Cleaning

Many products require a preparation step prior to coating. This step may also be called pretreatment for new products and stripping for products that need rework.

Cleanliness of Parts
The first step for reducing waste in pretreatment is assessing the cleanliness of parts. Determine the sources of contaminates to reduce or eliminate them. Consider to what degree surfaces become contaminated with substances such as oil from machining, dirt from the manufacturing environment and oil from people's skin.

Cleanliness of the Process
Next, determine the cleanliness standard needed to satisfy the pretreatment process. Once contaminant sources are identified and cleanliness standards are set, determine which contaminants can be eliminated. Then, if contaminants cannot be reduced enough through process changes, assess the cleaning methods used.

Aqueous Cleaning Equipment Manufacturers Aqueous cleaning equipment suppliers offer a wide range of cleaning equipment and related accessories.

Get It Plated Right Fact Sheet Series
This fact sheet series focuses on causes and solution for the most difficult cleaning problems for metal product manufacturers and designers. Although the series was originally written for plating, most of the same cleaning principles applies to other coating operations as well.

Cleaning and Design for Plating Lists some of the more troublesome parts for metal finishers to electroplate.

Cleaning Processes, Capabilities and Limits A large utensil manufacturer set up a custom-cleaning step to help eliminate troublesome soils. Also shows the value of eliminating soils at their source, before cleaning is needed.

Dried-on Process Fluids and Fluid Combinations Films of dried-on process fluids interfere with the bonding of plating to part surfaces. This sheet shows how to avoid the problems associated with dried-on process fluids.

High-Temperature Processing Burns on Soils Oils, coolants and many organic liquids form a varnish or paint-like coating on part surfaces when heated or aged. This fact sheet discusses how to prevent such soils from occurring.

Holes, Seams, Threads Recesses & Tubing Assemblies How to recognize and eliminate unseen pools of contaminates trapped in recessed part areas.

Particulate Contamination on Part Surfaces Explains how oversights that cause particulate contamination of parts before plating can be a costly mistake.

Selecting Materials for Plated Parts The type of metals used to construct a part can affect how easily it is cleaned and the part's physical condition after a finishing process.

Rinsing
Barrel Design Effect of Barrel Design On Dragout Rate is an Illinois Waste Management Research Center study that compares drag-out rates of plating barrels, in order to provide the metal finishing industry with guidance that can be used to reduce dragout rates.

Technical Plating Saves Over $45,000 by Reducing Water and Sewer Costs A MnTAP intern helped Technical Plating in Brooklyn Park improve flow control on one plating line and effluent reuse reduced water demand by 2,625,000 gallons per year, saving $7,100 a year plus $44,100 in one-time SAC fees.

Solvents and Vapor Degreasing
Solvent emissions should be reduced for many reasons.

• Solvent use can be costly. Traditional solvents-like trichloroethylene, methylene chloride and perchloroethylene-are expensive to use due to regulations, while newer ones are expensive to purchase.
• A National Emissions Standard for Hazardous Air Pollutants (NESHAP) limits emissions from degreasers using traditional solvents.
• Toxic exposure to workers is another concern.
• Large uses of traditional solvents, over 10,000 pounds a year, require reporting under the Superfund Amendments and Reauthorization Act (SARA)/Toxic Release Inventory (TRI) regulations and pollution prevention planning under the Minnesota Toxic Pollution Prevention Act (TPPA).

Solvent use can be reduced by process and procedure improvements. Releases can be made safer by switching to a less hazardous chemical. Solvent use can sometimes be eliminated through the use of aqueous products.

Alternative Solvent Degreasers These degreasing and cleaning solvents are marketed as alternatives to halgonated solvents—especially chlorinated solvents. In some cases, these solvents require more time or stronger physical action for cleaning surfaces. All have lower rates of evaporation and drying than the chlorinated solvents they replace.

Reducing Solvent Emissions from Vapor Degreasers Reducing solvent emissions can benefit your company in many ways. This fact sheet outlines strategies for reducing emissions from drag-out, drafts, diffusion and sprays.

Selecting a Still for On-site Solvent Recycling Become better prepared to select the right still for your on-site solvent recycling.

Solvent Recycling Equipment Many solvents can be reprocessed and recycled for reuse. Distillation is the most common method, but filtration can also be used. MnTAP maintains this list of solvent recycling equipment suppliers solely as a service to Minnesota companies.