Solve Common Problems Of Printed Materials

- Apr 12, 2019-

Several common problems and solutions in printing process production


1: Color migration color is added to the coloring of the glue, color migration occurs in some colors, the deep color migrates to the light color position or the colored print migrates to the white flower position, or the printed color runs to the unprinted fabric. Call color migration. In order to avoid color migration during the production process, it is necessary to carry out the glue migration test for the color.


Test method: Color (3%) + transparent pulp (97%) - printing - flashing - cover white glue (100%) - self-drying -130 ° C × 3 seconds pressing. It is not recommended to use the inner eye to see the migration phenomenon. It is not recommended for the glue printing. For the water slurry (paint printing) printing, pay attention to the white or light-colored fabric. The results of different glue test will be different. The difference is not too. Most of the fluorescent colors do not migrate with the glue, so it is necessary to communicate clearly with the customer before production.


2: Heat treatment discoloration Most of the glue printing needs to be heat treated, and some of the color types have poor heat resistance. After the treatment, serious color difference will occur, especially when mixed with the thermosetting ink thick plate. Therefore, it is necessary to conduct heat resistance test on the color. The test method is: 37% white glue + 60% transparent pulp + 3% color natural drying, heat treatment at 180 ° C for 30 seconds, the highest level 5, the naked eye can not be distinguished before and after heat treatment Level 5


3: Lightfastness test At present, many companies are accepting brand companies in single or European and American singles. The requirements for lightfastness are relatively strict. If customers have such requirements, they can request the supplier to provide the lightfastness data of the pigment or the test report of the third party, or print the printed sample. Go to the three-party testing agency for testing. The general test method and standard is: JIS L-0842 carbon arc lamp for 20 hours


4: Solvent resistance test At present, more and more clothing is used for dry cleaning. If the pigment has poor solvent resistance, the clothing will be discolored and discolored after dry cleaning, causing consumer dissatisfaction and complaints. Therefore, the clothing company will sample and send the goods before receiving the goods, and then accept the goods after passing the test. If the customer has this requirement, the supplier can be required to provide the lightfastness data or third-party test report of the pigment, or the printed sample can be printed to a third-party testing agency for testing. Test method: JISL-0860 (tetrachloroethylene, 40 ° C 30 seconds)


5: Endurance test Before the printing, the color should be tested for pull-out resistance. Some pigments are not resistant to reducing agents. When they are overheated, they become completely two colors, in order to avoid unnecessary losses. Therefore, it is necessary to test the color samples for the pull-out test before the goods are opened. Test method: Add 5% of the white powder at 105 °C for 8 minutes, or 170 °C for 3 minutes.


Other precautions: such as environmental performance, aromatic amines, formaldehyde, heavy metals, APEO (alkylphenol polyvinyl chloride). Also react with the slurry, some of the pigment will react with the slurry, stir thicken and thin, glue Chemical. Dry and wet friction, etc.


6: The glue washing water falls off and cracks


The same fabric has different glues, the same glue has different fabrics. Washability and elasticity are different. Therefore, before the goods are opened, the washing performance of the glue must be tested. According to the requirements of the customer, the standard test (national standard, American standard, European standard) is required. The national standard washing machine and the test method are required. Some customers use the domestic washing machine to wash the problem, and once they go to the third-party organization, they will fail. There are also customers who wash by hand, and when the test is started, it will not work. The same person has different environments, moods, etc., and the strength is different. Therefore, any test requires standards, different standards, different test methods, and different test results.


7: Elasticity test


At present, there are many kinds of textiles, different ingredients, different weaves, and different elasticity. A kind of pulp can't satisfy the elasticity of all the fabrics, so the glue that has been used all the time is applied to the different elastic fabrics to retest the elasticity of the glue. Some customer boards are used to pull the glue without cracking. On the goods, after printing the large goods, after the heat treatment, after the completion of the wash test, it was found that the printing surface wash water cracked. Some of the glue will change its elasticity and feel after heat treatment and washing. Therefore, it will be finished after heat treatment and washing to confirm the elasticity and feel. The elasticity of the printed surface can be adjusted according to the specific crack of the transparent pulp and white glue. Increasing the proportion of the transparent paste or making a base with a clear paste, or increasing the number of times of printing can increase the elasticity of the print.