In a season when you might be feeling the lingering cold of winter one day and the heat and humidity of summer the next, you need to be ready to counter the effects of either extreme.
Depending on your location, springtime may bring wild temperature variations. We certainly feel them here! Now more than ever, it’s important to know how hot and cold weather can affect your screen printing. Temperature can have a big impact on your ink and emulsion. Cold weather can increase the viscosity of plastisol ink, making it difficult to print manually. Water-based ink and emulsion can even freeze if they get too cold. On the flip side, excessive heat can actually start curing your ink in its container. What steps can you take to keep your ink ready for printing?
Remember, it’s not only the hot sun that can affect your ink performance – any heat source in your shop can alter your ink’s consistency. You should also avoid storing your ink too close to your flash cure or conveyor dryer. Your ink and emulsion manufacturers should provide suggestions for storing your supplies to maximize their shelf lives and performance. An accurate thermometer is a helpful tool to keep around your shop to make sure conditions are just right for your supplies.
The weather’s effect on your screen printing supplies is one thing, but maybe even more important is the effect it has on your employees. Workers are most productive in a comfortable environment, so be sure to take that into consideration when operating in extreme weather. On hot days, having an air conditioner, fan or open window for a cool breeze can be a life saver. However, try to keep cool air away from your conveyor dryer – it can make it more difficult to find the right temperature to properly cure your garments.
Temperature isn’t the only part of the weather report you should keep your eye on; excess humidity can cause even more problems with your screen printing. High humidity can weaken your stencils, leading to issues like pinholes, ghosting, loss of detail and premature stencil breakdown. When it’s humid, your screens may take longer to dry after reclaiming and being coated with emulsion. Before exposing your screens, make sure your emulsion has dried completely; if it’s still tacky, it’s not ready.
High humidity can also increase your curing time, so closely monitor your conveyor dryer settings to cure your garments thoroughly. Cotton garments hold more moisture than synthetic, so they may need more time in the dryer to cure properly on days with high humidity. On humid days, it’s a good idea to run some test prints through the dryer to get a better idea of what settings you’ll need for proper curing.
While humid days are unavoidable, there are some steps you can take to avoid the negative effects of humidity on your screen printing. A dehumidifier is a simple solution to keeping your humidity under control. Keep in mind that your screens are susceptible to humidity up until they’ve been exposed, so you want to make sure the humidity is in check in all areas of your shop where your screens are stored and prepared. You should look to maintain a relative humidity level under 50% – anything higher than that and the integrity of your stencils is at risk. You can measure the humidity of your shop with an inexpensive device called a hygrometer.
Keeping your humidity at a reasonable level isn’t just good for your stencils, it’s also good for your equipment. Reduced moisture will keep metal parts from rusting, helping extend the life of your screen printing press and other gear.
The weather might be at its craziest this time of year, but by following the advice above you can keep your supplies and your prints at top quality no matter what the forecast says.