Palram PALSU - Manual (Page 26)

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Recommended Band Saw blade Properties
Property Sign Units Value
Clearance angle α 10 – 20°
Rake angle γ 5 – 15°
Cutting speed m/min (ft/min) 1,000 - 6,000 (1,950 - 3,300)
Rate of feed mm/sec (inch/sec) 20 (13/6)
Thin gauge: 1.5-2.5 mm tooth pitch (1/16” - 3/36” ) t Teeth per mm (Teeth per in.) 1.5 - 2.0 (12 - 18)
Heavy gauge: 3.2 - 12 mm tooth pitch (1/8” - 1/2” ) t Teeth per mm (Teeth per in.) 2.5 - 3.5 (7 - 10)
Notes:
1. A band saw is suitable for cutting curved lines and 3-dimensional, formed parts.
2. For cutting a few formed objects of the same shape, they must be firmly clamped together.
3. A band saw cutting usually yields rougher finished edge, which must be smoothed by sanding and polishing.
An endless belt sander is a preferred tool for such an operation.
4. Palram recommends using a circular saw for better-finished edges, whenever possible.
Portables: Jigsaw or Saber Saw
Portable saws of these types use short movement, reciprocating blades, instead of one-direction orientation, continuous
movement blades like those of circular or band saws, and are much slower in operation.
ƒ Chipping: Various sized chips are broken off on both edges of the sawing line, leaving the cut edges rough and uneven.
ƒ Gumming: Chips and splinters from the advancing saw blade overheat during the sawing process, melt and create a mass of
cooled down material in front of the blade and on both sides of the cut. The swarf sticks to the edges, leaving an unsightly, rough
edge finish, which would be difficult to clean.
Jigsaw or saber saw cutting usually results in an inferior finish of the cut edges, worse than the results achieved by a circular
saw. Palram recommends sanding and polishing of the cut edges as standard practice. An endless belt sander is the preferred
tool for such an operation.
Gummed material may also stick to the blade itself and cause seizure.
The same uncontrolled heat that creates gumming may also induce undue internal stresses along the edges of the cut,
necessitating cooling of the sheet.
Recommended Remedies:
ƒ Choose the correct tooth size and pitch.
ƒ Select a more appropriate saw speed.
ƒ Lower the feed rate.
ƒ Examine the sharpness of the blade.
ƒ Examine the blade alignment.
ƒ Cool the blade with compressed air when long cuts are required.
ƒ Take frequent pauses during long production runs, to let the saw blade cool down.
ƒ Begin sawing with the blade already running at the full recommended speed.