The hottest talk about the application of thermose

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On the application of thermosetting ink and common problems in its operation

thermosetting ink is also known as plastic ink, or self-adhesive ink. Its ingredients: it is mainly composed of polyvinyl chloride (PVC) and phthalates, and the thermosetting ink is composed of polyvinyl chloride, phthalates, fixative, stabilizer and thickener

thermosetting ink is a non solvent ink. After heating, it dissolves and plasticizes between powder and additives, infiltrates into fibers, and closely adheres to cloth to form a solid film. Due to the current restrictions on the use of polyvinyl chloride, polyvinyl chloride can be replaced by modifiers to make thermosetting inks that meet environmental requirements. Because the plasticizing temperature of PVC is different, thermosetting inks can be divided into high temperature and low temperature

thermosetting ink entered the market early, but its promotion speed is relatively slow due to the unfamiliar operation and the limitation of production equipment. Now it is very mature from its market promotion to production and operation

basic requirements for thermosetting ink

polyester hard board should be used for other boards, and hard board should also be used for table board. Now tempered glass is more common, and the use of silk should be flexibly applied according to the printed pattern. For example, it is recommended to apply fine dot transition to silk between 150 mesh and 250 mesh, and thermosetting ink itself has no requirements for photosensitive adhesive. It is recommended to use water and oil dual-purpose printing patterns for ordinary printing. In this way, no matter water or solvent, it can increase production capacity and use less when wiping the plate

three dimensional thick film printing pattern

use special thick film plate and photosensitive adhesive coating to make thick film?. The inside of the plate is coated once with ordinary thickness, and the outside is coated once with a round knife according to the pattern thickness or coated many times with an ordinary sizing machine, and then placed in the plate drying box for 40, 50, 60 minutes to dry for exposure. The exposure time must be tested because of the different photosensitive adhesives and the different power of the exposure box. After developing, you must put it in the baking box to dry the water at low temperature. Do not expose yourself to the sun when it is not dry. Temperature is the key to the performance of thermosetting ink characteristics. Therefore, it is recommended to use tunnel drying and heating equipment with good thermal insulation and stable heating constant temperature

special additives for thermosetting ink

thermosetting ink is a very independent printing material. She has her own special printing aids. Such as diluent, thickener, softener, color fixing agent, etc. If there are many additives to be added or reduced during operation, it is recommended to contact the manufacturer first. Listen to the suggestions before operation. Do not add or subtract additives without authorization according to experience, resulting in unnecessary waste and loss

process of thermosetting inks

thermosetting inks are divided into ordinary and special processes according to different printing effects

ordinary printing process generally refers to simple, solid, line monochrome chromatic printing. In addition to heating, this kind of process is no different from ordinary printing process. It is easy to operate without wiping and plasticizing, and its properties are several times higher than those of water-based printing materials

special printing process generally refers to three-dimensional printing, foaming printing, suede printing, gravel printing, wire drawing printing, etc

three dimensional printing requires two kinds of thermosetting ink and three-dimensional gel. For example, three-dimensional thermosetting special dry brush thick film. After the printing pattern is plasticized, it has soft hand feel, strong tensile strength, good washing fastness, and clear 90 ° right angle contour. It is suggested that the thickness of the film thick film plate should be lower than that of the printed pattern. In this way, the printing effect will be better and more ideal if it is printed in two to three times to reach the required thickness of the pattern

the operation of special thermosetting ink effects such as foaming, suede, gravel, wire drawing is no different from that of ordinary thermosetting ink. The effect of printing depends on the amount of additives added

grasp the curing temperature of curing ink

most of the failure cases are due to the failure to grasp the curing temperature and time. For ordinary printing patterns, curing usually takes 170 ° -180 ° for 1 minute. For special printing patterns, curing generally requires pre drying for 100 °/30 seconds, and then entering the drying channel dryer for 170 ° -180 ° minutes after the surface is dried. (the white surface cloth is easy to change color at high temperature, the temperature is appropriately reduced, and the time is extended) in addition, the thermosetting ink foaming is suitable for pressing and ironing with the foaming machine, and the surface is smoother

common problems in the operation of thermosetting ink

1, the ink drawing is not clean... If the viscosity is not large, add diluent, 1%, that is, if you drive the same large load, you can

2, the edge of the pattern is uneven... There are too many knife returns, or the ink is too thin

3, bubbles in the thick film pattern or on the surface... The curing temperature is not high enough or the time is not long enough

4, the surface of the pattern is Matt, there is no tension, it falls off in powder form... There is no curing

5, Ink discoloration after overheating... After the cloth color sublimates, the traction is absorbed by the ink. It is recommended to make a prepress sample test. If the cloth color is easy to sublimate, it is necessary to use anti sublimation thermosetting ink

6, water-based adhesive paste and thermosetting ink are superimposed on each other for printing, but the thermosetting ink

7 can be covered on the water-based paste. The color of water-based printing cannot be mixed with thermosetting ink

8. Thermosetting ink is not a universal ink. Fabrics of different materials should choose corresponding thermosetting ink

9. Changes in climate and environment will affect the viscosity of thermosetting ink. Diluents or thickeners (no more than 2%) can be added as needed

note: this information is provided by Qingdao Shengcai

experience exchange: efforts should be made to reduce the use of powder spraying in printing

8:47 on September 22, 2006 source: 0 comments from printing magazine friends entered the forum

in printing, powder spraying is used to prevent the back of the product from rubbing dirty. Now many advanced printing equipment have eliminated the powder spraying device and adopted three groups of drying methods, namely, two groups of infrared and one group of ultraviolet. At present, most of our domestic printing equipment are infrared plus powder spraying or only powder spraying devices

usually in production, when the ink layer is thick and the dark tone area is large, the printing operator always hopes to put the powder amount more, so that the product will not be scrapped because the back is rubbed dirty, but often ignores the problem that the powder amount should be as small as possible. In fact, too much powder will also bring a lot of harm

1. If the amount of powder is too large, it will directly affect the shift output when printing the reverse side due to the excessive amount of powder on the front side. In severe cases, the blanket needs to be cleaned every hundreds. Therefore, the ink color of the product will be unstable, which will not only affect the quality but also affect the output

2. Too much powder will affect the gloss of the product. When printing some high-end products, operators always hope that the ink saturation is higher. In this way, foreign fixture printing products are bright and bright, and at the same time, in order to prevent rubbing dirt, increase the amount of powder. The powder spray is absorbed by the ink on the ink layer that has not been dried, which will form a layer of fog on the color, and the gloss of the product will be reduced

3. Excessive powder will cause serious wear and tear to machinery and equipment. During production, while spraying powder into products, a considerable amount of powder flies to the paper receiving chain, paper teeth and rollers of the machine. Although there is maintenance time every week, it may not be able to clean up all the dust, and the wear of the machine will inevitably increase over time

4. Too much powder will also have a certain impact on the health of the operator. Although the salesperson said that powder spraying was harmless to human body, the operator stayed in the workshop with fine dust flying every day, and his lungs did not know how much dust to breathe

5. Too much powder will also affect the post process processing, such as glazing and film covering

therefore, in production, we should pay enough attention to the use of powder spraying, and try to spray less or no spray to achieve the purpose of controlling the dirt on the back. There are many factors that cause the back to rub dirty in production, and the key is how to effectively control it

1. Strictly control the density value. The value of each color density is obtained by proofing, observing its K value, point expansion value and ink saturation to obtain the best value. In another sense, the best value (density) obtained by this method is also the best amount of ink that the paper can bear. For example, the best density values obtained by using 128 grams of Japanese coated paper are yellow 1.05, red 1.35, blue 1.45, and black 1.70. We can keep this data for printing in production. Under normal circumstances, it is impossible to get dirty. It will be safer to add a small amount of dusting. But the density is too high, even if the ink layer is not thick, it will still rub dirty. For example, compared with the four-color dark tone overprint, the yellow and magenta overprint with 100% overprint respectively are obviously not thick. If the Yellow density value is increased by more than 1.30 and the magenta density value is increased by more than 1.50, which exceeds the critical value of the ink capacity of the paper, the product is easy to rub the back dirty

2. The reason why we use powder spraying is that the dark tone area of the product is large, and the ink layer will be 1 billion US dollars for the research and development of chemical materials. In case of such originals, we should use plate making means and adopt the background color removal method to reduce the thickness of the darkened ink layer on the premise of trying not to lose the importance of the original darkening. The ink volume is controlled between 235% and 270%, which is 125% to 90% less than the total ink volume of the traditional method. This can not only ensure the density requirements of the dark tone, but also prevent the middle dark tone level from being affected by too much ink reduction. According to relevant data, the total ink volume 235% and the total ink volume 360% reduce the ink volume 125%, and the displayed density value is basically similar. When the total ink volume of the actual dark tone is 235%, the printing can be controlled without powder spraying or a small amount of powder spraying

3. The sample is the customer's credential and the basis for printing. If the printed product is too different from the sample, the customer will politely refuse to accept it. The problem is whether the sample truly reflects the original. For example, the ink layer on the original is not so thick. When proofing or signing, in order to meet the user's satisfaction, we desperately increase the amount of ink. This will cause serious point expansion, which is the diffusion from the center to the surrounding, and the ink in the center will certainly exceed the amount borne by the paper, so it is difficult to avoid getting dirty without increasing the amount of powder

4. Ink emulsification will seriously affect the drying time of products. When the ink contains a certain amount of acidic aqueous solution, it will prolong the time of oxidation conjunctiva on the imprinted surface, resulting in slow drying, which is easy to cause the back to rub dirty. There are many factors that cause serious emulsification of ink, but the most important is water. At the same time, we should control the ink load. When reaching a certain density value, we should use the least amount of ink and the least amount of water, which is the best way to control the serious emulsification of ink

5. The printing pressure is too light, so that the ink cannot be transferred normally. The ink transferred to the paper cannot be well combined with the paper. The ink just floats on the surface of the paper, which is not firm, and will also cause the back to rub dirty. Therefore, the printing pressure should be appropriately increased within the normal range of point expansion

to sum up, in order to control the dirt on the back with less or no powder spraying, we must carry out serious process research from the original, formulate an effective process construction scheme, and make the original and standard samples suitable for printing by means of plate making. During printing, we should strictly follow the data-based operation, control the density value of various colors, pressure and ink balance, maintain a certain printing speed, appropriately increase some dry oil, and reduce the stacking height of semi-finished products

source: silk screen special printing

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