Application Examples

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Tackiness of industrial greases : a quantitative method

WHY ?  : Lubricating greases are used in various industrial fields ranging from food, transportation, aeronautical, construction, mining and steel industry. The aim is to decrease frictional forces and to protect industrial components from wear and/or corrosion damage. Their performance depends on interaction properties like adherence to the substrate, cohesion or consistency, and tackiness. However, up to date there is no established quantitative methodology that can be easily applied to efficiently and accurately evaluate the adhesion and tackiness of a grease.

HOW ?  : A test procedure is established, based on approach-retraction curves, by using an upgraded TETRA Basalt-N2 micro-tribometer, with a Millinewton light load sensor. In this procedure a user selectable indenter body (ball, pin) gradually approaches the grease layer until they come into contact, then the indenter body keeps moving down until a pre-set contact load is reached. Then, the indenter body moves away from the greased substrate under well controlled conditions, until complete physical separation. During this approach-retraction cycle, the force on the load sensor is measured as a function of time and distance moved. This technique is the same as pull-off force experiments with an atomic force microscope for studying physical interactions.

b2ap3_thumbnail_PICTURE tackiness - Application examples | FACTLABS.ORG

RESULT  :

- The approach-retraction methodology combined with the Basalt-N2 high precision sensor provide a useful tool that is capable of evaluating the pull-off force and tackiness of greases under variable conditions, depending on the industrial application.

- The ranking of different greases at variable conditions is possible. This will allow developers and end-users to differentiate between available greases and select the one that fits better to an application, whereas grease producing companies can quantitatively evaluate the quality of their products more easily. 

b2ap3_thumbnail_tackiness-graph tackiness - Application examples | FACTLABS.ORG

b2ap3_thumbnail_effect-of-speed-on-pull-off-force tackiness - Application examples | FACTLABS.ORG b2ap3_thumbnail_Ranking-of-greases tackiness - Application examples | FACTLABS.ORG

 

 

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How to measure the friction and adhesion of skin creams

WHY ?  : Skin creams are commonly used to improve skin health and create a smooth, soft, and moist perception. This is achieved by altering the surface roughness, friction, and adhesion of skin surface. Despite the fact that there are many commercial creams available, there is no consistent approach to determine their frictional and adhesive properties.

HOW ?  : Two different test procedures are developed to evaluate the friction and adhesion of commercial skin creams. To investigate the frictional behavior, a reciprocating sliding was performed by applying a film of cream on an artificial skin. As a counter material, silicone was used to simulate the actual tribosystem. Different sliding speeds, applied loads and sliding distances can be used to evaluate and compare different contact conditions. In addition, the adhesion of the skin creams was measured based on approach-retraction curves. In this procedure a silicone counter body gradually approaches the artificial skin with the cream, until a pre-set contact load is reached. Then, the silicone moves away from the greased substrate under well controlled conditions, until complete physical separation is achieved.  During this approach-retraction cycle, the force on the load sensor is measured as a function of time and distance moved. 

 

b2ap3_thumbnail_PICTURE tackiness - Application examples | FACTLABS.ORG

 

RESULT  :

- The frictional behavior of various creams can be investigated in an accurate and efficient way, under realistic conditions.

- The same apparatus and setup can also be used to measure the adhesion and separation energy of creams on artificial skin. 

b2ap3_thumbnail_COF_skin-vs-silicone-and-cream-page-001 tackiness - Application examples | FACTLABS.ORG b2ap3_thumbnail_Cream_adhesion-page-001 tackiness - Application examples | FACTLABS.ORG

 

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