VFFS Film Waste: Where Packaging Film Is Lost During Production
Packaging film waste is easy to recognize when rejected bags are sitting beside a VFFS line. What is harder to see is the film lost in smaller amounts throughout a production run.
A production report may show total packages produced, rejects, downtime, and packaging material issued or consumed. These metrics help describe line performance, but they do not necessarily show how much of the film consumed during the run was converted into acceptable finished packages.
Film can be consumed during startup, changeovers, roll transitions, recovery from production interruptions, and in packages that are ultimately rejected. Individually, each loss may appear minor. Repeated across a shift, production campaign, or year, they can create a meaningful difference between the amount of film represented by good packages and the amount actually consumed.
For plant and maintenance engineers, that difference is worth understanding. Before trying to reduce VFFS film waste, the first step is to account for where the film is actually going.
Table of Contents
Start With the Film That Should Have Been Used
Before plant teams can understand VFFS film waste, they need to establish a simple material balance, in other words, account for how much film was consumed during the run and where that film went.
For example, assume a VFFS line produces 50,000 acceptable packages and each package uses 200 mm, or 0.2 metres, of film.
50,000 packages × 0.2 m = 10,000 m of film
The 50,000 good packages therefore account for 10,000 metres of film.
Now suppose the line actually consumed 10,600 metres during the full production run. The difference between the film consumed and the film represented by good output is 600 metres:
10,600 m − 10,000 m = 600 m
This difference can be treated as a film-use variance, the amount of film that has not yet been accounted for in good packages.
The next question for plant teams is:
Where did those additional 600 metres go?
Some may have been consumed during machine startup or changeovers. Some may have gone into rejected packages, while additional film may have been used during roll changes or while the line recovered from production stops.
Breaking this variance into identifiable loss categories gives plant and maintenance teams a clearer picture of where film is being consumed without becoming acceptable finished packages. Instead of working from one overall scrap number, they can see which parts of the production run are contributing most to VFFS film waste.
Film Yield and VFFS Conversion Efficiency Are Different
Film yield and conversion efficiency describe two different parts of film utilization.
ASTM D4321 defines plastic-film yield as the area of film per unit mass. In practical terms, it tells a plant how much film area is available from a given weight of material.
Conversion efficiency, in this context, looks at what happens once that film enters the VFFS process: how much of the material consumed becomes acceptable finished packages.
The distinction is:
Film yield: How much usable film area is available from the material?
Conversion efficiency: How much of that film becomes good output?
This distinction becomes useful when production output does not match expectations. If the amount of usable film available differs from what was expected, the issue may begin with the material quantity or yield. If the expected film is available but fewer good packages are produced, the material balance can help identify where film was consumed elsewhere in the process.
Build a Material Balance Around the Production Run
Once actual film consumption has been established, the production run can be reconciled using a material balance:
Total film consumed = Film in accepted packages + Identified process losses + Unaccounted material
In the previous example, 10,600 metres of film were consumed while 10,000 metres were converted into acceptable packages, leaving 600 metres to account for.
Suppose production records show that 120 metres were consumed during startup, 80 metres during changeover, 70 metres while recovering from production stops, 150 metres in rejected packages, and 40 metres as discarded roll-end material. Together, these known losses account for 460 metres.
That leaves 140 metres unaccounted for.
This residual is more useful to an engineering team than the original 600-metre difference because the known process losses have already been separated from the material that cannot yet be reconciled. The remaining gap may point to material that is not being captured consistently in production records, such as manual film advancement, unrecorded scrap, partial-roll handling, or other consumption outside the defined loss categories.
The distribution of the identified losses also matters. Two runs can consume the same additional 600 metres while arriving there in very different ways. One may lose most of its film during startup and changeover, while another may generate the majority through rejected packages or repeated recovery after short stops.
Looking at where the loss occurs, not only the total amount, gives plant and maintenance teams a better basis for deciding where engineering attention is likely to have the greatest effect.
Startup Loss: Measure Film, Not Only Time
Startup performance is often measured in minutes, but time alone does not show how much packaging film is consumed before the line reaches acceptable production.
For film-utilization analysis, a useful measure is the amount of web consumed between the start of the run and the first sustained acceptable output. Tracking this value alongside startup time provides a clearer picture of how repeatably the process is being established.
For a recurring SKU, plants can track how much film is normally consumed before stable production begins. If that amount suddenly increases from one run to the next, it can indicate that the startup process is becoming less repeatable, even if the total startup time has not changed.
The objective is not to assume that all startup consumption can be eliminated. Some material use may be inherent to bringing a specific package and process into a stable production condition. The more useful question is whether startup consumption remains consistent with the established baseline.
A sustained increase in film used during startup gives plant and maintenance teams a measurable reason to investigate what has changed rather than allowing the additional material to disappear into the overall scrap figure.
Keep Changeover Loss Separate From Startup Loss
Film-loss data is easier to compare when the same type of loss is recorded the same way every time.
For example, film used while switching from one SKU to another should always be recorded under the same category. If one shift records it as changeover loss and another records it as startup loss, the total amount of wasted film may still be correct, but the individual categories will no longer be reliable.
Using consistent definitions helps plant and maintenance teams compare runs, identify which types of loss are increasing, and see where the biggest opportunities for improvement are.
Stop-and-Restart Loss Can Be Hidden by Downtime Data
Downtime measures how long production is unavailable, but it does not show how much packaging film is consumed as the line returns to acceptable output.
After a short interruption, the machine may require several package cycles before good production is re-established. The film consumed during that recovery period may be small for a single stop, but repeated interruptions can make restart-related loss a meaningful part of total film consumption.
For that reason, plant teams can look at two separate measures:
Downtime: How long was production stopped?
Restart loss: How much film was consumed between restart and the return of acceptable output?
Tracking both helps distinguish a time-loss problem from a material-loss problem. If restart film consumption begins increasing while downtime remains relatively unchanged, the change may not be visible in the downtime data alone.
Every Rejected Package Contains Film That Did Not Become Good Output
Reject percentage is usually treated as a quality metric.
It is also a film-utilization metric.
Once a complete package has been formed, sealed, cut, and subsequently rejected, the full film repeat associated with that package has been consumed without contributing to good output.
For a fixed package repeat, the film associated with rejected packages can be estimated directly:
Rejected packages × Package repeat = Film represented by rejects
If 500 rejected packages each use a 200 mm repeat:
500 × 0.200 m = 100 m of film
That does not explain why the packages were rejected, and this analysis should not try to.
It does show the material consequence of the reject rate.
Plant teams can then decide whether that category is large enough to warrant further investigation.
Normalize Film Consumption Against Good Output
Total film consumption is difficult to compare from one production run to another when output volume changes. A normalized measure provides a more consistent basis for comparison.
One practical metric is:
Film consumed per 1,000 good packages
For a package with a 200 mm repeat, 1,000 acceptable packages represent 200 metres of film. If an established SKU typically consumes 205 metres for every 1,000 good packages, the additional 5 metres reflects the normal combined effect of process losses for that run.
If consumption later increases to 220 metres per 1,000 good packages, the process is now using 15 metres more film than its established baseline for the same amount of good output.
The metric does not identify the cause of the increase. It shows that film consumption relative to acceptable production has changed enough to warrant further investigation.
Tracking this value over repeated runs can help plant and maintenance teams distinguish normal process variation from a sustained increase in film use.
Establish the Baseline by SKU and Line
Film consumption should be evaluated against a comparable production baseline rather than a single plant-wide waste percentage.
Different SKUs can require different package dimensions, film repeats, run lengths, and operating conditions. The same SKU may also show a different loss profile when produced on a different line. For that reason, the most useful baseline is usually established for a specific SKU and production line.
Across repeated runs, plant teams can track the typical range for film consumed per 1,000 good packages as well as the individual losses associated with startup, changeovers, restarts, rejects, and roll transitions.
Over time, those measurements establish the expected material-consumption profile for that job. A deviation can then be evaluated against the normal range for that SKU and line rather than against a plant-wide average that combines very different packaging applications.
The baseline gives the variance context. A change in film consumption becomes meaningful when it falls outside what is normally observed under comparable production conditions.
Use the Loss Profile to Decide Where Engineering Effort Belongs
The value of measuring VFFS film waste is not simply in reporting a lower or higher scrap number. It is in showing where material is being lost during the production cycle.
If startup loss is consistently above the established baseline, the startup process may warrant closer review. If restart-related loss is increasing, the way the line returns to acceptable production after interruptions becomes a more relevant area to investigate.
A high proportion of film in rejected packages points attention toward the conditions producing those rejects, while increasing roll-related losses may justify reviewing roll utilization and material-handling practices.
Unexplained material is different. If a large portion of film consumption cannot be assigned to a known production event, the first priority may be improving how film use is recorded before drawing conclusions about machine performance.
Breaking total film loss into categories helps plant and maintenance teams prioritize investigation based on where material is actually being consumed, rather than treating all film waste as one problem.
Do Not Confuse Film-Waste Reduction With Simply Using Less Film
Reducing process waste is different from reducing the amount of film designed into the package.
Package repeat, seal dimensions, package geometry, and film structure are established to meet the requirements of filling, sealing, handling, product protection, and distribution. Reducing those material requirements is a package-design decision and should be evaluated separately.
The focus of film-loss analysis is the material consumed beyond what is required to produce the validated package.
For plant and maintenance engineers, the immediate question is therefore not whether the package can be made with less film. It is whether the existing package is being produced with a consistent and controlled level of material loss.
Keeping those two objectives separate prevents process inefficiency from being confused with package-material reduction.
Make Film Waste Measurable Before Trying to Reduce It
VFFS film waste becomes easier to address once total material consumption is connected to good output and the difference is assigned to specific production events.
The starting point is a material balance: determine how much film is represented by acceptable packages, compare it with actual film consumption, account for known process losses, and identify what remains unexplained.
This gives plant and maintenance teams more useful information than a single scrap percentage. It shows whether material loss is concentrated in a particular part of the production cycle, whether consumption is moving away from an established baseline, and where further investigation is most likely to be worthwhile.
The objective is not simply to reduce the amount of film moving through the line. It is to improve how consistently the film being consumed is converted into acceptable finished packages.
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