Flow Wrappers vs Vertical Form-Fill-Seal Machines: What to Choose

Choosing your primary packaging format shapes everything that follows. It sets your film spend, your line layout, your labour requirement and how quickly you can switch between products. Get it right, and packing keeps pace with production. Get it wrong and a new machine becomes the slowest point on the line.

For most UK food manufacturers the decision comes down to two families of equipment: horizontal flow wrappers and vertical form-fill-seal machines. Both wrap the product in film. Both seal, cut and deliver a finished pack. They suit completely different products, though, and the reason sits in how each one handles the item before it ever meets the film.

This guide explains how each format works, which products suit which machine, and what to check before you commit a budget to new or used equipment.

A flow wrapping machine, also called a horizontal form fill seal machine, runs product lying down. An infeed conveyor carries each item forward at a controlled pitch and pushes it into a forming box, sometimes called a forming shoulder. Film unwinds from a reel above or below the line and wraps around the product as it travels through that box.

Three seals complete the pack. The film edges meet underneath the product and pass through crimp wheels or a heated bar, creating a longitudinal seal along the pack. That seal is either a fin seal, where the two inner faces of the film join and stand up as a small fin, or a lap seal, where one edge overlaps the other and lies flat. Rotating end jaws then crimp and cut across the film between items, forming the two end seals.

The result is the familiar pillow pack you see around biscuits, cereal bars, bread rolls, cucumbers and hardware components. The product controls the pack size, because the film simply follows the shape of whatever passes through the former.

Why product shape matters so much

A flow wrapping machine needs an item that holds its shape and arrives in a predictable position. Anything that slumps, rolls unpredictably or sticks to its neighbour causes trouble at the infeed. The machine cannot correct a badly presented product, so the wrapper is only ever as reliable as the feeding system in front of it.

A vertical form fill seal machine turns the same principle on its end. Film unwinds from a reel, travels up the machine and passes over a forming collar that shapes it into a tube around a vertical filling pipe. A vertical sealing bar closes the back seam of that tube. Horizontal jaws below then seal the bottom.

At that point the bag sits empty and open at the top. A weigher, auger or volumetric filler mounted above drops the measured portion down the filling pipe. The jaws close again, sealing the top of the filled bag and simultaneously forming the bottom of the next one, then a knife separates the finished pack.

VFFS suits anything that flows and is sold by weight or volume rather than by count. Crisps, frozen vegetables, nuts, pasta, powders, granules, pet food and salad leaves all fill this way. Gravity does the work, so the product never needs to be handled individually.

Pack styles a VFFS can produce

A vertical machine offers more pack variety than most buyers expect. Pillow bags are the default, but gusseted bags, block-bottom bags, quad-seal bags, doypacks and sachets all come from the same platform with different forming tooling. Adding a zipper applicator or a euro slot punch is straightforward on many models.

Treat those figures as a guide. Age, control system, condition and included format parts move real prices considerably in both directions.

What Each Format Needs Around It

The machine itself is rarely the whole cost. Flow wrapping machines and vertical baggers both depend on the equipment feeding them.

Feeding a flow wrapper

The product has to reach the forming box in a single file, correctly spaced and correctly orientated. Simple lines use a hand-feeding conveyor where operators place items onto lugs. Higher speeds need an automatic feeder, a lane divider or a robotic pick and place cell that uses vision to find product on a distribution belt. Budget for that feeding system early, because it often costs as much as the wrapper.

Feeding a VFFS

Everything sits above the bagger. A multihead weigher gives the best accuracy and speed for mixed shapes such as crisps or frozen produce. Auger fillers handle powders. Volumetric cups suit granular products where cost matters more than precision. All of them need a support platform, an elevating conveyor and enough ceiling height for the whole stack. Measure your building before you order.

Film, seals and shelf life

Both formats run heat-sealable laminates, and film choice drives seal quality more than machine brand does. Check that your film has a sealant layer compatible with your jaw temperatures and dwell time. Both formats support modified atmosphere packing, with a gas lance flushing the pack before the final seal, though vertical machines usually reach lower residual oxygen because the bag is a closed tube during flushing.

Date coding integrates on either platform. Thermal transfer overprinters mount into the film path and print onto the web before sealing, which gives a cleaner result than coding a finished pack.

Used packaging equipment offers strong value, and a well-maintained ten-year-old flow wrapping machine often outperforms a cheap new import. Inspect these points before you buy:

1. Seal jaw condition and temperature control, checking for pitting, worn knurling, uneven heating and cartridge heaters that have been repaired rather than replaced.

2. Film tracking and tension control, watching a full reel run to see whether the web wanders, creases or stretches at speed.

3. Servo drive versus mechanical cam design, since servo machines store recipes and change pack size from the screen, while cam-driven machines need physical adjustment and specialist setters.

4. Control system age and support, confirming the PLC and HMI are still supported and that replacement screens remain available.

5. Guarding, interlocks and emergency stops, verifying that nothing has been bypassed and that all fixed guards are present.

6. CE or UKCA marking with a declaration of conformity and the original manual.

7. Format parts for your pack sizes, because missing forming boxes, tubes, collars and jaws are the most common and most expensive surprise after delivery.

Ask the seller to run the machine on your film with your product if possible. Nothing on a specification sheet tells you as much as watching seals form.

Ask one question: can a robot or a conveyor pick up your product and place it down in one piece?

If the answer is yes, and you sell that product by count, choose a flow wrapping machine. Biscuits, bars, rolls, trays, produce and hardware all belong on a horizontal form fill seal wrapper, because the film follows the item and the pack looks tight around it.

If the answer is no, and your product pours, tumbles or is sold by weight, choose a vertical form fill seal machine. Crisps, powders, frozen vegetables, nuts and pet food need a weigher above a bagger, not a conveyor and a former.

Where a product could go either way, such as grated cheese or a bag of small bakery items, decide on shelf presentation and shelf life. Then check headroom, because that single building constraint settles more of these decisions than any other factor.

Find Packaging Machinery on Machinery Masters

Machinery Masters is a UK B2B marketplace for new and used industrial equipment, connecting buyers with verified sellers across the food and manufacturing sectors. Buyers pay no commission, and financing is available to qualified applicants. Browse the packaging equipment category to compare flow wrappers, vertical baggers, weighers and ancillary kits in one place. If you have surplus machinery standing idle, list it and reach buyers actively searching for it.

Frequently Asked Questions

What is the difference between a flow wrapper and a VFFS machine?

A flow wrapper runs the product horizontally into a forming box, wrapping film around the item to make a pillow pack with one long seal and two end seals. A vertical form fill seal machine forms a tube downwards, seals the bottom, drops product in from above, then seals the top.

Which products suit a flow wrapping machine?

Discrete solid items that hold their shape suit horizontal flow wrapping machines best. Typical examples include biscuits, cereal bars, chocolate bars, bread rolls, trays of meat, cucumbers, single-portion cakes and hardware components. The product needs to arrive in single file at a consistent pitch for reliable sealing.

How fast does a flow wrapper run?

Speed varies with product, film and specification. An entry-level flow-wrapping machine typically manages around 40 to 100 packs per minute, while high-specification servo-driven models reach several hundred. Infeed presentation limits real output more often than the wrapper itself does.

Do I need a weigher with a VFFS machine?

Almost always. A vertical bagger forms and seals the pack but does not measure the product. A multihead weigher, auger filler or volumetric cup mounted above supplies the measured portion. Include the weigher, the support platform and the elevating conveyor in your budget from the beginning.

Can both machine types do modified atmosphere packing?

Yes. Both formats accept a gas lance that flushes the pack before final sealing. Vertical machines often reach lower residual oxygen because the film tube encloses product tightly during flushing. Confirm your seal integrity and residual gas levels through testing before committing to a shelf life claim.

What should I check on a used flow wrapping machine?

Inspect seal jaws for wear and even heating, watch film tracking at full speed, confirm whether drives are servo or mechanical cam, check PLC and HMI support, verify guards and interlocks, and confirm CE or UKCA marking. Above all, confirm the format parts for your pack sizes are included.