How to Evaluate Flow Wrapper Safety Before You Buy | A Practical Guide for Food Manufacturers
- PacMatix
- 3 days ago
- 11 min read
When evaluating a flow wrapper, most buyers focus on speed, product range, film compatibility, and price.
While these factors are important, safety should never be overlooked.
A horizontal flow wrapper contains moving chains, sprockets, sealing jaws, sealing wheels, electrical systems, pneumatic components, and heated surfaces. If these hazards are not properly controlled, operators can be exposed to unnecessary risk during production, cleaning, maintenance, and changeovers.
The purpose of this guide is not to compare specific machine brands, but to help food manufacturers understand what to look for when assessing flow wrapper safety.
Start By Identifying The Hazard Areas
Before evaluating safety features, it is important to understand where the risks exist.
Typical hazard areas on a flow wrapper include:
Infeed conveyors
Product pushers and pusher chains
Chain drives and sprockets
Rotary sealing jaws
Fin sealing wheels
Film pulling rollers
Slip rings
Pneumatic systems
Electrical cabinets
Heated sealing components
A safe machine should either prevent access to these hazards during operation or remove hazardous movement when access is required.
Evaluate The Infeed Conveyor
The infeed area is one of the most important areas to inspect.
Many flow wrappers use moving pusher chains to transport products through the machine. These chains travel around sprockets at the front and rear of the conveyor, creating potential pinch points.
Ask yourself:
Are all moving chains enclosed?
Can fingers reach moving sprockets?
Are chain return points protected?
Are covers robust and securely mounted?
Any area where a chain passes around a sprocket should be carefully assessed for potential access by operators.
Particular attention should be paid to the return point of the pusher chain at the beginning of the infeed conveyor. If this area is not properly guarded, operators may be able to place their fingers into the return path of the pusher, creating a significant pinch hazard.
Pay Particular Attention To The Pusher Chain Return Area
One of the most commonly overlooked hazards on a flow wrapper is the point where the pusher chain returns underneath the machine after passing through the forming box.
This area is typically located beneath or immediately behind the forming box and contains a chain and sprocket assembly that can create a serious pinch point if left exposed.
As the chain travels around the return sprocket, there is potential for fingers, clothing, cleaning cloths, or other objects to become trapped between the chain and sprocket. Depending on the machine design, the risk of injury can be significant.
When evaluating a flow wrapper, look specifically at:
The pusher chain drop-down position behind the forming box
The chain return path underneath the machine
The return sprocket area
Any exposed chain and sprocket combinations
If the chain and sprocket are visible or accessible, ask the supplier how this hazard is controlled.
A properly designed flow wrapper should prevent accidental access to moving components in this area.
Inspect The Sealing Jaw Area
The rotary sealing jaws are often the most obvious hazard on a flow wrapper.
These jaws operate at high speed and generate considerable force during sealing.
When evaluating a machine:
Check that access is restricted during operation.
Ensure guards are interlocked.
Verify the machine stops safely if a guard is opened.
Confirm that a manual reset is required before restarting.
Look for sufficient guard coverage around the entire sealing area.
Particular attention should be paid to the exit conveyor guarding.
If the exit conveyor guard is too short, operators may be able to reach into the sealing jaw area while the machine is operating. As a general guide, a guard length of approximately 900mm is often used to prevent access to the hazard zone.
The sealing jaw area should also be protected from the fin wheel side of the machine. It is not uncommon to see machines that prevent access from the front but still allow access from the side.
A machine may appear safe from one angle while still allowing access from another.
Don't Overlook The Fin Sealing Wheels
Many buyers focus on the sealing jaws and overlook the fin sealing wheels.
The fin wheels create another significant pinch point and are often positioned close to operator access areas.
In some machine designs, covers are fitted to prevent access to the sealing jaws, yet operators can still reach the fin sealing wheels themselves.
Consider:
Are the wheels fully guarded?
Can an operator accidentally reach the sealing area?
Are covers fitted with appropriate interlocks?
Are the guards robust enough for long-term industrial use?
A machine should protect operators from all hazardous movements, not just the most visible ones.
Check Film Pulling Rollers And Pinch Points
Driven Film pulling rollers can create additional pinch hazards if not adequately guarded.
Some flow wrappers utilise pinch rollers to pull and control film through the machine. If these rollers are accessible during operation, operators may be able to accidentally place fingers into the nip point between the rollers.
Even relatively small rollers can generate sufficient force to cause serious finger injuries.
Any accessible roller-to-roller nip point should be carefully assessed during a machine evaluation.
Check The Quality Of The Guards
Not all guarding systems are equal.
Some machines use heavy-duty steel guarding, while others rely heavily on lightweight plastic covers.
When assessing guarding, ask:
Will the guard withstand accidental impact?
Could a broken cover expose moving components?
Does the guard feel rigid and secure?
Is it suitable for a food manufacturing environment?
This is particularly important in busy production environments where trolleys, bins and equipment are regularly moved around machinery.
During site visits, we occasionally encounter machines where plastic guards have been damaged by trolleys, bins, or other equipment moving through the factory. In some cases, the damaged guard has exposed moving chains, sprockets, or drive components, creating a potential hazard for operators working around the machine.
When evaluating a flow wrapper, consider not only how well the machine is guarded when new, but also how well those guards are likely to withstand years of operation in a busy production environment.
A guard is only effective if it continues to provide protection throughout the life of the machine.
Safety Should Not Come At The Expense Of Usability
Traditionally, some machine manufacturers have argued that guarding the pusher chain return area makes the machine difficult to operate or maintain.
However, this is not necessarily the case.
Many modern flow wrappers successfully incorporate guarding around the pusher chain return area while remaining easy to clean, simple to thread with film, and straightforward to change over between products.
The real issue is often not the guard itself, but the amount of operator intervention required to keep the machine running correctly.
If a flow wrapper requires operators to constantly adjust forming box settings, reposition guides, correct film tracking issues, or intervene in the film forming area during production, then unrestricted access becomes a necessity.
In these situations, safety guarding may be viewed as an obstacle because operators are continually working around the area.
Conversely, a well-designed flow wrapper should provide reliable and repeatable changeovers, allowing machine settings to be recalled accurately from one production run to the next.
When product setups remain consistent and film tracking is stable, operators spend significantly less time making adjustments around the forming box and pusher chain area.
As a result, hazardous areas can be properly guarded without compromising productivity or usability.
Evaluate Changeover Safety
Many safety discussions focus on normal production, but operators are often exposed to greater risk during product changeovers.
During a typical changeover, operators may be required to:
Change film reels
Adjust forming boxes
Set product guides
Check film tracking
Test machine operation
Remove and reinstall components
The more frequently operators need to intervene around moving parts, the greater the potential exposure to hazards.
When evaluating a flow wrapper, consider:
How repeatable are changeovers?
How often are operators required to adjust the forming box?
Can settings be recalled accurately?
Does film tracking remain stable after a changeover?
Is excessive manual intervention required to achieve acceptable performance?
We regularly encounter machines where operators have become accustomed to reaching into the forming box area to clear jams, reposition film, or correct tracking issues during production. While these actions may become routine over time, they often place operators in close proximity to moving components and potential hazard zones.
A well-designed flow wrapper should minimise the need for this type of intervention by delivering stable film tracking, repeatable changeovers, and consistent machine performance.
A machine with reliable and repeatable changeovers is often a safer machine because operators spend less time working around moving components and potential hazard areas.
Safety is not only about guards, switches, and emergency stops. It is also about reducing the need for operator intervention wherever possible.
Evaluate The Electrical Safety System
Mechanical guarding is only one part of machine safety.
The machine's electrical safety system is equally important.
Ask the supplier:
What safety category is used?
Are dedicated safety relays installed?
What happens when a guard is opened?
Does the machine safely remove hazardous movement?
Is a manual reset required before restart?
For modern food manufacturing environments, Category 3 safety systems are commonly considered the minimum expectation.
In a Category 3 safety system, a single fault should not result in the loss of the safety function. This is achieved through dual-channel safety circuits and continuous fault monitoring.
When reviewing a machine, ask the supplier for the electrical drawings. A qualified electrician can often determine whether the machine uses a genuine Category 3 safety architecture and whether recognised safety components have been used throughout the design.
Recognised safety manufacturers commonly used throughout the industry include Pilz, Sick and Omron.
Evaluate Slip Ring Safety
Many flow wrappers use slip rings to transfer power and signals to rotating components.
Although slip rings are typically located behind machine covers, operators often remove these covers during cleaning, maintenance, and troubleshooting activities.
When evaluating a machine, ask whether sealed slip rings are used and how operators are protected from accidental contact with live electrical components.
Older brush-and-ring style slip rings can present a potential electrical hazard if exposed while energised.
If non-sealed slip rings are used, the slip ring assembly should have its own independent protective cover to prevent accidental contact.
Ask the supplier:
Are the slip rings fully sealed?
Can operators access the slip rings during cleaning?
Is an additional protective cover fitted around the slip ring assembly?
What happens if a cover is removed while power remains on?
Electrical safety should be assessed with the same level of attention as mechanical guarding.
Ask For A Safety Demonstration
One of the simplest ways to evaluate a machine is to ask the supplier for a demonstration.
Request that they show:
Emergency stop operation
Guard interlock operation
Reset procedures
Safe jogging functions
Access during cleaning and changeovers
A reputable supplier should be able to clearly explain how operators are protected in each scenario.
Safety Is More Than Compliance
Many buyers assume that if a machine carries a compliance mark, it must be safe.
In reality, compliance is only one part of the picture.
The more important question is:
How effectively does the machine protect operators during production, cleaning, maintenance, troubleshooting, and changeovers?
These are the situations where safety systems are truly tested.
Frequently Asked Questions About Flow Wrapper Safety
What are the most common safety hazards on a flow wrapper?
The most common hazards include pusher chains, sprockets, sealing jaws, fin sealing wheels, film pulling rollers, electrical components, and heated sealing elements.
What is a Category 3 safety system?
A Category 3 safety system uses dual-channel safety circuits and continuous fault monitoring. If a single safety component fails, the machine should still maintain its safety function.
Are all flow wrappers equipped with Category 3 safety systems?
No. Safety systems vary significantly between manufacturers and machine models. Buyers should ask suppliers what safety category is used and request electrical documentation if required.
Why is the pusher chain return area considered a safety risk?
The pusher chain return area contains a chain and sprocket assembly that can create a serious pinch point if left exposed, particularly during cleaning, film threading and changeovers.
What should I look for when inspecting flow wrapper guards?
Look for robust guarding that prevents access to moving components and is capable of withstanding years of operation in a production environment.
How long should a flow wrapper exit conveyor guard be?
The required guard length depends on the machine design and applicable safety standards. As a general guideline, sufficient guarding should be provided to prevent operators from reaching into the sealing jaw area.
How can I assess the safety of a flow wrapper before purchasing?
Inspect the guarding, evaluate the electrical safety system, review changeover procedures, assess cleaning access, ask for a safety demonstration, and request electrical drawings if you wish to have the machine independently reviewed by a qualified electrician.
Why is changeover safety important?
Many operator interactions with a flow wrapper occur during product changeovers. Machines that require constant adjustment, film tracking corrections, or manual intervention can increase operator exposure to moving chains, sealing jaws, forming box components, and other hazardous machine areas. Reliable and repeatable changeovers can improve both operator safety and production efficiency.
Are plastic machine guards safe?
Plastic machine guards can provide effective protection when properly designed and maintained. However, buyers should consider how well the guards will withstand accidental impacts from bins, trolleys, and daily production activities. Damaged guards can expose moving chains, sprockets, and other hazardous machine components if not repaired or replaced.
Why are sealing wheels considered a safety hazard?
Fin sealing wheels can create significant pinch points and are often located close to operator access areas. While many machines provide protection around the sealing jaws, the sealing wheels themselves may still be accessible. Buyers should ensure all moving sealing components are adequately guarded and protected by appropriate safety systems.
What are slip rings and why are they important for safety?
Slip rings transfer power and signals to rotating machine components. Although they are typically located behind machine covers, operators may be exposed to them during cleaning, maintenance, or troubleshooting. Sealed slip rings and properly designed protective covers can help reduce the risk of accidental contact with live electrical components.
What should I ask a supplier about flow wrapper safety?
Ask about machine guarding, Category 3 safety compliance, emergency stop circuits, safety relays, interlocked guards, slip ring protection, changeover procedures, cleaning access, and operator training requirements. A reputable supplier should be able to clearly explain how operators are protected during production, cleaning, maintenance, and troubleshooting.
How can I tell if a flow wrapper is genuinely safe?
A flow wrapper should have robust machine guarding, interlocked safety covers, emergency stop circuits, a Category 3 safety system, protected pinch points, adequate sealing jaw guarding, and minimal need for operator intervention during production and changeovers. Buyers should always request a safety demonstration and inspect the machine in operation before making a purchasing decision.
About the Author
Ettienne van Vuuren is the founder and director of PacMatix Pty Ltd and has more than 25 years of hands-on experience working with horizontal flow wrappers and packaging machinery.
Since establishing PacMatix in 2017, Ettienne has helped food manufacturers throughout Australia and Papua New Guinea evaluate, install, commission, optimise, and maintain flow wrapping systems ranging from entry-level machines to high-speed automated packaging lines.
His experience includes machine safety, operator training, changeover optimisation, troubleshooting, preventative maintenance, film selection, and packaging line integration.
As the Australian distributor for GSP and Tecno Pack flow wrappers, Ettienne works directly with food manufacturers to improve packaging performance, reliability, machine safety, and long-term operational efficiency.
25+ years hands-on flow wrapper experience | Founder, PacMatix Pty Ltd
Final Thoughts
A flow wrapper is a long-term investment that will be operated, cleaned, adjusted, and maintained thousands of times throughout its life.
Before making a purchasing decision, take the time to inspect the flow wrapping machine carefully, ask detailed questions, and understand how operators are protected from potential hazards.
The safest machine is not necessarily the one with the lowest price or the most impressive specification sheet.
It is the machine that has been thoughtfully designed to minimise risk while remaining practical to operate, maintain, clean, and change over.
By understanding the common hazard areas and asking the right questions, food manufacturers can make more informed purchasing decisions and create a safer workplace for their teams.
Safety should be evaluated with the same level of attention as machine performance, reliability, serviceability, and total cost of ownership.
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