There’s no question that purchasing a vertical form fill seal bag machine is a major purchase that can take a months to accurately specify, quote, build and deliver. The process can become easier by improving communication between the vendors and customer early in the design stages. This will make that process a much quicker and smoother experience for everyone involved – and deliver a form fill seal machine that’s ready for action the first day it is installed.
One of the main components of the design process is the integration of the vertical form fill seal machine to an auger filler. These two pieces of equipment need to be in-sync with one another to properly deliver the desired performance for the customer’s application.
To get started, the vendors and customer need to share basic information with each other, including:
- What is the product being filled?
- What is the density?
- What are the flow characteristics?
- What is the bag size?
- What is the bag style?
- What is the desired fill rate per minute?
- What is the target product weight?
- What is the ID of the forming tube?
Knowing this information upfront helps vendors determine the scope of the project, and allows the auger filler supplier to determine if the customer’s desired performance specifications for the application can be achieved.
The reason to have answers to the questions in the early stages is that each one influences the other four; if one of the answers to a question is unknown, it can change the scope of the project.
The size and shape of the forming tube is one of the most important pieces of information a filler vendor needs in designing a system to integrate with a form fill seal machine. The amount and speed of which the product can be filled depends largely on the diameter of the auger, and that is dictated by the diameter and shape of the forming tube.
Simple physics comes into play in determining the fill rate. Obviously, the larger the forming tube, the more product that can be dispensed in a single auger revolution. For example, an auger that is 2 1/2 inches in diameter delivers 12.27 cubic inches of product per revolution, whereas an auger that’s just a half inch larger in diameter delivers 24.74 cubic inches of product per revolution – that’s twice as much. The size of the forming tube is of great interest to the filling machine vendor because they want to know how much space they have to work with inside that tube. Knowing this up front allows the supplier to determine if the specified speed can be met for the designed pouch size. If it does not, either the bag needs to be redesigned to a larger size or speed requirements must be reduced.
It is also important to review the flow characteristics for each product to be filled. In general products are free flow or non-free flow, and each requires a different tooling set up. In some cases products can be a little of both, and the result is anything from an occasional drip to a steady stream of product flowing after the auger has completed its cycle. This may require a tooling set up that calls for a clam shell cut off, a cone cut off, or possible the latest technology: vacuum cut off. All three of these special tooling set ups take up additional room in the form tube, causing the size of the auger, and therefore the output speed to be reduced.
Dust removal is an area that also needs to be factored into the integration of the vertical form fill seal machine with the filling machine. Since the foil pouch is sealed on three sides, any dust from the fill will escape going up. If the application calls for dust collection, then dust collection is required to capture it, and it needs to be located within the forming tube – and that takes up valuable space.
Electrical specifications of each system are another area to consider. Often the end user will have an electrical specification that must be met. The filler supplier needs to know this upfront when quoting the project. There is also the possibility of the VFFS supplier and the filler supplier to share components. A good example of this would be to integrate control screens on a common HMI, thus giving the end user single point control for the complete system. To do that effectively, it’s best to approach this objective early on.
One final point on machine integration - discuss the factory acceptance test up front during the quoting process. Will there be a test at the filler company, the bagger company, or both? What are the criteria for these tests? Will the VFFS company require technical assistance from the filler supplier for the test? What are the criteria for the start, installation and training at the customer’s plant? Technical assistance requirements should be defined and planned for in advance.
Bringing in all vendors together with the customer to discuss performance goals and share information early on in the design process will help streamline the integration between the form fill seal machine and filling machine. Vendors have expertise in their specific areas, and sharing information ensures all aspects of the integration move along in a smooth and efficient manner.
Timm Johnson is the vice president sales/marketing of Spee-Dee Packaging Machinery. He can be reached at 262-321-6103 or [email protected].