How to Burn a Screen for Screen-Printing: A Comprehensive Guide

Burning a screen for screen-printing is a crucial step in the screen-printing process. It involves coating a screen with a light-sensitive emulsion and exposing it to a design image, creating a stencil that can be used to print designs onto various substrates. In this article, we will provide a step-by-step guide on how to burn a screen for screen-printing, covering the necessary materials, equipment, and techniques.

Materials Needed

• A screen printing screen (available in various mesh counts)
• Photo emulsion (light-sensitive coating)
• A degreaser (to clean the screen)
• A scoop coater (to apply the emulsion)
• A drying rack (to dry the emulsion)
• A design image (printed on transparent paper or film)
• A light source (e.g., a UV lamp or sunlight)
• A timer (to control the exposure time)

Step 1: Prepare the Screen

Before burning a screen, it's essential to clean and degrease the screen to ensure a smooth coating process. Use a degreaser to remove any dirt, oil, or other substances from the screen. Rinse the screen with water and let it dry.

Step 2: Apply the Photo Emulsion

Use a scoop coater to apply a thin, even layer of photo emulsion to the screen. Make sure to cover the entire screen, but avoid applying too much emulsion, as this can lead to a thick, uneven coating.

Step 3: Dry the Emulsion

Place the screen on a drying rack and let it dry in a dark room or under a yellow light. The emulsion should be completely dry before proceeding to the next step.

Step 4: Create a Design Image

Create a design image using software like Adobe Illustrator or Photoshop. Print the design onto transparent paper or film, making sure to mirror the image (since it will be reversed during the burning process).

Step 5: Expose the Screen

Place the design image on the screen, ensuring it's centered and smooth. Use a light source (e.g., a UV lamp or sunlight) to expose the screen to the design image. The exposure time will depend on the type of emulsion and light source used. A general rule of thumb is to expose the screen for 10-30 minutes.

Step 6: Develop the Screen

After exposure, remove the design image from the screen and wash it with water to remove any unexposed emulsion. Use a developing solution to reveal the design image on the screen.

Step 7: Dry and Cure the Screen

Let the screen dry completely before using it for screen printing. To cure the screen, place it in a warm, dry area or use a heat gun to speed up the process.

Tips and Tricks

• Use a high-quality photo emulsion to ensure a smooth, even coating.
• Make sure the screen is completely dry before exposing it to the design image.
• Use a timer to control the exposure time and avoid over- or under-exposure.
• Experiment with different mesh counts and emulsion types to achieve the desired print quality.

Common Mistakes to Avoid

• Applying too much emulsion leads to a thick, uneven coating.
• Not degreasing the screen properly, results in poor emulsion adhesion.
• Exposing the screen for too long or too short a time affects the print quality.
• Not drying the screen completely before using it for screen-printing.