A pour point depressant (PPD) is a lubricant and fuel additive that keeps oils flowing in cold weather. It works by modifying the way wax crystals form in paraffinic oils, preventing them from building a gel network that stops the oil from pumping. For engine oils, diesel, hydraulic fluids and gear oils operating in cold climates, the PPD is a small but indispensable part of the formulation.
How a Pour Point Depressant Works
When a paraffinic oil cools, wax molecules crystallise into plates that link together into a three-dimensional network, trapping the oil and raising the pour point. PPD polymers adsorb onto the growing wax crystals, co-crystallise with them, and disrupt their growth, keeping the crystals small and discrete so the oil keeps flowing. The effect is measured as pour point depression in degrees C (ASTM D97).
Main PPD Chemistries and Grades
| Type | Minglan grade | Application |
|---|---|---|
| Fumarate-vinyl acetate (FVA) | T818A | Paraffin base oils, engine and industrial oils; also increases viscosity index |
| Polymethacrylate (PMA) | T819, T826 | Aviation hydraulic oil, gear oil, multigrade engine oil |
| Ethylene-vinyl acetate (EVA) | T1805, T388 | Diesel and fuel oil fluidity improvers (CFPP reduction) |
| Specialty crude oil PPD | T1806 | Crude oil pipeline flow improvement |
PPD vs Cold Flow Improver
Engine and industrial oil PPDs lower the pour point of the finished lubricant. Diesel flow improvers (such as T1805 and T388) additionally reduce the cold filter plugging point (CFPP), which is the property that matters for winter diesel. The same chemical family – EVA copolymers – is tuned differently for each job.
Selection and Dosage
- Base oil dependence: PPD performance depends on the wax content and distribution of the base oil; always test in your own base stock.
- Dosage: typically 0.1-1.0% for engine and industrial oils (T818A at 0.3-1.0%, T826 at 0.1-1.0%); 0.03-0.1% for diesel flow improvers.
- Compatibility: PMA PPDs work synergistically with PMA VIIs; check compatibility with the full additive package.
Source PPDs From Minglan
Shanghai Minglan Chemical manufactures the full pour point depressant range – FVA, PMA, EVA diesel flow improvers and crude oil PPDs – with laboratory testing on every batch. Contact info@minglanchem.com for samples and pricing.
