Metal Finishing Guide Book


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from the dry off oven. The TMC treatment has a lower surface tension than phosphate surface conversions due to lower TMC coating weights requiring less heat to dry the parts. Maintenance-related costs are generally lower for a TMC. The absence or extreme reduction of phosphate in the treatment solution significantly reduces the formation of precipitates that accumulate as sludge that makes scale. If you have particulate filtration for your phosphate system, then this cost is virtually eliminated. Washer descaling frequency will by substantially reduced and perhaps eliminated as you won���t have the sludge that forms scale. Product ��� Process Research Start your research by determining potential vendors and products. Get references���good and bad. I wouldn���t be shy to ask the hard questions of where they have had problems and how they were resolved. We���re talking about new technology and manufacturing���stuff happens. You need to find ways to shorten your TMC learning curve. This is one of the reasons I think you should ask for ���bad��� references. It is helpful to know what has gone wrong and how those issues were resolved. You also want to know how your vendor will respond in times of need. It may or may not relate to your situation. At the very least, the discussion can motivate questions that need addressing prior to implementation. If your risk is substantial, you should consider taking some tours. Somewhere in the same time frame you should conduct testing of the chosen TMCs. You can use laboratory panels as control panels but should include production substrates to make sure the process is viable. If possible, treat your own parts through an existing TMC production pretreatment system. When you compare lab-prepared TMC panels to a production phosphate panels you are not only comparing the pretreatment technologies but also the washers. You need to also research the requirements of the chosen TMC. Will the construction of your existing washer be compatible with the TMC���s chemistry? Some products require stainless steel construction and all products have better bath life when used in acid-resistant construction. Water quality is also an issue. Most TMCs will require RO or DI water. Solution control equipment and procedures should also be reviewed to make sure you have, or are capable of conducting, pertinent solution control procedures. Successful implementation requires vendor support. Prior to implementation you need to define support for the start-up and in the following days or weeks. Generally you don���t need a representative for weeks but a plan for the vendor to check in on the process is warranted. Implementation Strategy Once you have a viable product and process, you should conduct some training prior to charge-up. Include wash line operators as well as painters and appropriate management to familiarize them with the TMC operation as well as the treatment���s appearance. The appearance will most likely be different from what they are accustomed. There will probably be several questions that would be better addressed prior to charging up the TMC. Discuss your and your vendor���s concerns. They know their product, requirements and limitations. You know your system, requirements and constraints. These need to be fully discussed to make sure that all the necessary steps are taken to ensure a successful implementation. Those who have used iron phosphates for a substantial time have probably seen 148

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