Impact of Amber Light on Screen Printing Emulsion: A Comprehensive Guide

When it comes to the screen printing process, understanding the effects of different light types on emulsions is crucial. This article delves into the specific impact of amber light on screen printing emulsion, its relevance to different emulsion types, and practical strategies for maintaining optimal printing conditions.

Understanding Amber Light and Its Impact

Does amber light affect screen printing emulsion? Yes, it can; however, the degree of impact varies based on the specific type of emulsion used. Most screen printing emulsions are formulated to be sensitive to UV light, which is why they are typically exposed using UV radiation sources. Amber light, characterized by a lower UV output compared to other light sources, generally has a lesser effect on the emulsion's exposure and hardening process.

It is advisable to avoid prolonged exposure of the emulsion to any light source, including amber light, before the exposure process. While amber lights can be used safely during the setup and preparation stages, it is recommended to switch to a controlled UV light source for the actual exposure of the emulsion. Always follow the manufacturer's recommendations for the emulsion you are using to ensure the best results.

Light Sources and UV Exposure

Screen printing emulsions are designed to be sensitive to specific wavelengths of UV light in the range of 300–420 nanometers. Most amber light sources do not emit any significant UV light in this range. However, it's important to be aware of other light sources that might emit UV radiation:

LED lamps: These can be harsh without a diffuser. It's best to use gentle, diffused lighting when working with sensitive emulsions.

Bug lights: These are often yellow and can work as a safer alternative. They do not emit much UV radiation.

Fluorescent lights: Yellow fluorescents or yellow sleeves purchased from Encapsulite can provide excellent UV protection. Clear UV blocking sleeves for fluorescent bulbs with end caps are also effective.

To test the suitability of your light source, perform a simple experiment. Coat a screen and place it under your light source overnight. Add some coins on top of the emulsion and leave it undisturbed. In the morning, develop the screen. If you see circles forming in the emulsion or see the emulsion developing differently in certain areas, it indicates light contamination. If no circles form and the emulsion develops evenly, your lights are safe.

In environments with amber lights, it's also beneficial to cover coated screens with cardboard to provide additional protection. While this can help mitigate contamination, it's important to note that cumulative contamination over time can lock up the screen, making it difficult to develop the image accurately. Therefore, it's essential to keep coated screens stored behind cardboard or plywood to prevent any light contamination.

Conclusion

Proper maintenance and understanding of the effects of light sources on screen printing emulsion are crucial for successful screen printing. By following recommended practices and using suitable light sources, you can ensure that your emulsions remain unaffected, leading to high-quality prints and efficient workflows.

Additional Tips

Light Source Selection: Choose diffused, gentle lighting sources to avoid unnecessary exposure to UV radiation.

Lighting Setup: Use clear UV blocking sleeves or yellow fluorescent lights to protect your emulsions effectively.

Safeguarding Stored Screens: Store coated screens behind cardboard or plywood to prevent contamination from any ambient light sources.