Understanding Different Methods of Automated Retort Loading & Unloading

What is retort room automation?

One of the many considerations to be addressed when designing and equipping a retort room is how best to convey the containers/product through the system.

First of all, the multitude of containers that are available to food manufacturers today require different types of container handling equipment to properly handle and protect the containers, and to facilitate the required production levels needed to operate efficiently and cost-effectively.  Here are some examples of the different types of container loading and unloading systems that are available:

• Rigid containers, such as steel or aluminum cans and glass bottles or jars, are typically loaded into and unloaded from baskets with a sweep-type loader & unloader.  In these machines unprocessed sealed containers from the capper or seamer are received, accumulated, and formed into a pattern/layer.  A basket is moved into position and the layer of containers is swept into the basket.  Divider sheets are placed between the layers and this process is repeated until the basket is full.  The opposite process occurs in the unloader, and containers are discharged in mass, one layer at a time from the baskets, and eventually combined into a multiple or single file lane(s) to meet downstream packaging equipment needs.  These machines can be designed to provide various degrees of automation from semi-automatic to fully automated.
• Semi-rigid and flexible containers, such as pouches and thermoformed bowls, tubs, trays, and bottles, are handled differently because the containers cannot support the weight of layers stacked above.  These applications require self-stacking and supporting trays, and containers are picked and placed into and out of these trays with either gantry style or multi-axis robotic type loaders and unloaders.

The second major material handling component of an automated retort room involves delivering the loads of product from the loading area to the retort(s) and then from the retort(s) to the unloading area, otherwise known as the retort delivery system.  Here too, varying degrees of automation can be considered, from manual to fully automated systems depending on how the retort room is laid out, and there are several options for accomplishing automatic conveyance of containers/product to and from the retorts.

• Basket or tray stack conveyors are typically used in situations where the available floor space is minimal and/or there are obstacles in between the loader/unloader area and the retorts. Other items that are typically part of the basket conveyor system can include the following.
  • Tippers are used to shed excess water from the tops of the containers before they are delivered to the unloader.
  • Pop-ups allow 90° directional changes.
  • Turntables can perform the same function while also changing the orientation of the baskets or tray stacks by 90°. 
• Shuttles are typically used when there is unobstructed space between the container loading and unloading area(s) and the retorts.  These are highly efficient retort delivery systems that can be used to transport complete or partial retort loads at a time and can even load and unload two retorts in one trip.  And they can also be equipped with on-board systems to push and pull loads of product into and out of the retort, respectively, thus eliminating the need to have a chain conveying system installed in the retort which must withstand the harsh environment.
• Automated Guided Vehicles are typically used where there might be obstacles and/or the path between the loading and unloading area(s) and retorts are not straightforward. Because these types of vehicles are typically limited to the size and weight of load they can carry, either multiple vehicles are required and/or product mandate and retort cycle times are long enough to accommodate the greater amount of time it takes to transport loads to and from the retorts and the loading/unloading area, and to load and unload the retorts.

Other available types of retort delivery solutions to allow for the insertion and removal of product into and out of the retorts in a more automated or mechanized fashion include internal retort mounted conveyors, Ergo Loaders/Unloaders and Rigid Chain Loaders/Unloaders.  These devices help to reduce the risk of moving heavy product basket and tray stacks into and out of the retort. 

While the above-mentioned systems can add considerable upfront investment cost to a retort operation, conversely, they provide for lower labor costs and a higher level of personnel and product safety to the retort operation.  In high volume production lines in particular, these automation systems can provide very attractive returns on investment, and significant personnel and product safety enhancement benefits.