According to Wikipedia, the Kauri-butanol value ("Kb value") is an international, standardized measure of solvent power for a hydrocarbon solvent, and is governed by an ASTM standardized test, ASTM D1133. And why is this number important? Because solvents are typically used to dissolve materials, and the higher the Kb value, the better the solution dissolves and ultimately cleans. Unfortunately if the number is too high, the solvent can pull color from and possibly damage garments.
According to a Dow MSDS sheet, the Kb value of perchloroethylene (typically called perc) is 90. In the past, the benefit of using perc as your solvent was that it was a better cleaner. Perc easily dissolves most oils, greases, and fats in the cleaning process. But over the years the use of perc has declined as more environmentally friendly options have been developed.
At Tri-State, we are all for being more environmentally friendly whether it is ensuring best practices are followed or if a client wants to seek an alternative cleaning method besides perc. Over the years, dry cleaners have been trying more eco-friendly cleaning products, but few have performed at an adequate level. Customers ultimately were disappointed with the results.
Recently a long-time customer of ours, Bowen Cleaners in Greenville, North Carolina, switched from a couple of perc machines to a Realstar 80lb Dry Cleaning machine using DF2000, a synthetic hydrocarbon fluid which has a Kb value of 27. We were happy to be a part of that process and consider Rich Volk, the owner, an extremely knowledgeable resource as to the changeover of performance and results. So far, Rich has been pleased with the results. “I grew up using perc, and it is still the best cleaner by far,” said Rich. “But using the hydrocarbon solvent and upgrading to the optional Realstar solvent heater, I’m getting better results on water-soluble stains and my spotting has gone down 50-60%.” I learned a number of things during my conversation with Rich, and here is my takeaway:
• Perc is still the best cleaner, especially at getting out oil-based stains.
• Hydrocarbon, even with the lower Kb value -- as long as you are using the right soap, is a great alternative, and it is great at getting out water-soluble stains.
• Hydrocarbon produces significantly less waste than perc. Rich was disposing 4-6 drums every 5 weeks and is now disposing 1 drum roughly every 10 weeks.
• On a down side, his cycle times have increased significantly but he has combated that by using a machine with a larger capacity.
• He is getting better mileage out of hydrocarbon solvent, so he is recognizing a cost saving there as well.
• Hydrocarbon isn’t limited to just Realstar machines; he is also using the same process in a Union machine.
• There isn’t as much federal or state red tape involved with using DF2000.
If you are in the market for a new dry cleaning machine and are debating on which solvent to go with, weigh the pros and cons of all the options out there. As you weigh your options, be sure to speak with a machine manufacturer, such as Realstar USA, who can suggest an experienced distributor to help bring the project to fruition. You may just decide that hydrocarbon could prove to be a great choice for your business just as it has been for Bowen Cleaners.