PETG

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Glycol-modified PET. Claimed to be like ABS but as easy to print as PLA

Notes:

  • ~80C print bed seems to be sufficient, but can stick to as cool as 60C on clean glass.
  • PETG likes to stick to the print nozzle, so "lay" the initial layer instead of mashing it.
  • PETG on-glass can stick exceedingly well, and can 'bite' flakes of glass off if the glass is cooled too quickly on prints that cover a large surface area of the bed.
  • Glass transition temp seems to be around 80°C. It will do slightly better in a hot car than PLA would, but not as well as ABS.

PETG needs higher temperature than PLA to be printed and an all metal hotend shall be preferred. Due to these higher temperature, it shall be generally printed at slower speed than PLA. Hotend with longer heat zone are preferable to print PETG.

Parts are more resistant to temperature than PLA, but less than ABS. Unfortunately, no manufacturer supplied engineering data.

Density is higher than PLA and ABS.

Stiffness is significantly lower than PLA and may be compared to ABS.

Like ABS, PETG can readily be solvent welded. Cyclohexanone, Methyl ethyl ketone (MEK) and possibly acetone can be used. The Handbook of Plastics Joining suggests a mixture of cyclohexanone and MEK, but cyclohexanone alone also works.

Cyclohexanone is relatively benign, similar to acetone, but it considerably more expensive and less commonly available. MEK is, for the time being, still available in hardware stores, but is nastier and seems to take longer to reach full strength than cyclohexanone.

Some hints on printing PETG

Wikipedia: