VFFS Bag Types: Matching Bag Format to Product, Line and Industry

Bag format is often the last thing settled on a packaging project and the first thing a customer sees. It is also the decision that sets the terms for everything else: the film specification, the tooling on the machine, the cycle time, how many packs fit on a pallet and how the product presents on a shelf. Treating it as a marketing choice made late in the process is how manufacturers end up with a format their line cannot run economically.

For New Zealand food and consumer goods manufacturers the pressure runs in two directions at once. Export packs have to survive sea freight and satisfy a retailer in another market, while the line making them typically runs several SKUs across a working week. VH Vertical Packaging builds vertical form fill seal machines that form all their bag formats from a single roll of film, which means the format range is genuinely a specification decision rather than a machine purchase decision — but only if the format is chosen with the line in mind.

What changes when the bag format changes

A vertical form fill seal machine forms a tube of film around a forming shoulder, seals it, doses product into it and seals it again. Every bag format is a variation on that sequence, and each variation asks something different of the machine:

• Forming set — the shoulder and forming tube are matched to bag width and format; a gusseted or corner-sealed bag needs additional forming devices
• Sealing arrangement — the number and position of seals changes the jaw configuration and the time spent sealing per cycle
• Film width and tension — a format with a formed base or folded corners consumes more film per unit of product than a plain pillow bag
• Speed — formats with more forming steps generally cycle more slowly than the simplest format the machine can run
• Changeover — moving between formats is a tooling and setup exercise, so the number of formats a line runs is an operational cost as much as a capability

Product behaviour then narrows the field again. Free-flowing powders fill quickly but aerate and need a settled headspace before the top seal is made. Fragile snacks need a longer drop and gentler handling. Sticky or oily products contaminate the seal area, and a seal contaminated with product is the most common cause of leakers. These are format questions as much as filler questions, because some formats give more seal area to protect than others.

The formats VH machines produce, at a glance

The VFFS bag types below are all formed from a roll of film on the same class of machine. What separates them is the forming hardware they need, the number of seals they carry and the film each one consumes.

Format	What it is	Typically used for
Pillow bag	The base format: a back seal with top and bottom cross seals. Widths 57–440 mm, lengths 40–950 mm, volumes to around 60 litres	Frozen vegetables and fries, fresh produce, bulk and foodservice packs, powders
Gusseted bag	A pillow bag with folded sides. Widths 30–380 mm, lengths 60–900 mm, gussets 10–140 mm	Pet food, coffee, cereals and grains, larger retail volumes
Flat bottom bag	A formed square base so the bag stands unaided. Widths 30–380 mm, lengths 60–800 mm, base 30–85 mm	Coffee, rice, pet food and dry bulk products to around 60 litres
Quad seal	Four sealed corners producing flat front and side panels. Widths 44–380 mm, lengths 60–800 mm, depths 42–140 mm	Premium coffee, pet food, powders and snacks
Corner creased bag	Creased corners with a folded base for a squared-off retail pack	Coffee, snacks, cereals and powders where shelf presentation matters
Brick bag	A compact block-shaped stand-up bag. Roughly 44–230 mm wide, 60–230 mm high, 42–102 mm deep	Flour, sugar, pasta, nuts, cereals and other dense dry goods
Flex can	A resealable quad seal bag in a cylindrical form	Snacks and portions eaten directly from the pack
Stand-up pouch (doypack)	A shaped base that opens flat on the shelf. Widths 80–380 mm, heights 120–380 mm, depths 40–100 mm	Coffee and tea, nuts, dried fruit, baby food, pet food, confectionery
Easy Doy	A stand-up pouch with a resealable flap or tape strip applied in-line	Resealable retail lines across food and non-food
3-side sealed bag	A flat bag sealed on three edges with a large print area	Single portions, sample packs, small powder packs and sachet-scale formats
Expander	A small expanding format. Widths 60–140 mm, lengths 60–330 mm, depths 40–100 mm	Small retail packs where fill volume is needed in a narrow face width
Dispense pouch	A small pouch offered with an easy-open feature. Widths 20–360 mm, lengths 40–250 mm	Single-dose and dispensed portions, samples and small non-food packs

Dimensional ranges are VH’s published figures for its machine range and should be confirmed against the specific model and product.

The bag workhorses: pillow, gusseted and flat bottom

Most vertical packing lines in New Zealand run one of three formats, and the progression between them is a useful way to think about the trade-off.

The pillow bag is the simplest and cheapest to run. It uses the least film for a given fill weight, has the fewest forming steps and generally runs fastest, which is why it dominates frozen vegetables, fresh produce and foodservice packs where the bag is a container rather than a display surface.

The gusseted bag adds folded sides. The practical gain is fill capacity for a given face width, and denser packing into cartons and onto pallets — worth calculating, because freight economics on export lines are often decided by cube rather than weight. Pet food and coffee sit here for exactly that reason.

The flat bottom bag adds a formed base. That changes the pack’s behaviour rather than just its capacity: it stands square without support, stacks, and gives a printable base panel. It is the usual answer when a dry bulk product needs shelf presence without moving to a premium format.

Premium formats, and what they cost to run

Quad seal, corner creased and brick bags all do the same basic job — they square the pack up so it stands, stacks and prints well. The mechanism differs: a quad seal stiffens the pack with four sealed corners and produces large flat front and side panels; a corner creased bag achieves a similar squared look through creased corners and a folded base; a brick bag is a compact block form suited to dense products such as flour, sugar and pasta where the pack is small and heavy.

The flex can is a different proposition again — a resealable quad seal bag in a cylindrical form, aimed at products consumed straight from the pack rather than decanted. It competes with rigid canisters rather than with other bags, which is where its case is usually made.

These different formats are not free. Each consumes more film per unit of product than a pillow bag, adds forming hardware, and usually costs some line speed. The comparison worth running before committing is total delivered pack cost, film, machine time, cartons and pallet efficiency, rather than the price of the film alone.

Stand-up pouches without a pre-made pouch line

Stand-up pouches have conventionally been bought pre-made and filled on a horizontal machine, which means holding printed pouch inventory for every SKU and every size. Forming the pouch on a vertical machine from roll stock changes that: one printed film roll replaces a set of pouch stock lines, and short runs stop being penalised by minimum order quantities.

VH’s Easy Doy format applies a resealable flap or tape strip in-line and, allows up to 16 pack variants on one machine with changeovers of 5 to 45 minutes and speeds to 100 bags per minute. For a producer running many SKUs at moderate volumes each, which describes a large share of New Zealand food manufacturing, that flexibility usually matters more than peak speed.

Matching format to product and industry

Format selection follows the product and its route to market more than it follows the sector, but some patterns hold in New Zealand:

• Dairy and nutritional powders — pillow and gusseted bags for bulk and ingredient packs; flat bottom, quad seal or stand-up formats for retail nutritional products, with dust control at the seal the recurring issue
• Snacks and confectionery — pillow bags for standard retail and Easy Doy where resealability drives repeat purchase, 3-side sealed bags for single portions and sampling
• Pet food — gusseted and flat bottom bags at larger volumes, quad seal where the brand sits at the premium end; carry handles and easy-open features are common additions
• Frozen vegetables, fries and produce — pillow bags dominate, with sealing through frozen product and film dust the practical constraints; 3-side sealed formats for portion packs
• Coffee and tea — gusseted, quad seal, corner creased and stand-up formats, all typically with a degassing valve and a resealable closure
• Meat, seafood and cheese — pillow and 3-side sealed formats, where seal integrity through product residue is the governing requirement
• Horticulture, seed and animal health — pillow and gusseted bags for non-food and semi-bulk duties, where durability outranks presentation

Where the format decision meets the film

Mono-material recyclable films (single-polymer laminates that can be recycled in one stream) are steadily replacing multi-layer structures, and they seal within a narrower temperature and dwell window than the films most lines were commissioned on. That interacts directly with format choice: the more seals a format has, and the more corners it folds, the less forgiving it is of a film with a narrow sealing window. A quad seal or flat bottom format that runs cleanly on a conventional laminate may need seal parameters revisited on a mono-material equivalent.

This matters for anyone exporting into markets tightening their packaging rules, including the EU. The practical step is to trial the actual film on the actual format before committing to artwork and tooling, rather than qualifying the film and the format separately.

Specifying a format with local support

Advanced Packaging Systems supplies the VH Centurion SI and SC vertical form fill seal range in New Zealand, in bag widths from 50 mm to 440 mm, in stainless steel construction with an IP 65 operator display and remote diagnostic access.

Three things are worth settling before a format is locked in: run the product and the intended film on the format rather than assuming compatibility; check the changeover time between every format the line will actually run, not just the primary one; and confirm the downstream equipment, checkweighing, cartoning, case packing and palletising,  handles the pack shape you have chosen. A format that runs beautifully on the bagger and then jams a case packer is a common and expensive discovery.

Frequently asked questions

What bag formats can a VFFS machine make?

A vertical form fill seal machine forms bags from a roll of film, and the format is determined by the forming set and sealing arrangement fitted. VH’s range covers pillow, gusseted, flat bottom, quad seal, corner creased, brick, flex can, stand-up pouch, Easy Doy and 3-side sealed formats, along with the Expander and dispense pouch, with bag widths from 50 mm to 440 mm.

What is the difference between a quad seal bag and a flat bottom bag?

A quad seal bag is squared by four sealed corners, which stiffen the pack and create flat front and side panels for print. A flat bottom bag is squared by a formed base, so it stands unaided and stacks. Both give a premium squared appearance; the quad seal emphasises panel area and rigidity, the flat bottom emphasises stability and stacking.

Can a vertical machine make a stand-up pouch?

Yes. Stand-up pouches are conventionally bought pre-made and filled horizontally, but a vertical machine can form the pouch from roll stock, including resealable variants such as Easy Doy. The trade-off is that some heavily shaped or spouted pouch designs remain the preserve of pre-made pouch lines.

Does changing bag format mean buying another machine?

Usually not. Moving between formats is normally a matter of format parts and setup on a machine specified for the range from the outset. The cost is changeover time rather than capital, which is why the set of formats a line will run should be agreed before the machine is specified rather than after.