Bama Companies Inc. manufactures pies, biscuits and dough products for sale directly to consumers, as well as ingredients for other products. Bama Foods Ltd., Bama Frozen Dough and Bama Pie facilities are located in Tulsa, Oklahoma.
A few years ago Bama Foods began a total productive maintenance (TPM) initiative to improve productivity, machine reliability and quality.
Select operators are part of the TPM program, which includes training on lubrication and inspection methods for their respective production centers. Roughly 100 employees are involved in TPM activities, which greatly expand the opportunities to inspect the assets during daily activities.
Randell Powers was hired as a predictive maintenance technician (PMT) approximately three years ago. A major initiative occurred at Bama Foods following the company’s visit to the Lubrication Excellence 2003 conference class on oil room design and improvement.
With the support of a local oil supplier, Bama PMTs began to evaluate lubricants for the sake of product consolidation and more thorough compliance to USF/USDA-designated food-grade use requirements at the site.
Powers and an associate PMT, Roy Carter, attended the Noria Oil Analysis seminar, where they gained additional insight into oil analysis program management and integration of multiple condition assessment technologies.
The lubrication and oil analysis program began to change following Powers’ and Carter’s attendance at a Noria Machinery Lubrication public seminar. It was in this training that they began to realize the potential benefits that could be derived from upgraded lubrication practices.
Figure 1. Lubricant ID Table
Figure 2. Engraved Grease Gun
The initial consolidation reduced the number of product types from 15 to 9 items, including both oil and grease. Three of the nine items are greases. One is a polyurea-thickened lubricant for electric motors, one is a food-grade specific product and one is a broad temperature (-65°F to +356°F range) general-purpose lubricant.
All lubricants are tagged with a plant-designated color, shape and number system, and the TPM manuals incorporate this labeling system to prevent unnecessary changes if at any point in the future the plant determines that a lubricant change is in order.
The site settled on three greases to simplify practices, reduce the risk of contamination and improve the quality of grease relubrication practices. Each gun is labeled by grease type and by the output that the gun produces with each stroke of the lever. The various grease guns are all stored exclusively by the type of lubricant maintained with the gun. An isolation cap secures the end of each grease gun nozzle.
At the same time, Bama technicians were determined to radically improve the method of handling and the condition in which the lubricants were delivered to the machines.
According to Powers, before any changes were implemented, the oil storage room had the appearance of a typical industrial lube crib: open drum bungs, unfiltered vents, open containers, no filtration of new lubricants, multiple types of grease guns with multiple products in use, and the absence of defined handling and new lubricant verification testing.
From this humble beginning, the site built a new lube room to create a precision work environment for this important function. The PMTs began to upgrade handling methods, replacing flexible galvanized funnels, open cans and the old standard coffee can-type containers with closed-top Oil Safe containers.
Other changes included incorporating filters for drum vents, upgrading existing grease guns, disposing of grease lubricants that did not make the cut and then clearly labeling all grease guns by product type.
The PMTs also implemented a new product test program that applied special attention to the cleanliness of the new lubricant right out of the container. There have been occasional instances of products that failed to meet defined performance and cleanliness specification. Prior to the change, these products would have been put into service without consideration of the potential impact on the production machinery.
Another big part of the program included integration of oil analysis into other existing technologies for the sake of assessing operating condition and changes in machine condition during operation. The site program now incorporates use of periodic vibration, ultrasonic, thermographic and lubricant analysis. According to Powers, the site always tries to verify any expected machine condition changes with more than one technology before initiating corrective work orders.
Currently, Bama Companies conducts oil analysis through National Tribology Services, whom Bama has found to be a proactive and helpful supplier. Standard test slates were devised with input from technologists at NTS.
The slates include spectroscopy for additive and wear metal concentrations, particle counting for lubricant cleanliness, acid number for lubricant health assessment, viscosity to verify health and correct lubricant in use, and moisture analysis for cleanliness control. All large sumps are now changed only when oil analysis dictates that a change is necessary.
PMTs also began to experiment with side-stream filtration to lubricant sumps with a portable filter system to condition lubricant sumps whenever the particle exceeded the target cleanliness level. There is now a standard practice in place to filter units based on International Organization for Standardization (ISO) code alarms. Additionally, all lubricants are prefiltered before the lubricant is placed into service.
Nonroutine ferrographic tests have been used following early indication of problems from the routine scans. In one situation, these tests lead to early diagnosis of gear failure on a critical production center. After recognition of the gear surface wear condition, PMTs were able to track declining health of the unit and pull the unit from service at an appropriate scheduled time. According to Powers, an uncontrolled failure on this machine would have carried a high production cost penalty.
Figure 4. Oil Room “After”
Another area of improvement has been in motor bearing lifecycles on cooler drives. Once the PMTs took a hard look at motor life, it was determined that bearings were failing prematurely. Upon consulting with the motor rebuild shop, the program managers discovered that a lubricant incompatibility problem existed between the lubricants selected by the rebuilder and those used upon installation.
Corrosive byproducts were produced from mixing the two greases, which were degrading bearing condition. The site worked with the rebuilder engineering group on product selection, labeled the motors for correct lubricant use, refined the relubrication practice and corrected the problem.
Failures on the cooler drive motors could lead to momentary shutdown of the entire plant, with a high associated cost. Since the review, discussions, improved product selection and application changes, the motor bearings now operate according to expected design.
|Figure 6. Cooler Reducer||Figure 7. Cooler Spiral Drive Motor|
After initial experimentation with airborne and structure-borne ultrasound technology, the PMTs have trained the operators and mechanics on the use and benefit of this type of assessment with bearing relubrication. There was some initial apprehension, but now that the technology is more fully recognized and understood, Powers believes that the mechanics and operators are more effective and more comfortable lubricating bearings with the tools than without.
Figure 8. Polyrex Lubrication Tag
The results that Bama Foods achieved are a product of a good strategic plan, clearly defined objectives, management support and persistence on behalf of the technicians and technical specialists that serve as the change agents. The results are tangible and sustainable if the strategies are integrated into the mainstream fabric of mechanic and operator behavior.
Editor’s Note: Both Powers and Carter are certified by ICML in Machinery Lubrication and Oil Analysis.