Guidelines for machining Polyamide

Alkaline Polyamide (PolyJARID) can be easily machined on ordinary metalworking machines if the tools are well-sharpened.

Maturing:A cast semi-product made of PolyJARID should be processed after at least 6 weeks maturing from the date of its casting. An environment with higher humidity helps to reach water content equilibrium because the cast is virtually in a dried state after it is made. Maturing reduces residual stresses in casts, which occur particularly in solid blocks.

 

Cutting plates:We recommend using circular saws with sintered carbide blades, speed to 900 min^-1, shift to 500 mm.min^-1(only indicative values), emulsion cooling.

 

Milling: We recommend using milling speed steel heads, max. Rpm 2000 min^-1 / displacement max. 450 mm.min^-1 or 0.5 mm/cog (indicative values), both depending on the tool diameter and desired surface roughness; disproportionate peripheral speeds and feed rates lead to undesirable chip melting, which can be eliminated by using a cooling liquid. Recommended clearance angle α = 10 – 20°, head g = 5 – 15°.

 

Turning: When roughing, We recommend using a knife with a polished groove (chip breaker) for a smooth chip flow, speed 1200 to 2000 min^-1 / displacement max. 600 mm.min^-1(indicative values), both depending on the tool diameter and desired surface roughness; disproportionate peripheral speeds and feed rates lead to undesirable chip melting, which can be eliminated by using a cooling liquid. Recommended blade geometry: clearance angle α = 10 – 20°, head angle g = 5 – 15°. When turning tubular products from solid blocks, We recommend first machining the shape coarsely with larger additions followed by final machining only after 24-hour maturing (external dimension).

 

Predrilling:For holes from 10 mm ? and above, We recommend using only a manual drill feed, and lubricating with machine oils J4, J5. If a through hole is required, We recommend drilling the block from both sides using a ?15 - 20 mm drill to a depth of 30 mm, and leaving it at least 24 hours to rest for blocks of ?150 mm and above. Recommended drill geometry: clearance angle ? = 10 to 20 °, head angle g = 5 to 15 °, tip angle j = 90, helix pitch angle must be about 12 to 16°.

 

Reaming:Machining a roughing hole is recommended after a 24-hour rest. We also recommend using a manual feed for reaming and lubricating the reamer with machine oil.