We can provide texture analysis services and a variety of methods to help characterise mechanical deformation, texture or other physical behaviours. We have a variety of probes and custom attachments which enable us to design an experiment custom to your specific area of interest.
If you would like to discuss texture characterisation or experimental design please feel welcome to contact us.
In a normal mode of operation, a probe descends at a set rate onto/through a sample or can be programmed to pull itself away from a sample. We can apply a controlled deformation along a single axis, and measure the resistance to this mechanical process.
The variety of attachments and probes enables texture analysers to mimic a variety of real world interactions:
- Pulling/Pulling off
- Extrusion/Back Extrusion
- Snapping/Tensile Testing
An output graph will typically plot resisting force (N) as a function of either time or distance travelled by the probe.
Texture Profile Analysis (TPA)
Within multiple industries, texture profile analysis seeks to quantify various physical properties such as hardness, adhesiveness, fracturability, cohesiveness, springiness, gumminess, chewiness and resilience by driving a probe into a sample at a specific rate, and repeating the compression.
Below is a schematic from a TPA test, indicating how one might use readings from the graph in calculations of a specific physical property or behaviour.
A TPA test generally follows a set format:
- 1st Compression
- The probe descends onto the sample, once contact is detected measurement begins and the probe descends at a defined speed, for a set distance or a set time.
- 1st Withdrawal
- Once the target distance/time is reached, the probe ascends away from the sample at a typically faster speed for a set distance or a set time.
- The sample can be allowed to recover before the process is repeated in the 2nd Compression and 2nd Withdrawal.
Fracturability (N) = F0
- The first significant peak in first compression.
Hardness (N) = F1
- The highest peak force measured during first compression.
Adhesiveness (N.s) = c
- The area above the curve for the first negative peak.
Cohesiveness = (d+e)/(a+b)
- The area underneath the second compression curve divided by the area underneath the first compression curve.
Springiness (%) = (Distance 2)/(Distance 1)*100 or (Time 2/Time 1)*100
- A ratio or percentage of a products recovery to its original height.
Gumminess (N) = F1 * ((d+e)/(a+b))
- Hardness x Cohesiveness.
Chewiness (N) = (F1*Distance 2)/(Distance 1*(d+e)/(a+b))
- Hardness x Cohesiveness x Springiness.
Resilience = b/a
- The area under curve after peak force is reached divided by area under curve before peak force is reached.
Texture profile analysis is one of our most popular tests to perform on a texture analyser. It is important however, to use an appropriate method for the physical property of interest. While it is possible to get an idea of adhesion from a TPA profile, it is better to perform another test designed specifically to look at adhesion.
If you are unsure which method is appropriate to objectively quantify your behaviour or property of interest, feel welcome to contact us to discuss your requirements.