The issue of poor drying of UV flexographic ink in non-woven printing is a complex problem involving multiple factors. The following is an analysis of this phenomenon, including possible causes and corresponding solutions:
1、 Cause analysis
The ultraviolet spotlight is not working properly
UV lighting is a key equipment for UV ink drying. If it does not work properly, such as insufficient power or aging light sources, it can lead to poor ink drying.
UV lamp has been used for too long
The lifespan of UV lamps is limited, typically ranging from 1000 to 1500 hours. Long term use of UV lamps can significantly reduce their luminous efficiency, thereby affecting the drying effect of ink.
Ink problem
Foreign objects mixed into the ink, such as cleaning solution and general oily ink, can affect the drying performance of UV ink.
Poor ink blending: Poor transferability, hardness, emulsification and other properties of ink, or improper adjustment of ink concentration and hardness, can all lead to poor drying.
Improper selection of ink types: For different substrates (such as non-woven fabrics), it is necessary to choose suitable UV ink. If the ink does not match the substrate, it can also lead to poor drying.
Printing process issues
Thick ink layer: Especially for black ink, due to its dark color, ultraviolet rays are difficult to penetrate, so a slightly thick ink layer can easily cause poor drying.
Printing speed too fast: During the drying process of UV ink, if the printing speed is too fast and the UV lamp irradiation time is insufficient, it can also lead to poor drying.
Substrate issue
The surface treatment, moisture absorption, thickness and other characteristics of non-woven fabrics can affect the drying effect of UV ink.
environmental factor
Environmental factors such as workshop temperature, humidity, and air circulation can also affect the drying speed of UV ink.
2、 Solution
Ensure that the ultraviolet light shining on the spotlight is working properly
Regularly check the working status of the ultraviolet lighting fixtures to ensure that their power and light source quality meet the requirements.
Regularly replace UV lamps
According to the service life of UV lamps, regularly replace them with new ones to ensure their luminous efficiency.
Strictly control the quality of ink
Prevent foreign objects from entering the ink and ensure the cleanliness of the ink.
Adjust the transferability, hardness, emulsification and other properties of ink to meet printing requirements.
Choose UV ink that matches the substrate.
Optimize printing process
Control the thickness of the ink layer to avoid excessive thickness causing poor drying.
Adjust the printing speed to ensure that the UV lamp has sufficient illumination time.
Choose the appropriate substrate
Select the appropriate non-woven fabric substrate according to printing requirements, ensuring that its surface treatment, moisture absorption, thickness, and other characteristics meet the drying requirements of UV ink.
Improve environmental conditions
Control the temperature, humidity, and air circulation in the workshop to provide good environmental conditions for the drying of UV ink.
Using additives
Add an appropriate amount of additives to UV ink, such as those that slow down the drying speed, to improve the drying performance of the ink.
Through the above measures, the problem of poor drying of UV flexographic ink in non-woven printing can be effectively solved, and the printing quality and efficiency can be improved.
If the problem persists, please contact StarColor. eva@starcolor-ink.com