Due to the wide range of screen printing applications, there are a variety of printing methods and types of printing machines based on their USES, substrate materials and shapes.
Screen printing methods can be divided into plane printing and surface printing, which includes paper printing and long-stage printing.The plane printing mainly takes the advertisement, the card kind, the metal and the plastic label and so on the single sheet printing as the object.Curved printing is a method of printing on metal, plastic, ceramic, glass and other cylindrical and conical surfaces.
I. Classification according to the degree of automation
Screen printing presses can be divided into the following three types according to their degree of automation.
Manual screen printing machine – ink – scraping plate for manual printing.
Semi-automatic screen printing machine – the ink – scraping plate for mechanical transmission, substrate feeding and taking out for manual.
Automatic screen printing machine – - the scraping of ink plate, the movement of substrate for mechanical transmission.
(I) Manual screen printing machine
A manual screen printing machine is usually a mechanical device consisting of a frame gripper, a hinge, and a table.
After fixing the screen frame on the gripper, various actions in the printing process, such as up and down the workpiece, scraping, returning ink, screen frame check
Printing one color at a time.
Because the manual screen printing is more economical, simple and easy to operate, it still occupies a considerable proportion in some industries, and gradually develops from simple to complete functions.
1. Simple screen frame holder
The simplest screen frame, can be fixed on any work table, clamping screen frame, according to the substrate, the height can be adjusted.
Most of the manual screen printing machines are made with this flat platform structure, especially some simple screen printing devices can be used by themselves.
2. Manual screen printing machine
Its feeding, receiving and scraping are manually operated.But the printing plate is equipped with perforated plate printing by vacuum pump air, substrate is firmly sucked by the plate hole, can save manual fixing trouble.
Precision manual screen printing machine
In fact, it is a kind of manual adjustment device with simple structure and complete adjustment function.The screen frame gripper has four degrees of freedom adjustment function, which can make movement adjustment along all directions and rotation adjustment along a certain direction, so as to ensure the necessary positioning and screen distance adjustment for precise screen printing.Among them, the adjustment of three axial degrees of freedom is accomplished by cylindrical sleeve and adjusting screw, and the rotation is accomplished by hinged shaft. Each degree of freedom has its own locking device.
The machine is equipped with a corresponding table to print a variety of substrate, in order to be the most widely used in the circuit board, signage industry.
In the process of screen printing of some substrate, for the convenience of positioning, the screen frame gripper is only adjusted up and down, the substrate is fixed on the work table to do a trace adjustment of horizontal direction, that is, only requires the screen frame gripper to move up and down, and the other three degrees of freedom are adjusted on the work table.The most commonly used manual screen printing machines with vacuum adsorption devices are of this type, mainly used for printing various paper and film substrate.
4. Multi-color overprinter manual screen printing machine
This type is mainly used for continuous multi-color screen overprinter. The machine can be installed with four screen frames at a time. The four tables rotate around the fixed axis.One or four working tables can be provided as required.This machine is suitable for printing knitwear with better ink absorption performance, such as T-shirts, handkerchiefs, etc.
5. Characteristics of manual printing press
Manual printing is slower than mechanical printing and the amount of ink pressed varies greatly with each printing.Due to too much or too little ink, printed matter tends to produce text or unclear lines and other shortcomings.Manual printing, to master a variety of printing materials different printing technology, it takes a long time.But in order to adapt to the variety of printing materials, manual and automatic printing machines are now used in screen printing.
The greatest advantage of manual printing is that no matter what kind of materials, shapes and weights may be changed, as long as there is the right plate, different sizes of printing tables, skilled technology and the right workplace, it can meet the needs of various printing.All the operation and use of full-automatic printing machine originated from manual printing, which contains all the essentials of printing technology.In this sense, proficiency in hand printing is very important.Learn screen printing, the first to grasp the ink allocation, pressure, printing scraper material and hardness, Angle selection, layout and substrate clearance adjustment, multi-color printing overprinter rules.Learn screen printing from the manual printing hand.In manual printing, paper feeding, paper receiving, plate lifting and dropping, plate use, printing drying, etc.The whole process can be completed by one person, but in most cases, paper feeding, paper receiving, drying, etc. should be completed by 1~2 people, 2~3 people to form an operation group is more common.
Because of the advantages of hand printing as mentioned above, many developed countries still keep hand printing.But in the large quantity, the precision request high and the batch quality request in the industrial product printing, USES the automatic way.