TPM Wash Solvent

Tripropylene Glycol Monomethyl Ether (TPM) is a non-flammable, mild-smelling solvent that can be used to clean and dissolve uncured resin in 3D printed parts with SLA technology. TPM is not currently certified for use with Formlabs biocompatible resins.

TPM has a lower evaporation rate than Isopropyl Alcohol (IPA) and therefore allows to wash approximately three times more parts than isopropyl alcohol before having to replace it.

When to use TPM

If you haven't used biocompatible resins, it's recommended to use TPM if:

• Isopropyl alcohol (IPA) cannot be used due to flammability risks.
• Isopropyl alcohol (IPA) cannot be easily acquired / stored / disposed of due to restrictions on where the activity takes place.
• A more durable solvent is sought.
• Sensitivity to odor from isopropyl alcohol (IPA) vapors occurs.

The effect of TPM on resin

Washing parts printed with TPM and rinsed with water produces different results depending on the resin used. The surface of the piece can have a wax-like feel until it dries completely. Some resins, discussed later, can maintain this waxy texture on their surface for up to a week if they are not post-cured.

Standard Resins: The resin remains waxy when printed with a layer thickness of 50 or 100 microns. Post-curing eliminates that waxy texture. Without post-curing, the waxy texture disappears after about a week.

Castable Resin: The resin remains waxy when printed with a layer thickness of 50 or 100 microns, but the waxy texture disappears after 3-12 hours.

Castable Wax Resin: The resin comes out of the wash clean and without waxy texture, so it isn't necessary to post-cure to eliminate said texture. However, post-cure is recommended for optimum casting results.

Color Kit: The resin remains waxy when printed with a layer thickness of 50 or 100 microns. Post-curing eliminates that waxy texture. Without post-curing, the waxy texture disappears after about a week.

Draft Resin: The resin remains waxy when printed with a layer thickness of 50 or 100 microns, but the waxy texture disappears after 3–12 hours.

Elastic Resin: The resin maintains a waxy texture with any layer thickness with which it's printed and requires post-curing. Post-curing eliminates that waxy texture.

Flexible Resin: The resin maintains a waxy texture with any layer thickness with which it's printed and requires post-curing. Post-curing eliminates that waxy texture.

Grey Pro Resin: The resin comes out of the wash clean and without a waxy texture, so there is no need for post-curing.

High Temp Resin: The resin comes out of the wash clean and without a waxy texture, so there is no need for post-curing.

Model Resin: The resin remains waxy when printed with a layer thickness of 50 or 100 microns, but the waxy texture disappears after 3–12 hours.

Rigid Resin: The resin comes out of the wash clean and without a waxy texture, so there is no need for post-curing.

Tough 2000 Resin: The resin comes out of the wash clean and without a waxy texture, so there is no need for post-curing.

Tough 1500 Resin: The resin remains waxy when printed with a layer thickness of 50 or 100 microns, but the waxy texture disappears after 3–12 hours.

Compatibility with other FormLabs products

The TPM is compatible with the Formlabs, Form Wash and Form Cure finishing kit.

Form Wash: TPM is compatible with all Formlabs resins in Form Wash. However, the hydrometer included with the Form Wash does not measure the correct relative density spectrum for use with the TPM. A hydrometer capable of measuring a relative density of 0.962–1000 can be used to measure the resin concentration in the TPM. It should be noted that if the relative density of the TPM used is greater than 1,000, it will not be fully effective as a final wash.

Form Cure: The Form Cure does not expel air during operation, so the evaporating solvent condenses on the heater, fan, and internal surfaces. If a print with traces of TPM is introduced into the Form Cure, the solvent will evaporate from the part and condense on the internal surfaces of the Form Cure. This can occasionally cause turbidity on reflective surfaces. It's recommended to always allow prints to dry completely (regardless of whether they have been washed with isopropyl alcohol, tripropylene glycol monomethyl ether, or water) before placing them in the Form Cure.

Finish Kit: The TPM is compatible with all Formlabs resins in the Finish Kit wash bowls.

Formlabs SLA Printers: TPM shouldn't be used to clean the optical surfaces of Formlabs SLA printers.