Dewaxing Process Enables Major Improvement in Through-put and Safety
A MicroCare client was among the very first companies in the US to deploy Vertrel® Sion™ fluid. Importantly, this product is not being used in a traditional degreasing application but in another process: removing wax from parts made using metal injection molding (MIM). This innovation helped the company reduce operating costs, speed through-put and improve worker safety.
Background: After years of research, the U.S. Environmental Protection Agency approved in July 2015 the commercialization of a new molecule, called MPHE, which is optimized for critical cleaning. The molecule is marketed as Vertrel® Sion™ and MicroCare is the authorized source for these fluids in many parts of the world. MicroCare made the first commercial shipments of drums and pails of the new product to customers in the U.S. in October 2015.
With a Kb value of 103, Vertrel® Sion™ fluid is a very powerful degreaser. It can replace aggressive hydrocarbon, chlorinated or brominated solvents including nPB. With an 8-Hour TWA exposure limit of 200 ppm the product generally is considered very safe for people. The cleaner can be used in standard vapor degreasing equipment. These characteristics make Vertrel® Sion™ an outstanding choice for dewaxing metal parts after injection molding.
The MIM Application: In previous years, this particular customer produced a large number of precision metal components that required very tight tolerances. Those tolerances were maintained through industry-standard machining processes, but those processes were expensive, time-consuming and required highly skilled operators.
The client moved to a process of making the same parts and shapes using the MIM process. This process uses a dry powder mixture of different metals. The metal powder is mixed with wax to form a viscous non-Newtonian fluid. The fluid is injected into molds to shape the metal. The semi-finished parts then are sintered at thousands of degrees in a specialized oven where the metal powder melts into a single, unified metal alloy of exactly the right dimensions and strength.
This is very efficient but the wax must be removed prior to follow-on processing.
After numerous tests, it was discovered that solvents could penetrate into the porous molded parts, dissolve the wax and remove it from the molded parts. The first attempts used hydrocarbon solvents but these slow drying liquids took days to evaporate out of the molded parts. MicroCare introduced an improved fluid in a vapor degreasing process, using the Bromothane™ precision cleaners which are based on a chemical called nPB. This process worked very well.
However, to enhance worker safety the client wished to migrate to solvents safer than nPB. So MicroCare presented the Vertrel® Sion™ cleaner. This fluid evaporates quickly, has an excellent toxicity profile, is better for the environment, is affordably priced, and has sufficient cleaning “muscle” to dissolve the wax. This innovation was a win-win for everybody. In terms of cost, it made an enormous difference to the client because almost all of the skilled labor machining costs were replaced. Through-put was improved because instead of taking three days to dewax the process now takes 4-8 hours. Lastly, worker safety is greatly enhanced by the elimination of the nPB-based dewaxing fluid.