Every Esteem butyl polyalkylene grade on the product table is listed as a lubricant for metal cleaner. The variables that change performance are molecular weight, 1% cloud point, viscosity at 100 °C, and pour point. This guide maps BEP and PBP grades so formulators specify a window—not “send any PAG.”
What Butyl PAG Is Doing in a Cleaner
A metal cleaner has to wet, lift oil, and often leave a temporary lubricious film so parts do not gall in process or flash-rust in a way the next step cannot handle. Butyl-started polyalkylene glycols are 100% active liquids in Esteem’s table. They sit in the alkoxylates family with other EO/PO products, but they are not interchangeable with a detergent FAE or an end-capped low-foam wetter. Those molecules clean; these grades are specified as lubricants.
How to Read the Spec Table
| Lever | What it tells you | Examples on the Esteem table |
|---|---|---|
| Average MW | Chain length / film body | PBP-340 (340) vs PBP-2500 (2500); BEP-1000/2000/2020 in the 1000–2000 band |
| Cloud point (1% aq.) | When the nonionic phases out of water | PBP-340 at 11 °C; BEP cluster ~54–62 °C; high PBP grades much hotter |
| Viscosity at 100 °C | Hot-film thickness / drain | PBP-340 at 2 cSt vs PBP-2500 at 52 cSt; BEP-1000 at 11 cSt |
| Pour point | Winter handling and tank flow | BEP < 0 °C; PBP < −20 °C |
BEP-1000, BEP-1320 (MW listed 1400), BEP-2000, and BEP-2020 (MW 2000) are mid-range liquids with cloud points 54–62 °C and pour points below 0 °C. PBP-340 through PBP-2500 cover the wide MW ladder, with pour points below −20 °C—useful if the drum sits in an unheated shed.
Cloud Point vs Bath Temperature
If the cleaner runs at 60 °C, a grade that clouds at 11 °C has already gone hydrophobic long before the setpoint. That can be useful (phase-out lubricity) or a mess (oil on the surface, spots on parts). If you need the molecule dissolved at 60 °C, start in the BEP band or higher-cloud PBP grades (PBP-1200 at 80 °C and up). Confirm with a 1% cloud-point check in your builder and electrolyte—salts depress cloud point versus the distilled-water table.
Building a Cleaner Around PAG Lubricity
Typical partners: a wetting nonionic surfactant or low-foam surfactant for soil removal, a chelating agent for hard water and flash rust metals, and only then a BEP/PBP for film. Alkali-stable low foam is an end-capped problem, not a PAG prefix problem. Related mill/cleaner reading: metal parts cleaning surfactants.
How to Specify with Esteem
- Give bath temperature, pH, spray vs soak, and metal.
- Name the soil (cutting oil, drawing compound, mill scale plus oil).
- State whether you need dissolved PAG or phase-out film at temperature.
- Pick a viscosity band (thin rinse vs heavier film) from the butyl polyalkylene table.
- Trial two adjacent grades (for example PBP-1100 vs PBP-1200) rather than jumping 340 to 2500.
Related chemistry: metal chemicals, defoamers if the package foams, custom synthesis for a non-catalogue MW/cloud-point cut.
Contact Esteem for BEP/PBP samples with your bath window on the request.