To achieve projected benchmarks, Goodyear Tire and Rubber Company determined that they needed to reduce both rubber mix cycle times and unacceptable mixer batches in order to boost production.
The Goodyear Tire and Rubber Company plant in Norfolk, Nebraska fabricates a wide array of rubber materials for finished and semi-finished hose and belt goods. They also supply rubber to other Goodyear assembly plants. With the addition of a Cyclonaire bulk material handling system, the Norfolk facility became one of the most efficient production plants in the Goodyear Tire and Rubber system because of its ability to increase production output and product quality levels, while maintaining overall costs of operation.
To achieve projected benchmarks, Goodyear determined that they needed to reduce both rubber mix cycle times and unacceptable mixer batches in order to boost production. To create a more environmentally acceptable workplace, Goodyear also wanted to minimize lower back stress and excessive dusting from material handling. Reducing unit costs of materials by moving to bulk supply, they also would be able to cut unit cost of material.
These goals were not simple to attain, since the Norfolk plant handles seven major ingredient materials in addition to carbon black, and several minor ingredients in its manufacturing processes. Goodyear had also traditionally relied upon mechanical and manual processes for material transfer.
The key to reducing batch loading, mixing times, and erroneous mixes while also fighting back strain was to eliminate the manual feeding of 50 pound bags of materials into the mixer. This required a shift to bulk and semi-bulk material supplies. The goal of reducing or eliminating material dusting was also realized by specifying pneumatics as the preferred mode of conveying.
The key was how to achieve all of these goals in a cost-effective, process efficient manner. Cyclonaire, a leading provider of pneumatic conveying solutions, was contacted since it had a reputation for success with difficult to move materials such as carbon black (pictured) and other materials such as clay, calcium carbonate, silicas, talc, etc. Cyclonaire had also proven itself with similar assignments in rubber production, including several Goodyear Tire and Rubber plants.
Cyclonaire dedicated itself to a thorough study of the Norfolk plant layout, the materials used and the process requirements long before making its formal proposal.
The highest volume ingredient, Kaolin Clay, required railcar supply and pneumatic transfer to a bulk silo with a high capacity semi-dense conveyor using a medium pressure blower air. A second, on-demand convey completes the transfer of clay to filter receivers, and then onto weigh hoppers above a large Banbury mixer. The hoppers discharge clay based on predetermined batch sizes and recipes via integrated loss in weight controls.
Four other major ingredients were specified for semi-bulk supply in bulk bag units. These products include two grades of silica gel, plastic resin, and calcium carbonate.
Dedicated lines for each ingredient were specified to avoid material cross contamination. Bulk bag unloaders and bottom discharge dense phase units conveying to filter receivers and individual hoppers are also used to avoid delay times that would have been required for bag switch outs and vessel clean outs before unloading and conveying additional materials.
Cyclonaire provided custom sized and configured bulk bag unloaders with integrated electric hoists to eliminate the need for forklifts. Each bulk bag unloader, access hoppers and dust collectors provide a clean and convenient method for bag opening and discharging. Additionally, the 80 cubic foot hoppers provide enough working material volume to reduce bag rehanging frequency and allow enough material for several batches within a short period, avoiding hopper refill and mixer cycle delays.
For control ease and safety, filter receivers are equipped with three level sensors; one each for high level and low level, plus an emergency low level sensor to protect from a “short” batch that would have to be discarded as waste. All level control and conveyor control inputs are integrated into a central process control panel and also to a distributed control panel that integrates functional controls with the Banbury mixer and several minor material ingredient feeders.
The Norfolk Goodyear plant realized and actually surpassed all of its goals. Specifically, it decreased its cost of raw materials, decreased its manpower costs, and decreased its mixer load and cycle times.