How an Airway Buffing Wheel Is Made

What An Airway Buff Is

An airway buff, also sold as a ventilated sisal buff, airflow buff or bias airway buff, is a polishing wheel whose plies are folded onto a metal centre so that air passes through the body while the wheel runs. The open structure keeps the workpiece cooler than a solid pleated or disc wheel on long polishing cycles.

The wheel is built from three inputs: fabric or sisal cut on the bias, a metal centre in the form of an iron claw or an iron plate, and the machine time to fold and clamp the plies in a repeatable pattern.

Step One Bias Cutting And Rolling

Fabric has to enter the forming machine on the bias. Straight cut material will not fold evenly and shows up later as loose ply spacing. A CRA-500 bias fabric cutting slitting and rolling machine cuts the cloth on the bias and winds it into the roll the former takes.

The same step applies to sisal cloth. Sisal grades commonly used are African white sisal 10x8, Brazil sisal and China Guangxi sisal 8x7.

Step Two Forming

The forming machine folds ply after ply onto the metal centre while a turntable indexes the wheel body. The CRA-800 covers 200 to 600 mm outer diameter, runs on 380 V three phase at 6 kW, measures 2.8 m by 1.8 m by 1.6 m and is rated up to 5000 pieces per day with one operator. For smaller wheels the CRA-300 iris machine covers 100 to 250 mm.

Moulding and finishing pressure are both held at 7 MPa. If the gauge drops, ply density loosens before the wheel diameter changes, so the pressure reading is the first thing to check when wheels start running soft.

Step Three Pressing And Step Four Trimming

Formed bodies go to a CRA-600 pressing machine, which compacts the plies against the centre. Send them the same shift, because a ply stack that sits overnight relaxes.

Edge cutting on a CRA-700 gives the wheel its running face and its final outer diameter. After that the wheel is inspected and packed.

Choosing The Centre

Forming machines accept iron claws in 2 inch, 2.5 inch and 5 inch, and iron plates with round or hexagon holes. Iron clinch rings are pressed from 1.2 mm steel plate through 5 to 8 operations, in diameters from 3 inch to 8 inch with 43 teeth as standard. Square teeth rings come in 1.5 mm and 2.0 mm thickness.

The centre decides how the wheel mounts on the customer's spindle, so it is usually fixed by what the end user already runs rather than by the wheel maker.