Rheometry is used to determine the viscoelastic properties of materials, that is the qualitative and quantitative relationships between stresses and strains and their derivatives. Viscoelasticity is the property of a substance exhibiting both elastic and viscous behavior. Viscoelastic materials behave like both solids and liquids when undergoing deformation. When stress is applied, it causes temporary deformation if quickly removed and permanent deformation if the stress is maintained.
How rheometry works:
The viscoelastic properties of a material are measured by a rheometer (Figure 1). A rheometer is a device used to measure how a liquid, suspension, or slurry flows in response to applied forces. In one type of method, a test specimen is placed in a die cavity, closed, and maintained at an elevated temperature. The die cavity is constructed by two dies, one of which is oscillated through a rotary amplitude. This produces a sinusoidal torsional strain in the test specimen, resulting in a sinusoidal torque, which measures the viscoelastic quality of the test specimen.
These viscoelastic measurements are made based on (1) a frequency sweep, in which the frequency is programmed to change in steps under constant strain amplitude and temperature conditions, (2) a strain sweep, in which the strain amplitude is programmed to change, or (3) a temperature sweep, in which the temperature is programmed to either increase or decrease. Rheological properties are measured for each set of frequency, strain, and temperature conditions.
Strengths of the rheometry technique:
Sample preparation is easy.
Can test both Newtonian & non-Newtonian fluids.
Allows high shear rates without flow instabilities
Prevents evaporation and contamination of samples
Limitations of the rheometry technique:
The tests are carried out till the specimen’s failure.
High energy requirement.
Requires expertise to carry out.
Limited maximum applied strain.
Uses of the rheometry technique:
Characterization of viscoelastic property data is useful for quality control, process control, and manufacturing. The study of flow properties of liquids is important for many industrially important substances, such as cement, paint, and chocolate, which have complex flow characteristics. Rheometry has applications in materials science, engineering, geophysics, physiology, human biology, and pharmaceutics.
Viscoelastic property data is useful in the preparation of pharmaceutical products such as ointments, creams, pastes. Viscoelastic properties are used as a criterion to maintain the quality of the product.
Small sample size requirement (26µL – 100µL). In one type of test, the test specimen should be circular, with a diameter smaller than the test chamber of the instrument to be used.
Core Materials Testing Services
A variety of microscopy and spectroscopy tools available for precise measurements from the nano to the meter
ASTM E572 test method covers the analysis of stainless and alloy steels by Wavelength Dispersive X-ray Fluorescence Spectrometry (WDXRF). It provides rapid, multi-element determinations with sufficient accuracy to assure product quality.
The ASTM D2674 test is a standard test method for the analysis of sulfochromate etch solutions used in the surface preparation of aluminum. The ASTM D2674 standard specifies a method for determining the efficacy of an etchant used to prepare the surface of aluminum alloys for subsequent adhesive bonding.
An immunological method for quantization of Hevea Natural Rubber (HNRL) proteins using rabbit anti-HNRL serum. Rabbits immunized with HNRL proteins react to the majority of the proteins present, and their sera have the capability to detect most if not all the proteins in HNRL.
ASTM G65 measures the resistance of metallic materials to abrasion using the dry sand/rubber wheel apparatus. The quality, durability, and toughness of the sample are determined using this test. Metallic materials are ranked in their resistance to scratching abrasion under a controlled environment.
ASTM E2141 test methods provide accelerated aging and monitoring of the performance of time-dependent electrochromic devices (ECD) integrated in insulating glass units (IGU). This test helps to understand the relative serviceability of electrochromic glazings applied on ECD.
ASTM C724 test method is used in analyzing the quality and ease of maintenance of a ceramic decoration on architectural-type glass. This test method is useful in the acknowledgment of technical standards.
Send us a request
Process for testing
You share material and testing requirements with us
We ensure your sample pick-up in an ensured manner
We deliver test report to your inbox
Just share your testing requirements and leave the rest on us!
Free, no-obligation consultation
Quick turnaround time
Let us combine our capabilities to achieve success!!