In recent years, greater focus has been directed toward production efficiency. Every factor in the production process is under increasing demand for yield and productivity, while regulatory and environmental restrictions continue to tighten. Diminishing natural resources and increased cost of raw materials have forced manufacturers to consider ways of reducing consumption and waste of valuable materials. While recycling of metal scrap and packaging materials has been relatively easy to accomplish, recycling stamping fluids raises many issues affecting safety and quality.

 

Chemical Cross-Contamination

Once stamping fluids are applied to a metal substrate, they immediately interact with mill oils and/or pre-lubes applied at steel mills. Oil-free stamping fluids need to penetrate or "wet" this film on the substrate to provide lubrication to the dies and work piece. In most conventional stamping/forming processes, the lubricant should perform adequately when the solution is fresh. Once the used solution is reclaimed, it will have some amount of oil contamination from the substrate as well as other possible contaminants (hydraulic fluids, greases, etc.) that can interfere with the proper functioning of the lubricant chemistry. This oil contamination can interfere with the surface wetting of the lubricant, creating areas on the blank/coil that are not properly lubricated during forming. Improper lubrication can lead to galling and breakage of parts, build up on dies and excessive tool wear. Cross contamination may also contribute to plugging of application equipment, selectively stripping components or binding with ingredients in synthetic fluids.

 

Microbial Contamination 

Contamination of stamping fluids and increased exposure to air borne particulate increase the potential for microbial growth in stamping fluids. Filtration of fluids to remove oily contaminant can also selectively strip functional ingredients from the stamping fluid itself. The use of sump-side biocide additives raises safety concerns related to dosing as well as worker exposure. It is difficult to determine the proper microbicide to use as the contamination can be bacteria, fungi, mould or yeast. If action isn't taken, the microbial populations generate odours as well as degrade functional ingredients in the stamping fluid and create waste products that contribute to corrosion of dies/fixtures and production parts.

 

Water-Related Issues

The water used to dilute stamping fluids can vary greatly from one facility to the next. Hard water as well as excessively softened water can create major issues when recycling stamping fluids. While filtration may remove small amounts of "insoluble/dissimilar" contaminants from the stamping fluid, water minerals will be largely unaffected and increase over time. Even low levels of calcium, magnesium, manganese and sulphate may build over time to create water insoluble soaps that build up on fixtures, dies and applicators. These soaps can create numerous problems relating to quality and process efficiencies. Chlorides and sulphates can build in systems over time and increase the potential for corrosion on parts and dies/fixtures - especially carbide coatings, where pitting and premature failure may be accelerated.

 

Welding Related Issues

Oil contamination in synthetic fluids can contribute to increased weld defects. Synthetic stamping fluids burn more cleanly and completely than mill oils and pre-lubes. Oil contamination can contribute to increased chances for weld porosity and increased or more severe residues that may be harder to clean completely in subsequent pre-treatment processes.

Based on these major factors, IRMCO believes the solution to increased efficiency lies in minimising waste of fluid through more precise application and lower "coating weight" during stamping. IRMCO FLUIDS are specifically designed to use in thinner films, applied more precisely and uniformly on stamped parts to optimise performance and economy.