Positioning and Registration of Textile Screen Printing

The process of patterning a dye or paint on a fabric by screen printing is called fabric silk screen printing. With the rapid development of screen printing technology, special printing technologies such as foam printing, fluorescent printing, luminous printing, pearl printing, conversion effect printing, electro-aluminum transfer printing, electrostatic flocking transfer printing, etc. have also been correspondingly developed, which makes the application of fabrics. The scope is broader. Various colorful fabrics are more practical, but also have a certain degree of artistic appreciation.

However, in order to obtain an ideal textile screen product that meets the design requirements, in addition to the reasonable selection and deployment of printing materials, the positioning and registration of the fabric should also be taken into consideration during printing. Because of its soft texture, the positioning of the silk screen and the accuracy of overprinting also have a great influence. An introduction is made on the positioning and registration of textile screen printing (suitable for manual screen printing).

First, silk screen positioning method

There are two kinds of screen printing methods: one is fixed screen, and the substrate moves. The other is screen movement (running version), the substrate is fixed. There are many ways to position it;

1. The backing method can be used to position the vertical and horizontal edges of a substrate with a certain thickness and a neat edge against the backing fixed on the console.

2. The hole method For holes with the substrate, can be identified as 2-3 holes as positioning holes, set on the console fixed nail (nail height is lower than the thickness of the substrate) for positioning.

3. Illumination method The work surface is made of a material with good light transmission such as glass, and light is installed below. For a substrate with a certain transparency, rely on light to align and overprint the baseline on the substrate and the baseline on the operator table.

4. Suction method For small or thin substrates, suction holes on the operating platform are sucked and positioned.

5. The adhesive method is coated on the operating table with adhesive to stick the substrate and locate it in this way.

6. The platen method screen printing is performed by screen movement (running version), the substrates are fixed in advance on the long operation board, and the regular holes on the screen are consistent (can be inserted)

Second, the positioning of fabric screen printing

1, for a small area of ​​a certain thickness and hardness of the fabric, such as clothing trademarks, brims, shoes, children, etc. can be used for the positioning method. If the substrate is too soft, the substrate can be sizing without compromising the screen printing effect and the effect of the screen printing product.

2, for the clothing sheet, sheets, towels, pillowcases, drapes, curtains, tablecloths and other large-area fabric printing, substrates are relatively soft, the use of platen positioning (running version) screen printing is appropriate.

Third, the Taiwan plate method positioning

1. Platen structure

The platen is erected on the foot of wooden, iron or cement bricks, with a height of about 0.7 meters. Countertops are covered with artificial leather, flat and tight, and seamless. Underneath the artificial leather is a cotton velvet blanket, which gives it a certain degree of elasticity. On the side of the table reserved for regular holes. There are sinks on both sides of the high-level operator's desk, and drains are provided at the table top to wash the plate with water at the end of screen printing.

The length of the platen depends on the area and quantity of the substrate, the drying speed of the printing material, the number of overprints, and the production conditions. The long platen is over 100 meters. The length of the platen is conducive to overprinting for large-scale production. If it is limited by the length of the factory building, a few more short platens can be set up to solve the problem.

In order to improve the utilization rate of the platen, especially for overprinting, the indirect steam pipe or the heat of the electric heat pipe is often installed under the tabletop so that the temperature of the tabletop can be maintained at about 45°C. This is often referred to as hot platen screen printing. Unheated cold platens are usually used. Special printing on the hot platen screen printing should pay attention to the final screen printing effect.

2. Frame construction

Fabric silk screens are made of wood or iron. Aluminum alloy pipe net frame has been widely used due to its advantages of light weight, firmness and rust resistance.

Fabric silk screen frames are the same as other silk screen frames. There are two tapped holes (5 centimeters from the hole) on the side of the frame that is approximately 2 centimeters from the horizontal border. You can screw in 6 centimeters (or 8 centimeters) of screws (the length of the screw can be inserted into the tabletop Suitable). There are two threaded holes corresponding to the lower end of the frame. Screwing on four screws can be used as the rule of the frame. When making the screen plate, it can be screwed down. When the screen is printed, it can be screwed on. It is very convenient.

3. Fix the fabric on the platen

One method is to stick a single piece of fabric (not too large in area) around the platen with an adhesive tape. Another common method is to brush a layer of water-soluble (starch) slurry on the platen and spread the fabric over the countertop to make it stick.

Fourth, the accuracy of overprinting

The fabric is flattened and adhered to the platen. After the first color of silk screen printing, the material to be printed is not sticky (slightly than), and the second color and the third color can be set until the requirements for overprinting (including overprinting) are completed and the printing is removed. Post-processing (drying, fixing, pressing, etc.) Replace with new substrates. The registration accuracy is improved by the stretch tension of the entire trapping screen, the regularity of the frame, and the consistency of the screen registration at the same position.

1. Frame rules

The four rules on one side of the frame are the positioning devices for the screen printing, so they are still positioned by the rules when overprinting. The rules for the overprinting net frame should be unified and the error should be small. Rules and rules on the platen hole can not be too loose or too tight, too loose affect the accuracy of overprinting, too tight and unfavorable screen printing operation.

2. Screen production

Fabric overprinting should be based on the design of the original, screen printing plate color separation first to overlap, check whether the registration accuracy meets the design requirements. After the requirements are met, two horizontal and vertical reference lines are determined on each film. When making the screen, look for the reference line on the negative so that the negatives coincide with the baselines of the screens respectively. This pattern can be made on the uniform parts of the frames to align with the screen printing. This is also the fabric. Silk screen registration key.

Most of the manuscripts of the silk screen printing pattern on the tracing paper are directly used as the negative film, so the registration baseline can be determined at the time of drawing.

3. Overprint order

Textile screen printing is both practical and artistic. Overprinting sequence is very important for the performance of silk screen printing and meeting the design requirements.

According to the color of screen printing products, shades of shades, pattern size, ease of overprinting, ordinary printing special printing (appearing on the same screen printing product), overprinting, and overprinting, etc., choose a reasonable printing sequence. Print sequence with the final silkscreen

Quality is the basis for consideration.

Usually, common printing (dye or paint screen printing) and special printing (foaming, luminous, pearlescent, etc. silk screen printing) designed in the same silk screen printing, should be printed ordinary printing and then printing special printing.

If multiple colors are overprinted, especially when the overprinting requirement is proposed, the dark color should be printed first and the light color printed afterwards. If overprint and overprint exist at the same time (refer to different colors), they can be overprinted and overprinted first. If the size of each pattern is very different, you can print small, large prints first.

The printing sequence cannot be considered from one aspect alone. It should be comprehensively considered in all aspects in order to obtain an ideal textile screen product.

Source: Henghui Screen Printing