Emulsion Remover Direct Application vs. Using a Dip Tank
Many years ago, one of the most common means by which a screen was cleaned was through the use of a “hot tank”. A dip tank of sorts was filled with solvent and then heated to the point where a thorough soaking would allow the ink and emulsion to release from the mesh. Not only was the process slow and inefficient, it was also nearly impossible to reproduce consistent results screen after screen.
Recognizing the downfall of such a process, chemical manufacturers in the industry began developing products that required neither heat or soaking. And for several decades the dip tank method fell out of use as companies began realizing that a consistent screen could only be achieved via a consistent process. As well, as environmental concerns began to be considered, disposal and overall handling of chemicals and their resulting effluents demanded companies to find a better way.
There is no way around it. If a dip tank is used the solution will become contaminated. Contaminated chemistry ultimately leads to a contaminated process.
Proponents of the dip tank will report that it reduces labor through the unmanned soak time and reduces chemical use through the reuse of the original product added to the tank. In reality, the direct apply method provides the greatest reduction in labor by providing a consistent process. By applying fresh chemical, exactly where it’s needed each time, the reclaim process runs at the optimum efficiency and free of unexpected contamination issues or emulsion staining as found during the use of the dip tank. At the same time the direct apply method maintains a much lower use of chemical because the product is only applied where needed and there is no carry out as there is when using a dip tank.
Weigh the Pros and Cons then decide which will work best for you!
- Applying the product directly to the emulsion allows the chemical to remain consistent from start to finish. Unlike the dip tank method, each screen is cleaned in a controlled process.
- Direct apply requires less product inventory.
- No open vat of chemistry.
- Chemical remains exactly as it was manufactured-contamination free and unaltered. Each application yields the same result every time during the reclaim process.
- Chemical is only applied to the area coated with emulsion.
- Because screens are never left to soak, frames do not become full of chemical. Frame glue less likely to release unintentionally.
- Because the chemical was applied as part of screen cleaning process, designed to be safely rinsed to the drain, there is no tank of chemistry to dispose of.
DIP TANK METHOD
- After cleaning the same number of screens as if fresh product had been applied, there is no way to avoid the contamination of the chemistry in the dip tank. Once contaminated with the combination of released press cleaners, residual ink and loosened emulsion the chemical performance decreases in effectiveness.
- Most dip tanks take a minimum of 15 gallons of product to fill.
- Finding a safe and secure space for an open vat of chemical is a challenge in many shops.
- Consistency of chemical solution in dip tank becomes impossible to maintain as chemical becomes contaminated. Due to a high volume of carry out, new product must be added to the tank to maintain the proper working level which again causes the tank to become inconsistent.
- Entire screen is saturated and covered with a mixture of partially degraded chemical, ink and emulsion.
- Material in dip tank often becomes trapped in frames after soaking.
- Once chemical in tank finally fails due to the load factor, it must be replaced. Proper disposal of contaminated solution is a concern.
All shops require different methods to maintain an acceptable production flow.
It is understood that not every screen printing operation has the same needs. For this reason, there are many choices when it comes to the types of emulsion removers from which you can select.
Many find Ready-To-Use products offer the best choice in the performance they desire.
Still others prefer the concentrate approach when mixing is not an issue or to reduce shipping cost as well as to reduce the number of empty containers ending up in the land fill.
Whichever way you go, direct apply or dip tank, RTU or concentrate, the goal should always be to develop and implement the most consistent and sustainable process possible for the operation and resources you are working with. And once determined be very diligent in monitoring that the process is being followed.
As with all such tasks, rely heavily on your suppliers and dealers as well as the many resources made available at annual tradeshows when determining which is the best approach for you.
*All ideas expressed in this post are the exclusively those of the author, and do not necessarily represent the policies or opinions of Decorated Apparel Magazine. The author represents that he or she is exclusively responsible for the content contained, and that he or she is the owner of any intellectual property used or expressed, and has the right to publish any statements or images contained herein. All content is offered 'as-is' and Decorated Apparel Magazine does not endorse or guarantee the accuracy of any statements contained in this or any other post. Your use of any advice or statements of fact or opinion offered are completely at your own risk.