【Printing machine principle classification】What is the principle of printing presses Printing presses classification details
What is the principle of printing machine
1、Screen printing machine working principle
To commonly used hand-shaped screen plane screen printing machine, for example, the working principle of the screen printing machine can be described as follows: by the transmission mechanism to transmit power, so that the ink scraper in motion squeeze the ink and screen printing plate, so that the screen printing plate and the substrate to form an embossed line, as the screen has tension N1 and N2, the scraper plate force F2, rebound force so that the screen printing plate in addition to the embossed line are not in contact with the substrate, the ink in the scraper Ink in the squeegee plate under the action of squeezing pressure F1, through the mesh, from the movement of the embossing line leakage to the substrate.
In the printing process, the screen printing plate and squeegee relative movement, squeezing pressure F1 and rebound force F2 also moved simultaneously, the screen in the role of rebound force, timely return to the substrate out of contact, so as not to scuff the print. That is, the screen in the printing stroke, constantly in the deformation and rebound.
Squeegee in the completion of one-way printing with the screen printing plate from the substrate, while the return journey back to the ink, that is, to complete a printing cycle. After the ink back to the top of the substrate and the distance between the reverse side of the screen printing plate is called the same distance or screen distance, generally should be 2 to 5 mm. manual printing, the operation of workers and the degree of skill directly affect the formation of the embossed line. In practice, screen printing workers have accumulated a lot of valuable experience, specifically can be summarized as six points, namely to ensure that the movement of the ink scraper plate straightness, uniformity, equal angle, equal pressure pieces, neutral and vertical edge. In other words, when printing the scraping board should be straight ahead, can not sway left and right; can not be slow before and after the fast, fast before and after the slow or slow and fast; to the tilt angle of the ink plate should remain unchanged, pay special attention to overcome the tilt angle gradually increase the general problem; printing pressure to maintain uniformity; keep the scraping board and the inner sides of the screen frame at an equal distance; to the ink plate and edge frame to maintain vertical.
2、The working principle of flat screen curved screen printing machine
Screen printing on curved surfaces with a flat screen means screen printing on cylindrical or conical surfaces with a flat screen. Under certain conditions, it is also possible to screen print on oval, drum, curved surfaces and other curved surfaces. The dry screen curved surface screen printer is a machine that uses a flat screen to print on these curved surfaces.
The working principle of Ping Tong surface screen printing machine: a-roller support b-axis will support c-inlay support. Printing, flat screen printing plate and substrate movement, while the scraper plate is stationary. Flat screen printing plate clamped in the screen frame by the flat screen curved screen printing machine with the action of uniform translation, due to the friction of the screen plate will be placed on the support device of the substrate with the rotation. The linear speed of the curved substrate at the embossing line is the same as the moving speed of the flat screen printing plate to achieve ink scraping printing.
Theoretically, the embossing line should be in the curved substrate at the highest a bus line, in order to facilitate the increase of the off-screen angle, to ensure the quality of printing. For the convenience of adjustment, the scraper plate is generally used 60 ° ± 15 ° top angle, requiring vertical degree and up and down the size of the adjustment. Adjusted to vertical is to ensure that the up and down adjustment edge line does not produce lateral displacement, always aligned with the highest one bus A; using the top angle of 60 ° ± 15 ° scraper plate is to ensure that the vertical installation after the formation of the scraper plate inclination α. In the actual adjustment, in order to ensure that the plane screen printing plate and curved substrate in a timely manner, the embossing line can be appropriate bias forward a little, especially when the substrate diameter is larger, the embossing line must The support device for curved printing is a special device of various forms, designed and manufactured by the user according to product requirements.
Cylindrical container or conical container surface printing can be used for two pairs of roller support, length and diameter ratio of less than 1.5 cover and cups with sleeve support, soft hollow containers available inflatable device support. Elliptical surface approximates a part of the cylindrical surface, can be supported by cylindrical inlay approach.
In the cone of the surface for printing principles, and in the cylindrical surface for printing principles are basically the same, the difference is the shape of the screen printing plate graphics and screen printing plate movement form. In the production of screen printing plate for cone surface printing, we must first draw the surface of the cone expansion chart, and according to the expansion chart to find out the center of the sector, and then select the appropriate screen frame to produce the screen printing plate.
On the plate efgh, which can fully accommodate the fan abed, a plate is made to match the fan shape. A right-angle rod is fixed to the plate efgh, and the plate is mounted on the o-axis so that it can be rotated in a fan shape. Then the same as the cylindrical surface printing, in the bottom of the plate with four rollers to support the substrate, the squeegee is fixed, according to the fan-shaped mobile plate frame, squeegee pressure can be carried out on the surface of the conical plate printing. Printing, conical printing in a certain scraper pressure and screen printing plate is a line contact; when the screen printing plate around the axis of the fan-shaped expansion chart for horizontal fan-shaped movement, the substrate in the support device for synchronous rotational movement; ink in the scraper pressure squeeze, leakage of printing to the surface of the substrate, complete printing.
(1) The work cycle procedure of flat screen flat screen printing machine. Take the flat screen platform type monochrome semi-automatic hand surface screen printing machine as an example, one of its work cycles is: give the piece → positioning → drop the plate → lower to the ink plate, raise back to the ink plate → scrape the ink stroke → raise to the ink plate → lower back to the ink plate → lift the plate → return to the ink stroke → release the positioning → collect the piece.
In the continuous cycle action, as long as the function can be achieved, each action should occupy as short a time as possible, in order to shorten each work cycle and improve efficiency.
(2) Imprinting line. In the printing stroke, to the ink plate squeeze ink and screen printing plate, so that the screen printing plate and the substrate to form a contact line, known as the embossing line. This line at the edge of the scraper plate, numerous embossing lines constitute the printing surface. Achieving the ideal impression line is difficult because the printing stroke is a dynamic process.
Printing machine classification details
1、Classification according to the form of printing plate
Divided into letterpress, lithographic, gravure and hole-plate printing presses; mounting plates and impression structures are divided into flat, round and round presses
（1）Toppan Printing Machine
Relief printingpress: A machine that uses a letterpress plate to complete the printing process. Such as business card machines (resin plates), lead printing, zinc letterpress, and overlay lettering.
（2）Lithographic printing machine
Lithographic press: planographicpress. a machine that uses lithographic plates to complete the printing process. Such as multi-color, four-color, two-color, single-color, and quick printing presses.
（3）Gravure printing machine
Intaglio printing press: intaglioprintingpress, a machine that uses intaglio plates to complete the printing process. For example, glass bag printing for instant noodles, aluminum foil bag packaging for cookies, etc.
（4）Screen printing machine
Screen printing press: screen-processprintingpress machines that use screen plates to complete the printing process. Hole plate printing: such as screen printing, circuit board printing, fabric flower printing, can printing, inscription plate printing, partial varnishing, etc.
2、Classification by printing paper
（1）Sheetfed printing machine
Sheet-fed printing press: Sheet-fedprintingpress uses a single sheet of paper for printing.
（2）Web printing machine
Web presses: roll-fedprintingpress presses that use rolls of paper.
3、Classification by printing method
Flat presses: platenpress presses in which the plate support body and the impression body are both flat
（2）Round and flat printing machine
Round-bed printing press (platform press): flat-bedcylinderpress plate support body is flat, while the impression body is cylindrical printing press.
（3）Stop rotary printing machine
Stop-cylinderpress: stop-cylinderpress plate cooperation reciprocating motion, forward, the impression cylinder rotation a week, return, the impression cylinder stop rotation, complete a printing process of the press.
（4）One-turn printing machine
Single-revolution printingpress: single-revolutionprintingpress plate table each reciprocal movement, the impression cylinder turn a week, to complete a printing process of the printing press.
（5）Two-turn printing machine
Two-revolution printingpress: two-revolutionprintingpress plate table each reciprocal movement, to complete a printing process of the printing press
（6）Reciprocating printing machine
Reversible printingpress: A printing press in which the reversibleprintingpress cylinder rotates once per reciprocation to complete a printing process.
Circular printing press: rotaryprintingpress printing plate support body, transfer body are cylindrical, complete the printing process when the full rotational motion of the printing press.
4、Classification by printing ink color type
（1）Single color printing machine
Single-color printing press: single-colorprintingpress a printing process in which one ink color is printed on one side of the paper.
（2）Two-color printing machine
Two-color printing press: two-colorprintingpress a printing process in which two ink colors are printed on one side of the paper.
（3）Multi-color printing machine
Multi-color printing press: multi-colorprintingpress a printing process in which more than two ink colors are printed on one side of the paper.
（4）Double-sided single-color printing machine
Double-sided monochrome press: perfectingpress a press that prints on both sides of the sheet in the printing process.
（5）Double-sided multi-color printing machine
Multi-color press: multi-colorperfectingpress A double-sided press in which at least one side of the paper is printed with two or more ink colors in the printing process.