Oil absorption in mineral powder is an important parameter that characterizes the performance and functionality of mineral powders in different applications. Whether you need mineral additives for coatings, rubber, plastics, or paints, the parameter can have a direct bearing on viscosity, dispersion, surface interaction, and even formulation economics. Let’s quickly explore what oil absorption really means, how it is measured, and the practical differences between Linseed oil and DOP (Dioctyl Phthalate) as testing mediums.
Understanding Oil Absorption in Mineral Powders
Oil absorption, as the term suggests, refers to the amount of oil (in ml) a 100g of mineral powder can absorb to form a coherent paste. In general, this parameter is expressed in ml/100g.
How The Parameter Affects Mineral Fillers
This is an important aspect of choosing mineral additives for paints and coatings. Oil absorption varies based on particle size, shape, surface area, and porosity — and thus stands as a key performance indicator during the choice of mineral fillers, such as Calcium Carbonate, Talc, Dolomite, or Dolo Talc Powder.
Rheology (flow behavior)
The increased oil absorption of mineral fillers implies that they can absorb more plasticizers or binders. It is linked with viscosity of the mixture. In paint and coating, it affects sprayability, and in the rubber industry, it decides melt flow.
Film thickness
Mineral additives with higher oil absorption require more binder to wet the surface. It leads to thicker films as a result. Vice-versa if the absorption is low, it may lead to weaker or fragile outer film.
Gloss and texture
This is an important aspect of choosing mineral additives for paints and coatings. Oil absorption is inversely related to particle size, shape, surface area, and porosity — and thus stands as a decisive performance indicator during the choice of mineral fillers, such as Calcium Carbonate, Talc, Dolomite, or Dolo Talc Powder.
Processability
The increased oil absorption of mineral fillers implies that they can absorb more plasticizer or binder. On the other hand, high oil absorption can lead to difficulties while processing.
Cost of formulation
Every addition of resin, binder, or filler can add to the overall cost of mineral additives. Therefore, it’s important to understand oil absorption to keep formulations economical.
Linseed Oil vs DOP Oil: Measuring Oil Absorption in Mineral Fillers
Did you know that the same mineral powder can show different oil absorption values depending on the oil used. To measure oil absorption in mineral fillers, primarily, two oils are used in laboratories. Let’s quickly compare two:
Linseed Oil
Linseed is a natural drying oil that is used in paint and coating industries. It is extracted from flaxseed and often reacts with oxygen to form a solid film. Linseed oil is organic, and due to its better wetting properties and lower viscosity, it generally shows lower oil absorption values compared to more viscous oils like DOP — especially in volume-based methods.
For example, a Talc Powder may show 52 ml/100g in DOP oil however it will show 40 ml/100g in Linseed oil. This means that more DOP oil is required to wet the same surface area as compared to Linseed Oil.
DOP (Dioctyl Phthalate)
DOP is a synthetic plasticizer, often used in the rubber and plastics industries. However, the limitation is it is derived from phthalic acid posing environmental threats. However, the bright side is that DOP oil shows controlled and consistent readings. However, due to its higher viscosity, it may result in higher oil absorption values in volume-based tests. Still, it is preferred in industries like rubber and plastics where such consistency matters. Additionally, it is a cost-effective and stable oil for testing purposes.
Therefore, it is important to select the right oil, based on your needs, to find the oil absorption value. If you still have a concern or query, collaborate with Silver Stone Industries, Talc, Dolomite, and Calcium Carbonate Powder Manufacturer and Supplier, to make an informed decision for your formulations.
