How a full-servo IS machine can radically reduce glassworks operating costs

In container-glass production, by mid-2026 every penny counts on every bottle made. For technical directors and plant managers, relying on technologies that waste costly utilities and energy is no longer sustainable. The move from pneumatic systems to fully electric drives is now assessed primarily on hard data: total cost of ownership (TCO), absolute forming-cycle stability and the speed of product changeovers. An integrated full-servo IS machine has a direct, measurable impact on electricity consumption, compressed-air demand, start-up reject rates and unplanned hot-end downtime.

Why traditional pneumatic mechanisms add cost to every bottle produced

A conventional pneumatic IS machine inherently depends on air pressure, the condition of proportional valves and complex mechanical linkages. The physics of gases is unforgiving. Motion accuracy deteriorates over time as it is affected by seal wear, microscopic leaks in the distribution system and the delayed response of the valves themselves. The result is a process that continually drifts and demands constant operator attention.

The hidden costs of older technology are not limited to direct maintenance and replacement parts. They appear in far more expensive areas: poorer motion repeatability, disproportionately long set-up times during product changeovers, and high sensitivity to any variation in plant conditions. Significant compressed-air losses continually increase the load on the compressor station and raise operating costs.

When the behaviour of pneumatic mechanisms changes with temperature and wear, operators spend hours making manual corrections and fine-tuning timings. Production quality then depends critically on the experience and judgement of a particular shift, rather than on precise process data.

• Valve and piston degradation mechanically alters the response and delay of mechanisms by milliseconds, directly affecting the forming process.
• Air-pressure fluctuations across the plant network disrupt cycle stability and can lead to inconsistent gob weights.
• Product changeovers require extensive manual mechanical adjustments, extending downtime and generating unnecessary cullet during start-up.
• Compressor loading caused by air leaks and inefficient pneumatic cylinders can dramatically increase electricity consumption per tonne of melted glass.

For a closer look at the technical parameters and real-world performance of a modernised production line, see our expert article on IS machine innovation.

How digital motion control stabilises the entire glass-forming process

A modern full-servo IS machine replaces unreliable pneumatic mechanisms with electric servo drives controlled in a tightly closed control loop. The travel, speed, acceleration and timing of every movement follow an exact digital profile. That profile does not change whether the machine is on its first day of operation or its fifth year.

In container-glass production, this absolute control covers critical equipment: from the servo gob feeder, with a capacity of 30–220 tonnes per day, through the precision shear mechanism, to the e-pusher and servo stacker. T&T, Turnov s.r.o. builds its architecture around the Siemens industrial standard, specifically using CPU 1518TF processors, with recipe management handled by an Industrial PC. This ensures not only precise recipe management, but also globally available components and compliance with IEC, CE and UL standards.

  The control architecture is where the fundamental gap between the two concepts lies. Pneumatics merely respond to the physical state of the air system, whereas a servo motor actively executes a precisely defined motion with positioning accuracy of up to 0.01 mm.

Key parameter improvements at the forming-section level

Completely stable movement of the shears, feeder plunger and container-transfer mechanisms helps maintain consistent gob weight and an ideal forming process. In advanced NNPB (Narrow Neck Press & Blow) production, where the aim is to lightweight bottles while retaining strength performance, microsecond timing accuracy is critical. Any timing deviation can create a wall defect and send the container straight to the cullet collection system.

Why rapid product changeovers require absolute repeatability of settings

When changing to a different bottle type, a full-servo system can simply load stored recipes from the HMI panel. The operator immediately returns to historically proven, optimised motion-profile settings, without lengthy mechanical adjustment of stops or valve restrictions. The line reaches nominal output with minimal delay.

Our specialist page on IS machine research and development explains our detailed design approach and in-house cam-development capabilities. The differences between a traditional pneumatic IS machine and a modern full-servo IS machine are clear:

1. Motion-control philosophy. A pneumatic machine depends on air compressibility and valve performance, so mechanism movement is always subject to a degree of inaccuracy and variation. A full-servo machine controls every movement precisely through a closed-loop servo drive, continuously monitoring and correcting the actual position of each mechanism.
2. Long-term repeatability. On a pneumatic machine, motion repeatability is highly sensitive to mechanical wear: every worn seal or valve changes machine behaviour. On a full-servo machine, repeatability is governed by a digital cam profile that remains consistent regardless of operating hours.
3. Efficiency during product changeovers. A pneumatic machine requires lengthy manual set-up and tuning, dependent on the experience of the setter. A full-servo machine enables immediate loading of a digital recipe from the HMI, recalling proven product settings directly from memory.
4. Energy demand. A pneumatic machine consumes substantial energy through losses in the compressed-air system; a large share of the energy is lost before it ever reaches the machine. A full-servo machine has significantly lower energy demand because electrical power is converted directly into motion, without compressed air as an intermediate stage.
5. Maintenance profile. A pneumatic machine requires reactive maintenance: seals, valves and air lines are replaced once they wear out or fail. A full-servo machine supports predictive diagnostics via TCP/IP protocols, with servo-drive data continuously indicating machine condition so maintenance can be planned before a failure occurs.

How to reduce compressed-air and energy consumption efficiently at the hot end

Compressed air is one of industry’s most expensive utilities. Reducing its use substantially at the hot end has an immediate effect on plant profitability. Replacing the main pneumatic cylinders with servo motors drastically lowers air consumption and can allow part of the compressor station to be shut down or placed in standby.

With advanced ISX technology, the design can deliver up to 50% energy savings compared with conventional IS technology. The precise benefit always depends on the specific line layout, glass type and product range being produced, including BB and PB processes; however, savings in the hundreds of thousands of kWh per year are a standard outcome. These systems are also designed to support future decarbonisation.

“Reducing compressed-air consumption and mould cooling demand not only stabilises the container’s thermal profile, but also demonstrably lowers the energy intensity of the entire line per tonne of melted glass.”

Greater cooling capacity can accelerate the forming cycle and stabilise production without extreme pressure requirements for cooling air. This helps eliminate internal stress in the glass before it enters the annealing lehr, which for maximum efficiency is fitted with 300 mm insulation.

Which parameters to track when calculating total cost of ownership

For an investment decision, it makes little sense to assess only the purchase price of the equipment (CAPEX). The TCO (Total Cost of Ownership) calculation must also reflect real operating data (OPEX).

• Electrical energy consumption of drives: compare installed and actual power demand in kW before and after the introduction of servo technology.
• Compressed-air volume: monitor the reduction in consumption in Nm³ and the resulting lower load on the compressor station.
• Changeover downtime: measure the reduction in time required for product changeovers enabled by digital recipes.
• Reject rate after a product change: assess the reduction in cullet generated while the line returns to operating parameters.
• Predictive maintenance interventions: analyse savings achieved through early detection of anomalies.

As a practical first step, we offer a no-obligation feasibility study within 48 hours. Our engineers will assess your operating data and propose the optimum technical solution. For larger investments in new capacity, we provide complete project management, from layout design through to the first bottle produced.