return knife are installed. The function of the squeegee is to squeeze the screen-printed paste onto the liquid crystal glass to complete the printing. The function of the ink return knife is to return the ink to the initial point of the remaining paste after printing for recycling.
(3) Lifting structure of scraper frame: It has the function of lifting and lowering scraper frame.
(4) Horizontal support structure: supports the scraper frame structure and provides guidance for the scraper frame structure to move along the printing direction.
Technical parameters of screen printing
1. Printing cycle: from the liquid crystal glass entering the worktable through the feeding port, to the completion of printing, and the liquid crystal glass is sent out for one cycle. The duration of each cycle does not exceed 30s.
2. The size of the substrate (liquid crystal glass or substrate): 550X650mm, the basic thickness is 0.4-1.1mm.
3. Dimensions of the screen printing machine: about 1900mm long, 1800mm wide and 2250mm high.
4. Scraper/Ink Return Knife
(1) Scraper moving method: Scraper moving method is divided into up and down movement and horizontal movement. The up and down movement is controlled by the cylinder, and its purpose is to give a certain pressure to the wire mesh. The horizontal movement of the squeegee is actually the horizontal movement of the squeegee frame along the screen printing direction, and the speed of its horizontal movement is the speed of screen printing, which is less than or equal to 300mm/s.
(2) Scraper stroke: The scraper is divided into horizontal stroke and vertical stroke. The horizontal stroke is the stroke along the printing direction, about 850mm; the vertical stroke is the up and down movement of the scraper, which is 30mm.
(3) The length of the scraper is 670mm, and the angle of the scraper is 60-90 degrees.
(4) Squeegee pressure: Scraper pressure is the force exerted by the scraper on the workbench through the wire mesh. The blade pressure range is 0-4kgf/cm2.
(4) The moving method of the scraper frame: the up and down movement is controlled by the air cylinder, and the up and down movement amount is 45mm. Movement along the printing direction is controlled by a servo motor.
Automatic alignment system components
(1) Adjustment of the worktable: The worktable has three directions of movement, namely X, Y and θ directions, so the worktable has three directions of travel. The adjustment stroke in the plane x and Y directions is 5mm, and the adjustment stroke in the θ direction is 2°
(2) Workbench treadmill: The workbench treadmill is the movement of the workbench from the parts of the automatic alignment system to the parts of the screen frame. The travel of the worktable treadmill is 1500mm, and the displacement deviation is 5um
(3) The CCD positioning accuracy of the mechanical vision system is 5um, and the alignment is performed by identifying the cross target. The size of the wire mesh frame is 100-1100mm, and the parallelism with the workbench is required to be plus or minus 0.1mm.
The size of the wire mesh is 1200X1200mm, and the positioning method on the wire mesh frame is the way of clamping the four corners of the cylinder.