Techniques for Painting Photopolymer Sheets
The way you paint a photopolymer sign affects the tipping processing with hot stamp foil. The standard Matthews Acrylic Polyurethane (MAP) paint is applied and dries differently than the Matthews LVOC paint as they are different paint technologies.
When using MAP mixed at the recommended ratios, you need to make sure that the signs are hot-stamped within a 24 – 48 hours for proper foil adhesion. The LVOC paint dries faster when mixed at the recommended ratio which means that the hot stamp foil can be applied sooner.
You can extend your working time with the LVOC paint by reducing the amount of accelerator you add in your mix ratio. Each application is effected by film build, temperature, humidity, and airflow but reducing the percentage amount by volume of the accelerator will provide more open time for the paint film allowing better adhesion for both a foil or tipping application.
Utilizing the recommended amount of accelerator in the Matthews LVOC line will allow you to adjust your production time to be able to apply both foil and tipping process faster than with normal Matthews paint, testing on site is recommended. The Matthews LVOC line has a greatly enhanced rate of cure than standard Matthews so you can adjust your production according to completion of basic testing along these lines.
Reducers not only affect the speed of dry but also the flow of Matthews, it is possible to adjust the volume of reducer in your mixture either a bit more or a bit less to affect the viscosity of the paint which in turn may allow for better hang time, the flow of the paint over edges, or reduce an “orange peel” appearance.
Example: a mixture rate of 3:1:1 is standard so you can try 3:1:1 ¼, or 3:1:1 ½ to change how the product flows. Keep in mind that changing reducer volume in a mixture can lower the wet film build so you will want to initially check your applied wet paint film by using a wet film gauge, proper use and reading of a wet film gauge that is demonstrated here.
Contact Technical Support with additional questions.