| Company: |
An automotive trim supplier. Toronto, Ontario, Canada |
| Manufacturing Process: |
Metal sheet (stainless, aluminum and steel) is strung through a rolling mill which transforms the flat metal into one of over 75 trim profiles. When the trim emerges from the rolling mill it must be cleaned and dried before rubber is extruded onto 1 or more of the surfaces. When the product reaches the end of the line it is cut to specified length and packaged. |
| Initial Cleaning Method: |
Hydrofluoric acid bath. The trim passes through a 3 part cleaning system. In the first chamber a water rinse removes particles and some oil. In the 2nd recirculating chamber an acid shower removes oils and then in the 3rd chamber a water shower removes the acid. When the trim exits the system an airknife is used to remove moisture and then the trim passes into an oven to heat it up and remove all moisture. |
| Cleaning validation: |
The company uses a proprietary method of measuring surface tension using specially formulated drops. The system allows measurement between 1 (poor) to 14 (excellent) based on how the drops bead up or spread out. The target cleanliness was established as a 6. |
| Problems/challenges: |
- At best the acid wash system was able to provide cleanliness results of a 6 but between a 2 and 3 was normal. If the surface wasn’t adequately cleaned the rubber would not adhere properly and would delaminate after some period of time resulting in an expensive recall.
- Health and safety requirements had been changed and the company was mandated to install air scrubbers if it continued to use the acid wash system.
- The trenches that were under the cleaning system needed to be relined to comply with Environmental legislation.
- The systems themselves were 5 years old and no longer reliable – unscheduled downtime was an issue and complete overhauls were needed.
- The waste water from the cleaning operation had to be pumped to a central holding tank and then filtered and treated before it could be trucked away.
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| Results/outcome: |
Two new gas fired boilers were installed (the second unit was a backup for the first to eliminate unscheduled downtime of the extrusion lines due to boiler failure or scheduled maintenance). Hydra cleaning systems were installed on the company’s 7 lines and the existing acid wash systems removed and scrapped. High volume steam lances were also provided to allow for effective cleaning of the rolling mill during scheduled maintenance activities.
The company realized the following benefits:
- Product cleanliness improved to a consistent 6 or 7 using UltraVapor only and jumped to over 12 when small amounts of environmentally friendly detergents where added to the steam.
- Saved significant capital costs compared to the costs they would have incurred to overhaul the existing systems and install required upgrades or to install new acid wash systems.
- Saved significant operating costs and the Hydra systems provided a payback of less than 1 year.
- Freed up 20 feet of line space – the acid bath systems took up approximately 25 feet of inline space. The new Hydra units took up 4 ½ ft.
- No longer had to treat the waste water as the ppm levels of oils and other contaminants was below the municipal limit for discharging the waste to the sewer. This freed up additional floor space and contributed to the operational savings for water treatment and eliminated the hassle and cost associated with trucking waste water away.
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