Key Takeaways
The product travels through a film tube on a conveyor while the machine seals, crimps and cuts around it, so packs leave one after another without the line stopping.
A longitudinal seal closes the film along the back, then rotating crimp jaws seal both ends and set the pack length.
Uneven product spacing or inconsistent film tension shows up as weak seals, wrinkled film and incorrect cut lengths.
A flow wrap machine works by carrying the product along a conveyor into a tube of film, sealing that tube along its length, then crimping and cutting both ends to release a finished pillow pack. The whole sequence runs continuously, so one product leaves the machine sealed while the next is still being wrapped.
This guide takes the flow wrap process stage by stage, from product infeed and film forming through to sealing, cutting and discharge. It also covers the machine’s main parts, the difference between a fin seal and a lap seal, and which products suit flow wrapping. To see the machines themselves, specifications and configurations, visit the flow wrap packaging machine page.
Top-roll and bottom-roll flow wrappers with single or double cutters, with the models, configurations and rated outputs.
A flow wrap machine packages products by continuously feeding them through a series of automated stations. Each stage of the process is designed to produce consistent, professionally sealed packages at high production speeds while minimising waste and downtime.
The packaging process begins when products enter the machine using either a manual loading system or an automated infeed conveyor. Products are spaced evenly using timing belts or flighted conveyors to ensure each item reaches the sealing area at the correct position.
Accurate product spacing is essential. If products are too close together or unevenly positioned, the machine may produce poorly sealed packages or incorrect cut lengths. Modern servo-driven flow wrap machines automatically synchronise product movement with the packaging film for maximum accuracy.
A roll of flexible packaging film is mounted onto the unwind shaft at the rear of the machine. As products move through the system, the film is unwound under controlled tension.
Guide rollers and tension control systems ensure the film feeds smoothly without stretching or wrinkling. Maintaining consistent film tension helps produce straight seals and professional-looking packages.
The flat packaging film passes through a forming box (also called a forming collar), which folds the film around the product to create a continuous tube.
At this stage, the product is completely enclosed by the packaging material while remaining open along one edge for longitudinal sealing.
Once the film has been formed around the product, heated sealing wheels create a continuous seal along the length of the package. This is known as the longitudinal seal and forms the back of the finished pack.
The quality of this seal depends on the correct combination of temperature, pressure, and sealing time. Properly adjusted settings produce strong, consistent seals while preventing film damage.
Flow wrap machines typically produce either a fin seal or a lap seal, depending on the product requirements and packaging film being used.
| Feature | Fin Seal | Lap Seal |
|---|---|---|
| Film Edges | Folded together | Overlapped |
| Appearance | Raised seam | Flat, neat finish |
| Film Usage | Slightly more film | Slightly less film |
| Typical Applications | Bakery, snacks, confectionery | Premium retail products and printed packaging |
Fin seals are widely used because they are simple, reliable, and suitable for many food products. Lap seals create a flatter, cleaner appearance and are often preferred where presentation is especially important.
As the wrapped product continues through the machine, rotating crimp jaws seal both ends of each package simultaneously.
Heat and pressure create airtight end seals while also defining the final package length. These end seals give flow wrapped products their familiar pillow pack appearance.
After the end seals are completed, a rotary cutting knife separates each package from the continuous film tube.
Many flow wrap machines use photo-eye sensors to detect printed registration marks, ensuring logos, graphics, and product information are accurately positioned on every package.
Finished packages exit the machine via the discharge conveyor. Depending on the production line, products may then pass through metal detectors, checkweighers, vision inspection systems, or automatic cartoning equipment before being packed for shipping.
Every flow wrap machine consists of several key components that work together to create high-quality, consistent packaging.
| Component | Function |
|---|---|
| Infeed Conveyor | Feeds products into the machine at the correct spacing. |
| Film Unwind System | Holds and dispenses the roll of packaging film. |
| Tension Rollers | Maintain consistent film tension throughout the process. |
| Forming Box (Forming Collar) | Wraps the flat film around the product to create a tube. |
| Longitudinal Sealing Unit | Creates the continuous back seal along the package. |
| End Crimp Sealing Jaws | Seal both ends of each package. |
| Rotary Cutting Knife | Separates individual packages. |
| Discharge Conveyor | Transfers finished packages to the next production stage. |
| PLC & HMI Control System | Allows operators to monitor and adjust machine settings. |
Each component plays an important role in maintaining packaging quality, production speed, and machine reliability. Routine maintenance and regular inspections help ensure consistent performance and minimise downtime.
Flow wrap machines are purpose-built machines that can use punnets and trays for the flow wrapping of goods in many industries. Products like fresh produce, pastries, bakery goods, confectionery, consumer goods like scratch cards, stationery, and magazines, and household goods like napkins and disposable cutlery can be flow-wrapped to protect against damage. Additional gas flushing can replace oxygen with nitrogen inside the packaging to preserve goods’ shelf life.
A flow wrapping machine, also known as a horizontal flow wrapper, is a packaging machine designed to wrap products in a continuous flow of material. This type of machine is widely used in various industries, including food, pharmaceuticals, and consumer goods, to package items quickly and efficiently. Here’s how it works and its main components:
A flow wrap machine works in one continuous pass: infeed, film forming, longitudinal seal, end crimp, cut, discharge. Seal quality comes down to the combination of temperature, pressure and dwell, and pack accuracy comes down to product spacing and film tension.
To choose a machine for your own product, start with the flow wrap packaging machine page, which lists the models, configurations and rated outputs, or request a quote and send us your product and pack size.
These machines are compatible with several film types, such as PET (Polyethylene Terephthalate), PE (Polyethylene), and BOPP (Biaxially Oriented Polypropylene). The choice depends on the product requirements, shelf life needs, and branding considerations.
Yes — flow wrap machines are highly adaptable. They can be custom configured to handle various product sizes and shapes, and can also be integrated with conveyors, trays or punnets for specialised applications.
Gas flushing replaces oxygen inside the package with nitrogen. This slows oxidation and helps products stay fresh longer — especially useful for perishable items like baked goods and fresh produce.
Send us your product, its dimensions and the pack you want, and we will tell you which flow wrap configuration suits it and what the machine would be specified to do.
