Finding Balance in Manufacturing, Assembly, and Processing Operations

Using Carousel Buffer Systems to Efficiently Plan Operations

By Robert Rienecke, Vice President of Sales, Diamond Phoenix

For most of us, life is often in a state of imbalance. We try to coordinate bills with income, time with commitments, work with schedules, and home life with careers. We have to make adjustments to best balance these demands. If we could bank some of these commitments and use them later when we have more time or money, life would be much simpler.

We face similar challenges in business. Manufacturing output doesn’t always parallel assembly schedules; inventory availability may not match building or processing timelines. If the capability to manufacture product exceeds the ability to assemble it, then the excess manufactured product must be stored so that it’s available when assembly is ready to accept it. Fortunately in the business world, material handling systems can manage these imbalances for us and help us achieve production and delivery schedules.

One major wheel manufacturer was facing this very situation. The aluminum fabrication operation produces multiple wheel types. When the wheels are ready, they are passed on to painting and then finally onto shipping for delivery to the car manufacturer.

Between each of these steps in the process, the company needed a place to store the wheels until the next operation was prepared to handle them. Floor storage and accumulation conveyor had already been ruled out – both would consume too much floor space and would be too costly.

Instead, the company chose to install two buffer systems – one between the machining and painting operations and the other between the painting and shipping operations. Both buffer systems combine horizontal carousel technology with automatic extractors.

The carousel software system manages the orders and directs the extractor to either store or retrieve wheels, depending upon the stage in the process. When the wheels exit the manufacturing operation, a conveyor system transfers them to the first buffer system. Each wheel is read by a vision identification system just before it is moved onto the inserter/extractor. If the system can’t read the inbound wheel ID, then it is classified as a “no read” and the inserter/extractor places the wheel onto the outbound conveyor, where it is reintroduced into the system after the ID on the wheel has been identified. Otherwise, the system passes the part number of the wheel to the software system and a location is assigned based on the configuration of outbound transactions and the most time efficient carousel.

Once the wheel has been identified, the inserter/extractor moves into position near the inbound conveyor. The stop at the end of the conveyor is dropped and the wheel is moved onto the inserter/extractor bed; while the carousel is moving into position. The assigned carousel location is positioned in front of the inserter/extractor and the it moves up or down into the correct position and places the wheel into the carousel bin. The system records the wheel ID, its carousel location, and the storage date and time.

The wheels are stored in this buffer system until the plant schedules a painting operation. The wheels will then be automatically extracted from the first buffer and transferred to the painting operation via conveyor. When painting is complete, the wheels are conveyed to a second buffer, where they are stored prior to shipment.

Multiple wheel (batch) requests allow the carousel system to operate at the most efficient rate. When an automotive manufacturer places an order, the request is sent to the carousel system. The carousel software determines the order of the wheels by analyzing the fastest carousel travel times. The carousel spins to the correct bin and the inserter/extractor picks the required wheel and places it on the conveyor. This process repeats itself until the order is complete. The wheels are conveyed to the shipping area, where they are prepared for delivery to an automotive plant. This material handling solution minimizes floor space requirements and provides timely delivery of wheels to the desired operation.

This technology has also been applied to a major battery manufacturer. Small batteries, like the AAA, AA, B, C, and D types sold in retail stores, are produced at a manufacturing location and shipped to a central distribution center. The batteries are received by type and stored in bulk trays in a five-stack system of automatic inserter/extractors. Requests from retail stores are downloaded from the host computer and the inserter/extractor begins to retrieve the appropriate trays.

Once the tray moves out of the carousel, it is conveyed to an automated packaging station, where the batteries are removed from the tray automatically and moved to a packaging station to group quantities together prior to a blister packing. The finished package then moves to shipping for delivery to retail distribution facilities around the country.

The inserter/extractor system provided a way of storing multiple trays of batteries with a minimal amount of floor space. Additionally, the inserter/extractor’s dual cycle time of approximately 4 trays per minute provides quick delivery to packaging stations in order to meet customer demand.

Carousel buffer systems with automatic inserter/extractors have been used in a variety of industries. In each case, the system allows the company to balance its operations by providing space and time efficient storage systems for unfinished or work in process products. Because of the high dual cycle rates, users can efficiently plan production or shipping schedules to meet customers’ needs.