Density is one of the important indicators of the physical properties of rubber material.The density of different rubber material varies significantly.
The rubber density ranges of common used rubber materials
| Rubber Material | Density of rubber (g/cm³) |
| FKM (Fluoroelastomer/Viton) | 1.80–2.00 |
| FFKM (Perfluoroelastomer) | 2.10–2.20 |
| NBR (Nitrile Butadiene Rubber) | 1.00–1.20 |
| HNBR (Hydrogenated Nitrile Rubber) | 1.20–1.30 |
| EPDM (Ethylene Propylene Diene Monomer) | 1.00–1.2 |
| AEM (Ethylene Acrylic Rubber) | 1.10–1.20 |
| ACM (Acrylic Rubber) | 1.15–1.25 |
| Silicon rubber ((VMQ) | 1.1-1.3 |
| FVMQ | 1.4-1.6 |
Thus, the detacting of rubber density is a key quality control method in the production process of rubber products. It is crucial for garantee the stable quality and product performance.
The main function of detacting the density of rubber materials
1. Quality control of raw materials
Different types of rubber raw materials (such as FKM, NBR, EPDM, etc.) have their specific density ranges.
By measuring density, it is possible to quickly determine whether raw materials meet technical specifications, avoiding product performance issues caused by unqualified raw materials and whether there are any material errors.
2. Formula accuracy verification
In practical applications, the density deviation of a rubber material with a determined formula is usually controlled within ± 0.02g/cm3.
Density measurement can detect whether the amount of various fillers (such as carbon black, silica, plasticizers) added during rubber mixing meets the requirements of formula design. Abnormal density may indicate incorrect formula proportions or impurities mixed into the raw materials.
3. Product performance monitoring
Density is closely related to the physical properties of rubber products, such as elasticity, hardness, and wear resistance. By measuring density, it can indirectly reflect the performance changes of the product, ensuring its stability and reliability in the specified application.
How to measure the density of rubber material?
There are two main methods for measuring rubber density: balance method and pycnometer method. The basic principles of these two methods are the same. They calculate the volume by measuring the mass difference of rubber in air and water, and then obtain the density.
The specific steps are as follows:
1) Weigh the mass of rubber in air (m).
2) Immerse the rubber completely in water and weigh its mass in the water again.
3) Calculate the mass difference, i.e. the mass of water displaced, to obtain the volume of rubber (v).
4) Calculate density according to density formula ρ= m/v
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