Congratulations on the successful printing of the sample reflective road sign on Lingtie automatic screen printing machine

Customer's reflective foil and ink goes smoothly on this roll to roll screen printing machine .

This kind of road signs should be brightly colored and durable. Screen printing would be the best choice for the printing .

1. Heat transfer printing head

The Heat transfer printing head is mainly composed of a surface film protective layer, a bottom film protective layer and a heating element. The heating element is a conductive silk screen. With the help of the heat generated by the voltage pulse, the coarse particles of the ink layer in the graphic part are raised and melted to complete the ink transfer by thermal diffusion.

The printing speed of heat transfer depends on the time required for each line of graphics. Therefore, the transfer head and the transfer paper should have good heat transfer properties, so that the heat generated by the heating element can quickly pass through the protective layer, the transfer paper substrate and the gap and finally transfer to the surface of the substrate to ensure that the ink has sufficient transfer time.

2. Ink

The composition of heat transfer ink is generally three parts: pigment (pigment or dye), wax and oil. Among them, wax is the main component of heat transfer ink.

During printing, the viscosity of different inks has a direct relationship with the heating temperature, and the heating temperature and the viscosity of the ink should be strictly controlled. Practice has proved that when the heating temperature is 60-100 ℃, when the ink is melted, the viscosity value of the ink is stable at about 0.6pa·s, which is the most ideal. Generally speaking, the closer the ink is to this state, the better the transfer performance.

3. Transfer medium

Chemical properties: Making the ink adhere well and evenly is two important performances of the chemical properties of the transfer paper substrate. The chemical properties of transfer paper in production directly affect the quality of printing.

Good thermal performance: Since the transfer process is achieved by means of high temperature, the material of the transfer paper must be able to withstand the influence of the transfer temperature and keep the properties unchanged.

4. Substrates

Experience has shown that substrates with a slightly rough surface produce better quality prints, which is a characteristic of heat transfer printing. Because the rough surface of the substrate indicates that the substrate has a large surface energy, the ink on the transfer paper can be transferred to the substrate well, and the ideal level and tone can be obtained, but too rough will affect the normal operation of the ink. Transfer is not conducive to the realization of the printing process.

High Brightness El Backlight Electroluminescent Panel

There are many High Brightness El Backlight products are manufactured on screen printing machine .

See how to processing El Backlight Electroluminescent Panel on roll to roll screen printing machine .

• Prepare Ink and Film ,and screen mesh

• Start to print the phosphor ink on film on roll to roll screen printing machine, drying it through hot air dryer .

• Print the dielectric ink on the phosphor layer ,and dry it through hot air dryer

• Finally the Sliver ink will be printed on the dielectric layer and cured in hot air dryer .

• After curing the sliver ink ,you may processed to assembly department to complete the EL Panel See what you will get from printing and assembly

See what you will get from printing and assembly

guide rail, the printing plate and the working platform plays important role.

The adjustment of the parallelism between the three layers of the guide rail, the printing plate and the working platform: generally the guide rail or the platform is used as the reference for the adjustment. 1The platform and the guide rail should be parallel, and the squeegee plate moves along the guide rail. If the two are not parallel, the squeegee will not always touch the platform with a certain pressure, and even the gap will occur. This adjustment has been adjusted before the machine leaves the factory. 

 

 

 The screen printing plate and the platform should be parallel, otherwise the mesh distance (distance from the bottom surface of the screen printing plate to the printing surface) is inconsistent, causing the printing pressure and the screen printing plate to be inconsistent. Therefore, the flatness of the frame itself should be guaranteed. 

 

 

Adjustment to the plate: refers to the adjustment of the printing precision between the screen printing plate and the printed object on the screen printing machine.

 

Squeegee adjustment: 1 Adjusting the parallelism of the screen by the squeegee, adjusting the left and right screw to adjust the height of the ink plate; the left and right sides of the middle shaft can be adjusted with the top wire to adjust the left and right top wires, and the height is adjusted to the right and left of the ink plate respectively. 2 The adjustment amount of the blade inclination angle is generally in the range of 65 to 85 , and can be selected as needed. 3 The adjustment of the printing pressure is actually the adjustment of the position of the squeegee. 4 The length of the squeegee can not be adjusted, generally supplied as a kit, each set has several different lengths to choose from. Stroke adjustment: including adjustment of stroke size and stroke position. Through the adjustment of the crank and the radius R of the swing rod, the stroke adjustment is realized, and the R increase stroke is increased, and the stroke length generally exceeds the pattern of 20 to 50 mm. Network (table) distance adjustment: the net (table) distance adjustment can be realized by reducing the screen printing plate or raising the platform, generally adopting the method of raising the platform. The screen plate four-corner net table spacing should be consistent, the error is 0.5mm. The distance between the nets is generally 2 to 5 mm, and the net is allowed to be smaller from the front and the rear only 

The screen printing of the equipment shell panel is also a kind of screen printing. It is mainly used on equipment and machines. With the continuous progress and completeness of modern technology, this kind of panel screen printing is becoming more and more widespread. For example, the panel printing and decoration processing of electrical equipment.

The silk screen panel is an operation panel printed through the silk screen printing process, which is widely used in various industrial products, electrical appliances and other panel decorations that require identification and marking. It is widely used in equipment housing, electronic processing industry, printed circuit board silk screen logo, instrument housing panel logo, solder paste printing during circuit board processing, etc. There are also large-scale carton boxes that are printed using silk screen printing. Mainly include text screen printing, LOGO screen printing, various color screen printing and so on.

Button panel/membrane switch/electrical panel industry screen printing, label nameplate printing, automatic PP/PET/PVC sheet screen printing machine #screen printing equipment #Membrane switching screen printing ...

Lingtie insist on research, optimization and improvement, upgrades  ，Only for the best user experience and the most efficient screen printing  .

Printing head version 2021 ：

Printing head version 2022 ：

Maximize the advantages of screen printing

• Cost effective for large batches
• Versatile design placement – artwork can easily be moved and printed at a different angle or position.
• The more you order, the cheaper the cost per unit – although the initial setup fee can be expensive, the more copies you need, the cheaper it works out. Once your artwork has been setup, you don’t need to pay the fee again which is ideal if your design rarely changes.

The latest generation of roll-to-roll screen-printing systems marks a significant evolutionary step in the press technology that has dominated since the early 1900’s. Now, the incorporation of more sophisticated electronic controls reduces the need for time-consuming manual adjustments that typify earlier and less sophisticated equipment. In this discussion, we will consider how state-of-the-art electronic controls and software integration are changing the capabilities of roll-to-roll screen-printing systems, including both flatbed models and cylinder-based equipment.

The underlying electronics and software engineering that now have bearing on screen-printing technology are cut from the same cloth as the electronic controls we now see in a wide swatch of industrial equipment. At the core are programmable logic controllers (PLCs)— computers geared to provide stability in real-world manufacturing conditions and able to handle multiple inputs and outputs. PLCs, originally developed for the automotive industry, are now programmed with more sophisticated instructions than when they were originally introduced, enabling expert programmers to fine tune industrial controls to an unprecedented extent. This includes today’s PLCs that can fully automate the steps in roll-to-roll screen printing.

Adjustments to the screen clamps, as well as squeegee and floodbar pressures, can now be achieved with touch screens operating pneumatic controls via the system’s PLC. This eliminates a good deal of time that had previously been spent by operators making mechanical adjustments to balance these components for each job. On today’s roll-to-roll presses, no tools are required to make these adjustments—they are all done electronically and with greater precision and repeatability than what human operators can typically muster. If and when fault conditions arise, they can also be corrected with a few keystrokes.

Going from a manually sheet-fed printing process to an automated web process can speed throughput by 50% or more. The actual speed improvement varies, and is dependent on the size of the job, among other factors.

Once a skilled operator has set up all the required job parameters for a particular application—web speed, web transport settings, squeegee angle, screen height, dryer settings, etc.—the PLC will automatically store all these parameters. For repeat runs of the same job, a far less skilled operator is able to quickly initiate and set up the system by recalling those parameters.

The greater precision electronic controls also are key to enabling many specialty graphics companies to expand into electronics applications that have requirements for exact ink thicknesses and minimal screen stretch that non-automated presses cannot consistently achieve. Since membrane switches and other printed electronic products are a growing segment of the specialty graphics industry, we can expect that the capacity and sophistication of PLC-enabled control systems will become more and more a determining factor of where the industry can go.

More precisely, it is the software engineering that makes the real difference between one screen printing system and another. The best-in-class roll-to-roll systems use standard industrial components that one can source worldwide, and customize the software for the precise application requirements of a particular specialty graphics company. These systems typically use higher capacity PLCs that are able to finely control all the inputs and outputs of a web printing line, including unwinding, web tension, material positioning, printing head position, web transport, drying systems, and rewinder

Roll-to-roll screen printing machine is a high-efficiency production equipment, especially suitable for the production of photovoltaic cell backsheets. It can carry out continuous screen printing, thus greatly improving production efficiency. In the manufacturing process of photovoltaic cells, electrode printing is a key step that directly affects the performance and efficiency of the cells. Below, we will explore in detail how the roll-to-roll screen printing machine prints photovoltaic cell electrodes.
 
Basic Principle of Screen Printing
 
Screen printing is a process in which a squeegee extrudes printing ink, and the ink presents a reverse rolling state under the obstruction of the squeegee surface and the mesh knots of the screen plate. When the ink reaches the electrode pattern area of the screen plate that is not blocked by the emulsion film, it penetrates downward through the mesh holes to contact the printing substrate (silicon wafer). As the squeegee moves forward continuously, the ink detaches from the screen plate and adheres to the printing substrate due to the screen tension and the off-contact distance, achieving the purpose of printing. This process is crucial for the formation of photovoltaic cell electrodes, as it is related to the collection and extraction of electric current, as well as the series welding of individual cells.
 
Structural Characteristics of Roll-to-Roll Screen Printing Machine
 
The roll-to-roll screen printing machine features a more rational design and higher production efficiency. It consists of multiple components including an unwinding unit, a feeding unit, an unwinding film splicing storage rack, a corona dust removal device, an unwinding deviation correction device, a feeding storage rack, a screen printing unit, an auxiliary oven heating unit, a microwave curing unit, a corona device, a discharging unit, a winding deviation correction device and a winding unit. These units work collaboratively to ensure that the film material is stably and uniformly delivered to the auxiliary oven heating unit for heating.
 
Unwinding Unit and Winding Unit
 
The unwinding unit and winding unit are equipped with semi-automatic lifting devices for loading and unloading roll materials. This enables faster loading, unloading and roll changing of roll materials, improving production efficiency. The roll material rack includes a supporting base, an I-shaped rotating frame, a guide roller assembly and an air expansion chuck. Both ends of the I-shaped rotating frame are installed on the supporting base through rotating shafts and driven to rotate by a motor drive device. This design ensures the stability of the roll material during the unwinding and winding processes.
 
Splicing of New and Old Film Materials
 
The feeding unit is equipped with a film splicing device that realizes zero-speed splicing of new and old film materials. This splicing device can reduce waste generated during the splicing of new and old materials, improving the utilization rate of film materials. The film splicing device is composed of a frame, a first suction cup, a waste removal suction cup, a second suction cup, a working area, a pneumatic lever, a base and a linear guide rail. Through this structure, the pressing and cutting processes of the film material are more stable, and the operation time is shorter.
 
Unwinding Deviation Correction Device
 
The unwinding deviation correction device adopts a three-point double-roller deviation correction device with a three-point supporting deviation correction mechanism. This deviation correction device can improve the precision of unwinding deviation correction and has better applicability, while the costs of processing, assembly and maintenance are relatively low. The three-point double-roller deviation correction device includes a fixed frame, a floating frame, a drive device, a guide roller assembly and movable fulcrums. The movable fulcrums are arranged on the fixed frame in an isosceles triangle distribution, ensuring the precise alignment of the film material during the unwinding process.
 
Specific Process of Photovoltaic Cell Electrode Printing
 
In the manufacturing of photovoltaic cells, electrode printing usually includes steps such as back electrode printing, back electric field printing and front grid printing.
 
Back Electrode Printing
 
The function of back electrode printing is to form excellent ohmic contact characteristics, welding performance and adhesion. In terms of silver paste composition, silver-aluminum paste is composed of silver powder, aluminum powder, inorganic additives and organic carriers. When the printed pattern is intact, the pressure of the printing head should be as small as possible within the allowable range.
 
Back Electric Field Printing
 
The function of back electric field printing is to form a P+ junction area, so that the photogenerated carrier pairs excited by long-wave photons reaching the P/P+ junction are separated by the P/P+ junction, increasing the minority carrier diffusion capacity and improving the open-circuit voltage. The P/P+ junction can prevent the photogenerated electrons in the P region from recombining on the back surface. Compared with the structure without the P+ region, this high-low junction P/P+ structure can greatly reduce the recombination rate of the back surface. In terms of paste composition, aluminum paste is composed of aluminum powder, inorganic additives and organic carriers. The factors affecting the thickness of the printed aluminum paste include screen mesh count, mesh wire diameter, open area ratio, emulsion layer thickness, printing head pressure, printing head hardness, printing speed and paste viscosity.
 
Front Grid Printing
 
The function of front grid printing is to form excellent ohmic contact characteristics, welding performance and adhesion, as well as to collect and extract electric current. The front grid silver paste is composed of silver powder, inorganic additives and organic carriers. The adjustment of printing parameters is based on the criteria of complete patterns, full lines and appropriate weight of the printed paste.
 
Sintering Process After Printing
 
After the printing process is completed, a sintering process is required. Sintering can be regarded as a process in which atoms migrate from unstable high-energy positions in the system to positions with the lowest free energy. The purposes of sintering include burning out the organic components in the metal paste, burning through the insulating silicon nitride film, melting and alloying the metal in the paste with silicon to form ohmic contact, as well as annealing the silicon wafer subjected to plasma bombardment, activating the doped atoms and eliminating lattice damage.

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Lingtie (xiamen )machinary will go join in Mar.4th -6th , 

Welcome to join us and let show you the lasted version of highest configuration of roll to roll screen printing machine .