A pick and place machine needs air that is dry, filtered and at a stable pressure. In practice that means a refrigerated dryer, cascade filtration (a general filter then a fine filter, plus an activated carbon filter if the manufacturer asks for one), automatic drains and a regulator at the machine. The exact air class is in the machine manual, and you confirm it with our technicians.
Why is a placement machine so sensitive?
A placement machine picks each component with a vacuum nozzle. The vacuum is often produced by vacuum generators (venturis) fed with compressed air. Their orifices are tiny. A drop of water, an oil aerosol or a rust particle is enough to foul them. The nozzle picks less well, the component drops or lands crooked, and the machine stops on an error.
The valves and cylinders of the feeders and loaders suffer too: water washes out their grease and particles score the seals. That is why our page on compressors for electronics assembly puts air quality before flow.
The treatment chain, in order
- The compressor. Our screw compressors are oil-lubricated. At the outlet, the air still carries a few ppm of oil (3 to 5 ppm according to the S Series data sheets). This is not a fault: it is what the filtration is there to deal with.
- The refrigerated dryer. It cools the air to condense the water and drain it away. It is the baseline for an SMT line. Our article on which air dryer to choose compares the technologies.
- The general filter. It stops coarse particles and droplets.
- The fine filter. Fitted after the general filter, it captures oil aerosols. See our fine filters.
- The activated carbon filter, if needed. It holds back oil vapour and odours for the most sensitive uses.
- The point of use filter and regulator. Placed just before the machine, they stop whatever the network has added (rust, installation debris) and set the working pressure.
If the manual calls for a dew point below zero, a refrigerated dryer is no longer enough: you need a desiccant dryer.
Sizing the treatment: a worked example
The dryer and filters are chosen on the compressor flow, not on the machine flow. An undersized filter restricts the air and saturates quickly. Figures are indicative, check each manufacturer's data sheet.
- 3 placement machines at 150 L/min, running continuously: 450 L/min.
- 1 blow gun at 150 L/min, counted at half because it blows in bursts: 75 L/min.
- Subtotal: 525 L/min.
- 25% margin for leaks and peaks: 525 × 1.25 = 656 L/min, about 0.66 m³/min.
The K 75 delivers 1.1 m³/min at 8 bar. It carries the 420 L receiver, the refrigerated dryer and the filtration on one frame, already sized for its flow. There is room for a fourth machine.
Three cases, three answers
- A new workshop with no air treatment. A K Series 4-in-1 compressor saves you assembling the dryer and filters yourself. For two lines or more, the K 110 goes up to 1.7 m³/min at 8 bar.
- A network that already has a dryer and filters. The compressor alone is enough. The S 110 also delivers 1.7 m³/min at 8 bar. Check that the existing dryer can handle this flow.
- A machine that needs drier air. Keep the compressor and add a desiccant dryer, downstream of the refrigerated dryer or instead of it, as our technicians recommend.
Pitfalls to avoid
- Forgotten drains. The dryer and every filter collect oily condensate. Without an automatic condensate drain, it goes back into the network. Our article on water in compressed air lists the drain points.
- Cartridges never changed. A saturated cartridge lets oil through and creates a pressure drop. Replace it on schedule or when the indicator says so.
- Fluctuating pressure. Most placement machines work at around 6 bar. Set the compressor to 8 bar and let the regulator at the machine set the pressure: the machine always gets the same value.
- A network that rusts. Black steel pipe produces rust. The point of use filter catches it, but clogs faster.
ISO 8573-1 classifies air by water, oil and particles: our ISO 8573-1 air quality guide explains how to read the classes. Send us the manuals of your placement machines with a quote request and we will define the compressor, dryer and filtration with you.
For your trade: Compressor for electronics manufacturing and assembly.