Why This Guide?
The vertical form-fill-seal (VFFS) machine is the most widely manufactured packaging machine in the world. It packages salt and seeds, coffee and chips, screws and fertilizer. This guide summarizes what operators need to know before investing and before starting operations: design, dosing methods, a five-step selection process, film specifications, cost factors, and common beginner mistakes. The article covers the basics of how the machine works What is a vertical form-fill-seal (VFFS) machine? – It's all about depth.
The Structure: Seven Functional Groups
One Vertical filling and capping machine consists of seven groups, each of which is configured individually:
- Film Unwinding: One or two roll holders with a correction drive for the film center; for simple films, a "Tänzler" control loop is sufficient.
- Mold shoulder: The heart of the machine. It rolls the flat film into a tube. Each bag width requires its own forming shoulder—the most important component of the machine.
- Longitudinal Sealing Unit: It seals the follow-up tube lengthwise, either thermally using conveyor-fed sealing tapes or by impulse sealing. Conveyor-fed tapes protect the seam and enable higher cycle rates.
- Sealing Jaws: They cross the tube and create two seams in a single cycle—the cross seam of the finished bag and the bottom seam of the next one.
- Filling chute and dosing system: The dosing system is located above or inside the filling hopper: multihead weighers for bulk materials, screw feeders for powders, and piston feeders for liquids and pastes.
- Cutting knife: It separates the finished bag from the tube—either with a blade or a tear-off edge; for delicate seams, it transfers the bag to the conveyor belt using a suction cup.
- Controls: HMI with recipe management. As is standard in the industry, controllers store 50 to 100 recipes—sealing temperature, film length, and target weight—which can be retrieved as a block.
The Right Dosing Method for Each Product
The dosage determines accuracy and cycle rate—not the bagging machine itself:
| Product Type | Dosing System | Typical Accuracy | Frequency range |
|---|---|---|---|
| Granules, coffee beans, snacks | Multi-head scale | ±0.5 to ±1 g | 30 to 80 beats per minute. |
| Powders (flour, powdered milk, spices) | Volumetric Screw Feeder | ±0.5 to ±1 % | 30 to 60 bags per minute. |
| Powder with a variable bulk density | gravimetric net dosing | ±0.3 to ±0.5 % | 20 to 50 bags per minute. |
| Liquids and Pastes | Piston or Pipe Conveying System | ±0.5 to ±1 % | 20 to 40 bags per minute. |
| Loose goods (cookies, bars) | Feeding line with product detection | per item | 40 to 100 packages per minute. |
Details for each product category are covered in separate articles: Granules, Powder with a screw feeder and Coffee Beans with Flavor Protection.
Selection in Five Steps
Step 1: Product Analysis
It all starts with the product: particle size, bulk density, flow characteristics, moisture content, fat content, and susceptibility to breakage. These six parameters determine the dosing system, the hopper cross-section, and the material requirements—SS304 stainless steel for product contact, and SS316 for corrosive products.
Step 2: Select a formatting program
Bag widths and lengths define the format part set. Using a few widths with multiple lengths saves on format parts and changeover time—consolidating five formats into two widths cuts the number of format parts needed in half compared to five individual formats.
Step 3: Clear the film
The film is part of the machine’s logic: composite films with an inner PE layer seal at 120 to 180 °C; thicker laminates require more sealing time and reduce the cycle rate. If you wait until after the machine is installed to select the film, you risk having a line that can’t keep up with its target speed.
Step 4: Set a realistic performance target
80 cycles per minute apply to free-flowing material, medium-sized formats, and a well-broken film. When accounting for product changes, film warping, and fluctuations in bulk density, experienced operators plan for a continuous power output of 70 to 80 % of the rated power.
Step 5: Environment and Expansion
Conveyor systems upstream of the machine, recommendations for a weighing control system or metal detector downstream of the machine, inquiries about retrofit options—the answers to these questions will determine whether the line can grow along with the business.
Film Science: Sealing Is Chemistry
The seal is formed when the PE inner layer of the film melts and bonds under pressure. Three parameters control this: temperature, time, and pressure—they’re specified in every recipe. Typical defects include: a seam that’s too hot becomes brittle, a seam that’s too cold opens under load, and particles in the seam (dust, grease, product debris) weaken any seam. For dusty products, a filling chute extraction system should therefore be included on the list of options; for greasy products, temperature-controlled clamps with ±5 °C accuracy are required.
Two types of film dominate the industry: single-material structures for recyclable packaging and traditional laminates with aluminum or EVOH as a barrier. The barrier determines shelf life: coffee and snacks require protection from oxygen, while hygroscopic products require protection from moisture; both of these requirements are reflected in the choice of film and the price per bag.
Operations: Format changeovers, cleaning, replacement parts
The Format Change On a VFFS machine, this typically takes 20 to 45 minutes—the forming shoulders, sealing jaws, and filling chute are replaced. Tool-less quick-release fasteners cut this time in half and should be a mandatory item on the procurement list when frequent changes are required.
Cleaning: Food processing facilities should schedule daily cleaning of the product path; CIP-compatible designs reduce the time required to just a few minutes. Wear parts relevant to planning: sealing belts, blades, seals on the jaws, and the wear elements of the dosing system—the availability of these parts determines the system’s uptime in the second and third years of operation.
Cost Factors: What Determines the Price of a Line
The price of a VFFS line is determined by five factors: performance class (cycle rate and dosing system), degree of automation (recipe management, film web correction, roll change station), hygienic design (stainless steel, CIP, GMP-compliant design), component level (control system, drives, measurement technology), and scope of integration (conveyor technology, weighing control, gas flushing). To ensure a reliable cost estimate, the inquiry must include specific details—product data sheet, format list, film samples, and target capacity.
Five Mistakes People Make When Shopping
- Buy based on rated power; plan based on continuous power: The 80 beats per minute listed in the data sheet are peak values—the sustained performance is lower than that.
- Consider the dosing system and the machine separately: The scale and bagging machine must be synchronized; a scale that is too large for a small format compromises accuracy.
- Postpone the question regarding the slides: The foil is not a neutral part; it determines the sealing parameters and cycle rate.
- Accepting a variety of formats without verification: Every format requires format parts and changeover time—consolidating formats before making a purchase saves more than any discount negotiation.
- Do not contact Service or Parts: Questions regarding spare parts inventory, response times, and remote maintenance should be addressed during the proposal phase.
VFFS or pre-made bags?
The alternative to the tubular bag machine is the Bag-filling machine for pre-made bags: A more sophisticated appearance, stand-up pouches, and zip closures from the pouch rack, but 30 to 60 pouches per minute instead of up to 80 cycles, and higher pouch costs. The detailed comparison can be found in the article VFFS or pre-made bags.
Frequently Asked Questions
How much does a VFFS machine cost?
The price depends on the performance class, dosing system, hygiene design, component level, and scope of integration. A reliable estimate requires the product data sheet, format list, and target performance—please request both the data sheet and a quote.
How long does the format change take?
20 to 45 minutes with trained staff; significantly less time with tool-free quick-change format parts. The article on format changes describes the complete system.
What cycle count is realistic for my product?
For free-flowing granules, 60 to 80 cycles per minute; for powders, 30 to 60 bags per minute; for bulk goods, depending on the product. Plan for 70 to 80 % of the rated power as continuous power.
Can a VFFS machine handle multiple bag sizes?
Yes—every format requires its own format set. The changeover time between formats ranges from 20 to 45 minutes; recipe changes without a format change can be completed in a matter of minutes.
Related pages: What is a vertical form-fill-seal (VFFS) machine? | VFFS or pre-made bags | Format Change on Packaging Machines | Vertical Filling and Sealing Machine
Request technical specifications and a quote for your production line. Please specify the product, bag size, and target output (bags/min.) – Request Technical Specifications and a Quote.
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