Format Changes on Packaging Machines: Duration, Format Components, and 5 Factors That Influence Them

Changing Formats Means Increased Productivity

A format change occurs between two production runs—and the line is idle for every minute of that time. At 50 bags per minute, half an hour of downtime results in a loss of approximately 1,500 bags. By planning for the format change instead of simply enduring it, you can recoup this lost capacity. This article describes which format components are changed, how long this typically takes in the industry, and the five factors that determine the duration of the changeover.

What is a format change?

A format change adjusts the packaging machine to a new bag size or fill weight. It is more than just a product change: During a product change, the format remains the same and only the dosage and recipe change; during a format change, mechanical parts are replaced.

The format elements in detail:

In addition, the following steps are required on each machine: selecting the recipe on the HMI, conducting a test run with film or bags, adjusting the sealing parameters, and checking the first bags for proper dimensions and leak-tightness.

How It Works in Practice

1. Shut down the line and clear the area: Remove any remaining film or bags; stop the product flow.
2. Select a recipe on the HMI: Film length, sealing temperature, sealing time, target weight—saved recipes retrieve these values as a block.
3. Replacing molded parts: Remove old parts, install new ones, and check the fit. Tool-free quick-release fasteners save minutes here.
4. Changing the film or bag: Load a new roll of film or a new bag size into the magazine.
5. Test run: Let the machine run at idle speed, then pull out the first filled bags.
6. Approval: Check the fill weight, seal, bag length, and date stamp; production does not begin until approval is granted.

The 5 Factors That Influence the Duration of a Transition

1. Should we change the format section or not?. The biggest advantage: Machines with tool-less quick-change format parts and plug-in connections cut the pure changeover time in half compared to solutions that rely on screws. When purchasing a machine, it’s worth asking: How many screws does a format part hold?

2. Recipe management on the HMI. A control system that saves the sealing temperature, film length, and target weight as a recipe block—and loads it with the push of a button—completely eliminates the need for manual adjustments. Typically, control systems in this industry can store 50 to 100 recipes.

3. Turnover Rate and Staff. A line that is changed twice a day requires trained staff and a documented changeover procedure. According to industry standards, the same changeover takes two to three times as long when performed by untrained staff.

4. Format maintenance. All format parts in the production program must be readily available at the machine station—not in the warehouse. If a format part is missing, a 30-minute changeover time turns into half a shift spent procuring it.

5. Testing and Approval Procedure. The first bags produced after the changeover are inspection bags: Check the fill weight and verify that the seal is airtight. A documented checklist ensures that the approval process is repeatable—and protects against complaints if a faulty seal affects the order.

Planning Format Changes: Formulas Instead of Screws

The key lies in reducing mechanical changeovers: Formats that require only different film lengths but the same bag width are purely HMI recipe changes that require no tools. Therefore, plan your format program early: Using a few bag widths with multiple lengths drastically reduces the number of format parts. If you consolidate five formats into two widths, you’ll purchase format parts for two widths instead of for five formats.

For production control, the following applies: Schedule changeovers during shift breaks or at the end of jobs; treat changeover times as fixed values in capacity planning; and analyze the cumulative changeover time per month. This figure indicates whether a second line or format consolidation is more cost-effective.

Frequently Asked Questions

How long does a format change usually take?

On a VFFS machine, 20 to 45 minutes; on a pre-made bag line, 10 to 30 minutes; on a multihead weigher, only the recipe change takes about 5 minutes. These figures apply to experienced personnel with format parts readily available.

What is the difference between a format change and a product change?

When changing products, the bag format remains the same; only the recipe, product, and target weight change—a simple HMI adjustment requiring no tools. When changing formats, the forming shoulders, jaws, or grippers are replaced mechanically.

Can the format change be automated?

Partially. Format changes are fully automated; however, changing the format section still requires manual labor. Servo drives and tool-less quick-release fasteners reduce the time required—fully automated format change systems are custom-built and are used only for very high cycle rates and a wide variety of formats.

How much does a format change cost?

The costs are the line's downtime costs: cycle rate × downtime × contribution margin per bag. At 50 bags per minute and 30 minutes of downtime, this results in a production shortfall of approximately 1,500 bags—the amount in euros is based on your contribution margin.

Related pages: What is a vertical form-fill-seal (VFFS) machine? | What is a bagging machine for pre-made bags? | Predictive Maintenance for Packaging Machines | Packaging Machinery Guide for German Industry

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