Conveyors adapt as packaging evolves over time
Conventional flatbed conveyors still prevail
An overall view of the beverage arena immediately highlights the fact that beverage packaging is dominated by logistics: moving materials in some form or another from point A to point B and beyond.
From an operations perspective, and dealing with the basics and fundamentals of logistics, the obvious starting point is container input — containers must be washed, filled, closed, unitized and cased — all operations requiring movement, speed variations and container stability.
Throughout the production/packaging process, conveyor systems are the one category of equipment that links all the functional operations together. Because containers are not really standardized, conveyor designers are deciding which type of conveyor is best for a specific container.
Once a conveyor type is determined to run a container that is a certain size, material and weight, it should prevail throughout the entire line; however, even containers of various weights, sizes and types could require a specific conveyor at different locations in the line. The type of container also might determine whether the conveyor should be dry lubricated or lubricated by some other means to effectively reduce friction and allow ease of flow on the line.
The evolution of container conveyors has been prompted by the changes in the containers themselves. Cans are a good example. After the depalletizing operation, where cans are swept off a pallet layer onto a whip line and eventually to an upright position on a flatbed conveyor with guide rails, the cans go through the rinsing, filling and seaming operations. After those operations, final coding or inverting might take place. In this scenario, steel cans survived the line pressure, stability and line speed quite well.
With a change from steel to aluminum cans, the container material impacted conveyor type, speed and configuration. Aluminum cans became susceptible to damage caused by line pressure and speed that was not experienced with steel cans. Some conveyor design changes were made, aluminum can material also has changed and line speeds have increased, which have resulted in another evolutionary step for can conveying.
Conveyors for glass containers have transitioned from steel to stainless steel to plastic depending on the container size and line speed. With the introduction of various shapes and sizes coupled with a reduction in glass package mix, conveyor designs for glass have more or less stabilized regardless of the configuration variances.
Plastic containers have presented another challenge to conveyor designers. One- and two-piece configurations, including 67.5 ounce, 1- and 2-liter sizes, created unstable line pressure and separation problems. In addition, smaller size containers were developed and demanded alternative designs to effectively handle the new operating problems, which were different than the large bottles. After the larger size stabilized to 2-liter packages and smaller sizes to 8- or 20-ounce packages, some difficulties were eliminated. However, other line pressure and speed problems still were present.
Conventional flatbed conveyors still prevail and will for some time, but air and other conveying methods have been designed and successfully used for all sizes of plastic containers.
For any container, the identity is lost when it becomes part of a unit (six-, eight- or 12-pack) or a case of 24. Units or individual containers (in cases of 24) now are conveyed on flatbed case conveyors from the packer or packaging to the final operation. Case or unit conveyors must be flexible, easily maintained and designed to avoid damage. Most case conveyors, cases, units or trays are coded or identified by some method before moving to a palletizing operation.
Cases, trays or units are discharged from a case conveyor into the palletizer, an almost final step and placed on tiers of pallet layers to be discharged onto a pallet conveyor. During palletizing, configured conveyors can return cases to the initial case or unit drop point. Where returnable plastic cases are used, they can be conveyed into a wash machine or packaging operations depending upon the line design.
The almost-final step is where a pallet load of cases or units are removed from a discharge pallet conveyor onto a forklift truck for transport either to storage or dock for delivery. In more automated operations, pallet conveyors are programmed to discharge pallet loads onto automated guided vehicles (AGVs) for transport to storage.
But, conveyors still are not finished. In the forklift truck operation, pallet loads are discharged onto pallet conveyors that sequence movement to storage racks by forklift truck. In the AGV operation, pallet loads are transferred from cart to conveyor and eventually conveyed to specific storage cubicles. The cycle is reversed for order picking and distribution preparation, all with conveyors — except for loading the route vehicles.
The entire cycle for a beverage logistics plan (for any container and eventual unit or case) begins and ends with conveyors. In reality, it’s quite a movement. BI