Chapel Hill, North Carolina USA
Rheology Testing Services
Precise Rheology Testing. Clear Answers. Expert Interpretation. Streamlined. Fast Turnaround
Understanding your material's behaviour under varying and highly controlled stress, strain, shear, and temperature is essential to develop robust, high-performing products. Rheology Testing Services (RTS) provides custom rheological assays, rapid turnaround, and expert guidance to help R&D teams, formulators, and manufacturers solve problems, optimize formulations and processes, and confidently move projects forward.
With over 30 years of rheology and pharmaceutical development experience, RTS delivers the scientific rigor of a top-tier laboratory - without the bureaucracy, delays or lack of flexibility often encountered with large organizations.
What RTS Delivers
RTS is built for teams who value accuracy, clarity, and efficiency.
Scientific rigor backed by decades of expertise
Responsive, collaborative communication
Custom assay plans tailored to your material and goals
Rapid turnaround without corporate delays
Detailed, decision-ready reports
Flexible support for projects of all sizes
Cost-effective solutions for complex technical challenges
How Rheology Supports R&D and Manufacturing
Rheological insights play a critical role across multiple stages of product development and commercialization. RTS regularly supports clients in:
If your material spreads, pumps, mixes, coats, clings, sets, rebuilds, or flows, rheology can help you understand and optimize it.
Research & Development thru Manufacturing
Sensory and performance assessments
Formulation optimization
Quality control and QbD (Quality by Design)
Process development & scale-up
In-process monitoring
Batch consistency & stability evaluation
Proving or disproving equivalence for regulatory or IP needs (Q3)
A Partner for Technical Clarity - Especially When Problems Arise
Many RTS clients say the same thing: “We should have reached out earlier. Understanding the rheology would have changed our specs and saved significant time.” Whether you're exploring a new formulation, diagnosing instability, evaluating manufacturing changes, or navigating unknowns, rheological analysis is an efficient investment with a potentially large return. Even a single targeted assay can provide clarity that prevents costly revisions or regulatory delays. RTS specializes in helping teams who are unsure which assays they need, unsure what is happening in their material, or facing “Houston, we have a problem” situations. You do not need to arrive with a perfectly defined scope, we help you determine it. Performing either a single assay to address a specific technical need or an array of assays to generate a comprehensive rheological profile, is often a very small and highly efficient investment with a potentially large return.
Focused Expertise
Unlike large organizations that offer rheology as one small part of a broad service menu, RTS is dedicated to rheological science. Clients consistently appreciate:
Highly personalized, senior-level interaction
Highly flexible to meet client needs
Strategic guidance based on real-world experience
Clear explanations of what the results mean for your project
From academic research groups and startups to global manufacturers, RTS adapts to the needs of every project with strategic purpose.
Our Rheology Capabilities
RTS uses a Kinexus Pro rheometer and a suite of advanced methods to measure viscosity, viscoelasticity, tribology, adhesion/cohesion, surface tension, and more. We perform both standard and customized assays, including:
Assays can be connected in creative ways to simulate realistic processing conditions — pumping, mixing, heating/cooling cycles, rest periods, and more.
Commonly Requested Assays
Below are simplified overviews of some frequently requested assays and how they support decision-making.
See "Assays Performed" tab on top of page for many more
01
Viscosity is a foundational metric but only one part of a full rheological profile. A shear rate ramp measures viscosity across a wide range of conditions, revealing how the material behaves during spreading, mixing, pumping, or application.
- Newtonian materials such as honey show stable viscosity
- Non-Newtonian materials such as mayonnaise shear thin
These curves help model real-world processes and evaluate batch-to-batch consistency.
02
Yield stress defines the point at which a material begins to flow. It affects pumpability, spreadability, sedimentation potential, and overall feel.
Examples:
- Honey flows at very low yield stress
- Peanut butter requires far more force
RTS routinely uses yield stress analysis to evaluate stability and predict application performance.
03
An amplitude sweep gradually increases deformation to determine the Linear Viscoelastic Region (LVER) - the range where the material maintains structural integrity. LVER is a critical temperature dependent assay parameter for frequency modulated assays. Larger LVER values generally correspond to higher physical stability.
04
A frequency sweep quantifies how a material behaves across a spectrum of “movement speeds,” from slow spreading to high-impact forces.
Useful measurables include:
- G’ (elastic/solid-like behavior)
- G’’ (viscous/liquid-like behavior)
- G* (complex modulus; stiffness)
- Phase angle
- Complex viscosity
- Tan delta (=G"/G')
Understanding rheological properties helps predict how gels, creams, suspensions, semisolids, and engineered materials perform under real-world conditions.
A Straightforward, Collaborative Process
Working with RTS is simple and efficient:
01
Discuss goals & challenges
02
Develop a custom test plan & provide detailed quote A detailed quote will be prepared when the following information is provided. No problem if not known. RTS will partner with you to sort out details. Information in "FAQ & Assay Considerations" may be helpful. - Particular sample handling and storage requirements including presence of volatiles - Assays ("Assays Performed" tab in header) - # of samples for each assay - # of replicates/assay (suggest at least duplicate) - Temperature(s) including range and rate for heating/cooling cycling assays - Any other particular assay parameters if known such as shear rate range to model processing etc
03
Perform assays with rapid turnaround
04
General conclusions & potential impacts Experimental details Overlay plots Summary tables Embedded data files in Excel Results for rheometer performance standards
05
Follow-up discussions to ensure understanding results and implications
Clients value the direct, streamlined and efficient communication together with strategic support at every step.
Testimonials
RTS has supported hundreds of R&D teams across pharmaceuticals, cosmetics, food, materials engineering, and biomaterials. Clients frequently highlight responsiveness, clarity, scientific depth, and a true partnership approach.
