Understanding Filling Machine Technologies
Filling machines are the central and most critical component of any bottling or canning operation. The choice of filling technology directly impacts product quality, production speed, operational efficiency, and total cost of ownership. Understanding the different filling principles is essential for making informed purchasing decisions in the used equipment market.
Filling machines can be categorised by several criteria: filling principle (gravity, pressure, vacuum, volumetric, mass flow), product type (still, carbonated, viscous, foaming), container type (glass, PET, can, pouch), and speed range (linear machines for low speed, rotary for medium to high speed).
The global used filling machine market is one of the most active segments in secondary processing equipment. Fillers become available when producers upgrade capacity, change product types, optimise line speeds, or consolidate operations. Quality used fillers from established manufacturers can deliver 15-25+ years of reliable service, making them outstanding investments.
Gravity and Low-Pressure Filling
Gravity filling is the simplest and most economical filling technology. Product flows from an elevated tank into the container by gravity alone. Used for non-carbonated, non-viscous products such as still water, wine, and thin liquid foods.
Advantages: Simple construction, easy maintenance, low operating costs, minimal product stress. Limitations: Slower than pressure-based systems, not suitable for carbonated or viscous products.
Slight pressure/Light depression filling: A variation where gentle air pressure assists filling from above, or slight vacuum from below accelerates fill speed. Bridges the gap between pure gravity and full isobaric systems.
Key manufacturers: GAI, MBF, CFT, Bertolaso, and budget-oriented Asian manufacturers. Premium gravity fillers from European manufacturers like Bertolaso and GAI are excellent used market acquisitions for wine and artisanal producers.
Evaluation priorities: Tank/bowl condition (welds, surface finish), valve gasket wear, level control system accuracy, and frame/carousel bearing condition.
Isobaric (Counter-Pressure) Filling
Isobaric filling is the standard technology for all carbonated beverages (beer, CSD, sparkling water, sparkling wine). The process involves: pressurising the container with CO2 to match the filling pressure, opening the liquid valve to allow product to flow under equal pressure, and finally releasing residual gas (snifting) before capping.
This technology prevents CO2 breakout and foaming during filling, maintaining product carbonation levels and ensuring clean, accurate fills.
Mechanical vs Electronic: Older isobaric fillers use mechanical (pneumatic) valve control with spring-loaded filling elements. Modern electronic fillers use individually controlled servo valves with electronic flowmeters for precise volumetric filling. Both types are widely available in the used market.
Key manufacturers and models:
- Krones: Modulfill, Volumetic VP
- KHS: Innofill Glass DRS, Innofill PET DRV, Innofill Can DVD
- Sidel: Various isobaric platforms
- GEA (Huppmann): For beer filling
- Bertolaso: Traditional beer and CSD fillers
Speed ranges: From 5,000 BPH (small rotary) to 80,000+ BPH (large rotary with 120+ filling valves). Linear isobaric fillers are available for very small operations (1,000-3,000 BPH).
Critical evaluation points: CO2 consumption rate, filling valve gasket condition, flowmeter calibration (electronic fillers), CIP circuit integrity, rotary union condition, and PLC/control system version.
Volumetric and Mass-Flow Filling
Electronic volumetric filling uses electromagnetic flowmeters to measure exact product volume dispensed into each container. This technology provides exceptional accuracy (±0.5% or better) and flexibility for multiple container sizes without mechanical adjustments.
Mass-flow filling uses Coriolis flowmeters to measure product mass rather than volume. High accuracy for products with varying densities or temperatures. Commonly used for high-value products.
Weight-based filling: Uses load cells under each filling station to fill by net weight. Excellent for viscous products, sauces, and high-value liquids where accuracy directly impacts profitability.
Piston filling: Positive displacement technology for viscous products (sauces, creams, pastes). Each stroke delivers a precise volume. Available from manufacturers like Serac, Bosch (now Syntegon), and Tetra Pak.
Time-pressure filling: Simplest electronic technology — fills for a set time at constant pressure. Adequate for non-critical applications but less accurate than volumetric methods.
Hot-fill systems: Specialised fillers operating at 85-95°C for products requiring thermal pasteurisation during filling. Require temperature-resistant valve materials and careful thermal management. Krones, Sidel, and KHS offer hot-fill configurations.
Evaluation note: For electronic fillers, verify that the control software version is current and that all filling recipes/programs are included. Sensor calibration records should be reviewed to ensure measurement accuracy.
Choosing the Right Used Filler: Decision Framework
Selecting the right used filling machine requires matching technology to your specific requirements. Consider the following framework:
Step 1 — Product type: Carbonated products require isobaric technology. Still products can use gravity, electronic volumetric, or vacuum. Viscous products need piston or mass-flow fillers. Sensitive products may require aseptic capability.
Step 2 — Container type: Glass bottles, PET bottles, cans, and pouches each require specific handling. Some fillers are dedicated to one container type; others can be adapted.
Step 3 — Speed requirement: Define your required output in containers per hour. Size the filler at 120% of average demand to account for efficiency losses and peak requirements.
Step 4 — Manufacturer preference: For integration with existing equipment, matching manufacturers is advantageous. For standalone installations, focus on the best available machine regardless of brand.
Step 5 — Budget allocation: Allocate 30-40% of total line budget to the filler, as it is the most critical component. Never compromise on filler quality to save costs elsewhere.
Price ranges for used fillers:
- Linear fillers (1,000-5,000 BPH): €20,000-€80,000
- Small rotary (5,000-15,000 BPH): €80,000-€250,000
- Medium rotary (15,000-36,000 BPH): €250,000-€600,000
- Large rotary (36,000-80,000+ BPH): €600,000-€2,000,000+
BottlingScout maintains the largest curated inventory of verified used filling machines, covering all technologies and speed ranges from the world's established manufacturer.
Frequently asked questions
What is the most versatile type of used filling machine?
Electronic volumetric fillers offer the greatest versatility. They handle multiple container sizes without mechanical changes, accommodate various still products, and provide excellent accuracy. For carbonated products, electronic isobaric fillers with flow meters provide similar flexibility.
How long do used filling machines last?
Quality filling machines from manufacturers like Krones, KHS, Sidel, and Bertolaso routinely operate for 20-30+ years. The mechanical frame and main structure are virtually indestructible. Regular replacement of wear parts (gaskets, O-rings, sensors) maintains performance throughout the machine lifecycle.
Can a used filler be retrofitted for different products?
Often yes, depending on the required change. Converting a gravity filler to isobaric requires significant modification. Converting between different still products typically requires only CIP cleaning and recipe adjustment. Consult the manufacturer or an experienced dealer for specific conversion feasibility.
What is the difference between mechanical and electronic filling valves?
Mechanical valves use springs and pneumatic actuators for fixed-volume fills. Electronic valves use servo motors and flowmeters for programmable fills. Electronic valves offer superior accuracy, flexibility, and data logging but are more complex. Both technologies are established.
Should I buy a monoblock or separate filler and capper?
Monoblocks (integrated filler-capper) save space and eliminate bottle transfer between machines. Separate machines offer more flexibility for maintenance and format changes. For speeds above 20,000 BPH, monoblocks are standard. For lower speeds, either configuration works well.