How packaging film is made: 8 stages from the Podanin plant

Six minutes and eight stages: from pellets blown from a tanker into a silo, through a bubble inflated with compressed air, to a bag that has been sealed and tested in the lab. The crew of the Polish programme Fabryki w Polsce brought a camera onto our floor in Podanin and filmed the process without editing shortcuts. Below we break the film into stages: each one links to the exact minute and to the page where we describe that part of the process in more depth.

The Podanin plant: where this footage comes from (from 0:00)

The film was shot by the Fabryki w Polsce team at our plant in Podanin near Chodzież, Poland. It shows one hall and one pass through the process, so you will not see every line or every NEX product family. If you are looking for a specific technology, the products page is the faster route. The voice-over is in Polish; the chapters below carry the substance in English.

Watch the intro (0:00) or read who we are.

Raw material: from tanker to silo, by pipeline to the line (from 1:03)

We extrude film from polyethylene pellets of different densities, topped up with recycled material. Resin arrives in bags or in tankers; from a tanker it goes into a silo and from there by pipeline straight to the production line, with no manual transfer. The whole feeding path is computer controlled, so the recipe on the line matches the recipe in the system rather than an operator's memory.

Watch the raw material stage (1:03). The share of recycled content in a given film is agreed under the Closed Loop Programme.

Blown film extrusion: five layers from one die (from 1:39)

Molten polymer from the extruders reaches the die, and compressed air inflates it into a vertical bubble. The line in the film is fully automated and runs continuously. The film can have up to five layers, which lets us split functions between layers: one handles sealing, another the barrier, a third puncture resistance. That is how gauge can come down without losing the properties that matter on the packing line.

Watch blown film extrusion (1:39). What 3 and 5 layers deliver in numbers is covered in our article Multilayer extrusion.

Flexo printing: up to 10 colours in Full HD quality (from 2:36)

Simple print runs directly on the extrusion line. A more demanding design goes to the print shop, where the flexographic presses offer up to 10 colours in Full HD quality. Before the full run starts, a proof batch is measured with a spectrophotometer; only then does the press accelerate to 400 metres per minute.

Watch the flexo print shop (2:36). The scope of the service is on the NEX PRINT page, and the artwork requirements in the guide Preparing files for flexo printing.

Slitting and converting: from roll to bag (from 3:23)

The finished web goes to slitter rewinders, which cut it into rolls of the ordered width. Next come the bag-making machines: the operator loads a roll, enters the order specification, and the machine seals and cuts. A separate machine in this department stacks cut bags into bundles ready to feed the customer's line. This is also where products for high-hygiene sectors, food and chemicals, are made.

Watch bag converting (3:23). The bag and half-tube family: NEX-BAG.

Vented bags and bags with handles (from 4:12)

Some bags have features you only notice on the packing line or on the shelf. A vented bag lets air escape and closes the product in an airtight, flat pack, which translates into more units per pallet; it works well for seasonal clothing. A bag with a handle moves the load onto a reinforced section of film and is the standard wherever the end customer carries the pack by hand: tissue paper, fruit, vegetables.

Watch the special bags (4:12).

Recycling: production scrap goes back to the line (from 4:54)

Post-production film goes into a grinder that cuts it into flakes and remelts it into resin fit for extruding again. The loop closes inside the plant, before we even start the conversation about post-consumer material. It is the same mechanism that lets us discuss PCR content in a specific specification with a customer, rather than a company-level declaration.

Watch the recycling grinder (4:54). Collecting film from customers and closing the loop: POD ECO and the Closed Loop Programme.

Laboratory: five tests before a batch leaves (from 5:07)

Quality control runs alongside production, and the laboratory signs off each batch. We test the coefficient of friction, tensile strength, puncture resistance, seal quality and transparency. At the scale the plant runs, every batch needs its own numbers, because without them a complaint discussion ends as one word against another. Finished products ship to customers across Europe.

Watch the laboratory (5:07). Quality management systems and certificates: Certificates.

Transcript of the voice-over (translated)

Abridged English translation of the Polish narration from the Fabryki w Polsce footage, without the channel's promotional segments.

Films are a universal packaging material used in dozens of industries: from food, through household appliances, to construction and electrical engineering. To see how such films are made, we visit the Polish company Kablonex in Podanin near Chodzież. It is a family business with an advanced machine park, unique production methods and modern recycling solutions.

Film is made from polyethylene pellets of various densities. Recycled material is also used in production. The raw material can be delivered in bags or tankers. In the latter case it is stored in a silo, from which it is automatically transported by pipeline to the production line. The whole process is computer controlled. Kablonex aims to produce the lightest possible film, because the environmental side of plastic packaging matters a great deal to the company.

To turn pellets into film, blown extrusion technology is used. The automated line built for this purpose is one of the most modern in Europe. Molten polymer is fed from the extruders to the die, and compressed air inflates it into its characteristic shape. The film produced here can have up to five layers.

Film packaging should be smooth, allow repeated opening and closing, carry the required information and look attractive. That is why print can be applied directly on the line. If the design is more demanding, the material goes to a professional print shop. The flexographic presses offer a palette of up to 10 colours in Full HD quality. After the inks are prepared and the presses set up, the artwork file is loaded into the computer. Once a proof batch has been checked with a spectrophotometer, the actual print run starts at speeds of up to 400 metres per minute. Thanks to modern machinery, a large share of material is recovered for recycling, and water-based inks do not release harmful substances into the environment.

The film, wound into rolls, is then placed on slitter rewinders that cut it to the required dimensions. For the film to take the shape of a bag, the bag-making machines step in. A roll is loaded into the machine and the order specification is prepared, after which the machine makes the seal with special knives. The second machine in this department specialises in cut bags sorted into bundles. Products meeting the requirements of strict hygiene regimes, the food and chemical industries, are made here.

The hall also runs machines for special bags. One produces vented bags, which let the air out and create an airtight package that takes up little space, for example for seasonal clothing. Another makes bags with carrying handles, whose convenience we appreciate when buying toilet paper, fruit or vegetables.

Finally we see the recycling grinder, which processes post-production film by cutting it into pieces and heating it to obtain new, ready-to-use raw material. Quality control is carried out at every stage of production and after it is complete. The laboratory tests the coefficient of friction, tensile and puncture strength, seal quality and product transparency. This matters in a plant that processes large volumes of raw material daily and supplies products to customers across Europe.

Frequently asked questions about film production

How many layers can blown film have?

On our lines, up to five. Each layer can serve a different function: sealability, barrier, mechanical strength. With three and five layers it is usually possible to reduce basis weight while keeping the same performance, as described in our article on multilayer extrusion.

Is the print applied on the same line as the film?

Simple print is applied directly on the extrusion line. Multi-colour designs go to the flexographic presses, with up to 10 colours in Full HD quality. One supplier is then responsible for both the film and the print, so a complaint does not bounce between a film producer and a printer.

What happens to production scrap?

Post-production film goes to a grinder, where it is shredded and remelted into pellets fit for extruding again. Collecting post-use film from customers and closing the loop is handled separately, under POD ECO and the Closed Loop Programme.

What tests does the film pass before shipping?

In the laboratory we test the coefficient of friction, tensile strength, puncture resistance, seal quality and transparency. Results are assigned to a specific batch, so every delivery has its own set of numbers.

Can I see production in person?

Yes, we host customer audits and technical visits at the Podanin plant. Dates are arranged through the contact form or directly with your account manager.