On a folder gluer, compressed air supplies gluing, the ejection of faulty boxes, pneumatic adjustments and blow-off. Cylinders use little air; nozzles that blow continuously weigh far more. In the example below, a folder gluer and its delivery section need about 730 L/min including margin, which means a 7.5 kW screw compressor.
For the other machines in a carton plant, see our page on the compressor for printing and packaging.
What uses the air?
Depending on the manufacturer and options, a folder gluer has:
- gluing: a pneumatic glue pump or a pressurised glue tank, and glue heads driven by solenoid valves;
- the ejector for boxes rejected by glue inspection, driven by a cylinder or an air jet;
- pneumatic adjustments on the compression section and the delivery;
- blow-off for guiding or cleaning along the machine;
- the operator's blow gun.
Suction at the feeder and on the transport belts usually comes from a fan or vacuum pump built into the machine. The installation sheet states what is taken from the compressed air network.
The calculation, step by step
Step 1, the machine sheet. The manufacturer gives a consumption and a supply pressure. That is the base figure.
Step 2, added cylinders. For an ejector or a cylinder fitted later, calculate per cycle. A 32 mm cylinder, 12 mm rod, 100 mm stroke, at 6 bar:
- Piston area: 8.0 cm². Rod area: 1.1 cm².
- Volume per cycle: 80 cm³ out and 69 cm³ back, or 0.15 litre.
- Free air: 0.15 × 7 bar absolute = 1.05 litres per cycle.
- At 10 ejections per minute at most: about 10 L/min.
The full method is in our article on pneumatic cylinder air consumption.
Step 3, the nozzles. A nozzle left open uses around 150 L/min, as an indication, depending on its diameter and pressure: see blow-off nozzle air consumption.
Step 4, the total. Indicative example, values marked "assumption" to be replaced with those on your sheet:
| Item | Consumption |
|---|---|
| Folder gluer, manufacturer sheet (assumption) | 200 L/min |
| 2 continuous blow-off nozzles | 300 L/min |
| Ejector, 32 mm cylinder | 10 L/min |
| Blow gun, counted at 50% | 75 L/min |
| Total | 585 L/min |
With a 25% margin: 585 × 1.25 = about 730 L/min at working pressure.
Which compressor?
- One machine, no dryer in place: the K 75. 1.1 m³/min at 8 bar, 420 L receiver, built-in refrigerated dryer and filtration. It keeps a reserve for a second light machine.
- Receiver and dryer already installed: the S 75. The same flow, as a standalone compressor.
- Two folder gluers, or a folder gluer and a die cutter: the K 110. 1.7 m³/min at 8 bar.
Job changes stop the machine several times a day. The variable speed of our screw compressors avoids running the motor unloaded during these stops.
Traps in carton production
- Board dust. The compressor draws in the air around it. Placed next to a die cutter or folder gluer, it quickly clogs its intake filter and runs hot. Install it away from the machines and check the filter more often: see where to install your compressor.
- Water in the glue and solenoid valves. Air that pressurises the glue or drives the glue heads must be dry. A refrigerated dryer and filtration after the compressor keep water out of the tank and stop valves from sticking.
- Forgotten nozzles. A nozzle that blows while the machine is stopped uses as much air as in production. A solenoid valve controlled by the machine shuts it off during stops.
- Network pressure. Glue and nozzles often work at low pressure, set by their own regulator. Set the compressor for the most demanding machine, no higher.
Send us your folder gluer's data sheet with a quote request, or enter your equipment in the configurator.
For your trade: Compressor for printing and packaging.