Why There Are Ink Spots Next To The Pattern After Printing by The Screen Printing Machine?

The phenomenon of ink dots appearing next to the pattern after printing by the screen printing machine is usually caused by a combination of multiple factors. Here are some common causes and solutions:

1. Screen quality issues
   Uneven screen tension: If the screen tension is uneven, it may cause uneven distribution of ink during the printing process, resulting in redundant ink dots.
   Screen damage: Damage or wear on the screen may cause ink to leak and form ink dots.
   Uneven screen apertures: If the screen apertures are uneven, it may cause too much ink in some areas, resulting in ink dots next to the pattern.
   Solution:
   Check and adjust the tension of the screen to ensure uniform tension.
   Replace or repair damaged screens.
   Use a wire mesh with consistent pore sizes to ensure uniform mesh.

   
   

   

   
   2. Screen coating problem
   The screen coating is uneven: If the photosensitive layer of the screen
   Uneven coating, or an imperfect exposure process, may result in unclear printing or ink spots in some places.
   Insufficient cleaning of the screen: old ink or impurities remaining on the screen will cause ink dots to be brought to the target location during the printing process.
   Solution:
   Ensure the screen is evenly coated and the exposure and development processes are strictly controlled.
   Use clean tools and an appropriate detergent to clean the screen and make sure there are no impurities.
   3. Ink problem
   Ink viscosity is too high or too low: If the viscosity of the ink is inappropriate, it may cause the ink to flow unevenly during the printing process and easily produce excess ink dots.
   Too much or too little ink: If the ink tray
   Too much ink may cause excess ink to overflow, forming ink dots; insufficient ink may also cause uneven printing results.
   Solution:
   Adjust the viscosity of the ink as needed to ensure it is suitable for current printing conditions.
   Control the amount of ink in the ink tray to avoid too much or too little.
   4. Squeegee and printing pressure
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   Squeegee quality or positioning issues: If the squeegee is severely worn, or the squeegee is positioned improperly, it may result in uneven ink distribution or unwanted ink dots at the edges of the pattern.
   Uneven pressure from the squeegee: If the pressure exerted by the squeegee is uneven, or the pressure is too high, it may also lead to the formation of ink dots.
   Solution:
   Check and replace the scraper regularly to make sure it is not worn.
   Make sure the squeegee is in the correct position and angle to avoid uneven ink distribution.
   Adjust the pressure of the scraper to ensure even pressure.
   5. Printing speed problem
   Printing speed is too fast or too slow: If the printing speed of the screen printing machine is too fast or too slow, the ink may not be distributed evenly, resulting in ink dots next to the pattern.
   Solution:
   Adjust printing speed
   , making sure the speed is appropriate for the current material and ink.
   6. Problems with the surface of printed materials
   Uneven or contaminated material surface: If the surface of the printing material (such as paper, plastic, metal, etc.) is stained, greased, or uneven, it will cause the ink to adhere unevenly and form ink dots.
   Improper surface preparation of materials: Some materials may require special surface preparation (e.g. oil removal, dust removal, pre-coating
   etc.), if not handled properly, it can easily lead to printing defects.
   Solution:
   Thoroughly clean the material surface before printing to remove oil, dust and other impurities.
   Pre-treat materials requiring special surface treatments to ensure they are suitable for screen printing.
   7. Environmental factors
   Changes in temperature and humidity: Changes in temperature and humidity will affect the fluidity and drying speed of ink, resulting in uneven distribution of ink during the printing process, resulting in ink dots.
   Static electricity: Static electricity may cause ink to adhere unevenly to the material surface during the printing process, especially on plastic and film materials, which can easily lead to ink spots.
   Solution:
   Control the temperature and humidity in the printing workshop to maintain stable environmental conditions.
   Use anti-static equipment to reduce the impact of static electricity on printing quality.
   Summary: Ink spots appear next to the pattern after printing on the screen printing machine, which is usually caused by many factors such as screen, ink, scraper pressure, material surface, and equipment settings. The key to solving this problem is to conduct detailed inspections from every aspect to optimize the printing process, including adjusting screen tension, ink viscosity, squeegee pressure, printing speed, and ensuring the suitability of the environment and materials. By adjusting these factors, the occurrence of ink dots during the printing process can be effectively reduced or avoided.

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