Screen printing plate classification - metal plate (2)

4 plating plate. This is a method of lithography and electroplating combined with a plate-making method, that is, photographic imaging, electroplating method of molding, the process flow is: metal base → surface treatment → photosensitive coating → printing plate → development → stencil plating → Internet plating → Strip the metal plate base, screen frame → glue fixed → metal screen version.

Metal base: 0.15-0.25mm thick stainless steel, copper or molybdenum foil. The surface treatment is required before plate making so that when plating the nickel layer on the plate surface, it can be plated and peeled off. The molybdenum plate can be treated with a solution of sodium dichromate in water, and the stainless steel plate is treated with 10% sodium hydroxide solution for electrolytic degreasing.

Photosensitive film: To be resistant to the plating solution, available are: PVA + dichromate, polyvinyl alcohol, cinnamic acid and rubber sensitive adhesive.

Stencil Plating: The sensitized stencil prepared by printing and developing can be plated with a nickel sulfamate solution, a high concentration plating solution, or a nickel sulfate solution to obtain a 10 to 15 μm thick nickel stencil.

Plating on the Internet: The prepared nickel stencil must be pasted onto a stainless steel wire mesh, adhered by a sticking method, electroplating, and pressure. Among them, the electroplating bonding method is most commonly used. That is, the screen is placed on a nickel stencil and then plated thereon. A 5 to 10 μm layer of nickel is finally stripped of the metal base.

Compared with the photosensitive stencil, the metal stencil prepared by the etching method and the electroplating method has the characteristics of resistance to printing, sharp lines, and uniform film thickness. The disadvantages are higher costs and poor elasticity.

Corrosion compared with the plating method, the former film is thick, but the quality of the line is slightly poor; the latter film is thin, the quality of the line is good, so there is also a hybrid method using a combination of the two, the process is: metal plate base ( Copper) → coated on both sides of the photosensitive film → image and screen respectively drying → both sides of the development of → plating on both sides → stripping the photosensitive film → metal base corrosion → stencil upper frame.

5 Use laser method to manufacture metal diaphragm. Due to the popularization of CAD (Computer Aided Design), CAM (Computer Aided Manufacturing) and the improvement of the functions of laser devices, there are more and more laser processing CAMs in the manufacture of metal models and the production of precision parts.

When CAD is used for precise pattern design, high-precision diaphragms can be rapidly manufactured with computers and software. This is a great advantage, and there is no fear of problems such as errors due to single-sided etching and moving of both sides of the etched diaphragm. , can be made of excellent metal diaphragm.

6 Metal mesh and metal film composite processing. Wire mesh and metal films are more flexible than polyester meshes and stainless steel meshes, but can not be flexibly flexibly printed on important surfaces and openings during printing. Put the wire mesh and friends on the aluminum frame, leaving a white space around the wire steel and metal film, and the remaining part of the wire is attached to the polyester wire mesh with an adhesive and stretched over the frame. The polyester mesh part is very soft and can be filled with a solvent-resistant resin. This bonding process is called composite processing and plays an important role in high-density and high-precision printing. If the width of the part of the polyester mesh around the plate is not enough, the tension and the elasticity during printing will be affected, so an appropriate width must be given. In addition, in the case of high positional accuracy, it is necessary to determine whether to fix the metal mesh and the metal film directly on the frame only when the scraper starts moving, or to connect the aluminum frame with a thin metal plate to increase the strength. .

The image formed by the wire mesh is very good compared with the image formed by the resin photosensitive film, and the intersection point between the image formed by the nickel foil and the metal wire fixed by the nickel-plated stainless steel wire mesh is very good, especially after the hybrid processing. Fixed on the frame, its cumulative size is very accurate.

7 round net plate making method. Rotary screen printing is a method of rotating a cylindrical printing plate on a substrate. Rotary screen printing substrate sheet and roll two. The latter press has unwinding, take-up, and tape tension adjustment devices.

The heart part of the rotary screen printing is the cylinder printing plate mentioned above. The cylindricity, dimensional stability, plate thickness, and through-hole uniformity of the printing plate are highly demanding. The basic manufacturing method of the rotary screen plate includes an electronic plate making method and a bonded thin plate multiple plate method. The former is suitable for printing continuous images. Certainly, there are certain restrictions on the number of meshes and the rate of opening, and there are certain difficulties in restoring fine images. Because the latter has the characteristics of a lithographic screen, the mesh and the aperture ratio can be arbitrarily selected. Of course, it is not suitable for continuous pattern printing.