Viscosity of Food Grade Lubricants
As food safety is an important topic, food grade lubricants are one of the most crucial requirements in the production line. They must fulfill the same tribological aspects as other lubricants and keep the machinery running. Selecting the wrong lubricant can have a detrimental impact on food quality and machinery. Costly product recalls or machinery downtimes can occur as a consequence. These lubricants are categorized into different classes, where only H1 lubricants are the "true" food grade lubricants which can have incidental food or beverage contact. Contrary to lube oils used in e.g. car engines, stringent directives for odor, cleanliness, toxicity and sanitary requirements must be fulfilled.
Food grade lubricants are usually industrial oils, their kinematic viscosity is classified according to ISO 3448 (ISO Viscosity Grades). Due to the various fields of application, food grade lubricants are formulated from different base stocks and additives. The tables give an overview about the kinematic viscosity at 40 °C and 100 °C, density at 20 °C and 15 °C, and Saybolt Universal Viscosity at 100 °F and 210 °F of some H1 lube oils with different chemical bases.
| Oil type | Intended use e.g. |
|---|
| Ester oil (ISO VG75) | High temperature chain oil for the food-processing industry, e.g. in the bakery industry |
| PAO (ISO VG220) | Can seaming oil (mineral oil free synthetic hydrocarbon oil) |
| Mineral (White) oil (ISO VG12) | Lube oil for lubricators and pneumatic installations (air compressors, air pipes, …) e.g. in packaging machines |
| PAG (ISO VG52) | Refrigeration compressor oil |
| PAG (ISO VG320) | Synthetic high-performance gear oil for the food processing and pharmaceutical industries |
| PFPE (core viscosity 425) | For incidental contact with products and packaging materials in the food processing, cosmetics, pharmaceutical, or animal feed industries. For chains, bearings, guides, or plastic-plastic friction points |
Viscosity and density tables – measurement data
H1 lube oils – kinematic viscosity vs. viscosity index
| Sample | Kin. viscosity [mm²/s] at 40 °C | Kin. viscosity [mm²/s] at 100 °C | Viscosity index |
|---|
| Ester oil (ISO VG75) | 71.14 | 10.33 | 130.4 |
| PAO (ISO VG220) | 226.6 | 2.91 | 150.9 |
| Mineral (White) oil (ISO VG12) | 21.11 | 4.23 | 103.9 |
| PAG (ISO VG52) | 51.33 | 11.09 | 215.6 |
| PAG (ISO VG320) | 314.7 | 55.68 | 244.3 |
| PFPE (425) | 410.7 | 39.16 | 143.3 |
Graph Kin. visc. 40 °C Kin. visc. 100 °C Viscosity index
H1 lubricants – Saybolt Universal Viscosity
| Sample | Saybolt Universal Viscosity [SUS] at 100 °F (37.78 °C) | Saybolt Universal Viscosity [SUS] at 210 °F (98.89 °C) |
|---|
| Ester oil (ISO VG75) | 61.23 | 10.71 |
| PAO (ISO VG220) | 1050 | 127.4 |
| Mineral (White) oil (ISO VG12) | 102.6 | 40.21 |
| PAG (ISO VG52) | 238.7 | 63.12 |
| PAG (ISO VG320) | 1458 | 260.5 |
| PFPE (425) | 1903 | 184.2 |
| Sample | Density [g/cm³] at 20 °C | Density [g/cm³] at 15 °C |
|---|
| Ester oil (ISO VG75) | 0.997 | 1.001 |
| PAO (ISO VG220) | 0.854 | 0.857 |
| Mineral (White) oil (ISO VG12) | 0.852 | 0.855 |
| PAG (ISO VG52) | 1.036 | 1.039 |
| PAG (ISO VG320) | 1.061 | 1.065 |
| PFPE (425) | 1.912 | 1.920 |
