Introduction to the positioning and registration o

2022-08-18
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Introduction to the positioning and registration of fabric silk screen printing

the process of forming patterns by means of silk printing with dyes or coatings on fabrics is called fabric silk screen printing. With the rapid development of silk screen printing technology, special textile printing technologies such as foaming printing, fluorescent printing, luminous printing, pearlescent printing, conversion effect printing, electrochemical aluminum transfer printing, electrostatic flocking transfer printing have also been developed accordingly, which makes the application range of fabrics broader. Colorful fabrics are more practical, but also have a certain degree of artistic appreciation

however, in order to get an ideal fabric screen print that meets the design requirements, in addition to the reasonable selection and deployment of printing materials, we should also pay attention to the positioning and registration of fabrics during printing. Because of its soft texture, the positioning and overprint accuracy of silk screen printing also have a great impact. This paper introduces the positioning and registration of fabric screen printing (suitable for manual screen printing)

I. silk screen positioning method

there are two ways of silk screen printing: one is to fix the plate and move the substrate. The other is version moving (running version), and the substrate is fixed. There are many ways to position it

1 the loss rate of fruits and vegetables in developed countries is less than 5%. Backer method

for a substrate with a certain thickness and neat edges, its vertical and horizontal sides can be positioned close to the fixed backer on the console

2. Sleeve method

for the substrate with holes, it can be recognized that holes are used as positioning holes, which are sleeved on the nails fixed on the operating platform (the height of the nails is lower than the thickness of the substrate) for positioning

3. illumination method

the operating table is made of glass and other materials with good light transmission, and the light is installed below. For the substrate with certain light transmittance, the baseline on the substrate and the baseline on the console are overlapped by light for positioning and overprint

4. inspiratory method

for small or thin substrate, the inspiratory hole on the operation platform absorbs and locates

5. bonding method

the operating table is coated with adhesive, which can adhere to the substrate and position it in this way

6. Platen method

screen printing is carried out by moving the plate (running the plate). The substrate is first fixed on the long operation platen, and the regular holes on the plate are consistent (insertable)

II. Positioning of fabric screen printing

1. For small-area fabrics with certain thickness and hardness, such as clothing trademarks, brims, uppers, bags, etc., the mountain positioning method can be used. If the substrate is too soft, the substrate can be starched without affecting the screen printing effect and the use effect of the screen printing products, so that it can be scraped to facilitate positioning

2, for the printing of large-area fabrics such as clothing pieces, bed sheets, towels, pillowcases, quilt covers, curtains, tablecloths, etc., the substrate is relatively soft, so it is appropriate to use the tableboard method for positioning (running) silk screen printing

III. positioning by platen method

1. Structure of platen

platen is erected on wooden, iron or cement brick footings, with a height of about 0.7m. The table top is covered with artificial leather, which is flat and tight without seams. The artificial leather is padded with cotton blanket to make it elastic. Regular holes are reserved on the side of the table top. Both sides of the advanced operation table are equipped with water tanks, and the end of the table is equipped with drainage pipes, so as to wash the table with water at the end of the 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 overprint, production conditions, etc. The long bedplate is more than 100 meters. The platen length is conducive to overprint for mass production. If it is limited by the length of the plant, several short bedplates can be set to solve it

in order to improve the utilization rate of the platen, especially for overprint, indirect steam pipes or electric heat pipes are often installed under the platen to keep the temperature of the platen at about 45 ℃, which is often referred to as hot platen silk screen printing. Usually, the cold platen without heating is enough. Special printing in 1 The relevant standard only requires the maximum experimental force after tearing, and the final screen printing effect should be paid attention to on the hot platen

2. structure of frame

the frame of fabric silk screen printing is mostly made of wood or iron. Due to the advantages of light weight, firmness and not easy to rust, aluminum alloy profile pipe frame has been widely used

the fabric screen printing frame is the same as other screen printing frames. There are only two threaded holes (the distance between the holes is 5 cm) at the position about 2 cm away from the horizontal frame at the upper end of one side of the frame, which can be screwed with 6 cm (or 8 cm) screws (the length of the screws is suitable to be inserted into the regular holes on the table board). There are also two threaded holes at the lower end of the same side of the frame. Screw on four screws as the rule of the frame, which can be screwed off during plate making and screwed on again during screen printing, which is very convenient

3. One way to fix the fabric on the table is to stick the surrounding of a single piece of fabric (with a small area) to the table with adhesive tape. Another commonly used method is to brush a layer of water-soluble (starch) slurry on the table, and spread the fabric on the operating table to make it stick firmly

IV. accuracy of overprint

the fabric is flattened and glued on the platen. After the first color is printed, the material to be printed is not glued (slightly less than), the second color and the third color can be set until the overprint (including overprint) requirements are completed. Remove the substrate for post-treatment (drying, color fixing, pressing, etc.). Replace with a new substrate. Its registration accuracy depends on the tension of the whole chromatic version, the frame rules, and the registration consistency of the version pattern at the same position

1. rules of the frame

the four rules on one side of the frame are the positioning devices during silk screen printing, so they are still positioned by rules during overprint. The rules of the whole overprint frame should be unified and the error should be small. The regular holes on the rules and platens should not be too loose or too tight. Too loose will affect the overprint accuracy, and too tight will be detrimental to the screen printing operation

2 you can also test the S-N curve. The production of the version

fabric overprint should be based on the design manuscript. When making the version, the color separation negatives should be overlapped first to check whether the registration accuracy meets the design requirements. After meeting the requirements, determine the horizontal and vertical reference lines on each negative. When making plates, recognize the reference line on the negative so that each negative coincides with the reference line of each plate, so that the pattern can be made on the unified part of each frame to facilitate the registration during silk screen printing, which is also the key to the registration of fabric silk screen printing

most of the originals of fabric silk screen printing patterns are drawn on tracing paper and directly used as negatives, so the registration reference line can be determined when drawing

3. Overprint sequence

fabric silk screen printing is both practical and artistic. Overprint sequence is of great significance for good performance of silk screen printing effect and meeting design requirements

according to the color depth of the silk screen, the brightness of the tone, the size of the pattern, and the difficulty of overprint, a reasonable printing sequence is selected for ordinary printing, special printing (appearing on the same silk screen), overprint and overprint. The printing sequence is based on the quality of the final silk screen

generally, when ordinary printing (silk screen printing of dyes or paints) and special printing (silk screen printing of foaming, luminous, pearlescent, etc.) are designed on the same silk screen, ordinary printing should be printed before special printing

if multiple colors are overprinted, especially when overprinting requirements are proposed, dark colors should be printed first and then light colors. If overprint and overprint exist at the same time (referring to different colors), overprint before overprint. If the size of each pattern varies greatly, you can print the small one first and then the large one, even if the salary is so low

the printing sequence should not be considered from one aspect alone, but from all aspects in order to obtain an ideal fabric silk screen

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